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Sample records for b12 cellular sequestration

  1. Anchoring secreted proteins in endoplasmic reticulum by plant oleosin: the example of vitamin B12 cellular sequestration by transcobalamin.

    Directory of Open Access Journals (Sweden)

    Laurent Pons

    Full Text Available BACKGROUND: Oleosin is a plant protein localized to lipid droplets and endoplasmic reticulum of plant cells. Our idea was to use it to target functional secretory proteins of interest to the cytosolic side of the endoplasmic reticulum of mammalian cells, through expressing oleosin-containing chimeras. We have designed this approach to create cellular models deficient in vitamin B12 (cobalamin because of the known problematics associated to the obtainment of effective vitamin B12 deficient cell models. This was achieved by the overexpression of transcobalamin inside cells through anchoring to oleosin. METHODOLOGY: chimera gene constructs including transcobalamin-oleosin (TC-O, green fluorescent protein-transcobalamin-oleosin (GFP-TC-O and oleosin-transcobalamin (O-TC were inserted into pAcSG2 and pCDNA3 vectors for expression in sf9 insect cells, Caco2 (colon carcinoma, NIE-115 (mouse neuroblastoma, HEK (human embryonic kidney, COS-7 (Green Monkey SV40-transfected kidney fibroblasts and CHO (Chinese hamster ovary cells. The subcellular localization, the changes in vitamin B12 binding activity and the metabolic consequences were investigated in both Caco2 and NIE-115 cells. PRINCIPAL FINDINGS: vitamin B12 binding was dramatically higher in TC-O than that in O-TC and wild type (WT. The expression of GFP-TC-O was observed in all cell lines and found to be co-localized with an ER-targeted red fluorescent protein and calreticulin of the endoplasmic reticulum in Caco2 and COS-7 cells. The overexpression of TC-O led to B12 deficiency, evidenced by impaired conversion of cyano-cobalamin to ado-cobalamin and methyl-cobalamin, decreased methionine synthase activity and reduced S-adenosyl methionine to S-adenosyl homocysteine ratio, as well as increases in homocysteine and methylmalonic acid concentration. CONCLUSIONS/SIGNIFICANCE: the heterologous expression of TC-O in mammalian cells can be used as an effective strategy for investigating the cellular

  2. Potentiation of cellular radiosensitivity by nitroprusside and vitamin B12

    International Nuclear Information System (INIS)

    The effects of two cyano-metal complexes, sodium nitroprusside and vitamin B12 on the radiosensitivity of plateau-phase V-79 monolayers were studied. Cells were irradiated under aerobic conditions or hypoxic conditions following degassing and purging with nitrogen. Concentrations of nitroprusside as low as 10-6M resulted in potentiation of radiation cell killing under aerobic and hypoxic conditions. Potentiation of radiation cell killing was also observed with the less-toxic vitamin B12 at concentrations of 10-3M; this effect was observed only under anoxic irradiation conditions. These results suggest that cyanide-releasing compounds might be used to augment the effect of radiation therapy, providing a different effect on aerobic compared to hypoxic cells

  3. Organometallic B12-DNA conjugate

    DEFF Research Database (Denmark)

    Hunger, Miriam; Mutti, Elena; Rieder, Alexander;

    2014-01-01

    humans and animals, through the endogenous B12 transport systems. Binding of the organometallic B12 octadecanucleotide to the three important human proteins of B12 transport was studied, to examine its structural suitability for the task of eventual in vivo oligonucleotide delivery. Binding was efficient......Design, synthesis, and structural characterization of a B12-octadecanucleotide are presented herein, a new organometallic B12-DNA conjugate. In such covalent conjugates, the natural B12 moiety may be a versatile vector for controlled in vivo delivery of oligonucleotides to cellular targets in...... with transcobalamin (TC), but not so efficient with the homologous glycoproteins intrinsic factor and haptocorrin. Binding of the B12 octadecanucleotide to TC suggests the capacity of the B12 moiety to serve as a natural vector for specific transport of single stranded, organometallic oligonucleotide...

  4. Vitamin B-12

    Science.gov (United States)

    MENU Return to Web version Vitamin B-12 Vitamin B-12 What is vitamin B-12? Vitamin B-12 is an important nutrient that is found naturally ... shellfish, meat, eggs, dairy products, and fortified foods. Vitamin B-12 helps make red blood cells and ...

  5. Vitamin B12 level

    Science.gov (United States)

    The vitamin B12 level is a blood test that measures how much vitamin B12 is in your blood. ... form of megaloblastic anemia caused by poor vitamin B12 absorption. This can occur when the stomach makes ...

  6. Vitamin B12

    Science.gov (United States)

    ... with other B vitamins, such as niacin, riboflavin, vitamin B6, and magnesium. A prescription form of vitamin B12 ... Nutrition Board. Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. ...

  7. Vitamin B-12

    Science.gov (United States)

    Vitamin B-12 is a cofactor for 2 enzymes. In the cytoplasm, methionine synthase requires vitamin B-12 in the form of methylcobalamin and catalyzes the conversion of homocysteine to methionine by transfer of a methyl group from methyltetrahydrofolate.This enzyme links the methylation pathway through ...

  8. Vitamin B12 in Health and Disease

    Directory of Open Access Journals (Sweden)

    Fiona O’Leary

    2010-03-01

    Full Text Available Vitamin B12 is essential for DNA synthesis and for cellular energy production. This review aims to outline the metabolism of vitamin B12, and to evaluate the causes and consequences of sub-clinical vitamin B12 deficiency. Vitamin B12 deficiency is common, mainly due to limited dietary intake of animal foods or malabsorption of the vitamin. Vegetarians are at risk of vitamin B12 deficiency as are other groups with low intakes of animal foods or those with restrictive dietary patterns. Malabsorption of vitamin B12 is most commonly seen in the elderly, secondary to gastric achlorhydria. The symptoms of sub-clinical deficiency are subtle and often not recognized. The long-term consequences of sub-clinical deficiency are not fully known but may include adverse effects on pregnancy outcomes, vascular, cognitive, bone and eye health.

  9. Vitamin B12 level

    Science.gov (United States)

    ... sprue Chronic myelogenous leukemia (CML) Cirrhosis Delirium Dementia Dementia due to metabolic causes Hepatitis Hyperthyroidism Malabsorption Pernicious anemia Polycythemia vera Reticulocyte count Vitamin B12 Update Date 2/24/2014 Updated by: ...

  10. Vitamin B12

    Science.gov (United States)

    ... prevent or treat dementia. Energy and athletic performance Advertisements often promote vitamin B12 supplements as a way ... 24, 2011 Share This Page: E-mail Twitter Facebook Google+ Pinterest Contact Us | Accessibility | Site Policies | Disclaimer | ...

  11. Positive newborn screen for methylmalonic aciduria identifies the first mutation in TCblR/CD320, the gene for cellular uptake of transcobalamin-bound vitamin B12.

    OpenAIRE

    Quadros,, Edward; Lai, Shao-Chiang; Nakayama, Yasumi; Sequeira (Reisman), Pedro (Twins); Hannibal,, Luciana; Wang, Sihe; Jacobsen,, Donald; Fedosov, Sergey; Wright, Erica; Gallagher, Renata; Anastasio, Natascia; Watkins, David; Rosenblatt, David

    2010-01-01

    Elevated methylmalonic acid in five asymptomatic newborns whose fibroblasts showed decreased uptake of transcobalamin-bound cobalamin (holo-TC), suggested a defect in the cellular uptake of cobalamin. Analysis of TCblR/CD320, the gene for the receptor for cellular uptake of holo-TC, identified a homozygous single codon deletion, c.262_264GAG (p.E88del), resulting in the loss of a glutamic acid residue in the low-density lipoprotein receptor type A-like domain. Inserting the codon by site-dire...

  12. Anemia - B12 deficiency

    Science.gov (United States)

    ... tongue or bleeding gums If you have low vitamin B12 level for a long time, you can have nerve damage. Symptoms of nerve damage include: Confusion or change in mental status ( dementia ) in severe cases Depression Loss of balance Numbness ...

  13. Radioactively labelled vitamin B12

    International Nuclear Information System (INIS)

    The application concerns the manufacture of radioactive forms of vitamin B-12 in which the cobalt atom present in the vitamin B-12 molecule is replaced with a radioactive isotope of cobalt, usually cobalt-57 or cobalt-58. Such radioactive forms of B-12 are used extensively in the diagnosis of B-12 deficiency states

  14. Vitamin B12 for cognition

    OpenAIRE

    Malouf, RM; Areosa Sastre, A

    2003-01-01

    Background An association between neuropsychiatric disorders and vitamin B12 deficiency has been recognized since 1849 when pernicious anaemia was first described. It has been suggested that deficiency of vitamin B12 might contribute to age-associated cognitive impairment. Low serum vitamin B12 concentrations are found in more than 10% of older people. A high prevalence of low serum vitamin B12 levels, and other indicators of vitamin B12 deficiency have been reported among people with Alzh...

  15. Elevated Vitamin B12 Levels

    OpenAIRE

    Melike Sezgin Evim; Rahime Tüten; Birol Baytan; Selin Yakarışık; Adalet Meral Güneş

    2014-01-01

    Vitamin B12 is essential to all cells in the body. Both high levels and low levels of vitamin B12 are significant. High serum cobalamin (vitamin B12) levels are found particularly in hematological disorders, solid tumors, autoimmune diseases, renal diseases and infectious diseases; and this elevation is associated with prognosis in some of these diseases. High levels of serum vitamin B12 should be taken into consideration and more studies should be performed on this issue.

  16. Elevated Vitamin B12 Levels

    Directory of Open Access Journals (Sweden)

    Melike Sezgin Evim

    2014-12-01

    Full Text Available Vitamin B12 is essential to all cells in the body. Both high levels and low levels of vitamin B12 are significant. High serum cobalamin (vitamin B12 levels are found particularly in hematological disorders, solid tumors, autoimmune diseases, renal diseases and infectious diseases; and this elevation is associated with prognosis in some of these diseases. High levels of serum vitamin B12 should be taken into consideration and more studies should be performed on this issue.

  17. Activation of mutant protein kinase Cγ leads to aberrant sequestration and impairment of its cellular function

    International Nuclear Information System (INIS)

    Mutations in protein kinase Cγ (PKCγ) cause the neurodegenerative disease spinocerebellar ataxia type 14 (SCA14). In this study, expression of an extensive panel of known SCA14-associated PKCγ mutations as fusion proteins in cell culture led to the consistent formation of cytoplasmic aggregates in response to purinoceptor stimulation. Aggregates co-stained with antibodies to phosphorylated PKCγ and the early endosome marker EEA1 but failed to redistribute to the cell membrane under conditions of oxidative stress. These studies suggest that Purkinje cell damage in SCA14 may result from a reduction of PKCγ activity due its aberrant sequestration in the early endosome compartment

  18. Maximal load of the vitamin B12 transport system

    DEFF Research Database (Denmark)

    Lildballe, Dorte L; Mutti, Elena; Birn, Henrik;

    2012-01-01

    Several studies suggest that the vitamin B12 (B12) transport system can be used for the cellular delivery of B12-conjugated drugs, also in long-term treatment Whether this strategy will affect the endogenous metabolism of B12 is not known. To study the effect of treatment with excess B12 or an...... inert derivative, we established a mouse model using implanted osmotic minipumps to deliver saline, cobinamide (Cbi) (4.25 nmol/h), or B12 (1.75 nmol/h) for 27 days (n = 7 in each group). B12 content and markers of B12 metabolism were analysed in plasma, urine, kidney, liver, and salivary glands. Both...... Cbi and B12 treatment saturated the transcobalamin protein in mouse plasma. Cbi decreased the content of B12 in tissues to 33-50% of the level in control animals but did not influence any of the markers examined. B12 treatment increased the tissue B12 level up to 350%. In addition, the transcript...

  19. B12 in fetal development.

    Science.gov (United States)

    Pepper, M Reese; Black, Maureen M

    2011-08-01

    Vitamin B12 (cobalamin) is necessary for development of the fetus and child. Pregnant women who are vegetarian or vegan, have Crohn's or celiac disease, or have undergone gastric bypass surgery are at increased risk of B12 deficiency. Low serum levels of B12 have been linked to negative impacts in cognitive, motor, and growth outcomes. Low cobalamin levels also may be related to depression in adults. Some studies indicate that B12 supplementation may improve outcomes in children, although more research is needed in this area. Overall, the mechanisms of B12 action in development remain unclear. Further studies in this area to elucidate the pathways of cobalamin influence on development, as well as to prevent B12 deficiency in pregnant women and children are indicated. PMID:21664980

  20. Maximal Load of the Vitamin B12 Transport System: A Study on Mice Treated for Four Weeks with High-Dose Vitamin B12 or Cobinamide

    OpenAIRE

    Lildballe, Dorte L.; Mutti, Elena; Birn, Henrik; Nexo, Ebba

    2012-01-01

    Several studies suggest that the vitamin B12 (B12) transport system can be used for the cellular delivery of B12-conjugated drugs, also in long-term treatment Whether this strategy will affect the endogenous metabolism of B12 is not known. To study the effect of treatment with excess B12 or an inert derivative, we established a mouse model using implanted osmotic minipumps to deliver saline, cobinamide (Cbi) (4.25 nmol/h), or B12 (1.75 nmol/h) for 27 days (n = 7 in each group). B12 content an...

  1. Bioavailability of vitamin B12

    Science.gov (United States)

    Vitamin B12 deficiency is common in people of all ages who consume a low intake of animal-source foods, including populations in developing countries. It is also prevalent among the elderly, even in wealthier countries, due to their malabsorption of B12 from food. Several methods have been applied t...

  2. Cellular sequestration of cadmium in the hyperaccumulator plant species Sedum alfredii.

    Science.gov (United States)

    Tian, Shengke; Lu, Lingli; Labavitch, John; Yang, Xiaoe; He, Zhenli; Hu, Hening; Sarangi, Ritimukta; Newville, Matt; Commisso, Joel; Brown, Patrick

    2011-12-01

    Spatial imaging of cadmium (Cd) in the hyperaccumulator Sedum alfredii was investigated in vivo by laser ablation inductively coupled plasma mass spectrometry and x-ray microfluorescence imaging. Preferential Cd accumulation in the pith and cortex was observed in stems of the Cd hyperaccumulating ecotype (HE), whereas Cd was restricted to the vascular bundles in its contrasting nonhyperaccumulating ecotype. Cd concentrations of up to 15,000 μg g(-1) were measured in the pith cells, which was many fold higher than the concentrations in the stem epidermis and vascular bundles in the HE plants. In the leaves of the HE, Cd was mainly localized to the mesophyll and vascular cells rather than the epidermis. The distribution pattern of Cd in both stems and leaves of the HE was very similar to calcium but not zinc, irrespective of Cd exposure levels. Extended x-ray absorption fine structure spectroscopy analysis showed that Cd in the stems and leaves of the HE was mainly associated with oxygen ligands, and a larger proportion (about 70% in leaves and 47% in stems) of Cd was bound with malic acid, which was the major organic acid in the shoots of the plants. These results indicate that a majority of Cd in HE accumulates in the parenchyma cells, especially in stems, and is likely associated with calcium pathways and bound with organic acid (malate), which is indicative of a critical role of vacuolar sequestration of Cd in the HE S. alfredii. PMID:22025609

  3. Cellular Sequestration of Cadmium in the Hyperaccumulator Plant Species Sedum alfredii

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Shengke; Lu, Lingli; Labavitch, John M.; Yang, Xiaoe; He, Zhenli; Hu, Hening; Sarangi, Ritimukta; Newville, Matt; Commisso, Joel; Brown, Patrick Hugh (UCD); (SLAC); (Zhejiang); (FSU); (UC)

    2012-07-23

    Spatial imaging of cadmium (Cd) in the hyperaccumulator Sedum alfredii was investigated in vivo by laser ablation inductively coupled plasma mass spectrometry and x-ray microfluorescence imaging. Preferential Cd accumulation in the pith and cortex was observed in stems of the Cd hyperaccumulating ecotype (HE), whereas Cd was restricted to the vascular bundles in its contrasting nonhyperaccumulating ecotype. Cd concentrations of up to 15,000 {micro}g g{sup -1} were measured in the pith cells, which was many fold higher than the concentrations in the stem epidermis and vascular bundles in the HE plants. In the leaves of the HE, Cd was mainly localized to the mesophyll and vascular cells rather than the epidermis. The distribution pattern of Cd in both stems and leaves of the HE was very similar to calcium but not zinc, irrespective of Cd exposure levels. Extended x-ray absorption fine structure spectroscopy analysis showed that Cd in the stems and leaves of the HE was mainly associated with oxygen ligands, and a larger proportion (about 70% in leaves and 47% in stems) of Cd was bound with malic acid, which was the major organic acid in the shoots of the plants. These results indicate that a majority of Cd in HE accumulates in the parenchyma cells, especially in stems, and is likely associated with calcium pathways and bound with organic acid (malate), which is indicative of a critical role of vacuolar sequestration of Cd in the HE S. alfredii.

  4. Cellular Sequestration of Cadmium in the Hyperaccumulator Plant Species Sedum alfredii1[C][W

    Science.gov (United States)

    Tian, Shengke; Lu, Lingli; Labavitch, John; Yang, Xiaoe; He, Zhenli; Hu, Hening; Sarangi, Ritimukta; Newville, Matt; Commisso, Joel; Brown, Patrick

    2011-01-01

    Spatial imaging of cadmium (Cd) in the hyperaccumulator Sedum alfredii was investigated in vivo by laser ablation inductively coupled plasma mass spectrometry and x-ray microfluorescence imaging. Preferential Cd accumulation in the pith and cortex was observed in stems of the Cd hyperaccumulating ecotype (HE), whereas Cd was restricted to the vascular bundles in its contrasting nonhyperaccumulating ecotype. Cd concentrations of up to 15,000 μg g−1 were measured in the pith cells, which was many fold higher than the concentrations in the stem epidermis and vascular bundles in the HE plants. In the leaves of the HE, Cd was mainly localized to the mesophyll and vascular cells rather than the epidermis. The distribution pattern of Cd in both stems and leaves of the HE was very similar to calcium but not zinc, irrespective of Cd exposure levels. Extended x-ray absorption fine structure spectroscopy analysis showed that Cd in the stems and leaves of the HE was mainly associated with oxygen ligands, and a larger proportion (about 70% in leaves and 47% in stems) of Cd was bound with malic acid, which was the major organic acid in the shoots of the plants. These results indicate that a majority of Cd in HE accumulates in the parenchyma cells, especially in stems, and is likely associated with calcium pathways and bound with organic acid (malate), which is indicative of a critical role of vacuolar sequestration of Cd in the HE S. alfredii. PMID:22025609

  5. Assay of vitamin B12

    International Nuclear Information System (INIS)

    A radioassay is described for vitamin B12 which involves denaturing serum protein binding proteins with alkali. In the denaturation step a dithiopolyol and cyanide are used and in the intrinsic factor assay step a vitamin B12 analogue such as cobinamide is used to bind with any remaining serum proteins. The invention also includes a kit in which the dithiopolyol is provided in admixture with the alkali. The dithiopolyol may be dithiothreitol or dithioerythritol. (author)

  6. Changes in Cellular mRNA Stability, Splicing, and Polyadenylation through HuR Protein Sequestration by a Cytoplasmic RNA Virus

    Directory of Open Access Journals (Sweden)

    Michael D. Barnhart

    2013-11-01

    Full Text Available The impact of RNA viruses on the posttranscriptional regulation of cellular gene expression is unclear. Sindbis virus causes a dramatic relocalization of the cellular HuR protein from the nucleus to the cytoplasm in infected cells. This is to the result of the expression of large amounts of viral RNAs that contain high-affinity HuR binding sites in their 3′ UTRs effectively serving as a sponge for the HuR protein. Sequestration of HuR by Sindbis virus is associated with destabilization of cellular mRNAs that normally bind HuR and rely on it to regulate their expression. Furthermore, significant changes can be observed in nuclear alternative polyadenylation and splicing events on cellular pre-mRNAs as a result of sequestration of HuR protein by the 3′ UTR of transcripts of this cytoplasmic RNA virus. These studies suggest a molecular mechanism of virus-host interaction that probably has a significant impact on virus replication, cytopathology, and pathogenesis.

  7. Radioactively labelled vitamin B12

    International Nuclear Information System (INIS)

    A method is described for preparing radioactively labelled vitamin B 12 (cyanocobalamin) by reacting α-(5,6-dimethylbenzimidazolyl) hydrogenobamide with active (sup(57,58)Co) cobaltous ion. The latter may be in the form of cobaltous chloride or sulphate in aqueous or aqueous alcoholic medium. The reaction is effected by heating the reactants in darkness at pH 4 to 8. An excess of cyanide is added to convert the hydroxocobalamin formed to cyanocobalamin. (U.K.)

  8. The role of Vitamin B12 in the critically ill-a review.

    Science.gov (United States)

    Romain, M; Sviri, S; Linton, D M; Stav, I; van Heerden, P V

    2016-07-01

    Vitamin B12 is an essential micronutrient, as humans have no capacity to produce the vitamin and it needs to be ingested from animal proteins. The ingested Vitamin B12 undergoes a complex process of absorption and assimilation. Vitamin B12 is essential for cellular function. Deficiency affects 15% of patients older than 65 and results in haematological and neurological disorders. Low levels of Vitamin B12 may also be an independent risk factor for coronary artery disease. High levels of Vitamin B12 are associated with inflammation and represent a poor outlook for critically ill patients. Treatment of Vitamin B12 deficiency is simple, but may be lifelong. PMID:27456173

  9. Vitamin B12 deficiency and depression

    OpenAIRE

    Milanlıoğlu, Aysel

    2011-01-01

    Vitamin B12 deficiency may cause psychiatric manifestations preceding the hematological and neurological symptoms. Despite a variety of symptoms, data on the role of vitamin B12 deficiency in depression are sparse. We report a case with B12 deficiency that is diagnosed with psychotic depression and treated successively with vitamin B12 replacement instead of using conventional therapy. Future investigations should focus on the role of vitamin B12 status in depression and other neurops...

  10. Vitamin B12 deficiency and depression

    OpenAIRE

    Aysel Milanlıoğlu

    2011-01-01

    Vitamin B12 deficiency may cause psychiatric manifestations preceding the hematological and neurological symptoms. Despite a variety of symptoms, data on the role of vitamin B12 deficiency in depression are sparse.We report a case with B12 deficiency that is diagnosed with psychotic depression and treated successively with vitamin B12 replacement instead of using conventional therapy.Future investigations should focus on the role of vitamin B12 status in depression and other neuropsychiatric ...

  11. Diagnosis of vitamin B12 deficiency.

    OpenAIRE

    HU, Rehman

    1984-01-01

    Vitamin B12 (cobalamin) deficiency occurs primarily as a result  of insufficient dietary intake or poor absorp-tion. There is widespread global prevalence of vitamin B12 deficiency, resulting in considerable morbidity.

  12. Diagnosis of Vitamin B12 Deficiency

    OpenAIRE

    HU, Rehman

    2016-01-01

    Vitamin B12 (cobalamin) deficiency occurs primarily as a result  of insufficient dietary intake or poor absorp-tion. There is widespread global prevalence of vitamin B12 deficiency, resulting in considerable morbidity.

  13. Vitamin B12 and Folate Test

    Science.gov (United States)

    ... be limited. Home Visit Global Sites Search Help? Vitamin B12 and Folate Share this page: Was this ... as: Cobalamin; Folic Acid; RBC Folate Formal name: Vitamin B12; Folate Related tests: Complete Blood Count , Methylmalonic ...

  14. 4-ethylphenyl-cobalamin impairs tissue uptake of vitamin B12 and causes vitamin B12 deficiency in mice

    DEFF Research Database (Denmark)

    Mutti, Elena; Ruetz, Markus; Birn, Henrik;

    2013-01-01

    Coβ-4-ethylphenyl-cob(III) alamin (EtPhCbl) is an organometallic analogue of vitamin B12 (CNCbl) which binds to transcobalamin (TC), a plasma protein that facilitates the cellular uptake of cobalamin (Cbl). In vitro assays with key enzymes do not convert EtPhCbl to the active coenzyme forms of Cbl...

  15. 7 CFR 15b.12 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Discrimination prohibited. 15b.12 Section 15b.12... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Employment Practices § 15b.12 Discrimination prohibited. (a... discrimination in employment under any program or activity receiving assistance from this Department. (2)...

  16. Vitamin B12 requirements in older adults

    NARCIS (Netherlands)

    Doets, Esmee; Groot, de C.P.G.M.

    2016-01-01

    This paper provides an overview of dose-response evidence relevant for estimating vitamin B12 requirements of healthy adults and elderly people, considering different indicators of health: vitamin B12 body stores, cognitive function, bone health, and biomarkers of vitamin B12 status.

    Vitami

  17. How common is vitamin B12 deficiency?

    Science.gov (United States)

    In considering the vitamin B-12 fortification of flour, it is important to know who is at risk of vitamin B-12 deficiency and whether those individuals would benefit from flour fortification.This article reviews current knowledge of the prevalence and causes of vitamin B-12 deficiency and considers ...

  18. Radioassay of vitamin B-12 employing bentonite

    International Nuclear Information System (INIS)

    Radioassay for vitamin B-12 using the unknown quantity of non-radioactive vitamin B-12 released from serum mixed with the radioactivity of a known quantity of radioactive vitamin B-12 tracer. A solution of intrinsic factor having a binding capacity less than the quantity of serum vitamin B-12 and radioactive vitamin B-12 is used to bind a portion of the vitamin B-12 mixture. The vitamin B-12 not bound to intrinsic factor is removed by addition of a bentonite-containing tablet. The quantity of radioactive vitamin B-12 bound to intrinsic factor is compared with standard values and the unknown serum vitamin B-12 obtained. In the steps of the procedure the acid assay medium is pre-combined with the radioactive tracer so that the radioactive vitamin B-12 tracer receives the same treatment as serum vitamin B-12. Certain of the other reagent solutions are pre-combined and the concentration of the components adjusted so that the volume used of each of these other reagent solutions is the same in different assay steps. Thus, fewer pipetting steps are necessary. 7 claims, 1 drawing figure

  19. [Therapy of hyperhomocysteinemia with vitamin B12].

    Science.gov (United States)

    Krajcovicová-Kudlácková, M; Blazícek, P; Sebeková, K; Valachovicová, M

    2002-11-01

    Prevalence of mild hyperhomocysteinemia in vegetarians and vegans is a consequence of vitamin B12 deficiency. Clinical study of homocysteine reduction by vitamin B12 consisted of subjective healthy adults on alternative nutrition (n = 9) with vitamin B12 deficiency and with mild hyperhomocysteinemia. Vitamin B12 treatment was implemented by 5 intramuscular cyanocobalamin injections of a total content of 2200 micrograms during two weeks. Homocysteine level was significantly reduced (from 22 mumol/l to 11.7 mumol/l; individual reduction 29-55%). Vitamin B12 concentration in blood was significantly increased (from 152 pmol/l to 277 pmol/l; individual % of increase 63-150). The results show a high effect of vitamin B12 treatment in homocysteine value reduction of subjects on alternative nutrition. PMID:12501494

  20. The difficulties with vitamin B12.

    Science.gov (United States)

    Dobson, Ruth; Alvares, Debie

    2016-08-01

    A 22-year-old woman presented with progressive sensory ataxia and optic neuropathy. Previous investigation by her general practitioner had found a low serum vitamin B12, which had been corrected with oral supplementation. Neurological investigations showed raised plasma homocysteine and methylmalonic acid towards the upper limit of normal with a low serum vitamin B12 MRI showed an extensive cord lesion in keeping with subacute combined degeneration of the spinal cord. We treated her with high dose parenteral vitamin B12 and she has made a partial recovery. We discuss the management of patients who present with neurological manifestations of vitamin B12 deficiency; highlighting the fact that parenteral replacement is needed in such cases, even if the serum vitamin B12 level appears to be normal. We also discuss ancillary investigations that should be performed in patients with suspected vitamin B12 deficiency. PMID:27009308

  1. [Vitamin B12 deficiency in the elderly].

    Science.gov (United States)

    Leischker, A H; Kolb, G F

    2015-01-01

    The prevalence of vitamin B12 deficiency increases with age. Patients with dementia and spouses of patients with dementia are at special risk for the development of vitamin B12 deficiency. In a normal diet this vitamin is present only in animal source foods; therefore, vegans frequently develop vitamin B12 deficiency if not using supplements or foods fortified with cobalamin. Apart from dementia, most of these manifestations are completely reversible under correct therapy; therefore it is crucial to identify and to treat even atypical presentations of vitamin B12 deficiency as early as possible. This article deals with the physiology and pathophysiology of vitamin B12 metabolism. A practice-oriented algorithm which also considers health economic aspects for a rational laboratory diagnosis of vitamin B12 deficiency is presented. In cases with severe neurological symptoms, therapy should be parenteral, especially initially. For parenteral treatment, hydroxocobalamin is the drug of choice. PMID:25586321

  2. Atypical B12 Deficiency with Nonresolving Paraesthesia

    OpenAIRE

    Haider, S.; Ahmad, N; Anaissie, E J; Abdel Karim, N.

    2013-01-01

    Vitamin B12 deficiency can present with various hematological, gastrointestinal and neurological manifestations. We report a case of elderly female who presented with neuropathy and vitamin B12 deficiency where the final work-up revealed polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS). This case suggests that, although POEMS syndrome is a rare entity, it can present with vitamin-B12 deficiency and thus specific work up for early diagnosis of P...

  3. [Approaches to vitamin B12 deficiency].

    Science.gov (United States)

    Russcher, Henk; Heil, Sandra G; Slobbe, Lennert; Lindemans, Jan

    2012-01-01

    A 28-year-old female vegetarian was referred to a specialist in internal medicine with persistent iron deficiency. Laboratory analysis revealed microcytic anaemia with low ferritin levels but normal total vitamin B12 levels. The red blood cell distribution width, however, showed a very wide variation in red blood cell sizes, indicating a coexisting vitamin B12 deficiency, which was confirmed by the low concentration of active vitamin B12. Another patient, a 69-year-old woman with a history of previous gastric surgery and renal insufficiency as a complication of diabetes mellitus, was suspected to be deficient in vitamin B12, as she had low total vitamin B12 levels and an accumulation of methylmalonic acid and homocysteine in her blood. Testing the total concentration of vitamin B12 alone has insufficient diagnostic accuracy and no accepted gold standard is available for diagnosing vitamin B12 deficiency. With the development of newer tests, such as measuring holotranscobalamin II (concentration of active vitamin B12), atypical and subclinical deficiency states can be recognized. A new approach to diagnosing vitamin B12 deficiency is presented, based upon these 2 case descriptions. PMID:22217304

  4. Radiometric microbiological estimation of vitamin B12

    International Nuclear Information System (INIS)

    Estimation of vitamin B12 in blood is very important to determine in deficiency and diagnosis of anemic patients. Vitamin B12 in blood can be estimated by spectrochemical, enzymatic, radioisotopic and microbiological methods. In the present study vitamin B12 was determined in 48 normal subjects of Rawalpindi/Islamabad by radiometric microbiological assay (RMA) technique using a very rapid, sensitive and automated instrument Bactec 460. In this procedure 14C-glucose media and microorganisms Lactobacillus leichmannii were used. The sensitivity of the method for vitamin B12 is 1 pg/ml and the vitamin B12 found in normal subjects was in the range of 105-535 pg/ml with a median value of 246±6 pg/ml. (author) 26 refs.; 1 fig

  5. Immunomodulation by vitamin B12: augmentation of CD8+ T lymphocytes and natural killer (NK) cell activity in vitamin B12-deficient patients by methyl-B12 treatment.

    Science.gov (United States)

    Tamura, J; Kubota, K; Murakami, H; Sawamura, M; Matsushima, T; Tamura, T; Saitoh, T; Kurabayshi, H; Naruse, T

    1999-04-01

    It has been suggested that vitamin B12 (vit.B12) plays an important role in immune system regulation, but the details are still obscure. In order to examine the action of vit.B12 on cells of the human immune system, lymphocyte subpopulations and NK cell activity were evaluated in 11 patients with vit.B12 deficiency anaemia and in 13 control subjects. Decreases in the number of lymphocytes and CD8+ cells and in the proportion of CD4+ cells, an abnormally high CD4/CD8 ratio, and suppressed NK cell activity were noted in patients compared with control subjects. In all 11 patients and eight control subjects, these immune parameters were evaluated before and after methyl-B12 injection. The lymphocyte counts and number of CD8+ cells increased both in patients and in control subjects. The high CD4/CD8 ratio and suppressed NK cell activity were improved by methyl-B12 treatment. Augmentation of CD3-CD16+ cells occurred in patients after methyl-B12 treatment. In contrast, antibody-dependent cell-mediated cytotoxicity (ADCC) activity, lectin-stimulated lymphocyte blast formation, and serum levels of immunoglobulins were not changed by methyl-B12 treatment. These results indicate that vit.B12 might play an important role in cellular immunity, especially relativing to CD8+ cells and the NK cell system, which suggests effects on cytotoxic cells. We conclude that vit.B12 acts as an immunomodulator for cellular immunity. PMID:10209501

  6. Bound vitamin B12 absorption in patients with low serum B12 levels.

    Science.gov (United States)

    Miller, A; Furlong, D; Burrows, B A; Slingerland, D W

    1992-07-01

    In many patients with low serum levels of vitamin B12, the absorption of the free vitamin has been normal. The present study, using a total body counter 57CoB12 absorption method that clearly separated those with intrinsic factor deficiency from controls, found that of 94 patients with low B12 levels and intact stomachs in whom the absorption of free and bound B12 was determined, 44 (47%) had normal absorption of both. However, 20 of the 94 (21%) with normal absorption of free B12 had low absorption of bound B12. The remainder (32%) had low absorption of both free and bound B12. All patients with high serum gastrin levels had low bound B12 absorption, but so did 21% of those patients with normal serum gastrin levels. PMID:1609768

  7. Assay for vitamin B12 absorption and method of making labeled vitamin B12

    Science.gov (United States)

    Anderson, Peter J.; Dueker, Stephen; Miller, Joshua; Green, Ralph; Roth, John; Carkeet, Colleen; Buchholz,; Bruce A.

    2012-06-19

    The invention provides methods for labeling vitamin B12 with .sup.14C, .sup.13C, tritium, and deuterium. When radioisotopes are used, the invention provides for methods of labeling B12 with high specific activity. The invention also provides labeled vitamin B12 compositions made in accordance with the invention.

  8. Pengaruh Pemberian Suplemen Vitamin B12 Terhadap Serum Vitamin B12 dan Hemoglobin Anak Prasekolah

    OpenAIRE

    Lubis, Zulhaida; . Hardinsyah; Syarief, Hidayat; Jalal, Fasli; Muhilal

    2010-01-01

    This research aimed to analyze prevalence of vitamin B12 deficiency and anemia, and effects of vitamin B12 suplement on vitamin B12 serum and hemoglobin of preschool children. A randomized controlled trial of 32 preschool children (4-6 year) for 6 months was appliad. Subjects divided in to 2 groups, treatment group (received 10 μg vitamin B12 syrup daily) and control group (placebo). Consentration of vitamin B12 serum and hemoglobin of children was measured before and after their intervent...

  9. Malabsorption of protein bound vitamin B12.

    OpenAIRE

    Dawson, D. W.; Sawers, A H; Sharma, R. K.

    1984-01-01

    Patients with subnormal serum vitamin B12 concentrations were tested for absorption of protein bound vitamin B12 and compared with controls. Absorption of the protein bound vitamin appeared to decrease with increasing age in healthy subjects. Differences between the result of this test and the result of the Schilling test in patients who had undergone gastric surgery were confirmed; such differences were also seen in some patients who had iron deficiency anaemia, an excessive alcohol intake, ...

  10. Sub-cellular partitioning of metals (Cd, Cu, Zn) in the gills of a freshwater bivalve, Pyganodon grandis: role of calcium concretions in metal sequestration

    International Nuclear Information System (INIS)

    cellular level. Metal concentrations increased proportionally in both the granules and the MT pool along the polymetallic gradient, suggesting a constant partitioning between these two compartments. Overall, despite an increase in Cd in the 'mitochondria' fraction, metal sequestration mechanisms seem to be reasonably effective in detoxifying cadmium: in the cytosol, Cd concentrations in the potentially metal-sensitive HDP fraction remained relatively low and constant, even in specimens collected from the most contaminated lakes

  11. B12Hn and B12Fn: Planar vs Icosahedral Structures

    OpenAIRE

    Gonzalez Szwacki, Nevill; Tymczak, C. J.

    2012-01-01

    Using density functional theory and quantum Monte Carlo calculations, we show that B12H n and B12F n (n = 0 to 4) quasi-planar structures are energetically more favorable than the corresponding icosahedral clusters. Moreover, we show that the fully planar B12F6 cluster is more stable than the three-dimensional counterpart. These results open up the possibility of designing larger boron-based nanostructures starting from quasi-planar or fully planar building blocks.

  12. [Vegetarians are at high risk of vitamin B12 deficiency].

    Science.gov (United States)

    Javid, Parva; Christensen, Erik

    2016-01-01

    Since vegetarians have a lower intake of vitamin B12 (B12) than non-vegetarians, they are at increased risk of developing B12 deficiency. The less animal products the food contains the worse the B12 status. However, even lacto-ovo-vegetarians run the risk of becoming deficient in B12. Vegetarians are recommended regularly to take supplements of B12, and they should be informed of the lacking content of B12 of plant products and the hazards of B12 deficiency. Furthermore, vegetarians should routinely be checked for possible B12 deficiency. PMID:26750191

  13. Production of vitamin B12 and labeled vitamin B12 by Streptomyces griseus

    International Nuclear Information System (INIS)

    In this study, the production of labeled vitamin B12 with one strain of actinomycet in a novel synthetic medium by batch fermentation method was investigated. After releasing vitamin B12 from microbial cells, the solution containing cobalamin analogues was fixed on amberlite XAD-4 exchanger and eluted by various solutions. Vitamin B12 in the collected fractions were measured by HPLC method and also in order to confirm the existence of cobalamin compounds in the samples, TLC technique was used. In the optimal conditions, production of vitamin B12 by this microorganism was 1456μg/1. The best recoveries of vitamin B12 from the column were obtained when the column was eluted by ethanol followed by acetone. The Rf, values for cyanocobalamin and methylcobalamin, produced by this microorganism were the same as the standard values of Rf. The desorption of labeled vitamine B12 was carried out by different eluants, including acetone, ethanol (absolute), ethanol 25% and deionized water. The activity of labeled vitamin B12 was 8.55, 6.90, 0.79, 5.75 Bq/ml, respectively. Therefore, the total specific activity of 21.99 Bq/ml was obtained for labeled vitamin B12 .

  14. Detection of vitamin B12 deficiency in older people by measuring vitamin B12 or the active fraction of vitamin B12, holotranscobalamin.

    OpenAIRE

    MOLLOY, ANNE MARIE; SCOTT, JOHN MARTIN

    2007-01-01

    PUBLISHED Background: Impaired vitamin B12 function and decreased vitamin B12 status have been associated with neurological and cognitive impairment. Current assays analyze total vitamin B12 concentration, only a small percentage of which is metabolically active. Concentrations of this active component, carried on holotranscobalamin (holoTC), may be of greater relevance than total vitamin B12. Methods: We compared the utility of serum holoTC with conventional vitamin B12 for detection ...

  15. Folate, vitamin B12 and human health

    Science.gov (United States)

    During the past decade the role of folate and vitamin B12 in human nutrition have been under constant re-examination. Basic knowledge on the metabolism and interactions between these essential nutrients has expanded and multiple complexities have been unraveled. These micronutrients have shared func...

  16. Vitamin B12 and eicosanoids in insects

    International Nuclear Information System (INIS)

    Vitamin B12 was not detected in the house fly, Musca domestica, which apparently cannot interconvert propionate and succinate. In contrast, the termite readily interconverts succinate and methylmalonate, and contains high amounts of vitamin B12. The intestinal bacteria were the major source of vitamin B12 in the termite, Coptotermes formosanus. The presence of arachidonic acid (20:4) and eicosatrienoic acid (20:3,n-6) at low levels in adult male and female house flies was demonstrated by chemical ionization-gas chromatography-mass spectrometry. After injection, over 80% of 20:4 was rapidly incorporated into the phospholipid (PL) fraction. Over 80% of the sequestered 20:4 was in the 2-position of PLs. The 20:4 was injected into the insect or was included in the diet prior to administration of [3H] 20:4; large amounts of radioactivity were recovered in the triacylglycerol and free fatty acid fractions. Arachidonic acid (20:4) injected into house flies was rapidly converted to prostaglandins, and was also catabolized rapidly. Radiolabeled 20:4 injected into the hemolymph was incorporated into the reproductive tissues of male insects. About 2.1% of the total radioactivity from [3H] 20:4 injected into males just prior to mating was transferred to females during mating

  17. Vitamin B-12 radioassay in the diagnosis of vitamin B-12 deficiency

    International Nuclear Information System (INIS)

    It became apparent in 1978 that some radioassays for Vitamin B-12 were falsely normal. This investigation was performed to assure the accuracy of our assay. False normal B-12 levels may result in permanent damage or delay in relieving distressful symptoms. False low levels result in no permanent sequalae. ''Normal'' values should be set with these consequences in mind. The authors reviewed clinical charts on patients with <300 pg/m1 serum B-12 in 1000 consecutive determinations and all patients newly diagnosed B-12 deficient 1/1/83 to 10/14/83. Simu1TRAC Radioassay, Becton Dickinson Co., modified by correction for serum nonspecific binding is used. ''Normal'' values (234-1000 pg/m1) are based on 47 outpatients. 176 of the 1000 assays resulted in levels <300 pg/m1. 87 were from other location with no clinical information. 89 assays on Marshfield Clinic patients included 2 duplicates. 45 patients were newly diagnosed B-12 deficient 1/1/83 to 10/14/83. 12 were diagnosed elsewhere and on therapy. 32 had assays <234 pg/m1. 1 with normal B-12 is ''possibly deficient'', a Schilling test is scheduled. The authors conclude that their B-12 assay has correctly identified 32 clinically accepted B-12 deficient patients. 1 possibly deficient patient was normal. 25 of 42 patients with levels below normal are deficient. The false positive rate is felt acceptable in view of the false negative rate and the consequences of the respective errors

  18. Preparation of vitamin B-12-free serum for the use in vitamin B-12 radioassays

    International Nuclear Information System (INIS)

    In radioassays for serum vitamin B-12, the separation of free and bound vitamin is usually made with charcoal absorption. The specificity of this separation depends on the amount of charcoal and the protein content and constitution of the medium. The large difference in protein concentration between the samples for the dilution curve and the serum samples introduces an uncontrolled variable in the test. In order to equalize the experimental circumstances, the standard dilutions were made in serum freed from vitimin B-12 after boiling the serum for 20 min in a 4-fold dilution with glutamic acid buffer at pH 3.3 and subsequent passage over a CH-Sepharose 4-B column complexed with hog intrinsic factor (IF). The vitamin B-12-binding capacity of such an affinity column prepared from 1 g CH-Sepharose and 20 mg IF, suffices for the absorption of vitamin B-12 in 3000 ml serum from which 300 series of vitamin B-12 standard solutions can be made. The first results with this method confirm that the charcoal absorption radioassay has become more accurate by the use of vitamin B-12-free serum in the standard dilutions. (Auth.)

  19. 21 CFR 862.1810 - Vitamin B12 test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vitamin B12 test system. 862.1810 Section 862.1810....1810 Vitamin B12 test system. (a) Identification. A vitamin B12 test system is a device intended to measure vitamin B12 in serum, plasma, and urine. Measurements obtained by this device are used in...

  20. Obsessive compulsive disorder as early manifestation of b12 deficiency

    OpenAIRE

    Maryam Valizadeh; Nasim Valizadeh

    2011-01-01

    B12 acts as a cofactor in synthesis of neurotransmitters such as serotonin and dopamine, thus B12 deficiency affects mood, emotions and sleeping and can lead to psychiatric disorders. Psychiatric manifestations of B12 deficiency are varied. They seldom precede anemia. We want to present a case of B12 deficiency which was presented with obsessive compulsive disorder.

  1. New method for the radioactive determination of vitamin B12

    International Nuclear Information System (INIS)

    A description is given of a method for the radioactive determination of vitamin B12 in a sample solution of serum in which a radioactive tracer of vitamin B12 and the vitamin B12 of the serum compete with respect to an intrinsic factor of limited linking capacity. The free radioactive vitamin B12 and the free vitamin B12 of the serum are separated from the intrinsic factor and from the radioactive vitamin B12 and from the serum vitamin B12 linked to this factor, before the radioactivity is measured against standard values. The method consists in separating the free radioactive vitamin B12 and the free serum vitamin B12 of the intrinsic factor and portions of radioactive and serum vitamin B12 linked to this factor, by adding an adequate quantity of bentonite to adsorb the free radioactive vitamin B12 and free serum vitamin B12 so that the intrinsic factor surface floating solution in association with the linked radioactive vitamin B12 and the linked serum vitamin B12 may be physically isolated from the solid bentonite that has adsorbed the free radioactive vitamin B12 and the free serum vitamin B12

  2. Vitamin B12 Deficiency in Relation to Functional Disabilities

    OpenAIRE

    Rasmussen, Heather E.; Gustashaw, Kristin A. R.; Tangney, Christy C; Breanna S. Oberlin

    2013-01-01

    This study was designed to assess whether symptoms, functional measures, and reported disabilities were associated with vitamin B12 (B12) deficiency when defined in three ways. Participants, aged 60 or more years of age, in 1999–2002 National Health and Nutrition Examination Surveys (NHANES) were categorized in relation to three previously used definitions of B12 deficiency: (1) serum B12 20 μmol/L; and (3) serum B12 < 258 pmol...

  3. Electronic Structure of B12 coenzymes

    Science.gov (United States)

    Ouyang, Lizhi; Ching, W. Y.; Randaccio, Lucio

    2001-06-01

    We have carried out an ab-initio local density functional calculations of the two most important B12 coenzymes, adoensyl-cobalamin (Ado-Cbl) and methyl-cobalamin (Me-Cbl). The crystal structures were determined by accurate X-ray synchrotron radiation measurements. Both crystals have space group P2121 with four molecules, or about 800 atoms, per unit cell. Our electronic structure calculation is based on one full molecule including the side chains. Results are analyzed in terms of atom and orbital resolved partial density of states (PDOS), Mulliken effective charges and bond orders. The PDOS analysis shows that the Co complexes of both B12 coenzymes had a HOMO/LUMO gap of about 1.5 eV. The Co-C bond order in Me-Cbl is smaller than that in Ado-Cbl. This appears to be in contradiction with the measured bond dissociated energies. However, this could also indicate the importance of the effects of solvents, which were not included in the calculation. We are investigating whether the effect of the solvents could dramatically modify the electronic structures of Ado-Cbl and Me-Cbl.

  4. Detection of vitamin B12 deficiency in older people by measuring vitamin B12 or the active fraction of vitamin B12, holotranscobalamin

    DEFF Research Database (Denmark)

    Clarke, Robert; Sherliker, Paul; Hin, Harold;

    2007-01-01

    BACKGROUND: Impaired vitamin B(12) function and decreased vitamin B(12) status have been associated with neurological and cognitive impairment. Current assays analyze total vitamin B(12) concentration, only a small percentage of which is metabolically active. Concentrations of this active component......) concentrations as a marker of metabolic vitamin B(12) deficiency in the overall population (n = 2403) and in subsets with normal (n = 1651) and abnormal (n = 752) renal function. RESULTS: Among all participants, 6% had definite (MMA >0.75 micromol/L) and 16% had probable (MMA >0.45 micromol/L) metabolic vitamin...... abnormal (AUC: 0.85 vs 0.74; P = 0.002) renal function. Similar findings were observed for detection of moderate vitamin B(12) deficiency. Whereas the positive predictive value for both holoTC and vitamin B(12) was greater for detection of probable than definite vitamin B(12) deficiency, both tests were...

  5. Vitamin B12: Unique Metalorganic Compounds and the Most Complex Vitamins

    Directory of Open Access Journals (Sweden)

    Lucio Randaccio

    2010-04-01

    Full Text Available The chemistry and biochemistry of the vitamin B12 compounds (cobalamins, XCbl are described, with particular emphasis on their structural aspects and their relationships with properties and function. A brief history of B12, reveals how much the effort of chemists, biochemists and crystallographers have contributed in the past to understand the basic properties of this very complex vitamin. The properties of the two cobalamins, the two important B12 cofactors Ado- and MeCbl are described, with particular emphasis on how the Co-C bond cleavage is involved in the enzymatic mechanisms. The main structural features of cobalamins are described, with particular reference to the axial fragment. The structure/property relationships in cobalamins are summarized. The recent studies on base-off/base-on equilibrium are emphasized for their relevance to the mode of binding of the cofactor to the protein scaffold. The absorption, transport and cellular uptake of cobalamins and the structure of the B12 transport proteins, IF and TC, in mammals are reviewed. The B12 transport in bacteria and the structure of the so far determined proteins are briefly described. The currently accepted mechanisms for the catalytic cycles of the AdoCbl and MeCbl enzymes are reported. The structure and function of B12 enzymes, particularly the important mammalian enzymes methyltransferase (MetH and methyl-malonyl-coenzymeA mutase (MMCM, are described and briefly discussed. Since fast proliferating cells require higher amount of vitamin B12 than that required by normal cells, the study of B12 conjugates as targeting agents has recently gained importance. Bioconjugates have been studied as potential agents for delivering radioisotopes and NMR probes or as various cytotoxic agents towards cancer cells in humans and the most recent studies are described. Specifically, functionalized bioconjugates are used as “Trojan horses” to carry into the cell the appropriate antitumour or

  6. Association of Biochemical B12 Deficiency With Metformin Therapy and Vitamin B12 Supplements

    OpenAIRE

    Reinstatler, Lael; Qi, Yan Ping; Williamson, Rebecca S.; Garn, Joshua V.; Oakley, Godfrey P

    2012-01-01

    OBJECTIVE To describe the prevalence of biochemical B12 deficiency in adults with type 2 diabetes taking metformin compared with those not taking metformin and those without diabetes, and explore whether this relationship is modified by vitamin B12 supplements. RESEARCH DESIGN AND METHODS Analysis of data on U.S. adults ≥50 years of age with (n = 1,621) or without type 2 diabetes (n = 6,867) from the National Health and Nutrition Examination Survey (NHANES), 1999–2006. Type 2 diabetes was def...

  7. [Hemolytic anemias and vitamin B12 deficieny].

    Science.gov (United States)

    Dietzfelbinger, Hermann; Hubmann, Max

    2015-08-01

    Hemolytic anemias consist of corpuscular, immun-hemolytic and toxic hemolytic anemias. Within the group of corpuscular hemolytic anemias, except for the paroxysmal nocturnal hemoglobinuria (PNH), all symptoms are caused by underlying heredetiary disorders within the red blood cell membran (hereditary spherocytosis), deficiencies of red cell enzymes (G6PDH- and pyrovatkinase deficiency) or disorders in the hemoglobin molecule (thalassaemia and sickle cell disease). Immune-hemolytic anemias are acquired hemolytic anemias and hemolysis is caused by auto- or allo-antibodies which are directed against red blood cell antigens. They are classified as warm, cold, mixed type or drug-induced hemolytic anemia. Therapy consists of glucocorticoids and other immunsuppressive drugs. Pernicious anemia is the most important vitamin B12 deficiency disorder. Diagnosis relies on cobalamin deficiency and antibodies to intrinsic factor. The management should focus on a possibly life-long replacement treatment with cobalamin. PMID:26306021

  8. Ferrocene analogues of sandwich B12.Cr.B12: A theoretical study

    Science.gov (United States)

    Yuan, Yuan; Cheng, Longjiu

    2013-01-01

    The bowl B12 cluster was previously reported to be analogous to benzene and predicted to be one of the best candidates to be new inorganic ligands. The structural stability and electronic properties of a new sandwich compound Cr(B12)2 (D3d) have been investigated by using density functional theory. It is found that the sandwich Cr(B12)2 (D3d) is a stable complex with large binding energy (-5.93 eV) and HOMO-LUMO gap (2.37 eV), as well as Fe(C5H5)2 and Cr(C6H6)2, following the 18-electron principle. The detailed molecular orbitals and aromaticity analyses indicate that the sandwich compound Cr(B12)2 (D3d) is electronically very stable. The natural bond orbital analysis suggests that spd-π interaction plays an important role in the sandwich compounds.

  9. Recurrent seizures: An unusual manifestation of vitamin B12 deficiency

    Directory of Open Access Journals (Sweden)

    Kumar S

    2004-01-01

    Full Text Available The present report highlights an unusual presentation of vitamin B12 deficiency— recurrent seizures in a 26-year-old man. His symptoms responded to parenteral vitamin B12 therapy. The relevant literature is reviewed.

  10. Metabolic engineering of cobalamin (vitamin B12) production in Bacillus megaterium.

    Science.gov (United States)

    Biedendieck, Rebekka; Malten, Marco; Barg, Heiko; Bunk, Boyke; Martens, Jan-Henning; Deery, Evelyne; Leech, Helen; Warren, Martin J; Jahn, Dieter

    2010-01-01

    Cobalamin (vitamin B(12)) production in Bacillus megaterium has served as a model system for the systematic evaluation of single and multiple directed molecular and genetic optimization strategies. Plasmid and genome-based overexpression of genes involved in vitamin B(12) biosynthesis, including cbiX, sirA, modified hemA, the operons hemAXCDBL and cbiXJCDETLFGAcysG(A)cbiYbtuR, and the regulatory gene fnr, significantly increased cobalamin production. To reduce flux along the heme branch of the tetrapyrrole pathway, an antisense RNA strategy involving silencing of the hemZ gene encoding coproporphyrinogen III oxidase was successfully employed. Feedback inhibition of the initial enzyme of the tetrapyrrole biosynthesis, HemA, by heme was overcome by stabilized enzyme overproduction. Similarly, the removal of the B(12) riboswitch upstream of the cbiXJCDETLFGAcysG(A)cbiYbtuR operon and the recombinant production of three different vitamin B(12) binding proteins (glutamate mutase GlmS, ribonucleotide triphosphate reductase RtpR and methionine synthase MetH) partly abolished B(12)-dependent feedback inhibition. All these strategies increased cobalamin production in B. megaterium. Finally, combinations of these strategies enhanced the overall intracellular vitamin B(12) concentrations but also reduced the volumetric cellular amounts by placing the organism under metabolic stress. PMID:21255303

  11. 21 CFR 184.1945 - Vitamin B12.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vitamin B12. 184.1945 Section 184.1945 Food and... Substances Affirmed as GRAS § 184.1945 Vitamin B12. (a) Vitamin B12, also known as cyanocobalamin (C63H88Co... is used in food at levels not to exceed current good manufacturing practice. Vitamin B12 also may...

  12. Neuro-regression in vitamin B12 deficiency

    OpenAIRE

    Agrawal, Sanwar; Nathani, Shweta

    2009-01-01

    Neuroregression in infants has varied aetiology and vitamin B12 deficiency is one of the uncommon causes. Infantile vitamin B12 deficiency is encountered in malnourished infants or in offspring of strict vegan mothers. We present two cases, both infants of 10 and 8 months of age, whose mothers had vitamin B12 deficiency. On admission, the patients were apathic, hypotonic and lethargic. Serum vitamin B12 levels were below normal limits. On cranial MRI, T2-weighted images revealed frontoparieta...

  13. Effects of Vitamin B12 in Neonates and Young Infants

    OpenAIRE

    Gian Maria Pacifici

    2016-01-01

    Vitamin B12 (cobalamin) is an essential coenzyme for nucleic acid synthesis. Animal protein is the major dietary source of vitamin B12. Deficiency of vitamin B12 leads to megaloblastic anemia, degeneration of the brain, spinal cord, peripheral nerves, and abnormalities of epithelial tissues. Two factors are necessary for the cure of megaloblastic anemia: one in food (extrinsic factor) and one in gastric juice (intrinsic factor). The extrinsic factor is vitamin B12. Intrinsic factor (a glycopr...

  14. Orthostatic Hypotension as a Manifestation of Vitamin B12 Deficiency

    OpenAIRE

    Ganjehei, Leila; Massumi, Ali; Razavi, Mehdi; James M Wilson

    2012-01-01

    A 90-year-old woman with orthostatic hypotension and near-syncope was found to have a low-normal level of vitamin B12 and no other medical findings that could explain her orthostasis. Her symptoms responded to vitamin B12 replacement therapy. This case shows that vitamin B12 deficiency can induce orthostatic hypotension and syncope that are correctable by vitamin B12 replacement.

  15. Involuntary movement in infants during vitamin B12 treatment

    OpenAIRE

    Ayşe Tosun; Yusuf Ziya Aral; Emre Çeçen; Ayvaz Aydoğdu; Bilin Çetinkaya Çakmak

    2011-01-01

    Megaloblastic anemia is rare in infants and is generally due to vitamin B12 (cobalamin) deficiency in the mother. Neurologic symptoms of vitamin B12 deficiency include irritability, failure to thrive, hypotonia, and developmental regression/delay. Herein we present 2 infants with vitamin B12 that developed movement disorder 5 d after initiation of vitamin B12 treatment. Symptoms included tremor and myoclonus, involving in particular the face, tongue, and hands. Clinical findings in infants as...

  16. 你缺少维生素B12

    Institute of Scientific and Technical Information of China (English)

    贺佩祥

    2007-01-01

    @@ 身体如何获得维生素B12 机体需要靠以下几个环节来获得足够的维生素B12: 1.食物在胃酸的作用下释放出维生素B12 2.维生素B12与一种称为"内因子"的物质结合

  17. Simultaneous radioassay of folate and vitamin B12

    International Nuclear Information System (INIS)

    An improved simultaneous radioassay for folate and vitamin B12 in biological specimens is described. A sample containing folate and vitamin B12 is contacted with 125I-folate and 57Co-vitamin B12 and their respective specific binders. After separation of the bound and free portions, the radioactivity in the portions is counted and the amounts of folate and vitamin B12 then determined from standard curves. (U.K.)

  18. Effects of Vitamin B12 in Neonates and Young Infants

    Directory of Open Access Journals (Sweden)

    Gian Maria Pacifici

    2016-06-01

    Full Text Available Vitamin B12 (cobalamin is an essential coenzyme for nucleic acid synthesis. Animal protein is the major dietary source of vitamin B12. Deficiency of vitamin B12 leads to megaloblastic anemia, degeneration of the brain, spinal cord, peripheral nerves, and abnormalities of epithelial tissues. Two factors are necessary for the cure of megaloblastic anemia: one in food (extrinsic factor and one in gastric juice (intrinsic factor. The extrinsic factor is vitamin B12. Intrinsic factor (a glycoprotein secreted by gastric parietal cells ensures cobalamin absorption by receptors in the terminal ileum. Vitamin B12 is actively transported across the placenta. Neonates have high serum levels and significant liver stores of vitamin B12. The neonates born to mothers with deficiency of vitamin B12 have deficiency of this vitamin. Pregnant women in resource-poor areas have low vitamin B12 status which is associated with adverse pregnancy outcomes, including anemia, low birth weight, and intrauterine growth retardation. Supplementation of vitamin B12 had significantly higher plasma of vitamin B12 in mothers and neonates. A single intramuscularly injection of vitamin B12 of between 250 µg and 1mg and a dietary intake of 1 µg/kg per day vitamin B12 is sufficient to combat vitamin B12 deficiency. Mean DNA damage scores in infants with vitamin B12 deficiency and their mothers were significantly higher before than after supplementation with vitamin B12. There were correlations between the infants' and their mothers' DNA damage scores. The aim of this study is the review of the effects of vitamin B12 in neonates and young infants.

  19. Oral vitamin B12 can change our practice

    OpenAIRE

    Nyholm, E.; Turpin, P; Swain, D; Cunningham, B.; Daly, S; P. Nightingale; Fegan, C

    2003-01-01

    Oral vitamin B12 can provide an effective alternative to intramuscular injections, so giving patients a choice and reducing costs in primary care. This study investigated the effectiveness, safety, and acceptability of oral vitamin B12 as replacement therapy in patients with vitamin B12 deficiency in a city general practice population. Forty patients previously maintained on vitamin B12 injections were given 1000 µg of oral cyanocobalamin daily for up to 18 months. All the patients maintained...

  20. Photoelectron spectroscopy of aromatic compound clusters of the B12 all-boron benzene: B12Au- and B12(BO)-.

    Science.gov (United States)

    Bai, Hui; Zhai, Hua-Jin; Li, Si-Dian; Wang, Lai-Sheng

    2013-06-28

    We report a photoelectron spectroscopy and density-functional theory study of the B12Au(-) and B13O(-) clusters and their neutrals, which are shown to be six π electron aromatic compounds between the quasi-planar all-boron B12 benzene-analogue and a monovalent Au or BO ligand. Electron affinities of B12Au and B13O are measured to be 3.48 ± 0.04 and 3.90 ± 0.04 eV, respectively. Structural searches are performed for B12Au(-) and B13O(-), which are compared with the isovalent B12H(-) cluster. The global minima of B12Au(-) and B13O(-) both feature an almost intact B12 cluster with the Au and BO ligands bonded to its periphery, respectively. For B12Au(-), a low-lying isomer is also identified, which is only 0.4 kcal mol(-1) above the global minimum, in agreement with the experimental observation of a weakly populated isomer in the cluster beam of B12Au(-). These aromatic compound clusters provide new examples for the Au/H isolobal analogy and the boronyl (BO) chemistry. PMID:23666408

  1. 21 CFR 582.5945 - Vitamin B12.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Vitamin B12. 582.5945 Section 582.5945 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5945 Vitamin B12. (a) Product. Vitamin B12. (b) Conditions of use. This substance...

  2. Investigation on the determination of serum vitamin B12 values

    International Nuclear Information System (INIS)

    Problems in the determination of serum vitamin B12 values using Phadebas B12 test kit were studied. Various causes considered to influence the results were investigated. There was no release of bound 57Co-B12 from Sephadex-intrinsic factor complex. Standard curves which were expressed by percentages of each sample versus zero sample, were slightly different from each other in their forms and inclines. Variations of the percentage from the zero samples showed a standard deviation of +-9.2% of the mean value. Percentage of B/T in various concentration of B12 also showed one standard deviation of 8-9%. Presence of serum in the sample caused no inhibition of the binding ability of B12 to the Sephadex-intrinsic factor complex. It was more suitable to use 0.5 ml of extracted dilution of serum because it did not change the measured B12 values, and because the standard curve was more accurate in lower B12 concentrations than in higher. The reproducibility and the recovery of serum B12 values showed quite excellent results by this method. The Phadebas B12 test kit gave accurate serum B12 values in general without difficult techniques. It was concluded that the Phadebas B12 test kit was one of the most suitable methods for the determination of serum B12 values in clinical samples. (auth.)

  3. Vitamin B12 deficiency and gastric histopathology in older patients

    Institute of Scientific and Technical Information of China (English)

    KR Dholakia; TS Dharmarajan; D Yadav; S Oiseth; EP Norkus; CS Pitchumoni

    2005-01-01

    AIM: To compare upper gastric endoscopic and histopathologic findings in older adults in the presence and absence of B12 deficiency.METHODS: A prospective analysis of upper gastric endoscopic and gastric histopathologic findings from 30 newly identified B12-deficient patients (11 males,19 females) and 16 controls with normal B12 status (6males, 10 females) was performed. For all subjects, the indication for upper endoscopy and gastric biopsy were unrelated to B12 status. A single pathologist, blinded to B12 status, processed and interpreted the biopsy samples. Endoscopic and histopathologic findings were correlated with age, gender, hematocrit (Hct), MCV and B12 status.RESULTS: The B12-deficient group had significantly lower mean serum B12 levels compared to the controls (P<0.00005) while their mean Hct, MCV and serum albumin levels were similar. Iron deficiency (ferritinbased) was present in 21% of B12-deficient patients and intrinsic factor antibodies were present in29% (5/17) of B12-deficient patients. The endoscopic findings revealed significantly different rates of gastritis and atrophy between the B12-deficient and control groups (P= 0.017).B12-deficient patients had significantly less superficial gastritis (62% vs 94%) and significantly more atrophic gastritis (28% vs 0%) as compared to the controls (P= 0.039). Intestinal metaplasia was similar in both groups. Helicobacter pyloriinfection rates were similar in the B12-deficient patients and controls (40% vs31%).CONCLUSION: Significantly different endoscopic findings and types of gastritis could often be observed in the presence and absence of B12 deficiency. Atrophy,based on endoscopy, and atrophic gastritis, based on histopathology, suggest the presence of B12 deficiency.Gastric histopathology is not influenced by the age,gender, Hct or MCV of the patients.

  4. Radiolysis of cyanocobalamin (vitamin B12)

    International Nuclear Information System (INIS)

    Research on the radiolysis of vitamins is of considerable interest since these compounds are important nutritional constituents in foods and in dietetic supplements. In spite of these considerations there are few data and very often difficult to compare for the radiolytic behavior of vitamins. In this work we focused our attention on to the study of the radiolysis of cyanocobalamin (vitamin B12) in solid state and in aqueous solutions. The procedure was followed by HPLC and UV-spectroscopy. The results obtained in aqueous solutions showed a dependence of the decomposition as a linear function of the dose. The G of decomposition for a 1x10-5 M solution was 3.3. In the solid state the vitamin was very stable towards the irradiation in the conditions used in this study with a G=2.1x10-3. A study made with Serratia marcescens as a microbiological contaminant showed that at the sterilization dose there is a destruction of the vitamin in aqueous solution. In the solid state the degree of decomposition was 7%. (author)

  5. Neuro-regression in vitamin B12 deficiency.

    Science.gov (United States)

    Agrawal, Sanwar; Nathani, Shweta

    2009-01-01

    Neuroregression in infants has varied aetiology and vitamin B12 deficiency is one of the uncommon causes. Infantile vitamin B12 deficiency is encountered in malnourished infants or in offspring of strict vegan mothers. We present two cases, both infants of 10 and 8 months of age, whose mothers had vitamin B12 deficiency. On admission, the patients were apathic, hypotonic and lethargic. Serum vitamin B12 levels were below normal limits. On cranial MRI, T2-weighted images revealed frontoparietal cortical atrophy. Both the infants responded to vitamin B12 treatment. PMID:21686891

  6. Cobalamin's (Vitamin B12) Surprising Function as a Photoreceptor.

    Science.gov (United States)

    Cheng, Zhuo; Yamamoto, Haruki; Bauer, Carl E

    2016-08-01

    Cobalamin (Vitamin B12) is an adenosyl- or methyl-donating cofactor for many enzymes, yet many proteins with unknown or nonenzymatic function also contain B12-binding domains. Recent studies show that light excitation energy can promote covalent linkage of B12 to transcription factors with this linkage, affecting gene expression. Thus, B12 now has a newly described regulatory function. Here, our bioinformatics analysis reveals other transcription factors, photoreceptors, kinases, and oxygen sensors that harbor a B12-binding domain that could also regulate activity in response to light absorption. PMID:27217104

  7. Progress on the studies of vitamin B12%维生素B12的研究进展

    Institute of Scientific and Technical Information of China (English)

    吕颖坚; 黄俊明

    2012-01-01

    本文对维生素B12的吸收与代谢、缺乏原因及疾病、营养水平鉴定、人群维生素B12营养状况、食物强化的研究进展进行了综述,以期提高对维生素B12的认识和重视、为解决维生素B12缺乏人群的健康问题提供参考.%In order to improve the awareness and attention on the importance of vitamin Bl2and to provide reference for solving problems of vitamin B12 deficiency, this review concentrates on five aspects of studies on vitamin B12: absorption and metabolism of vitamin BI2; cause/outcome of deficiency; biomarkers and their application; vitamin B12 status; and supplementation and fortification.

  8. Vitamin B12 Deficiency in Relation to Functional Disabilities

    Directory of Open Access Journals (Sweden)

    Heather E. Rasmussen

    2013-11-01

    Full Text Available This study was designed to assess whether symptoms, functional measures, and reported disabilities were associated with vitamin B12 (B12 deficiency when defined in three ways. Participants, aged 60 or more years of age, in 1999–2002 National Health and Nutrition Examination Surveys (NHANES were categorized in relation to three previously used definitions of B12 deficiency: (1 serum B12 20 μmol/L; and (3 serum B12 0.21 μmol/L. Functional measures of peripheral neuropathy, balance, cognitive function, gait speed, along with self-reported disability (including activities of daily living were examined with standardized instruments by trained NHANES interviewers and technicians. Individuals identified as B12 deficient by definition 2 were more likely to manifest peripheral neuropathy OR (odds (95% confidence intervals, p value: 9.70 (2.24, 42.07, 0.004 and report greater total disability, 19.61 (6.22, 61.86 0.0001 after adjustments for age, sex, race, serum creatinine, and ferritin concentrations, smoking, diabetes, and peripheral artery disease. Smaller, but significantly increased, odds of peripheral neuropathy and total disability were also observed when definition 3 was applied. Functional measures and reported disabilities were associated with B12 deficiency definitions that include B12 biomarkers (homocysteine or methylmalonic acid. Further study of these definitions is needed to alert clinicians of possible subclinical B12 deficiency because functional decline amongst older adults may be correctable if the individual is B12 replete.

  9. Vitamin B12-Containing Plant Food Sources for Vegetarians

    Directory of Open Access Journals (Sweden)

    Fumio Watanabe

    2014-05-01

    Full Text Available The usual dietary sources of Vitamin B12 are animal-derived foods, although a few plant-based foods contain substantial amounts of Vitamin B12. To prevent Vitamin B12 deficiency in high-risk populations such as vegetarians, it is necessary to identify plant-derived foods that contain high levels of Vitamin B12. A survey of naturally occurring plant-derived food sources with high Vitamin B12 contents suggested that dried purple laver (nori is the most suitable Vitamin B12 source presently available for vegetarians. Furthermore, dried purple laver also contains high levels of other nutrients that are lacking in vegetarian diets, such as iron and n-3 polyunsaturated fatty acids. Dried purple laver is a natural plant product and it is suitable for most people in various vegetarian groups.

  10. Vitamin B12 assays compared by use of patients sera with low vitamin B12 content

    International Nuclear Information System (INIS)

    The authors compared four radioisotope dilution (RD) methods and a microbiological assay for measuring concentrations of vitamin B12 in a selected panel of serum samples from patients known to be deficient in the vitamin. Low (less than 100 ng/L) and borderline (100-180 ng/L) results were similar between methods, but use of the manufacturers recommended ranges for borderline results would have changed the diagnostic classifications for 22 of 38 samples. Results of all the RD methods inter-correlated well, but less so with the microbiological assay. Borderline, nondiagnostic results were common to all methods, and no apparent advantage was gained from using the microbiological assay

  11. Regiospecificity of Chlorophenol Reductive Dechlorination by Vitamin B12s

    OpenAIRE

    Smith, Mark H.; Woods, Sandra L.

    1994-01-01

    Vitamin B12, reduced by titanium (III) citrate to vitamin B12s, catalyzes the reductive dechlorination of chlorophenols. Reductive dechlorination of pentachlorophenol and of all tetrachlorophenol and trichlorophenol isomers was observed. Reaction of various chlorophenols with vitamin B12 favored reductive dechlorination at positions adjacent to another chlorinated carbon, but chlorines ortho to the hydroxyl group of a phenol were particularly resistant to reductive dechlorination, even if the...

  12. Neuroenhancement with Vitamin B12—Underestimated Neurological Significance

    OpenAIRE

    Uwe Gröber; Klaus Kisters; Joachim Schmidt

    2013-01-01

    Vitamin B12 is a cofactor of methionine synthase in the synthesis of methionine, the precursor of the universal methyl donor S-Adenosylmethionine (SAMe), which is involved in different epigenomic regulatory mechanisms and especially in brain development. A Vitamin B12 deficiency expresses itself by a wide variety of neurological manifestations such as paraesthesias, skin numbness, coordination disorders and reduced nerve conduction velocity. In elderly people, a latent Vitamin B12 deficiency ...

  13. Vitamin B12 deficiency after irradiation for bladder carcinoma

    International Nuclear Information System (INIS)

    Vitamin B12 deficiency was found in 10 of 41 patients who underwent radiotherapy before cystectomy with Bricker urinary diversion for carcinoma of the bladder. Of 13 patients given full irradiation because of inoperable bladder cancer 5 had malabsorption of vitamin B12. Serum folic acid was normal in these patients, indicating predominantly ileal irradiation sequelae. Routine evaluation of serum vitamin B12 after radiotherapy is recommended so that appropriate medication can be given, if possible before neurological symptoms appear

  14. Vitamin B12 Deficiency due to Chlorofluorocarbon: A Case Report

    OpenAIRE

    Hemlata Bhaskar; Rekha Chaudhary

    2011-01-01

    Background. Vitamin B12 is vital for optimal functioning of various organ systems but more importantly the central nervous system and the hematological system. Deficiency of vitamin B12 clinically manifests as excessive daytime fatigue, memory difficulties, encephalopathy, myelopathy, peripheral neuropathy, and optic neuropathy. In occupational medicine, vitamin B12 deficiency has been reported with exposure to nitrous oxide in health care workers. However, not much is known about exposure to...

  15. Racial difference in serum Vitamin B12 levels

    International Nuclear Information System (INIS)

    Measurements of the serum Vitamin B12 concentrations of 49 black and 49 white healthy adults demonstrate a significantly higher mean serum Vitamin B12 level in blacks when compared to whites. The reason for this difference appears to be genetic, although environmental factors may also be involved. It is suggested that clinical laboratories should establish their own separate reference values of serum Vitamin B12 for blacks and whites in order to prevent misinterpretation of test results

  16. Vitamin B12 Deficiency and Epilepsy in Children

    OpenAIRE

    İNCECİK, Faruk; HERGÜNER, Mihriban Özlem; Altunbaşak, Şakir

    2010-01-01

    Objective: The abstract presents 7 striking cases who presented with the complaint of seizures showing concomitance of B12 vitamin deficiency. Material and Methods: Participant patients were those who presented at our hospital with seizures caused by B12 vitamin deficiency. Evaluation was based on clinical, physical and neurological signs of the patients. Complete hemogram, peripheral blood view, vitamin B12 level and folic acid level measurements were performed. Cerebral magnetic r...

  17. Vitamin B12 absorption after allogeneic bone marrow transplantation.

    OpenAIRE

    Milligan, D W; Quick, A; Barnard, D L

    1987-01-01

    The B12 absorption test (Schilling test) with intrinsic factor was used to examine ileal B12 absorption in 26 patients after allogeneic transplantation. The test was well tolerated and showed a profound fall in B12 absorption, which was maximal at two weeks after transplantation and recovered by eight weeks. The predominant influence on absorption at this stage was probably the conditioning schedule, and the presence of acute graft versus host disease (GVHD) was not associated with a further ...

  18. A vitamin B12 transporter in Mycobacterium tuberculosis

    OpenAIRE

    Gopinath, Krishnamoorthy; Venclovas, Česlovas; Ioerger, Thomas R.; Sacchettini, James C.; McKinney, John D.; Mizrahi, Valerie; Warner, Digby F.

    2013-01-01

    Vitamin B12-dependent enzymes function in core biochemical pathways in Mycobacterium tuberculosis, an obligate pathogen whose metabolism in vivo is poorly understood. Although M. tuberculosis can access vitamin B12 in vitro, it is uncertain whether the organism is able to scavenge B12 during host infection. This question is crucial to predictions of metabolic function, but its resolution is complicated by the absence in the M. tuberculosis genome of a direct homologue of BtuFCD, the only bact...

  19. Effect of vitamin B12 deficiency on otoacoustic emissions

    OpenAIRE

    KARLI, R.; Gül, A; UĞUR, B.

    2013-01-01

    SUMMARY The aim of this study was to investigate the possible association between otoacoustic emission (OAE) values and cochlear function in patients with vitamin B12 deficiency and no evidence of symptomatic hearing loss. Two groups were studied: Group 1: patients with vitamin B12 deficiency; Group 2: a matched control group of patients with normal vitamin B12 levels. There was no evidence of symptomatic hearing loss in either group. Transiently evoked OAEs (TEOAEs) and spontaneous OAEs (SOA...

  20. [Treatable Dementia due to Vitamin B12 and Folate Deficiency].

    Science.gov (United States)

    Yoshizawa, Toshihiro

    2016-04-01

    Vitamin deficiency is one of the major causes of treatable dementia. Specifically, patients suffering from dementia frequentry display low serum levels of vitamin B(12). There is a close metabolic interaction between folate and vitamin B(12). Folate deficiency causes various neuropsychiatric symptoms, which resemble those observed in vitamin B(12) deficiency. This review summarizes, the basic pathophysiology of vitamin B(12) and folate deficiency, its clinical diagnosis, associated neuropsychiatric symptoms such as subacute combined degeneration and dementia, and epidemiological studies of cognitive decline and brain atrophy. PMID:27056859

  1. Vitamin B12 and its effects on neurological disorders

    OpenAIRE

    Doğan, Melike; Demirci, Serpil

    2010-01-01

    Vitamin B12 is a water-soluble vitamin essential for growth and development in humans. It is required for methylation reactions and DNA synthesis. Vitamin B12 deficiency has a causal relationship with a variety of disease and is also recognized as a risk factor for some others. Megaloblastic anemia and neurological disorders are the most prevalent disorders seen with vitamin B12 deficiency. In this review, vitamin B12's absorption, the main physiological functions and the role of it in pathog...

  2. Regulation of phytoplankton dynamics by vitamin B12

    Science.gov (United States)

    Sañudo-Wilhelmy, S. A.; Gobler, C. J.; Okbamichael, M.; Taylor, G. T.

    2006-02-01

    Despite the biological necessity of vitamin B12 (cobalamin), its importance in phytoplankton ecology has been ignored for nearly three decades. Here we report strong and selective responses of phytoplankton communities to varying low levels (5-87 pM) of dissolved B12 in several coastal embayments. The ecological importance of this vitamin is inferred from observed declines in dissolved B12 levels as field populations of large (>5 μm) phytoplankton increased. In contrast, biomass of small (cobalamin, and implicates B12 as an important organic regulator of photoautotrophic fertility in marine systems.

  3. Comparison of Injection Vitamin B12 With Symptomatic Management in Clinically Suspected Vitamin B12 Deficent Patients: an Interventional Study

    OpenAIRE

    Janak Rathod , Taral Shah , Manisha Gupta, Rajendra Mehta

    2012-01-01

    Objectives: This study was an attempt to evaluate the advantage of empirical use of Injection. Vitamin B 12 versus symptomatic management in clinically suspected Vitamin. B 12 deficient patients. Methodology: A total of 100 patients over 20 years of age (irrespective of gender) were included in the study. The patients were divided into two groups, one group ( n = 50) receiving vitamin B12 injections and the other group (n = 50) received symptomatic treatment. Results: In clinically suspected ...

  4. Cobalamin (coenzyme B12): synthesis and biological significance.

    Science.gov (United States)

    Roth, J R; Lawrence, J G; Bobik, T A

    1996-01-01

    This review examines deoxyadenosylcobalamin (Ado-B12) biosynthesis, transport, use, and uneven distribution among living forms. We describe how genetic analysis of enteric bacteria has contributed to these issues. Two pathways for corrin ring formation have been found-an aerobic pathway (in P. denitrificans) and an anaerobic pathway (in P. shermanii and S. typhimurium)-that differ in the point of cobalt insertion. Analysis of B12 transport in E. coli reveals two systems: one (with two proteins) for the outer membrane, and one (with three proteins) for the inner membrane. To account for the uneven distribution of B12 in living forms, we suggest that the B12 synthetic pathway may have evolved to allow anaerobic fermentation of small molecules in the absence of an external electron acceptor. Later, evolution of the pathway produced siroheme, (allowing use of inorganic electron acceptors), chlorophyll (O2 production), and heme (aerobic respiration). As oxygen became a larger part of the atmosphere, many organisms lost fermentative functions and retained dependence on newer, B12 functions that did not involve fermentation. Paradoxically, Salmonella spp. synthesize B12 only anaerobically but can use B12 (for degradation of ethanolamine and propanediol) only with oxygen. Genetic analysis of the operons for these degradative functions indicate that anaerobic degradation is important. Recent results suggest that B12 can be synthesized and used during anaerobic respiration using tetrathionate (but not nitrate or fumarate) as an electron acceptor. The branch of enteric taxa from which Salmonella spp. and E. coli evolved appears to have lost the ability to synthesize B12 and the ability to use it in propanediol and glycerol degradation. Salmonella spp., but not E. coli, have acquired by horizontal transfer the ability to synthesize B12 and degrade propanediol. The acquired ability to degrade propanediol provides the selective force that maintains B12 synthesis in this group

  5. Gastric emptying in patients with vitamin B12 deficiency

    International Nuclear Information System (INIS)

    The clinical presentation of patients with vitamin B12 deficiency varies in a spectrum ranging from haematological disorders to neuropsychiatric diseases. In rare cases, orthostatic hypotension, impotence, constipation and urinary retention have been attributed to autonomic nervous system dysfunction due to vitamin B12 deficiency. The aim of this study was to evaluate the effect of vitamin B12 deficiency on autonomic nervous system function by studying gastric emptying times (T1/2). Twenty patients with newly diagnosed vitamin B12 deficiency and 12 control patients with gastritis and normal vitamin B12 levels were enrolled in this study. Gastroduodenoscopy, endoscopic biopsy, histopathological evaluation of the biopsy specimens and radionuclide gastric emptying studies were performed. After vitamin B12 replacement therapy for 3 months, radionuclide gastric emptying studies were repeated. Mean gastric emptying T1/2 in patients before and after treatment and in controls were 103.83±48.80 min, 90.00±17.29 min and 74.55±8.52 min, respectively. The difference in mean gastric emptying T1/2 between patients before treatment and controls was statistically significant (P12 treatment (P1/2 was somewhat shorter. There were no positive or negative correlations between gastric emptying T1/2 and the following parameters: haemoglobin, vitamin B12 level and Helicobacter pylori positivity. In conclusion, gastric emptying T1/2 was prolonged in patients with vitamin B12 deficiency and this prolongation was not corrected after vitamin B12 replacement therapy. Although autonomic nervous system dysfunction due to vitamin B12 deficiency rarely gives rise to clinical manifestations, latent dysfunction demonstrated by laboratory tests seems to be a frequent phenomenon. The level of vitamin B12 does not correlate with the degree of autonomic nervous system dysfunction measured by radionuclide gastric emptying studies. (orig.)

  6. Comparison of Injection Vitamin B12 With Symptomatic Management in Clinically Suspected Vitamin B12 Deficent Patients: an Interventional Study

    Directory of Open Access Journals (Sweden)

    Janak Rathod , Taral Shah , Manisha Gupta, Rajendra Mehta

    2012-01-01

    Full Text Available Objectives: This study was an attempt to evaluate the advantage of empirical use of Injection. Vitamin B 12 versus symptomatic management in clinically suspected Vitamin. B 12 deficient patients. Methodology: A total of 100 patients over 20 years of age (irrespective of gender were included in the study. The patients were divided into two groups, one group ( n = 50 receiving vitamin B12 injections and the other group (n = 50 received symptomatic treatment. Results: In clinically suspected vitamin B12 deficient patients after giving empirical therapy of Inj. Vit B 12; generalized fatigue (96%, pareshtesia (93.48%, myalgia (93.75%, loss of appetite (88.89%, confusion (93.75% and tremor (93.55% were improved with ( p<0.001. Labored breathing and depression were also improved with Inj.Vit B 12 as compared to symptomatic management, but this difference was statistically insignificant(p = 0.052 and p = 0.201 respectively. Conclusion: We conclude and recommend from the study to treat clinically suspected Vit. B 12 deficient patients with empirical Vit. B 12 Injections without the need of costly serum Vit. B 12 estimation

  7. Vitamin B12 Metabolism during Pregnancy and in Embryonic Mouse Models

    OpenAIRE

    Maira A. Moreno-Garcia; Rosenblatt, David S.; Jerome-Majewska, Loydie A

    2013-01-01

    Vitamin B12 (cobalamin, Cbl) is required for cellular metabolism. It is an essential coenzyme in mammals for two reactions: the conversion of homocysteine to methionine by the enzyme methionine synthase and the conversion of methylmalonyl-CoA to succinyl-CoA by the enzyme methylmalonyl-CoA mutase. Symptoms of Cbl deficiency are hematological, neurological and cognitive, including megaloblastic anaemia, tingling and numbness of the extremities, gait abnormalities, visual disturbances, memory l...

  8. Thermolability of mutant MMACHC protein in the vitamin B12-responsive cblC disorder

    OpenAIRE

    Froese, D.S.; Healy, S.; McDonald, M; Kochan, G; Oppermann, U.; Niesen, F.H.; Gravel, R. A.

    2010-01-01

    Methylmalonic aciduria and homocystinuria, cblC type, is the most common inborn error of cellular vitamin B12 metabolism. We previously showed that the protein carrying the mutation responsible for late-onset cblC (MMACHC-R161Q), treatable with high dose OHCbl, is able to bind OHCbl with wild-type affinity, leaving undetermined the disease mechanism involved [Froese et al., Mechanism of responsiveness, Mol. Genet. Metab. (2009).]. To assess whether the mutation renders the protein unstable, w...

  9. Vegan diet, subnormal vitamin B-12 status and cardiovascular health.

    Science.gov (United States)

    Woo, Kam S; Kwok, Timothy C Y; Celermajer, David S

    2014-08-01

    Vegetarian diets have been associated with atherosclerosis protection, with healthier atherosclerosis risk profiles, as well as lower prevalence of, and mortality from, ischemic heart disease and stroke. However, there are few data concerning the possible cardiovascular effects of a vegan diet (with no meat, dairy or egg products). Vitamin B-12 deficiency is highly prevalent in vegetarians; this can be partially alleviated by taking dairy/egg products in lact-ovo-vegetarians. However, metabolic vitamin B-12 deficiency is highly prevalent in vegetarians in Australia, Germany, Italy and Austria, and in vegans (80%) in Hong Kong and India, where vegans rarely take vitamin B-12 fortified food or vitamin B-12 supplements. Similar deficiencies exist in northern Chinese rural communities consuming inadequate meat, egg or dairy products due to poverty or dietary habits. Vascular studies have demonstrated impaired arterial endothelial function and increased carotid intima-media thickness as atherosclerosis surrogates in such metabolic vitamin B-12 deficient populations, but not in lactovegetarians in China. Vitamin B-12 supplementation has a favourable impact on these vascular surrogates in Hong Kong vegans and in underprivileged communities in northern rural China. Regular monitoring of vitamin B-12 status is thus potentially beneficial for early detection and treatment of metabolic vitamin B-12 deficiency in vegans, and possibly for prevention of atherosclerosis-related diseases. PMID:25195560

  10. Causes of Vitamin B12 and Folate Deficiency

    Science.gov (United States)

    This review describes current knowledge of the main causes of vitamin B12 and folate deficiency. The most common explanations for poor B12 status are a low dietary intake of the vitamin (i.e., a low intake of animal-source foods) and malabsorption. Although it has long been known that strict vegetar...

  11. Vegan Diet, Subnormal Vitamin B-12 Status and Cardiovascular Health

    Directory of Open Access Journals (Sweden)

    Kam S. Woo

    2014-08-01

    Full Text Available Vegetarian diets have been associated with atherosclerosis protection, with healthier atherosclerosis risk profiles, as well as lower prevalence of, and mortality from, ischemic heart disease and stroke. However, there are few data concerning the possible cardiovascular effects of a vegan diet (with no meat, dairy or egg products. Vitamin B-12 deficiency is highly prevalent in vegetarians; this can be partially alleviated by taking dairy/egg products in lact-ovo-vegetarians. However, metabolic vitamin B-12 deficiency is highly prevalent in vegetarians in Australia, Germany, Italy and Austria, and in vegans (80% in Hong Kong and India, where vegans rarely take vitamin B-12 fortified food or vitamin B-12 supplements. Similar deficiencies exist in northern Chinese rural communities consuming inadequate meat, egg or dairy products due to poverty or dietary habits. Vascular studies have demonstrated impaired arterial endothelial function and increased carotid intima-media thickness as atherosclerosis surrogates in such metabolic vitamin B-12 deficient populations, but not in lactovegetarians in China. Vitamin B-12 supplementation has a favourable impact on these vascular surrogates in Hong Kong vegans and in underprivileged communities in northern rural China. Regular monitoring of vitamin B-12 status is thus potentially beneficial for early detection and treatment of metabolic vitamin B-12 deficiency in vegans, and possibly for prevention of atherosclerosis-related diseases.

  12. Indications for Vitamin B12 Therapy: A retrospective study

    OpenAIRE

    Delva, M. Dianne; Anderson, J E

    1992-01-01

    A retrospective chart audit was undertaken to determine the clinical reasons for vitamin B12 therapy in family practice. Abnormal laboratory tests and symptoms were the most common reasons for initiating therapy. The high proportion of cases with little supporting evidence of B12 deficiency suggests that other factors influence treatment decisions.

  13. Vitamin B12 deficiency optic neuropathy detected by asymptomatic screening

    OpenAIRE

    Chu, Colin; Scanlon, Peter

    2011-01-01

    Asymptomatic bilateral optic disc swelling was detected in a 19-year-old man with type 1 diabetes through routine photographic screening for retinopathy. He was found to have significant vitamin B12 deficiency which the authors believe was the cause for the optic neuropathy. After B12 replacement, visual function and optic disc appearances returned to normal.

  14. Electron addition to alkyl cobalamins, coenzyme B12 and vitamin B12

    International Nuclear Information System (INIS)

    Exposure of dilute solutions of methyl and ethyl cobalamins and coenzyme B12 in dilute solutions (D2O+CD3OD) to 60Co #betta#-rays at 77 K gave a single broad feature in the free-spin region assigned to electron-capture species with the excess electron largely confined to a π* corrin orbital. On warming above 77 K the methyl derivative gave a novel species with spectral features characteristic of an unpaired electron in the Co(dsub(x2-y2)) orbital. The other two substrates gave spectra due to Cosup(II)Bsub(12r) both on warming and after photolyses with visible light. The acetyl derivative gave an electron-capture species whose e.s.r. spectrum was characteristic of an electron in the Co(dsub(z2)) orbital, which on warming above 77 K changed to the normal Cosup(II)Bsub(12r) spectrum. The cyano derivative (vitamin B12) gave electron addition into the Co(dsub(z2)) orbital, as evidenced by the large hyperfine coupling to 13C from 13CN ligands. On annealing, cyanide ions were lost irreversibly, Bsub(12r) being detected by e.s.r. spectroscopy. In contrast, the dicyano derivative on electron addition at 77 K gave a species containing only one 13CN ligand. Hence in this case one CN- ligand was lost at 77 K, with no return of the dimethylbenzimidazole ligand. These results are discussed in terms of a new mechanism for electron-addition to alkyl cobalamins. (author)

  15. Dietary vitamin B12 deficiency in an adolescent white boy.

    Science.gov (United States)

    O'Gorman, P; Holmes, D; Ramanan, A V; Bose-Haider, B; Lewis, M J; Will, A

    2002-06-01

    Dietary deficiency of cobalamin resulting in tissue deficiency in white individuals is unusual. However, several patients with dietary deficiency who were neither vegan nor Hindu have been described. This report describes the case of a 14 year old boy who was a white non-Hindu with a very low intake of cobalamin, which was not apparent until a detailed dietary assessment was performed. The patient responded rapidly to a combination of oral and parenteral B12. This case illustrates the fact that severe dietary vitamin B12 deficiency can occur in non-Hindu white individuals. Inadequate dietary content of B12 may not be apparent until a detailed dietary assessment is performed. This patient is likely to have had subclinical vitamin B12 deficiency for several years. Increased vitamin B12 requirements associated with the adolescent growth spurt may have provoked overt tissue deficiency. PMID:12037034

  16. Absorption of vitamin B12 and effect of pancreatic juice on gastric vitamin B12 binder in the dog

    International Nuclear Information System (INIS)

    The effect of pancreatic juice on vitamin B12 absorption was studied in dogs. It was found that dog gastric juice as well as pancreatic juice contain vitamin B12 binding proteins which differ in the elution pattern on DEAE-cellulose columns, the former being eluted at much lower sodium chloride concentrations. When radio-active vitamin B12 was fed or instilled in the proximal bowel and vitamin B12 recovered at different bowel levels, it was found that vitamin B12-protein complex behaved like gastric juice binder in the proximal bowel and like pancreatic binder in the distal. In vitro digestion of gastric binder with pancreatic juice altered vitamin B12-protein complex in such a way that elution pattern became similar to that of pancreatic juice. It was also shown that the change was not due to transfer of vitamin B12 from gastric binder to pancreatic binder. Trypsin digestion had similar effect on gastric binder, and Sephadex G-200 gelfiltration demonstrated reduction in the molecular size. In the doz, vitamin B12 first bound to gastric binder undergoes chemical changes in the bowel and becomes a readily absorbable form in the distal bowel. (auth.)

  17. Characterization of vitamin B12 in Dunaliella salina.

    Science.gov (United States)

    Kumudha, Anantharajappa; Sarada, Ravi

    2016-01-01

    Vitamin B12 is one of nature's complex metabolite which is industrially produced using certain bacteria. Algae could be an alternative source of vitamin B12 and in this study, vitamin B12 from a halotolerant green alga, Dunaliella salina V-101 was purified and characterized. The extract of Dunaliella was purified by passing through Amberlite XAD-2 and EASI-extract vitamin B12 immunoaffinity column. The total vitamin B12 content in purified sample fractions was 42 ± 2 μg/100 g dry weight as determined by the chemiluminescence method which was almost close to 49 ± 2 μg/100 g dry weight as estimated by microbiological method. Further quantification of total vitamin B12 using gold nanoparticle (AUNPs) based aptamer showed 40 ± 0.8/100 g dry weight. There was a good correlation among all the methods of quantification. Adenosylcobalamin, a form of vitamin B12 which is a cofactor for methylmalonyl CoA mutase was identified by HPLC. Upon quantification, Dunaliella was found to contain 34 ± 4 μg of adenosylcobalamin for 100 g dry biomass. Authenticity of adenosylcobalmin was confirmed by tandem mass spectrometry (MS/MS), selected ion recording (SIR) and multiple reaction monitoring (MRM) studies. PMID:26788012

  18. Organic/inorganic hybrid nanomaterials with vitamin B12 functions

    Directory of Open Access Journals (Sweden)

    Yoshio Hisaeda, Takahiro Masuko, Erika Hanashima and Takashi Hayashi

    2006-01-01

    Full Text Available A hybrid nanomaterial was prepared by human serum albumin (HSA and vitamin B12 derivatives. The incorporation of hydrophobic vitamin B12 derivatives, which have ester groups in place of the peripheral amide moieties of the natural cobalamin, into HSA is primarily controlled by the hydrophobicity of the peripheral ester groups. Microenvironmental property around the hydrophobic vitamin B12 in HSA was examined by fluorescence and fluorescence polarization measurements. The hydrophobic vitamin B12 itself in HSA is in a microenvironment equivalent in medium polarity to dichloromethane. The molecular motion of hydrophobic vitamin B12 in HSA was markedly suppressed under such microenvironmental conditions. Carbon-skeleton rearrangement reaction of an alkyl radical derived from an alkyl ligand bound to the hydrophobic vitamin B12 was markedly favored in HSA aqueous solution, relative to the reactions in methanol and benzene. The 1,2-migration of the electron-withdrawing group arises from both the suppression of molecular motion and desolvation effects on the alkylated hydrophobic vitamin B12 in HSA.

  19. Pulmonary sequestration

    International Nuclear Information System (INIS)

    Pulmonary sequestration is a congenital affection consisting in the presence of a cystic mass of no-functional pulmonary tissue without an obvious communication with tracheobronchial tree and that receives all or most of its bloodstream of the anomalous vessels from systemic circulation. Taking into account that presentation of this affection is rare compared to other pulmonary affections (between the 1% and the 2% of all pulmonary resections) and that also the more usual is its definitive treatment before adulthood. The case of man aged 44 is presented coming to consultation due to frequent episodes of pneumonias from more 10 years ago diagnosed as a bronchiectasis. The more significant facts of embryology origin of this affection including: anatomical and pathological features, imaging diagnosis, surgical treatment details, and postoperative course. (author)

  20. Influence of Buformin retard on vitamin B12 absorption

    International Nuclear Information System (INIS)

    In 18 test persons with a healthy metabolism a significant reduction of the vitamin B12 absorption rate was observed when Buformin retard was administered 90 minutes before starting the Schilling test. This biguanide-induced reduction of vitamin B12 absorption was not detectable in preliminary examinations in which the interval between the last Buformin administration and the administering of 58Co-vitamin B12 was 14 hours. Thus could be shown that the reduction was due to the method used. There is no increased danger of an anemia provided that the therapeutic rules are obeyed i.e. Buformin should be taken after breakfast and supper, respectively

  1. [Severe vitamin B12 deficiency in infants breastfed by vegans].

    Science.gov (United States)

    Roed, Casper; Skovby, Flemming; Lund, Allan Meldgaard

    2009-10-19

    Weight loss and reduction of motor skills resulted in paediatric evaluation of a 10-month-old girl and a 12-month-old boy. Both children suffered form anaemia and delayed development due to vitamin B12 deficiency caused by strict maternal vegan diet during pregnancy and nursing. Therapy with cyanocobalamin was instituted with remission of symptoms. Since infants risk irreversible neurologic damage following severe vitamin B12 deficiency, early diagnosis and treatment are mandatory. Vegan and vegetarian women should take vitamin B12 supplementation during the pregnancy and nursing period. PMID:19852900

  2. Determination of Vitamin B12 in Vitamin B12 Compound Ointment- Ⅰ by HPLC%复方维生素B12软膏Ⅰ号中维生素B12的HPLC测定

    Institute of Scientific and Technical Information of China (English)

    杨谊; 李兵; 史学慧

    2004-01-01

    建立了HPLC法测定复方维生素B12软膏Ⅰ号中维生素B12的含量.采用Hypersll BDS C18柱,流动相为乙腈-0.05mol/L磷酸二氢钾溶液(15:85),检测波长360nm.维生素B12在0.16~0.8μg范围内线性关系良好(r=0.9995),平均回收率为98.4%,RSD为0.9%.

  3. Neuroenhancement with vitamin B12-underestimated neurological significance.

    Science.gov (United States)

    Gröber, Uwe; Kisters, Klaus; Schmidt, Joachim

    2013-12-01

    Vitamin B12 is a cofactor of methionine synthase in the synthesis of methionine, the precursor of the universal methyl donor S-Adenosylmethionine (SAMe), which is involved in different epigenomic regulatory mechanisms and especially in brain development. A Vitamin B12 deficiency expresses itself by a wide variety of neurological manifestations such as paraesthesias, skin numbness, coordination disorders and reduced nerve conduction velocity. In elderly people, a latent Vitamin B12 deficiency can be associated with a progressive brain atrophy. Moderately elevated concentrations of homocysteine (>10 µmol/L) have been associated with an increased risk of dementia, notably Alzheimer's disease, in many cross-sectional and prospective studies. Raised plasma concentrations of homocysteine is also associated with both regional and whole brain atrophy, not only in Alzheimer's disease but also in healthy elderly people. Clinician awareness should be raised to accurately diagnose and treat early Vitamin B12 deficiency to prevent irreversible structural brain damage. PMID:24352086

  4. The photochemical mechanism of a B12-dependent photoreceptor protein

    Science.gov (United States)

    Kutta, Roger J.; Hardman, Samantha J. O.; Johannissen, Linus O.; Bellina, Bruno; Messiha, Hanan L.; Ortiz-Guerrero, Juan Manuel; Elías-Arnanz, Montserrat; Padmanabhan, S.; Barran, Perdita; Scrutton, Nigel S.; Jones, Alex R.

    2015-08-01

    The coenzyme B12-dependent photoreceptor protein, CarH, is a bacterial transcriptional regulator that controls the biosynthesis of carotenoids in response to light. On binding of coenzyme B12 the monomeric apoprotein forms tetramers in the dark, which bind operator DNA thus blocking transcription. Under illumination the CarH tetramer dissociates, weakening its affinity for DNA and allowing transcription. The mechanism by which this occurs is unknown. Here we describe the photochemistry in CarH that ultimately triggers tetramer dissociation; it proceeds via a cob(III)alamin intermediate, which then forms a stable adduct with the protein. This pathway is without precedent and our data suggest it is independent of the radical chemistry common to both coenzyme B12 enzymology and its known photochemistry. It provides a mechanistic foundation for the emerging field of B12 photobiology and will serve to inform the development of a new class of optogenetic tool for the control of gene expression.

  5. La Vitamine B12 et la Santé

    OpenAIRE

    VALDES SOCIN, Hernan Gonzalo

    2013-01-01

    Objectifs: Révision sur le rôle de la vitamine B12 et sur les évidences qui suggèrent que la vitamine B12 peut réduire le risque de certaines maladies chroniques. Evidences: recherche dans Medline depuis 1999 jusqu'en 2013 en utilisant le mot clé vitamin B12. Les articles les plus conséquents (150) étaient associés avec le cancer, la maladie cardiovasculaire, la santé mentale et les altérations du tube neural. Résultats: Le déficit avéré de la vitamine B12 est classiquement associé à...

  6. Dietary Sources of Vitamin B-12 and Their Association with Vitamin B-12 Status Markers in Healthy Older Adults in the B-PROOF Study

    OpenAIRE

    Brouwer-Brolsma, Elske M.; Dhonukshe-Rutten, Rosalie A. M.; van Wijngaarden, Janneke P.; van der Zwaluw, Nikita L.; Nathalie van der Velde; de Groot, Lisette C. P. G. M.

    2015-01-01

    Low vitamin B-12 concentrations are frequently observed among older adults. Malabsorption is hypothesized to be an important cause of vitamin B-12 inadequacy, but serum vitamin B-12 may also be differently affected by vitamin B-12 intake depending on food source. We examined associations between dietary sources of vitamin B-12 (meat, fish and shellfish, eggs, dairy) and serum vitamin B-12, using cross-sectional data of 600 Dutch community-dwelling adults (≥65 years). Dietary intake was assess...

  7. Analysis of the Market of Vitamin B12%维生素B12市场透析

    Institute of Scientific and Technical Information of China (English)

    张伦

    2004-01-01

    目的:掌握维生素 B12的市场现状及发展趋势.方法:对维生素 B12国内、外生产和销售情况进行分析.结果与结论:我国维生素 B12市场潜力巨大,制药企业应密切关注市场变化,完善自身条件,以求进一步发展.

  8. Coenzyme B12 and Its Model Compounds%辅酶B12及其模型化合物

    Institute of Scientific and Technical Information of China (English)

    陈慧兰

    1989-01-01

    @@辅酶B12即5′-脱氧腺苷钴胺素,是一个天然存在的有机金属化合物。它与维生素B12,即氰钴胺素组成和结构相似,但生理功能不同,维生素B12是一种抗恶性贫血的药物,而辅酶B12在生物体内多种代谢过程中起着重要作用,其中研究得最多的是与分子内重排有关的酶反应。弄清辅酶B12在生物体内的作用是当前医学、生物化学和生物无机化学中的一个重要课题。本文就辅酶B12在分子重排反应中的作用机理、模型体系的研究和钴-碳键能的测定等方面的最新进展作一评述。 一、辅酶B12的结构 辅酶B12和维生素B12同属于类钴啉(Corrinoid)化合物。由于光敏性和在酸中的不稳定性,它的发现比维生素B12晚了十年。经过X射线衍射结构分析确定:辅酶B12和维生素B12都由钴(Ⅲ)离子与咕啉环组成,二者之差别仅仅是C0(Ⅲ)的一个轴向配体的不同。

  9. Vitamin B12 and folate depletion in cognition: A review

    OpenAIRE

    Moretti Rita; Torre Paola; Antonello Rodolfo; Cattaruzza Tatiana; Cazzato Giuseppe; Bava Antonio

    2004-01-01

    In cross-sectional studies, low levels of folate and B12 have been shown to be associated with cognitive decline and dementia Evidence for the putative role of folate, vitamin B12 in neurocognitive and other neurological functions comes from reported cases of severe vitamin deficiencies, particularly pernicious anemia, and homozygous defects in genes that encode for enzymes of one-carbon metabolism. The neurological alterations seen in these cases allow for a biological role of vitamins in ne...

  10. Vitamin B12 absorption capacity in healthy children

    Energy Technology Data Exchange (ETDEWEB)

    Hjelt, K.; Krasilnikoff, P.A.

    1986-03-01

    B12 absorption was investigated in 47 healthy children aged 7 months to 15.8 years (median 4.9 years). The patients had either recovered from giardiasis, the post-gastroenteritis syndrome, or had celiac disease in remission (treated with a gluten-free diet). The B12 absorption was measured by a double-isotope technique using /sup 57/CoB12 and /sup 51/CrCl/sub 3/, the latter being the inabsorbable marker. The radiation dose was minimal. The results were presented as fractional absorption of B12 (FAB12). Within the different age groups, the absorption test was performed by means of the following oral amounts of B12: 0- less than 1 year, 0.5 microgram; 1-3 years: 1.7 micrograms, 4-6 years, 2.5 micrograms; 7-10 years; 3.3 micrograms; and 11-15 years, 4.5 micrograms. When using these oral amounts of B12, the medians (and ranges) of FAB12 were found to be: 1-3 years (n = 18), 37% (16-80%); 4-6 years (n = 10), 27% (19-40%); 7-10 years (n = 9), 32% (21-44%); and 11-15 years (n = 8), 27% (19-59%). The FAB12 in two children aged 7 and 11 months was 31% and 32%, respectively. These results may be interpretated as reference values for B12 absorption in children. Further absorption tests were performed in seven children representing the four age groups from 1 to 15 years. When a high oral amount of B12 was given (i.e., three times the saturation dose), the FAB12 ranged from 0 to 20% (median 9%), whereas a low amount (i.e., one-ninth of the saturation dose) produced fractional absorptions from 65 to 82% (median 74%).

  11. Vitamin B12 absorption capacity in healthy children

    International Nuclear Information System (INIS)

    B12 absorption was investigated in 47 healthy children aged 7 months to 15.8 years (median 4.9 years). The patients had either recovered from giardiasis, the post-gastroenteritis syndrome, or had celiac disease in remission (treated with a gluten-free diet). The B12 absorption was measured by a double-isotope technique using 57CoB12 and 51CrCl3, the latter being the inabsorbable marker. The radiation dose was minimal. The results were presented as fractional absorption of B12 (FAB12). Within the different age groups, the absorption test was performed by means of the following oral amounts of B12: 0- less than 1 year, 0.5 microgram; 1-3 years: 1.7 micrograms, 4-6 years, 2.5 micrograms; 7-10 years; 3.3 micrograms; and 11-15 years, 4.5 micrograms. When using these oral amounts of B12, the medians (and ranges) of FAB12 were found to be: 1-3 years (n = 18), 37% (16-80%); 4-6 years (n = 10), 27% (19-40%); 7-10 years (n = 9), 32% (21-44%); and 11-15 years (n = 8), 27% (19-59%). The FAB12 in two children aged 7 and 11 months was 31% and 32%, respectively. These results may be interpretated as reference values for B12 absorption in children. Further absorption tests were performed in seven children representing the four age groups from 1 to 15 years. When a high oral amount of B12 was given (i.e., three times the saturation dose), the FAB12 ranged from 0 to 20% (median 9%), whereas a low amount (i.e., one-ninth of the saturation dose) produced fractional absorptions from 65 to 82% (median 74%)

  12. Thermotoga lettingae Can Salvage Cobinamide To Synthesize Vitamin B12

    OpenAIRE

    Butzin, Nicholas C.; Secinaro, Michael A.; Swithers, Kristen S.; Gogarten, J Peter; Noll, Kenneth M.

    2013-01-01

    We recently reported that the Thermotogales acquired the ability to synthesize vitamin B12 by acquisition of genes from two distantly related lineages, Archaea and Firmicutes (K. S. Swithers et al., Genome Biol. Evol. 4:730–739, 2012). Ancestral state reconstruction suggested that the cobinamide salvage gene cluster was present in the Thermotogales' most recent common ancestor. We also predicted that Thermotoga lettingae could not synthesize B12 de novo but could use the cobinamide salvage...

  13. The photochemical mechanism of a B12-dependent photoreceptor protein

    OpenAIRE

    Kutta, Roger J.; Hardman, Samantha J O; Johannissen, Linus O.; Bellina, Bruno; Messiha, Hanan L.; Ortiz-Guerrero, Juan Manuel; Elías-Arnanz, Montserrat; S Padmanabhan; Barran, Perdita; Nigel S. Scrutton; Jones, Alex R

    2015-01-01

    The coenzyme B12-dependent photoreceptor protein, CarH, is a bacterial transcriptional regulator that controls the biosynthesis of carotenoids in response to light. On binding of coenzyme B12 the monomeric apoprotein forms tetramers in the dark, which bind operator DNA thus blocking transcription. Under illumination the CarH tetramer dissociates, weakening its affinity for DNA and allowing transcription. The mechanism by which this occurs is unknown. Here we describe the photochemistry in Car...

  14. Effect of Homocysteine ,Vitamin B12 , Folic acid during pregnancy

    OpenAIRE

    Arpita Patel; Chandan Chakrabarty; Arjun Singh; Jatin Patel; Hitesh Mewada; S L Sharma

    2012-01-01

    Vitamin B12, folic acid and homocysteine are metabolically closely related. At the same time homocysteine is found to be offending factor for vascular pathology causing preeclampsia. On the other hand periconceptional nutritional status influences the vitamin B12 & folic acid level. Which further affect the homocysteine level thus may affect pregnancy outcome. Various contributory factors lead these vitamin deficiencies, maternal nutrition is one of them. Ahmedabad being a predominantly veget...

  15. NEUROLOGICAL MANIFESTATIONS OF B12 DEFICIENCY IN BIDAR DISTRICT

    OpenAIRE

    Vijay Kumar; Sandeep,; Sajjal; Shivraj B

    2014-01-01

    OBJECTIVE: To investigate the etiological factors resulting in Vitamin B12 deficiency in patients with sub-acute combined degeneration (SACD) and other neurological manifestation manifestations. METHODS: We undertook a prospective study of 50 patients, all clinically suspected to have Vit B12 deficiency; they were investigated clinically, hematologically, biochemically and radiologically. RESULTS: There was a dominance of males (41of 50) with the majority in the age group ...

  16. Malabsorption of vitamin B12 in homozygous β-thalassemia

    International Nuclear Information System (INIS)

    Schilling tests were performed in ten children aged 5-12 years suffering from homozygous β-thalassemia. 57Co labelled vitamin B12 values excreted in the urine have been found much lower than normal and remained low when the same procedure was repeated with the addition of intrinsic factor. The possible factors responsible for this malabsorption of vitamin B12 seemed to be liver damage and folic acid deficiency. (orig.)

  17. Coenzyme B12 Repurposed for Photoregulation of Gene Expression.

    Science.gov (United States)

    Gruber, Karl; Kräutler, Bernhard

    2016-05-01

    Old cofactor, new tricks: In enzymes, coenzyme B12 has a well-known function as a radical initiator through homolysis of the Co-C bond. It has recently been shown that nature has repurposed this cofactor as a photosensitive switch for the regulation of bacterial carotenoid biosynthesis. Co-C bond breakage is again the key event in this process, triggering huge conformational changes in the B12 -binding protein. PMID:27010518

  18. Determining Functional Vitamin B12 Deficiency in the Elderly

    Science.gov (United States)

    Khodabandehloo, Niloofar; Vakili, Masoud; Hashemian, Zahra; Zare Zardini, Hadi

    2015-01-01

    Background: Elevated concentration of serum total homocysteine usually occurs in vitamin B-12 deficiency. This metabolite can be measured and used for screening functional vitamin B-12 deficiency. Objectives: We assessed functional vitamin B12 deficiency in Tehranian elderly admitted to elderly research center, University of Social Welfare and Rehabilitation Sciences. Patients and Materials: A cross-sectional study was performed on 232 elderly admitted to elderly research center in Tehran, Iran in 2012. According to other studies, individuals were classified into two groups: high risk of vitamin B-12 deficiency (homocysteine (> 15 micmol/L). Results: Cut-off of 15.0 pmol/L for homocysteine was identified for persons with normal or elevated concentrations. Among persons aged 65–74 and ≥ 75 years, respectively, 56% and 93% were at high risk of vitamin B-12 deficiency. Conclusions: The prevalence of B12 deficiency was higher in this study compared to other studies, so more attention and massive efficacious policy should be designed to reduce the deficiency of this vitamin. PMID:26430518

  19. A rare case of vitamin B12 deficiency with ascites.

    Science.gov (United States)

    Rajsekhar, Putta; Reddy, Mugannagari Maheshwar; Vaddera, Sameeraja; Rajini, G; Tikeli, Vinil

    2014-07-01

    Vitamin B12 deficiency is widespread than assumed in population. At risk are older people, pregnant women, vegans, patients with renal and intestinal diseases. Vitamin B12 deficiency can present with various hematological, gastrointestinal and neurological manifestations. In the population, the prevalence of vitamin B12 deficiency in younger people is 5% to 7% which is less compared to elderly people. In developing countries, deficiency is much more common, starting in early life and persisting across the life span. Here, we present a 16-year-old female patient presenting with ascites since 2 months who was subsequently investigated and diagnosed to have nutritional megaloblastic anaemia secondary to vitamin B12 deficiency after exclusion of other infective, neoplastic, autoimmune and inflammatory diseases. Inspite, patient was treated with antitubercular drugs but she did not respond. After supplementation of Vitamin B12, ascites responded well. Inadequate intake due to low consumption of animal source foods is the main cause of low serum vitamin B12 in younger adults and likely the main cause in poor population worldwide. PMID:25177593

  20. How prevalent is vitamin B(12) deficiency among vegetarians?

    Science.gov (United States)

    Pawlak, Roman; Parrott, Scott James; Raj, Sudha; Cullum-Dugan, Diana; Lucus, Debbie

    2013-02-01

    Vegetarians are at risk for vitamin B(12) (B12) deficiency due to suboptimal intake. The goal of the present literature review was to assess the rate of B12 depletion and deficiency among vegetarians and vegans. Using a PubMed search to identify relevant publications, 18 articles were found that reported B12 deficiency rates from studies that identified deficiency by measuring methylmalonic acid, holo-transcobalamin II, or both. The deficiency rates reported for specific populations were as follows: 62% among pregnant women, between 25% and almost 86% among children, 21-41% among adolescents, and 11-90% among the elderly. Higher rates of deficiency were reported among vegans compared with vegetarians and among individuals who had adhered to a vegetarian diet since birth compared with those who had adopted such a diet later in life. The main finding of this review is that vegetarians develop B12 depletion or deficiency regardless of demographic characteristics, place of residency, age, or type of vegetarian diet. Vegetarians should thus take preventive measures to ensure adequate intake of this vitamin, including regular consumption of supplements containing B12. PMID:23356638

  1. 4-ethylphenyl-cobalamin impairs tissue uptake of vitamin B12 and causes vitamin B12 deficiency in mice.

    Directory of Open Access Journals (Sweden)

    Elena Mutti

    Full Text Available Coβ-4-ethylphenyl-cob(III alamin (EtPhCbl is an organometallic analogue of vitamin B12 (CNCbl which binds to transcobalamin (TC, a plasma protein that facilitates the cellular uptake of cobalamin (Cbl. In vitro assays with key enzymes do not convert EtPhCbl to the active coenzyme forms of Cbl suggesting that administration of EtPhCbl may cause cellular Cbl deficiency. Here, we investigate the in vivo effect of EtPhCbl in mice and its ability, if any, to induce Cbl deficiency. We show that EtPhCbl binds to mouse TC and we examined mice that received 3.5 nmol/24h EtPhCbl (n=6, 3.5 nmol/24h CNCbl (n=7 or NaCl (control group (n=5 through osmotic mini-pumps for four weeks. We analyzed plasma, urine, liver, spleen, submaxillary glands and spinal cord for Cbl and markers of Cbl deficiency including methylmalonic acid (MMA and homocysteine (tHcy. Plasma MMA (mean±SEM was elevated in animals treated with EtPhCbl (1.01±0.12 µmol/L compared to controls (0.30±0.02 µmol/L and CNCbl (0.29±0.01 µmol/L treated animals. The same pattern was observed for tHcy. Plasma total Cbl concentration was higher in animals treated with EtPhCbl (128.82±1.87 nmol/L than in CNCbl treated animals (87.64±0.93 nmol/L. However, the organ levels of total Cbl were significantly lower in animals treated with EtPhCbl compared to CNCbl treated animals or controls, notably in the liver (157.07±8.56 pmol/g vs. 603.85±20.02 pmol/g, and 443.09±12.32 pmol/g, respectively. Differences between the three groups was analysed using one-way ANOVA and, Bonferroni post-hoc test. EtPhCbl was present in all tissues, except the spinal cord, accounting for 35-90% of total Cbl. In conclusion, treatment with EtPhCbl induces biochemical evidence of Cbl deficiency. This may in part be caused by a compromised tissue accumulation of Cbl.

  2. Vitamin B12 And Folate Deficiency In a Hospital Population

    Directory of Open Access Journals (Sweden)

    Wadia RS

    2001-01-01

    Full Text Available This is a study of B12 and folate deficiency in a hospital population. We studied the incidence of their deficiency by evaluating blood levels in every tenth hospital admission. Among the 450 patients chosen, 417 had normal levels of both, 2 had deficiency of folate alone (folate < 3ng.ml, 3 had B12 deficiency alone (B12<200pg/mland 11 had deficiency of both (total 3.5%. In addition 12 had borderline b12 level(200-300pg/ml, 2 had borderline folate level (3-4ng/ml(0.44%and 3 had borderline levels for both (0.66% . Thus 33% had definite or borderline deficiency. This deficiency was more common in the elderly and in patients on vegetarian diet (5.7% definite deficiency, 8.8% borderline levels compared to those on a non-vegetarian diet. During the 2 1/2 years of the study a total of 99 definite deficiency and 69 borderline deficiency were seen. In the definite deficiency group, 22.3% had neuropathy, 6.1% had evidence of myelopathy, 18.2% had neuropsychiatric changes (memory defect, dementia, behavioural abnormalities, depression and 4.1% had cerebellar signs. The neurologic findings in the borderline group were almost similar (neuropathy 29%, myelopathy 8.6% and neuropsychiatric changes 18.4%. High mean corpuscular volume (MCV> 95 was seen in 69% of those with both B12 and folate deficiency, 43.4% with B12 deficiency and 61.15 with folate deficiency. Hypersegmented polymorphs were seen in 21.7% with B12 deficiency, 27.5% with folate both B12 and folate deficiency had either megaloblastosis or dimorphic picture. It is to be noted that B12 and folate deficiency in this population was more frequent than we previously considered and reliance on haematologic parameters will miss half to one third of all cases. As expected B12 deficiency is more frequent in vegetarians than non-vegetarians.

  3. The EGG 57-CO B-12 absorption test, in the evaluation of patients with low serum B-12

    International Nuclear Information System (INIS)

    The Schilling Test (ST) is the standard test for diagnosing vitamin B-12 malabsorption (MA). However, patients with subtle gastric dysfunction may have normal ST, but impaired absorption of B-12 given with food. The authors have adapted an Egg B-12 Absorption Test (EBAT) in which 57-Co cyanocobalamin (57-Co B-12) is mixed with scrambled egg to evaluate this phenomenon in patients with low serum B-12, normal ST and possible subtle MA. Lyophilized egg yolk is reconstituted and mixed with 57-Co- B-12 of equal dose to that of ST. The authors studied 46 individuals: 13 controls, 5 patients with known pernicious anemia (PA), in addition to 28 patients with low serum B-12 levels and normal ST. ST/EBAT ratios were calculated. Twenty-eight test patients excreted 13.3% on ST and 3.5% on EBAT. Mean ST/EBAT ratio was 8.2 (1.4-35.9). Five had EBAT results in the PA range (<1%) and ST/EBAT ratios (14.4-35.9) that were significantly elevated. This group is also evaluated with pepsinogen I/II ratios, gastric analysis, deoxyuridine suppression tests, anti intrinsic factor, and antiparietal cell antibodies. The authors' results indicate that the EBAT can differentiate between PA and non PA patients, and that some patients with low serum B-12 levels and normal ST may, in fact, have subtle MA. The EBAT, combined with ST/EBAT ratio, may provide a means for identifying this group of patients

  4. Folate–vitamin B-12 interaction in relation to cognitive impairment, anemia, and biochemical indicators of vitamin B-12 deficiency

    OpenAIRE

    Selhub, Jacob; Morris, Martha Savaria; Jacques, Paul F.; Rosenberg, Irwin H.

    2009-01-01

    Previous reports on pernicious anemia treatment suggested that high folic acid intake adversely influences the natural history of vitamin B-12 deficiency, which affects many elderly individuals. However, experimental investigation of this hypothesis is unethical, and the few existing observational data are inconclusive. With the use of data from the 1999–2002 National Health and Nutrition Examination Survey (NHANES), we evaluated the interaction between high serum folate and low vitamin B-12 ...

  5. Multiple Roles of ATP:Cob(I)alamin Adenosyltransferases in the Conversion of B12 to Coenzyme B12

    OpenAIRE

    Mera, Paola E.; Escalante-Semerena, Jorge C.

    2010-01-01

    Our mechanistic understanding of the conversion of vitamin B12 into coenzyme B12 (a.k.a. adenosylcobalamin, AdoCbl) has been substantially advanced in recent years. Insights into the multiple roles played by ATP:Cob(I)alamin adenosyltransferase (ACA) enzymes have emerged through the crystallographic, spectroscopic, biochemical, and mutational analyses of wild-type and variant proteins. ACA enzymes circumvent the thermodynamic barrier posed by the very low redox potential associated with the r...

  6. Stabilization of HfB12 in Y1-xHfxB12 under Ambient Pressure.

    Science.gov (United States)

    Akopov, Georgiy; Yeung, Michael T; Turner, Christopher L; Li, Rebecca L; Kaner, Richard B

    2016-05-16

    Alloys of metal dodecaborides-YB12 with HfB12-were prepared via arc-melting in order to stabilize the metastable HfB12 high-pressure phase under ambient pressure. Previously, HfB12 had been synthesized only under high-pressure (6.5 GPa). Powder X-ray diffraction (PXRD) and energy-dispersive X-ray spectroscopy (EDS) were used to confirm the purity and phase composition of the prepared samples. The solubility limit for HfB12 in Y1-xHfxB12 (cubic UB12 structure type) was determined to be ∼35 at. % Hf by PXRD and EDS analysis. The value of the cubic unit cell parameter (a) changed from 7.505 Å (pure YB12) to 7.454 Å across the solid solution range. Vickers hardness increased from 40.9 ± 1.6 GPa for pure YB12 to 45.0 ± 1.9 GPa under an applied load of 0.49 N for the Y1-xHfxB12 solid solution composition with ∼28 at. % Hf, suggesting both solid solution hardening and extrinsic hardening due to the formation of secondary phases of hafnium. PMID:27115173

  7. Holo-transcobalamin is an indicator of vitamin B-12 absorption in healthy adults with adequate vitamin B-12 status

    DEFF Research Database (Denmark)

    von Castel-Roberts, Kristina M; Mørkbak, Anne Louise; Nexo, Ebba;

    2007-01-01

    vitamin B-12 at 6-h intervals beginning early morning (baseline) on day 1. Blood was drawn at 17 timed intervals over the course of 3 d for the analysis of holo-TC and other indicators of vitamin B-12 status. RESULTS: Mean holo-TC increased significantly (P < 0.001) from baseline at 6 h (11%) and 24 h (50......BACKGROUND: It has been hypothesized that the response of holo-transcobalamin (holo-TC) to oral vitamin B-12 may be used to assess absorption. To develop a reliable clinical absorption test that uses holo-TC, it is necessary to determine the optimal timeline for vitamin B-12 administration and...... postdose assessment. OBJECTIVE: The objective of this study was to assess the magnitude and patterns of change in the postabsorption response of holo-TC to oral vitamin B-12. DESIGN: Adult (18-49 y) male and female participants (n = 21) with normal vitamin B-12 status were given three 9-mug doses of...

  8. Vitamin B12 and folate depletion in cognition: A review

    Directory of Open Access Journals (Sweden)

    Moretti Rita

    2004-07-01

    Full Text Available In cross-sectional studies, low levels of folate and B12 have been shown to be associated with cognitive decline and dementia Evidence for the putative role of folate, vitamin B12 in neurocognitive and other neurological functions comes from reported cases of severe vitamin deficiencies, particularly pernicious anemia, and homozygous defects in genes that encode for enzymes of one-carbon metabolism. The neurological alterations seen in these cases allow for a biological role of vitamins in neurophysiology. Results are quite controversial and there is an open debate in literature, considering that the potential and differential role of folate and B12 vitamin in memory acquisition and cognitive development is not completely understood or accepted. What is not clear is the fact that vitamin B12 and folate deficiency deteriorate a pre-existing not overt pathological situation or can be dangerous even in normal subjects. Even more intriguing is the interaction between B12 and folate, and their role in developing hyperhomocysteinemia. The approach to the rehabilitation of the deficiency with adequate vitamin supplementation is very confusing. Some authors suggest it, even in chronic situations, others deny any possible role. Starting from these quite confusing perspectives, the aim of this review is to report and categorize the data obtained from the literature. Despite the plausible biochemical mechanism, further studies, based on clinical, neuropsychological, laboratory and (lastly pathological features will be necessary to better understand this fascinating biochemical riddle.

  9. Causes of vitamin B12 and folate deficiency.

    Science.gov (United States)

    Allen, Lindsay H

    2008-06-01

    This review describes current knowledge of the main causes of vitamin B12 and folate deficiency. The most common explanations for poor vitamin B12 status are a low dietary intake of the vitamin (i.e., a low intake of animal-source foods) and malabsorption. Although it has long been known that strict vegetarians (vegans) are at risk for vitamin B12 deficiency, evidence now indicates that low intakes of animal-source foods, such as occur in some lacto-ovo vegetarians and many less-industrialized countries, cause vitamin B12 depletion. Malabsorption of the vitamin is most commonly observed as food-bound cobalamin malabsorption due to gastric atrophy in the elderly, and probably as a result of Helicobacter pylori infection. There is growing evidence that gene polymorphisms in transcobalamins affect plasma vitamin B12 concentrations. The primary cause of folate deficiency is low intake of sources rich in the vitamin, such as legumes and green leafy vegetables, and the consumption of these foods may explain why folate status can be adequate in relatively poor populations. Other situations in which the risk of folate deficiency increases include lactation and alcoholism. PMID:18709879

  10. Neurological consequences of vitamin B12 deficiency and its treatment.

    Science.gov (United States)

    Chalouhi, Christel; Faesch, Sabine; Anthoine-Milhomme, Marie-Constance; Fulla, Yvonne; Dulac, Olivier; Chéron, Gérard

    2008-08-01

    In developed countries, the vitamin B12 deficiency usually occurs in children exclusively breast-fed, whose mothers are vegetarians, causing low stores of vitamin B12. Symptoms of vitamin B12 deficiency appear during the second trimester of life and include failure to thrive, lethargy, hypotonia, and arrest or regression of developmental skills. A megaloblastic anemia can be present. One half of the infants exhibit abnormal movements before the start of treatment with intramuscular cobalamin, which disappear 1 or 2 days after. More rarely, movement disorders appear a few days after treatment, whereas neurological symptoms are improving. These abnormal movements can last for 2 to 6 weeks. If not treated, vitamin B12 deficiency can cause lasting neurodisability. Therefore, efforts should be directed to preventing deficiency in pregnant and breast-feeding women on vegan diets and their infants by giving them vitamin B12 supplements. When preventive supplementation has failed, one should recognize and treat quickly an infant presenting with failure to thrive and delayed development. PMID:18708898

  11. Effect of Homocysteine ,Vitamin B12 , Folic acid during pregnancy

    Directory of Open Access Journals (Sweden)

    Arpita Patel

    2012-07-01

    Full Text Available Vitamin B12, folic acid and homocysteine are metabolically closely related. At the same time homocysteine is found to be offending factor for vascular pathology causing preeclampsia. On the other hand periconceptional nutritional status influences the vitamin B12 & folic acid level. Which further affect the homocysteine level thus may affect pregnancy outcome. Various contributory factors lead these vitamin deficiencies, maternal nutrition is one of them. Ahmedabad being a predominantly vegetarian city, its population is at higher risk of vitamin B12 deficiency. But no systematic study has been done in Ahmedabad to know whether B12, folic acid and homocysteine levels influence pregnancy. To know this answer this study was planned to know total homocysteine level and its correlation in preeclampsia and normotensive pregnant women.Vitamin B12, folic acid and homocysteine were measured in all the subjects using fluorescence polarized immunoassay in AxSym Immunochemistry analyzer on 60 non vitamin supplemented vegetarian women. Vitamin levels were within lower normal limit. Homocysteine level was higher among preeclampsia patient. From the findings of the present study it can be concluded that measurement of these biochemical parameter in ante natal care are useful for further management and prevention of complication of pregnancy like preeclampsia

  12. Isolation and analysis of vitamin B12 from plant samples.

    Science.gov (United States)

    Nakos, M; Pepelanova, I; Beutel, S; Krings, U; Berger, R G; Scheper, T

    2017-02-01

    Based on increased demands of strict vegetarians, an investigation of vitamin B12 content in plant sources, was carried out. The vitamin B12 concentration was determined by RP-HPLC with UV detection, after prior matrix isolation by immunoaffinity chromatography (IAC). Vitamin B12 was extracted in the presence of sodium cyanide, to transform all forms of cobalamin into cyanocobalamin. Diode array detector was used to monitor vitamin B12, after its chromatographic separation under gradient elution with a mobile phase consisting of acetonitrile and trifluoroacetic acid 0.025% (w/v). The method demonstrated excellent linearity with a limit of detection 0.004μg/ml. The method precision was evaluated for plant samples and it was below 0.7% (n=6). Significant amounts of vitamin B12 in plants were detected in Hippophae rhamnoides (37μg/100g dry weight), in Elymus (26μg/100g dry weight) and in Inula helenium (11μg/100g dry weight). PMID:27596424

  13. Dietary sources of vitamin B-12 and their association with vitamin B-12 status markers in healthy older adults in the B-PROOF study

    NARCIS (Netherlands)

    E.M. Brouwer-Brolsma (Elske); R.A.M. Dhonukshe-Rutten (Rosalie); J.P. van Wijngaarden (Janneke); N.L. van der Zwaluw (N.); N. van der Velde (Nathalie); L.C.P.G.M. de Groot (Lisette)

    2015-01-01

    textabstractLow vitamin B-12 concentrations are frequently observed among older adults. Malabsorption is hypothesized to be an important cause of vitamin B-12 inadequacy, but serum vitamin B-12 may also be differently affected by vitamin B-12 intake depending on food source. We examined associations

  14. Nitrous oxide misuse and vitamin B12 deficiency.

    Science.gov (United States)

    Massey, Thomas H; Pickersgill, Trevor T; J Peall, Kathryn

    2016-01-01

    A 36-year-old man presented to hospital with a 5-week history of ascending limb paraesthesiae and balance difficulties. He had no medical or travel history of note, but admitted habitual nitrous oxide (N2O) inhalation. Neurological examination revealed a sensory ataxia with pseudoathetosis in the upper limbs and reduced vibration sensation to the hips bilaterally. Significant investigation results included a low serum vitamin B12 concentration, mild macrocytosis and raised serum homocysteine concentration. T2 MRI of the spinal cord demonstrated increased signal extending from C1 to T11 in keeping with a longitudinal myelitis. The patient was diagnosed with a myeloneuropathy secondary to vitamin B12 deficiency, resulting from heavy N2O inhalation. He was treated with intramuscular vitamin B12 injections and received regular physiotherapy. At discharge, he was able to mobilise short distances with the aid of a zimmer frame, and was independently mobile 8 weeks later. PMID:27247211

  15. CO2 sequestration

    International Nuclear Information System (INIS)

    This document presents the summary of a conference-debate held at the Academie des Sciences (Paris, France) on the topic of CO2 sequestration. Five papers are reviewed: problems and solutions for the CO2 sequestration; observation and surveillance of reservoirs; genesis of carbonates and geological storage of CO2; CO2 sequestration in volcanic and ultra-basic rocks; CO2 sequestration, transport and geological storage: scientific and economical perspectives

  16. Neuroenhancement with Vitamin B12—Underestimated Neurological Significance

    Directory of Open Access Journals (Sweden)

    Uwe Gröber

    2013-12-01

    Full Text Available Vitamin B12 is a cofactor of methionine synthase in the synthesis of methionine, the precursor of the universal methyl donor S-Adenosylmethionine (SAMe, which is involved in different epigenomic regulatory mechanisms and especially in brain development. A Vitamin B12 deficiency expresses itself by a wide variety of neurological manifestations such as paraesthesias, skin numbness, coordination disorders and reduced nerve conduction velocity. In elderly people, a latent Vitamin B12 deficiency can be associated with a progressive brain atrophy. Moderately elevated concentrations of homocysteine (>10 µmol/L have been associated with an increased risk of dementia, notably Alzheimer’s disease, in many cross-sectional and prospective studies. Raised plasma concentrations of homocysteine is also associated with both regional and whole brain atrophy, not only in Alzheimer’s disease but also in healthy elderly people. Clinician awareness should be raised to accurately diagnose and treat early Vitamin B12 deficiency to prevent irreversible structural brain damage.

  17. [Psychiatric manifestations of vitamin B12 deficiency: a case report].

    Science.gov (United States)

    Durand, C; Mary, S; Brazo, P; Dollfus, S

    2003-01-01

    Psychiatric manifestations are frequently associated with pernicious anemia including depression, mania, psychosis, dementia. We report a case of a patient with vitamin B12 deficiency, who has presented severe depression with delusion and Capgras' syndrome, delusion with lability of mood and hypomania successively, during a period of two Months. Case report - Mme V., a 64-Year-old woman, was admitted to the hospital because of confusion. She had no history of psychiatric problems. She had history of diabetes, hypertension and femoral prosthesis. The red blood count revealed a normocytosis with anemia (hemoglobin=11,4 g/dl). At admission she was uncooperative, disoriented in time and presented memory and attention impairment and sleep disorders. She seemed sad and older than her real age. Facial expression and spontaneous movements were reduced, her speech and movements were very slow. She had depressed mood, guilt complex, incurability and devaluation impressions. She had a Capgras' syndrome and delusion of persecution. Her neurologic examination, cerebral scanner and EEG were postponed because of uncooperation. Further investigations confirmed anemia (hemoglobin=11,4 g/dl) and revealed vitamin B12 deficiency (52 pmol/l) and normal folate level. Antibodies to parietal cells were positive in the serum and antibodies to intrinsic factor were negative. An iron deficiency was associated (serum iron=7 micromol/l; serum ferritin concentration=24 mg/l; serum transferrin concentration=3,16 g/l). This association explained normocytocis anemia. Thyroid function, hepatic and renal tests, glycemia, TP, TCA, VS, VDRL-TPHA were normal. Vitamin B12 replacement therapy was started with hydroxycobalamin 1 000 ng/day im for 10 days and iron replacement therapy. Her mental state improved dramatically within a few days. After one week of treatment the only remaining symptoms were lability of mood, delusion of persecution, Capgras' syndrome but disappeared totally 9 days after the

  18. [Neurological signs due to isolated vitamin B12 deficiency].

    Science.gov (United States)

    Martinez Estrada, K M; Cadabal Rodriguez, T; Miguens Blanco, I; García Méndez, L

    2013-01-01

    Isolated vitamin B12 deficiency is a common condition in elderly patients but uncommon in patients younger than 30 years, with an average age of onset between 60 and 70 years. This is because the dietary cobalamin, which is normally split by enzymes in meat in the presence of hydrochloric acid and pepsin in the stomach, is not released in the stomachs of elderly patients, usually due to achlorhydria. Although the body may be unable to release cobalamin it does retain the ability to absorb vitamin B12 in its crystalline form, which is present in multivitamin preparations. Other causes are due to drugs that suppress gastric acid production. Neurological signs of vitamin B12 deficiency can occur in patients with a normal haematocrit and red cell indices. They include paresthesia, loss of sensation and strength in the limbs, and ataxia. Reflexes may be slowed down or increased. Romberg and Babinsky signs may be positive, and vibration and position sensitivity often decreases. Behavoural disorders range from irritability and memory loss to severe dementia. The symptoms often do not fully respond to treatment. A case is presented of an isolated vitamin B12 deficiency in 27 year-old female patient who was seen in primary health care. During anamnesis she mentioned low back pain, to which she attributed the loss of strength and tenderness in the right side of the body, as well as the slow and progressive onset of accompanied headache for the previous 4 days. PMID:23834987

  19. Considering the case for vitamin B12 fortification of flour

    Science.gov (United States)

    Reasons to fortify flour with vitamin B12 are considered, which include the high prevalence of depletion and deficiency of this vitamin that occurs in persons of all ages in resource-poor countries and in elderly in wealthier countries, as well as the adverse functional consequences of poor vitamin ...

  20. Evaluation of vitamin B 12 deficiency in various clinical condition

    International Nuclear Information System (INIS)

    Low levels of vitamin B 12 have been associated with several clinical conditions. However no single symptom or group of symptoms can be made responsible. Reported causes of deficiency among older population are hematologic or neurological, followed by gastrointestinal and possibly vascular symptoms. The present prospective observational study was, hence, initiated to evaluate the underlying clinical condition or symptoms associated with vitamin B12 deficiency. The study was prospective observational and carried out on 121 patients (males, n=63 and females, n=58) for the period from January 1, 2004 to January 24, 2007. Age ranges were between 16 - 70 years, and categorized as > 60 yrs and < 60 years. All blood parameters were analyzed by standardized methods on automated analyzers. The deficiency was found to be more prevalent in males and increased from 52.06% to 58.10% in individuals with vitamin B12 <150 pg/ml. Mal nourishment was noted among the most subjects and weakness and anemia were frequent clinical findings (35.55%, n=43, 14%, n=51). Other clinical conditions were neuropsychiatric. Whereas less frequent findings were paraesthesia and gastrointestinal symptoms. Hypertension was more prevalent in vitamin B12 deficient individuals followed by diabetes, dementia, stroke, ischemic heart disease and Parkinson's disease. (author)

  1. Vitamin-B12 deficiency following therapy in gynecologic oncology

    International Nuclear Information System (INIS)

    Vitamin-B12 deficiency results from inadequate absorption of the vitamin by the distal ileum and depletion of available stores. Both radiotherapy and intestinal resection can contribute to development of this condition. The significance of this problem in gynecologic oncology is discussed and two patients are described

  2. Vitamin B-12 and folate deficiency in chronic heart failure

    NARCIS (Netherlands)

    van der Wal, Haye H.; Comin-Colet, Josep; Klip, Ijsbrand T.; Enjuanes, Cristina; Grote Beverborg, Niels; Voors, Adriaan A.; Banasiak, Waldemar; van Veldhuisen, Dirk J.; Bruguera, Jordi; Ponikowski, Piotr; Jankowska, Ewa A.; van der Meer, Peter

    2015-01-01

    Objective To determine the prevalence, clinical correlates and the effects on outcome of vitamin B-12 and folic acid levels in patients with chronic heart failure (HF). Methods We studied an international pooled cohort comprising 610 patients with chronic HF. The main outcome measure was all-cause m

  3. Vitamin B12 deficiency reduces proliferation and promotes differentiation of neuroblastoma cells and up-regulates PP2A, proNGF, and TACE

    OpenAIRE

    Battaglia-Hsu, Shyue-Fang; Akchiche, Nassila; Noel, Nicole; Alberto, Jean-Marc; Jeannesson, Elise; Orozco-Barrios, Carlos Enrique; Martinez-Fong, Daniel; Daval, Jean-Luc; Guéant, Jean-Louis

    2009-01-01

    Vitamin B12 (cobalamin, Cbl) is indispensable for proper brain development and functioning, suggesting that it has neurotrophic effects beside its well-known importance in metabolism. The molecular basis of these effects remains hypothetical, one of the reasons being that no efficient cell model has been made available for investigating the consequences of B12 cellular deficiency in neuronal cells. Here, we designed an approach by stable transfection of NIE115 neuroblastoma cells to impose th...

  4. Prevalence of Vitamin B12 Deficiency Among Pregnant Women in Samsun Province of Turkey

    OpenAIRE

    Ebru Yilmaz Keskin; Basar Demir; Mahir igde; Banu Gulcan Oksuz

    2014-01-01

    Purpose: Vitamin B12 deficiency in infancy can cause severe demyelinating central nervous system disorder. Most cases are exclusively breast-fed infants born to mothers with deficient vitamin B12 stores. As maternal vitamin B12 stores are the main determinant of neonatal vitamin B12 status, we aimed to determine the vitamin B12 status of pregnant women at term in our region. Materials and Methods: Serum vitamin B12, folate and plasma homocysteine concentrations in addition to routine test...

  5. Genetic animal models to decipher the pathogenic effects of vitamin B12 and folate deficiency.

    Science.gov (United States)

    Peng, Lu; Dreumont, Natacha; Coelho, David; Guéant, Jean-Louis; Arnold, Carole

    2016-07-01

    Vitamin B12 and folate are essential micronutrients that provide methyl groups for cellular methylations through the so-called one-carbon metabolism. Deficits in the absorption and transport or defects of the enzymes can lead to human pathogenesis comprising hematologic, neural, gastrointestinal, hepatic, renal, cardiovascular and developmental manifestations. One-carbon metabolism is a complex, multistep and multi-organ metabolism, and the understanding of the mechanisms at work have benefited from human inborn errors and population studies, as well as from nutritional animal models. Since 15 years, a wide variety of genetically engineered mice has been developed and has proved to be useful to decipher the underlying mechanisms. These genetically engineered mice target all the genes that are important for the intestinal absorption, cellular transport and metabolism of vitamin B12 and folate, which are detailed in this article. In conclusion, these mouse models represent valuable experimental paradigms for human pathogenesis. Since no animal model recapitulates the full spectrum of a human disease, researchers have to choose the one that is the most relevant for their specific needs, and this review may help in this respect. PMID:27178438

  6. Dietary Sources of Vitamin B-12 and Their Association with Vitamin B-12 Status Markers in Healthy Older Adults in the B-PROOF Study

    Directory of Open Access Journals (Sweden)

    Elske M. Brouwer-Brolsma

    2015-09-01

    Full Text Available Low vitamin B-12 concentrations are frequently observed among older adults. Malabsorption is hypothesized to be an important cause of vitamin B-12 inadequacy, but serum vitamin B-12 may also be differently affected by vitamin B-12 intake depending on food source. We examined associations between dietary sources of vitamin B-12 (meat, fish and shellfish, eggs, dairy and serum vitamin B-12, using cross-sectional data of 600 Dutch community-dwelling adults (≥65 years. Dietary intake was assessed with a validated food frequency questionnaire. Vitamin B-12 concentrations were measured in serum. Associations were studied over tertiles of vitamin B-12 intake using P for trend, by calculating prevalence ratios (PRs, and splines. Whereas men had significantly higher vitamin B-12 intakes than women (median (25th–75th percentile: 4.18 (3.29–5.38 versus 3.47 (2.64–4.40 μg/day, serum vitamin B-12 did not differ between the two sexes (mean ± standard deviation (SD: 275 ± 104 pmol/L versus 290 ± 113 pmol/L. Higher intakes of dairy, meat, and fish and shellfish were significantly associated with higher serum vitamin B-12 concentrations, where meat and dairy—predominantly milk were the most potent sources. Egg intake did not significantly contribute to higher serum vitamin B-12 concentrations. Thus, dairy and meat were the most important contributors to serum vitamin B-12, followed by fish and shellfish.

  7. Metformin increases liver accumulation of vitamin B12 - An experimental study in rats

    DEFF Research Database (Denmark)

    Greibe, E; Miller, J W; Foutouhi, S H;

    2013-01-01

    AIMS/HYPOTHESIS: Patients treated with metformin exhibit low levels of plasma vitamin B(12) (B(12)), and are considered at risk for developing B(12) deficiency. In this study, we investigated the effect of metformin treatment on B(12) uptake and distribution in rats. METHODS: Sprague Dawley rats (n...... = 18) were divided into two groups and given daily subcutaneous injections with metformin or saline (control) for three weeks. Following this, the animals received an oral dose of radio-labeled B(12) ((57)[Co]-B(12)), and urine and feces were collected for 24 h. Plasma, bowel content, liver, and...... kidneys were collected and analyzed for B(12), unsaturated B(12)-binding capacity, and (57)[Co]-B(12). RESULTS: Three weeks of metformin treatment reduced plasma B(12) by 22% or 289 [47-383] pmol/L (median and [range]) (p = 0.001), while no effect was observed on unsaturated B(12)-binding capacity...

  8. Vitamin B12 deficiency presenting as acute ataxia.

    Science.gov (United States)

    Crawford, John Ross; Say, Daphne

    2013-01-01

    A previously healthy 7-year-old Caucasian boy was hospitalised for evaluation of acute ataxia and failure to thrive, initially suspicious for an intracranial mass. Weight and body mass index were below the third percentile and he demonstrated loss of joint position and vibratory sense on examination. Laboratory studies revealed megaloblastic anaemia while an initial MRI of the brain showed no evidence of mass lesions or other abnormalities. A dietary history revealed the child subscribed to a restrictive vegan diet with little to no intake of animal products or other fortified foods. The child was diagnosed with presumed vitamin B12 deficiency and was treated with intramuscular B12 injections. Neurological symptoms resolved promptly within several days after starting therapy. This case underlines the importance of assessing nutritional status in the evaluation of neurological dysfunction in the pediatric patient. PMID:23536622

  9. Forms of vitamin B12 in radioisotope dilution assays

    International Nuclear Information System (INIS)

    Since the presence of analogues of vitamin B12 (B12, cobalamin, Cbl) has been postulated as the basis for the high values obtained by some radioisotope dilution assays (RIDA) of serum Cbl, serum was examined for analogues. None could be demonstrated in the extracts of serum prepared for RIDA as sought by both direct and indirect techniques. The natural forms of serum Cbl were converted to cyanocobalamin (CN Cbl) by this process of extraction which included cyanide (CN). The correctly performed RIDA for Cbl based on R binder gave higher values than a RIDA based on intrinsic factor or than by bioassay. By exclusion, the difference appeared to be due to unidentified factors rather than the presence of analogues. (author)

  10. Decreased Vitamin B12 Levels in Children with Nocturnal Enuresis

    OpenAIRE

    Bülent Altunoluk; Mehmet Davutoglu; Mesut Garipardic; Vedat Bakan

    2012-01-01

    Objectives. Nocturnal enuresis is a common pediatric problem, the etiology of which is unclear. In the present study, vitamin B12 and folate levels were measured in children with nocturnal enuresis and compared with those in healthy control group children to investigate whether there was any relation with enuresis and neurogenic maturation as a first time in the literature. Methods. In this cross-sectional study, we included thirty children (16 girls, 14 boys) who had presented with primary n...

  11. Vitamin B12 (cobalamin) deficiency in elderly patients

    OpenAIRE

    Andrès, Emmanuel; Loukili, Noureddine Henoun; Noel, Esther; Kaltenbach, Georges; Abdelgheni, Maher Ben; Perrin, Anne Elisabeth; Noblet-Dick, Marie; Maloisel, Frédéric; Schlienger, Jean-Louis; Blicklé, Jean-Frédéric

    2004-01-01

    VITAMIN B12 OR COBALAMIN DEFICIENCY occurs frequently (> 20%) among elderly people, but it is often unrecognized because the clinical manifestations are subtle; they are also potentially serious, particularly from a neuropsychiatric and hematological perspective. Causes of the deficiency include, most frequently, food-cobalamin malabsorption syndrome (> 60% of all cases), pernicious anemia (15%–20% of all cases), insufficent dietary intake and malabsorption. Food-cobalamin malabsorption, whic...

  12. The cobalamin (coenzyme B12) biosynthetic genes of Escherichia coli.

    OpenAIRE

    Lawrence, J. G.; Roth, J R

    1995-01-01

    The enteric bacterium Escherichia coli synthesizes cobalamin (coenzyme B12) only when provided with the complex intermediate cobinamide. Three cobalamin biosynthetic genes have been cloned from Escherichia coli K-12, and their nucleotide sequences have been determined. The three genes form an operon (cob) under the control of several promoters and are induced by cobinamide, a precursor of cobalamin. The cob operon of E. coli comprises the cobU gene, encoding the bifunctional cobinamide kinase...

  13. Vegan Diet, Subnormal Vitamin B-12 Status and Cardiovascular Health

    OpenAIRE

    Kam S. Woo; Timothy C.Y. Kwok; Celermajer, David S

    2014-01-01

    Vegetarian diets have been associated with atherosclerosis protection, with healthier atherosclerosis risk profiles, as well as lower prevalence of, and mortality from, ischemic heart disease and stroke. However, there are few data concerning the possible cardiovascular effects of a vegan diet (with no meat, dairy or egg products). Vitamin B-12 deficiency is highly prevalent in vegetarians; this can be partially alleviated by taking dairy/egg products in lact-ovo-vegetarians. However, metabo...

  14. Vitamin B12 as a modulator of gut microbial ecology

    OpenAIRE

    Degnan, Patrick H.; Taga, Michiko E.; Goodman, Andrew L.

    2014-01-01

    The microbial mechanisms and key metabolites that shape the composition of the human gut microbiota are largely unknown, impeding efforts to manipulate dysbiotic microbial communities towards stability and health. Vitamins, which by definition are not synthesized in sufficient quantities by the host and can mediate fundamental biological processes in microbes, represent an attractive target for reshaping microbial communities. Here, we discuss how vitamin B12 (cobalamin) impacts diverse host-...

  15. White Centered Retinal Hemorrhages in Vitamin B12 Deficiency Anemia

    Directory of Open Access Journals (Sweden)

    Claus Zehetner

    2011-05-01

    Full Text Available Background: To report a case of severe vitamin B12 deficiency anemia presenting with white centered retinal hemorrhages. Methods: Interventional case report. Results: A 40-year-old man, general practitioner himself, presented with a 1-day history of diminished left visual acuity and a drop-shaped central scotoma. The corrected visual acuities were 20/20, OD and 20/100, OS. Ophthalmic examination revealed bilaterally pale tarsal conjunctiva, discretely icteric bulbar conjunctiva and disseminated white centered intraretinal hemorrhages with foveal involvement. OCT imaging through these lesions revealed a retinal thickening caused by a sub-ILM accumulation of hyperreflective and inhomogeneous deposits within the nerve fiber layer. Immediate laboratory work-up showed severe megaloblastic anemia caused by vitamin B12 deficiency requiring erythrocyte transfusions. Discussion: Most reports of white centered retinal hemorrhages have been described in patients with leukemic retinopathy and bacterial endocarditis. It is interesting that this case of vitamin B12 deficiency anemia retinopathy has a clinically indistinguishable fundus appearance. This is probably due to the common pathology of capillary disruption and subsequent hemostatic fibrin plug formation. In megaloblastic anemia, direct anoxia results in endothelial dysfunction. The loss of impermeability allows extrusion of whole blood and subsequent diffusion from the disrupted site throughout and above the nerve fiber layer. Therefore the biomicroscopic pattern of white centered hemorrhages observed in anemic retinopathy is most likely due to the clot formation as the reparative sequence after capillary rupture.

  16. NEUROLOGICAL MANIFESTATIONS OF B12 DEFICIENCY IN BIDAR DISTRICT

    Directory of Open Access Journals (Sweden)

    Vijay Kumar

    2014-07-01

    Full Text Available OBJECTIVE: To investigate the etiological factors resulting in Vitamin B12 deficiency in patients with sub-acute combined degeneration (SACD and other neurological manifestation manifestations. METHODS: We undertook a prospective study of 50 patients, all clinically suspected to have Vit B12 deficiency; they were investigated clinically, hematologically, biochemically and radiologically. RESULTS: There was a dominance of males (41of 50 with the majority in the age group of more than 40 years of age. There was no correlation between the socio-economic and dietary status on the one hand and the clinical manifestation on the other. Anti-intrinsic factor antibodies (AIFAB were positive in 19 of 50 patients (38% and anti-parietal cell antibodies (APCAB were positive in 28 of 50(56% patients. CONCLUSION: We conclude that Pernicious anemia is an important cause of various neurological manifestations including s ACD in the Vitamin B12 deficient population in the age group of more than 40 years, irrespective of the socio-economic and dietary status in the Indian subcontinent. It is supported by the presence of AIFAB ro APCAB in this group

  17. Absent ileal uptake of IF-bound vitamin B12 in vivo in the Imerslund-Grasbeck syndrome (familial vitamin B12 malabsorption with proteinuria).

    OpenAIRE

    Burman, J. F.; Jenkins, W. J.; Walker-Smith, J A; Phillips, A D; Sourial, N A; Williams, C B; Mollin, D. L.

    1985-01-01

    A Syrian family is described with three children who had inherited selective vitamin B12 malabsorption associated with proteinuria. (Imerslund-Grasbeck syndrome). Although inherited the defect was apparently not present at birth. A third child had less severe vitamin B12 malabsorption, was not vitamin B12 deficient and had no proteinuria. Studies on two of the affected children with subcellular fractionation of the uptake of radioactive vitamin B12 by ileal tissue in vivo indicate a defect in...

  18. Systematic review on daily vitamin B12 losses and bioavailability for deriving recommendations on vitamin B12 intake with the factorial approach

    NARCIS (Netherlands)

    Doets, E.L.; Veld, in 't P.H.; Szczecinska, A.; Dhonukshe-Rutten, R.A.M.; Cavelaars, A.J.E.M.; Veer, van 't P.; Brzozowska, A.M.; Groot, de C.P.G.M.

    2013-01-01

    Aims: To systematically review the literature on daily losses and bioavailability of vitamin B12. These estimates could be used for deriving recommendations on vitamin B12 intake for adults and elderly. Methods: We identified publications on daily vitamin B12 losses (July 2011) and publications on t

  19. Dietary source of vitamin B12 intake and vitamin B12 status in female elderly Koreans aged 85 and older living in rural area

    OpenAIRE

    Kwak, Chung Shil; Lee, Mee Sook; Lee, Hae Jeung; Whang, Jin Yong; Park, Sang Chul

    2010-01-01

    Recently, we found and analyzed vitamin B12 in some Korean traditional plant foods which had not reported, yet. This study was to investigate vitamin B12 intake and its dietary sources and the vitamin B12 status in the very old elderly Koreans. We measured serum vitamin B12 level and estimated the amounts of vitamin B12 intake from different dietary sources in female elderly Koreans aged 85 and over who had consumed a relatively low animal traditional diet for the whole life. The average age ...

  20. Crystallographic studies on B12 binding proteins in eukaryotes and prokaryotes

    OpenAIRE

    Sukumar, Narayanasami

    2013-01-01

    The x-ray crystal structures of several important vitamin B12 binding proteins that have been solved in recent years have enhanced our current understanding in the vitamin B12 field. These structurally diverse groups of B12 binding proteins perform various important biological activities, both by transporting B12 as well as catalyzing various biological reactions. An in-depth comparative analysis of these structures was carried out using PDB coordinates of a carefully chosen database of B12 b...

  1. Genetic disorders of vitamin B12 metabolism: eight complementation groups – eight genes

    OpenAIRE

    Froese, D. Sean; Gravel, Roy A

    2010-01-01

    Vitamin B12 (cobalamin, Cbl) is an essential nutrient in human metabolism. Genetic diseases of vitamin B12 utilisation constitute an important fraction of inherited newborn disease. Functionally, B12 is the cofactor for methionine synthase and methylmalonyl CoA mutase. To function as a cofactor, B12 must be metabolised through a complex pathway that modifies its structure and takes it through subcellular compartments of the cell. Through the study of inherited disorders of vitamin B12 utilisa...

  2. [Effects of Vitamin B12 in Patients with Amyotrophic Lateral Sclerosis and Peripheral Neuropathy].

    Science.gov (United States)

    Nodera, Hiroyuki; Izumi, Yuishin; Kaji, Ryuji

    2015-09-01

    Vitamin B(12)(vB(12)) deficient is regarded as iatrogenic in some cases. Although the recommended oral intake of vB(12) has been determined, administration of vB(12) exceeding the recommended dose could have multiple pharmacological effects. "Ultra-high dose" vB(12) therapy has been used for peripheral neuropathy and amyotrophic lateral sclerosis, suggesting its promising neuroprotective effects. PMID:26329154

  3. [Stability of folic acid and vitamin B12 in TPN].

    Science.gov (United States)

    Almodóvar, M J; Hernández Jaras, M V; León-Sanz, M; Ortuño, B; Estenoz, J; Negro Vega, E; Marfagón, N; Herreros de Tejada, A

    1991-01-01

    The stability of folic acid (FA) in mixtures of Total Parenteral Nutrition has been and is a controversial subject, with discussion concerning the influence of factors such as temperature, light and storage time. As regards the stability of the vitamin B12, there are few studies in scientific literature. For all those reasons, we consider it necessary to make a proper study to evaluate the influence of different factors in the stability of both vitamins. The study was made on 3 liter TPN bags of the EVA type, the composition of which was as follows: AA (85g), glucosa (225g), fat (50g), Na (86mEq), K (60 mEq), Ca (15 mEq), Cl (90 mEq), P (17 mmol) acetate (149 mEq) and 10 ml of MVI-12 which contain 400 micrograms of PA and 5 micrograms of Vitamin B 12. Consideration was also given to the stability of these two vitamins in the same diet, to which were added 10 ml of a commercial preparation of oligo-elements. Six TPN bags were prepared (without oligo-elements); two of them were kept in a fridge and protected from the light, two were kept at room temperature and protected from the light and the other two at room temperature without protection from the light. Samples were taken from all the bags immediately after their preparation and after 24, 48, 72 and 96 hours. The same process was carried with other TPN bags which did contain oligo-elements. The method for determining FA and Vitamin B12 was by radioassay.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1764534

  4. Low-dimensional boron structures based on icosahedron B12

    Science.gov (United States)

    Kah, C. B.; Yu, M.; Tandy, P.; Jayanthi, C. S.; Wu, S. Y.

    2015-10-01

    One-dimensional icosahedral boron chains and two-dimensional icosahedral boron sheets (icosahedral α, δ6, and δ4 sheets) that contain icosahedra B12 as their building units have been predicted in a computer simulation study using a state-of-the-art semi-empirical Hamiltonian. These novel low-dimensional icosahedral structures exhibit interesting bonding and electronic properties. Specifically, the three-center, two-electron bonding between icosahedra B12 of the boron bulk (rhombohedral boron) transforms into a two-center bonding in these new allotropes of boron sheets. In contrast to the previously reported stable buckled α and triangular boron monolayer sheets, these new allotropes of boron sheets form a planar network. Calculations of electronic density of states (DOS) reveal a semiconducting nature for both the icosahedral chain and the icosahedral δ6 and δ4 sheets, as well as a nearly gapless (or metallic-like) feature in the DOS for the icosahedral α sheet. The results for the energy barrier per atom between the icosahedral δ6 and α sheets (0.17 eV), the icosahedral δ6 and δ4 sheets (0.38 eV), and the icosahedral α and δ4 sheets (0.27 eV), as indicated in the respective parentheses, suggest that these new allotropes of boron sheets are relatively stable.

  5. Vitamin B12 Metabolism during Pregnancy and in Embryonic Mouse Models

    Directory of Open Access Journals (Sweden)

    Maira A. Moreno-Garcia

    2013-09-01

    Full Text Available Vitamin B12 (cobalamin, Cbl is required for cellular metabolism. It is an essential coenzyme in mammals for two reactions: the conversion of homocysteine to methionine by the enzyme methionine synthase and the conversion of methylmalonyl-CoA to succinyl-CoA by the enzyme methylmalonyl-CoA mutase. Symptoms of Cbl deficiency are hematological, neurological and cognitive, including megaloblastic anaemia, tingling and numbness of the extremities, gait abnormalities, visual disturbances, memory loss and dementia. During pregnancy Cbl is essential, presumably because of its role in DNA synthesis and methionine synthesis; however, there are conflicting studies regarding an association between early pregnancy loss and Cbl deficiency. We here review the literature about the requirement for Cbl during pregnancy, and summarized what is known of the expression pattern and function of genes required for Cbl metabolism in embryonic mouse models.

  6. Relationship between vitamin B12 and sensory and motor peripheral nerve function in older adults

    OpenAIRE

    Leishear, K; Boudreau, RM; Studenski, SA; Ferrucci, L.; Rosano, C.; De Rekeneire, N; Houston, DK; Kritchevsky, SB; Schwartz, AV; Vinik, AI; Hogervorst, E.; Yaffe, K.; Harris, TB; Newman, AB; Strotmeyer, ES

    2012-01-01

    OBJECTIVES: To examine whether deficient B12 status or low serum B12 levels are associated with worse sensory and motor peripheral nerve function in older adults. DESIGN: Cross-sectional. SETTING: Health, Aging and Body Composition Study. PARTICIPANTS: Two thousand two hundred and eightyseven adults aged 72 to 83 (mean 76.5 ±2.9; 51.4% female; 38.3% black). MEASUREMENTS: Low serum B12 was defined as serum B12 less than 260 pmol/L, and deficient B12 status was defined as B12 less than 260 pmol...

  7. Vitamin B12 transport from food to the body's cells--a sophisticated, multistep pathway

    DEFF Research Database (Denmark)

    Nielsen, Marianne J; Rasmussen, Mie R; Andersen, Christian B F;

    2012-01-01

    Vitamin B(12) (B(12); also known as cobalamin) is a cofactor in many metabolic processes; deficiency of this vitamin is associated with megaloblastic anaemia and various neurological disorders. In contrast to many prokaryotes, humans and other mammals are unable to synthesize B(12). Instead, a...... transport pathway are also known culprits of functional B(12) deficiency. Biochemical and genetic approaches have identified novel proteins in the B(12) transport pathway--now known to involve more than 15 gene products--delineating a coherent pathway for B(12) trafficking from food to the body's cells...

  8. Effect of X-irradiation on vitamin B12 binding capacity to intrinsic factor

    International Nuclear Information System (INIS)

    The effects of whole-body X-irradiation on vitamin bB12-protein complex formation in gastric juice after oral administration of [57Co]-B12 have been studied. Two proteins with B-12-binding activity have been isolated by gel filtration from gastric juice. 57Co-activity, recovered from B12-protein complex in gastric juice, is found to be about 30 percent less in the X-irradiated rat. In serum, vitamin B12 is mainly associated with alpha1-globulin. Radioactivity distribution in serum globulins after intraperitoneal injection of [57Co]-B12 was similar in control and X-irradiated rats. (author)

  9. Serum thymidine kinase in vitamin B12 deficiency

    International Nuclear Information System (INIS)

    In DNA synthesis deoxythymidine kinase (TK) catalyses the conversion of deoxythymidine to deoxythymidine monophosphate (dTMP) via the 'salvage pathway'. Serum deoxythymidine kinase (S=TK) was measured in this study in 75 patients with vitamin B12 deficiency by a new, very sensitive method, using 125I-deoxyuridine as substrate. Elevated S-TK levels were found in those patients who had developed haemolysis and anaemia and the more advanced the disease the higher the S-TK value. Thus there was a highly significant correlation between S-TK, haemoglobin level and lactic dehydrogenase activity. These findings are consistent with the theory that elevated levels of S-TK are due to release from unstable proliferating tissue. (author)

  10. Development on Fermentation Process of Vitamin B12%维生素B12发酵工艺进展

    Institute of Scientific and Technical Information of China (English)

    程瑶

    2012-01-01

    综述了维生素B12(VB12)发酵工艺路线、菌种选育、工艺优化等方面的研究进展,展望了VB12发酵工艺发展前景。%To Summary the fermentation process route,process optimization and strain transformation of vitamin B12. To prospect the development of vitamin B12.

  11. Vitamin B-12 Supplementation during Pregnancy and Early Lactation Increases Maternal, Breast Milk, and Infant Measures of Vitamin B-12 Status12

    OpenAIRE

    Duggan, Christopher; Srinivasan, Krishnamachari; Thomas, Tinku; Samuel, Tinu; Rajendran, Ramya; Muthayya, Sumithra; Finkelstein, Julia L; Lukose, Ammu; Fawzi, Wafaie; Allen, Lindsay H.; Bosch, Ronald J.; Kurpad, Anura V

    2014-01-01

    Pregnant women in resource-poor areas are at risk of multiple micronutrient deficiencies, and indicators of low vitamin B-12 status have been associated with adverse pregnancy outcomes, including anemia, low birth weight, and intrauterine growth retardation. To evaluate whether daily oral vitamin B-12 supplementation during pregnancy increases maternal and infant measures of vitamin B-12 status, we performed a randomized, placebo-controlled clinical trial. Pregnant women

  12. Extralobar pulmonary sequestration

    Directory of Open Access Journals (Sweden)

    Ulys A

    2011-04-01

    Full Text Available Albertas Ulys, Narimantas Evaldas Samalavicius, Saulius Cicenas, Tadas Petraitis, Mantas Trakymas, Dmitrij Sheinin, Leonid GatijatullinInstitute of Oncology, Vilnius University, Santariskiu, Vilnius, LithuaniaAbstract: Prevalence of pulmonary sequestration accounts for up to 6.4% of all congenital pulmonary malformations. We report on a 40-year-old woman who underwent excision of an aberrant solid retroperitoneal mass in the left subdiaphragmatic area. The mass was identified to be an extralobar pulmonary sequestration. The diagnosis could be made without surgery by percutaneous tissue biopsy and imaging. We encourage keeping in mind pulmonary sequestration anomaly presenting as an aberrant retroperitoneal mass. The aim of this case report is to increase awareness about the condition and review the criteria for its definitive diagnosis and treatment.Keywords: retroperitoneal aberrant mass, extralobar pulmonary sequestration

  13. Megalin is essential for renal proximal tubule reabsorption and accumulation of transcobalamin-B(12)

    DEFF Research Database (Denmark)

    Birn, Henrik; Willnow, Thomas E; Nielsen, Rikke;

    2002-01-01

    Megalin has previously been shown to bind and mediate endocytosis of transcobalamin (TC)-B(12). However, the physiological significance of this has not been established, and other TC-B(12) binding proteins have been suggested to mediate renal uptake of this vitamin complex. The present study...... demonstrates by the use of megalin-deficient mice that megalin is, in fact, essential for the normal renal reabsorption of TC-vitamin B(12) and for renal accumulation of this highly conserved vitamin. Megalin-deficient mice excrete increased amounts of TC and B(12) in the urine, revealing a defective renal...... tubular uptake of TC-B(12). The urinary B(12) excretion is increased approximately 4-fold, resulting in an approximately 28-fold higher renal B(12) clearance. This is associated with an approximately 4-fold decrease in B(12) content in megalin-deficient kidney cortex. Thus megalin is important to prevent...

  14. Formation of a vitamin B-12-serum complex on heating at alkaline pH

    International Nuclear Information System (INIS)

    The binding of vitamin B-12 to serum proteins during heating at alkaline pH was investigated by gel filtration of serum supplemented with cyano[57Co]-cobalamin. Heating for 5 min at 1000C destroyed most of the vitamin B-12 binding activity of serum but, with further heating, the vitamin B-12 became incorporated into a complex that did not correspond in molecular size to the original vitamin B-12 binding proteins. Radioassay of vitamin B-12 in heated serum showed correspondingly first an increase then a progressive decrease in the apparent vitamin B-12 level suggesting that, on heating, vitamin B-12 was initially released then subsequently complexed by the serum. The formation of complexed vitamin B-12 was abolished by the presence of the reducing agent dithiothreitol during the heating step. (Auth.)

  15. Structural, electronic and magnetic properties of heterofullerenes C48B12

    OpenAIRE

    Xie, Rui-Hua; Jensen, Lasse; Bryant, Garnett W.; Zhao, Jijun; Smith Jr, Vedene H.

    2003-01-01

    Bonding, electric (hyper)polarizability, vibrational and magnetic properties of heterofullerene ${\\rm C}_{48}{\\rm B}_{12}$ are studied by first-principles calculations. Infrared- and Raman-active vibrational frequencies of ${\\rm C}_{48}{\\rm B}_{12}$ are assigned. Eight $^{13}$C and 2 $^{11}$B NMR spectral signals of ${\\rm C}_{48}{\\rm B}_{12}$ are characterized. The first-order hyperpolarizability in ${\\rm C}_{48}{\\rm B}_{12}$ is zero because of the inversion symmetry. The average second-order...

  16. Negative symptoms presenting as neuropsychiatric manifestation of vitamin B12 deficiency

    OpenAIRE

    Sahoo, Manoj Kumar; Avasthi, Ajit; Singh, Parampreet

    2011-01-01

    Long lists of psychiatric illness or symptoms have been documented to be caused by vitamin B12 deficiency. We describe an atypical case of a young adult who presented with predominant negative symptoms followed by neurological symptoms consistent with vitamin B12 deficiency. The symptoms showed complete remission after vitamin B12 supplementation. The uniqueness of this case is that vitamin B12 deficiency presented with predominant negative symptoms without other psychotic and manic symptoms,...

  17. Link between vitamin B12, type 2 diabetes mellitus, and bone mineral density in elderly patients

    Directory of Open Access Journals (Sweden)

    Moatassem S. Amer, MD

    2015-12-01

    Conclusion: The prevalence of vitamin B12 deficiency was higher in the control group than the diabetic group who did not receive oral B12 supplementation. Low serum vitamin B12 is commonly overlooked in the elderly, with or without diabetes. The presence of diabetes mellitus did not affect BMD in the elderly. Furthermore, there is no significant relationship between serum vitamin B12 levels and BMD among diabetics.

  18. Serum Vitamin B12 and Folate Levels in Women Taking Oral Contraceptives

    OpenAIRE

    Mountifield, J. A.

    1986-01-01

    Serum vitamin B12 and erythrocyte folate levels were determined in a group of healthy women eating a balanced diet. Approximately 50% were using oral contraceptives. Vitamin B12 levels were lower in the oral contraceptive users. However, their folate levels were no different from those of non-users. Age had no effect on either vitamin B12 or folate levels. Oral contraceptive users taking multiple vitamin tablets containing vitamin B12 and folate had slightly higher folate levels, but their vi...

  19. Functions required for vitamin B12-dependent ethanolamine utilization in Salmonella typhimurium.

    OpenAIRE

    Roof, D M; Roth, J R

    1989-01-01

    When B12 is available, Salmonella typhimurium can degrade ethanolamine to provide a source of carbon and nitrogen. B12 is essential since it is a cofactor for ethanolamine ammonia-lyase, the first enzyme in ethanolamine breakdown. S. typhimurium makes B12 only under anaerobic conditions; in the presence of oxygen, exogenous B12 must be provided to permit ethanolamine utilization. Genes required for ethanolamine utilization are encoded in the eut operon. For complementation testing, an F' plas...

  20. Vitamin B 12 Deficiency and Multiple Sclerosis; Is there Any Association?

    OpenAIRE

    Mohamad Reza Najafi; Vahid Shaygannajad; Maryam Mirpourian; Ali Gholamrezaei

    2012-01-01

    Background: Vitamin B 12 (Cobalamin) deficiency can result in some clinical and paraclinical characteristics similar to what is seen in multiple sclerosis (MS) patients. This study aimed to evaluate the controversial association between vitamin B 12 deficiency and MS. Methods: We measured serum vitamin B 12 in 60 patients with MS and 38 healthy controls. Clinical disability was evaluated according to the Extended Disability Status Scale (EDSS). Serum B 12 concentration was measured with R...

  1. Evaluation of bioadhesive capacity and immunoadjuvant properties of vitamin B(12)-Gantrez nanoparticles.

    OpenAIRE

    Salman, H.H. (Hesham H.); Gamazo, C; de Smidt, P C; Russell-Jones, G. (Gregory); J.M. Irache

    2008-01-01

    PURPOSE: To design bioadhesive Gantrez AN (poly[methyl vinyl ether-co-maleic anhydride], PVM/MA) nanoparticles (NP) coated with Vitamin B12 (Vit B12), and investigate their application in oral antigen delivery. METHODS: The association of Vit B12 to Gantrez AN nanoparticles was performed by the direct attachment of reactive Vit B12 to the surface of the nanoparticles (NPB), or linking to the copolymer chains in dimethylformamide prior to NP formation (NPBDMF). Nanoparticles ...

  2. Evidence for intestinal origin of transcobalamin II during vitamin B12 absorption

    International Nuclear Information System (INIS)

    The plasma binding of newly absorbed, radioactively labelled vitamin B12 was studied during a urinary excretion (Schilling) test. Vitamin B12, after being absorbed from the gut, enters blood attached to transcobalamin II, which seemed to be derived from the ileal enterocyte. The absorbed B12 re-entered the blood stream after the transcobalamin II-B12 complex was cleared by the liver and it was then excreted into the urine during the Schilling test. (author)

  3. The association between vitamin B12, albuminuria and reduced kidney function: an observational cohort study

    OpenAIRE

    McMahon, Gearoid M; Hwang, Shih-Jen; Tanner, Rikki M.; Jacques, Paul F.; Selhub, Jacob; Muntner, Paul; Fox, Caroline S

    2015-01-01

    Background: Variants in CUBN, the gene encoding cubilin, a proximal tubular transport protein, have been associated with albuminuria and vitamin B12 (B12) deficiency. We hypothesized that low levels of B12 would be associated with albuminuria in a population-based cohort. Methods: We analyzed participants from the Framingham Heart Study (n = 2965, mean age 58 years, 53% female) who provided samples for plasma B12. Logistic regression models adjusted for covariates including homocysteine were ...

  4. Nutrient Acquisition: The Generation of Bioactive Vitamin B12 by Microalgae.

    Science.gov (United States)

    Grossman, Arthur

    2016-04-25

    Many microalgae acquire vitamin B12 from marine prokaryotes. A new study demonstrates that vitamin B12 is synthesized by planktonic cyanobacteria as pseudocobalamin, a form not bioactive in microalgae. However, some microalgae can remodel pseudocobalamin to the active cobalamin form, adding complexity to our assessment of active vitamin B12 in the environment. PMID:27115686

  5. Vitamin B-12 supplementation of rural Mexican women changes biochemical B-12 status indicators but does not affect hematology or a bone turnover marker

    Science.gov (United States)

    Based on the high prevalence of low serum vitamin B-12 concentrations and low dietary intake of the vitamin in Latin American studies including research in Mexico, it appears that vitamin B-12 deficiency is common. Whether this is associated with adverse effects on human function is unknown. To eval...

  6. Assessment of a radioisotopic assay for vitamin B12 using an intrinsic factor preparation with R proteins blocked by vitamin B12 analogues

    OpenAIRE

    Bain, Barbara; Broom, GN; Woodside, Jackie; Litwinczuk, RA; Wickramasinghe, SN

    1982-01-01

    A competitive protein binding radioassay kit for serum vitamin B12 has been assessed. Precision, linearity, sensitivity, and specificity have been found to be satisfactory. Falsely-normal assay results in patients with vitamin B12 deficiency have not been observed.

  7. Enhancing the vitamin B12 production and growth of Propionibacterium freudenreichii in tofu wastewater via a light-induced vitamin B12 riboswitch.

    Science.gov (United States)

    Yu, Yue; Zhu, Xuan; Shen, Yubiao; Yao, Huanghong; Wang, Peiheng; Ye, Kun; Wang, Xiaofeng; Gu, Qing

    2015-12-01

    The vitamin B12-dependent riboswitch is a crucial factor that regulates gene transcription to mediate the growth of and vitamin B12 synthesis by Propionibacterium freudenreichii. In this study, the effect of various wavelengths of light on the growth rate and vitamin B12 synthesis was studied. Red, green, and blue light-emitting diodes (LEDs) were selected, and a dark condition was used as the control. The microorganism growth rate was measured using a spectrophotometer and plate counting, while the vitamin B12 content was determined using an HPLC-based method. The optical density at 600 nm (OD600) values indicated that P. freudenreichii grew better under the continuous and discontinuous blue light conditions. Moreover, under the blue light condition, P. freudenreichii tended to have a higher growth rate (0.332 h(-1)) and vitamin B12 synthesis (ca. 10 μg/mL) in tofu wastewater than in dark conditions. HPLC analysis also showed that more methylcobalamin was produced under the blue light conditions than in the other conditions. The cbiB gene transcription results showed that blue light induced the synthesis of this vitamin B12 synthesis enzyme. Moreover, the results of inhibiting the expression of green fluorescent protein indicated that blue light removed the inhibition by the vitamin B12-dependent riboswitch. This method can be used to reduce fermentation time and produce more vitamin B12 in tofu wastewater. PMID:26373724

  8. Simultaneous radioassay of serum vitamin B12 and folic acid

    International Nuclear Information System (INIS)

    The radioassays of vitamin B12 and folic acid can be carried out in a single tube to give the simultaneous assay of both vitamins in 100 μl of serum. Release of bound vitamins from their endogenous binders and the destruction of these binders are effected by a heating step at pH 9.3. The subsequent binding reactions with hog intrinsic factor and milk binder protein proceed advantageously and simultaneously in the same tube at pH 9.3. A single set of dual reagents replaces two sets of reagents that would normally be used for separate radioassays. Complete separation of bound radioactivities, [57Co] cyanocobalamin and 125I-labeled folate derivative, is obtained in a dual-channel gamma counter with no requirement for any correction for spill-over of counting data. Analytical results are comparable to those found for previously developed individual radioassays. The simultaneous assay has decreased technical time of analysis for these interrelated vitamins by about 50%

  9. Solid-phase radioimmunoassay for vitamin B12 in serum, with use of radioiodinated tyrosine methyl ester of vitamin B12

    International Nuclear Information System (INIS)

    Although radioassays for vitamin B12 with use of any of several binding proteins have been available for many years, a radioimmunoassay for B12 has not been reported. We describe here such a radioimmunoassay, incorporating, for the first time, a radioiodinated tyrosine methyl ester of B12 as the radioactive tracer. Polypropylene tubes are coated with antiserum raised in a rabbit against B12/bovine serum albumin to simplify the separation of bound and free radioactivity. Factors affecting the preparation of coated tubes are described. The assay is accurate, sensitive, precise, and specific for vitamin B12. Accuracy of the assay is unaffected by the presence of denatured protein. The advantages of this radioimmunoassay over conventional radioassays are discussed

  10. Vitamin B12 supplementation during pregnancy and postpartum improves B12 status of both mothers and infants but vaccine response in mothers only: a randomized clinical trial in Bangladesh

    Science.gov (United States)

    Purpose Poor vitamin B12 (B12) status is associated with adverse outcomes in pregnancy and infancy. Little is known about effects of B12 supplementation on immune function. The present study aimed to evaluate effects of pre- and postnatal B12 supplementation on biomarkers of B12 status and vaccine-s...

  11. Translational regulation of genes in salmonella typhimurium by vitamin B12

    OpenAIRE

    Ravnum, Solveig

    2000-01-01

    In this thesis I have studied the mechanism by which vitamin B12 regulates the expression of the cob operon and the btuB gene in Salmonella typhimurium. The cob operon encodes most of the 25 genes required for the de novo synthesis of vitamin B12, and the butB gene encodes the outer membrane protein needed for transport of exogenous vitamin B12 into the cell. Vitamin B12 is used as a cofactor in four enzymatic reactions in Salmonella typhimurium. The regulation by vitamin B12 of the cob opero...

  12. Metformin increases liver accumulation of vitamin B12 - An experimental study in rats

    OpenAIRE

    Greibe, E; Miller, J. W.; Foutouhi, S H; Green, R.; Nexo, E.

    2013-01-01

    AIMS/HYPOTHESIS: Patients treated with metformin exhibit low levels of plasma vitamin B(12) (B(12)), and are considered at risk for developing B(12) deficiency. In this study, we investigated the effect of metformin treatment on B(12) uptake and distribution in rats.METHODS: Sprague Dawley rats (n = 18) were divided into two groups and given daily subcutaneous injections with metformin or saline (control) for three weeks. Following this, the animals received an oral dose of radio-labeled B(12...

  13. Evidence that a B12-Adenosyl Transferase Is Encoded within the Ethanolamine Operon of Salmonella enterica

    OpenAIRE

    Sheppard, David E.; Penrod, Joseph T.; Bobik, Thomas; Kofoid, Eric; Roth, John R.

    2004-01-01

    Adenosylcobalamin (Ado-B12) is both the cofactor and inducer of ethanolamine ammonia lyase (EA-lyase), a catabolic enzyme for ethanolamine. De novo synthesis of Ado-B12 by Salmonella enterica occurs only under anaerobic conditions. Therefore, aerobic growth on ethanolamine requires import of Ado-B12 or a precursor (CN-B12 or OH-B12) that can be adenosylated internally. Several known enzymes adenosylate corrinoids. The CobA enzyme transfers adenosine from ATP to a biosynthetic intermediate in ...

  14. Relation of Vitamin B12 Levels to Bone Mineral Density of Postmenopausal Women - Original Investigation

    OpenAIRE

    Nur Kesiktaş; Nurten Eskiyurt; Ayşe Karan; Semih Akı; Halim İşsever

    2009-01-01

    Aim: Although vitamin B12 (vit-B12) is known to influence the hemopoeitic and nervous systems, little is known about the skeletal effects of vit-B12. Researchs that demonstrated an association between serum vitamin B-12 concentration and osteoblastic function and its’ role in DNA synthesis, which suggesting a relationship between osteoporosis, this randomized controlled trial were planned. Material and Methods: Vit-B12 levels of 740 patients aged between 50-65 years, who were applied to ou...

  15. Clinical value of serum vitamin B12 and folate in cerebrovascular disease

    International Nuclear Information System (INIS)

    To study the clinical value of serum vitamin B12 and folate in cerebrovascular disease, the concentration of serum vitamin B12 and folate in 32 patients with cerebrovascular disease was measured by radioimmunoassay. The results showed that the changes in folate in all groups were not significant. The content of vitamin B12 in multi-infarct dementia was markedly lower than that in cerebral infarction and cerebral hemorrhage. Moreover, the level of vitamin B12 was lower in paralytic patients with muscular strength of grade 0-III. It can be concluded that serum vitamin B12 level had association with intelligent disorder and paralytic degree

  16. Cobas e 411 -analysaattorin validointi – B12- ja D-vitamiinitutkimukset

    OpenAIRE

    Kankare, Terttu; Toivonen, Hanna

    2016-01-01

    B12-vitamiinia tarvitaan ihmisen elimistössä solujen nukleiinihappojen valmistamiseen. Elimistö ei itse pysty valmistamaan B12-vitamiinia, vaan sitä saadaan eläinperäisestä ruoasta. Kokonais-B12-vitamiinimääritys P-B12-Vit on yleisimmin käytetty veren B12-vitamiinipitoisuuden laboratoriotutkimus. D-vitamiini on sekä ravinnosta saatava vitamiini että elimistön muodostama hormoni. D-vitamiinin kahdesta muodosta D2-vitamiinia saadaan ravinnosta tai lisäravinteista ja D3-vitamiinia muodos...

  17. Application of Vitamin B12 to Oral Ulcer%维生素B12在治疗口腔溃疡中的应用

    Institute of Scientific and Technical Information of China (English)

    涂晓田; 杨为民; 胡伊乐

    2014-01-01

    目的:探讨维生素B12在治疗口腔溃疡中的实际效果。方法将口腔溃疡患者随机分成4组,分别外敷维生素B12、维生素B2、冰硼散、氯已定含片,对比各组在愈合时间与疼痛抑制方面差别。结果外敷维生素 B12组在愈合时间与疼痛抑制方面明显优于其他组。结论维生素 B12在治疗口腔溃疡时不但愈合时间短于其他药物,而且能有效地抑制疼痛,可以作为一种治疗方法在临床应用。%Objective To explore the actual result of vitamin B12 in curing oral ulcer. Methods The groups in which the patients were divided in to four at random were external by applied Vitamin B12,Vitamin B2 ,Bingpeng powder,Chlorhexidine mouth lozenge differently to compare the differences of every group in healing time and pain suppression. Results The group externally applied by Vitamin B12 was better than the other groups in healing time and pain suppression. Conclusion When curing the oral ulcer,the healing time of Vitamin B12 is shorter than other drugs and Vitamin B12 and can suppress pain effectively.So the method of applying Vitamin B12 may become a new therapeutic method in clinical application in future.

  18. Vitamin B12: a tunable, long wavelength, light-responsive platform for launching therapeutic agents.

    Science.gov (United States)

    Shell, Thomas A; Lawrence, David S

    2015-11-17

    Light-responsive agents offer the promise of targeted therapy, whose benefits include (i) prolonged action at the target site, (ii) overall reduced systemic dosage, (iii) reduced adverse effects, and (iv) localized delivery of multiple agents. Although photoactivated prodrugs have been reported, these species generally require short wavelengths (property that is unique to light. However, discrimination between existing photoresponsive moieties has thus far proven to be limited. We have developed a vitamin B12/light-facilitated strategy for controlling drug action using red, far-red, and NIR light. The technology is based on a light-triggered reaction displayed by a subset of B12 derivatives: alkyl-cob(III)alamins suffer photohomolysis of the C-Co(III) bond. The C-Co(III) bond is weak (600 nm) is readily captured and used to separate the Co-appended ligand (e.g., a drug) from B12. Consequently, it is now feasible to preassign the wavelength of homolysis by simply installing a fluorescent antenna with the desired photophysical properties. The wavelength malleability inherent within this strategy has been used to construct photoresponsive compounds that launch different drugs by simply modulating the wavelength of illumination. In addition, these phototherapeutics have been installed on the surface and interior of cells, such as erythrocytes or neural stem cells, and released upon expoure to the appropriate wavelength. We have shown that cytotoxic agents, such as doxorubicin, anti-inflammatories, such as dexamethasone, and anti- and pro-vascular agents are readily released from cellular vehicles as biologically active agents. We have also demonstrated that the concept of "optical window of tissue" phototherapeutics is not just limited to prodrugs. For example, stem cells have received considerable attention in the area of regenerative medicine. Hydrogels serve as scaffolds for stem cell growth and differentiation. We have shown that the formation of hydrogels can be

  19. Biochemistry, function, and deficiency of vitamin B12 in Caenorhabditis elegans.

    Science.gov (United States)

    Bito, Tomohiro; Watanabe, Fumio

    2016-09-01

    Caenorhabditis elegans is a nematode that has been widely used as an animal for investigation of diverse biological phenomena. Vitamin B12 is essential for the growth of this worm, which contains two cobalamin-dependent enzymes, methylmalonyl-CoA mutase and methionine synthase. A full complement of gene homologs encoding the enzymes associated with the mammalian intercellular metabolic processes of vitamin B12 is identified in the genome of C elegans However, this worm has no orthologs of the vitamin B12-binders that participate in human intestinal absorption and blood circulation. When the worm is treated with a vitamin B12-deficient diet for five generations (15 days), it readily develops vitamin B12 deficiency, which induces worm phenotypes (infertility, delayed growth, and shorter lifespan) that resemble the symptoms of mammalian vitamin B12 deficiency. Such phenotypes associated with vitamin B12 deficiency were readily induced in the worm. PMID:27486161

  20. Electronic structure and optical properties of the B12O2 crystal

    Science.gov (United States)

    Li, Dong; Ching, W. Y.

    1996-07-01

    The electronic structure and the optical properties of the icosahedral B12O2 crystal are studied by means of first-principles calculations. The results are compared with the other B12-based compounds with the same rhombohedral crystal structure. B12O2 is a semiconductor with a direct band gap of about 2.40 eV at Z. It is shown that intericosahedral bonding is stronger than the intraicosahedral bonding in B12O2. There is no covalent bonding between the O atoms and a net charge transfer from the B12 icosahedron to the O atoms. From the calculated complex dielectric function and energy-loss function, the static dielectric constant and bulk plasmon frequency in B12O2 are estimated to be 3.4 and 26.9 eV, respectively, which are smaller than that of other B12-based compounds.

  1. Vitamin B 12 absorption: correction of intestinal retention by whole-body profile activity of vitamin B 12-58 cobalt and by double tracer technique

    International Nuclear Information System (INIS)

    Full text. Intestinal retention could give false negative results in determining the whole-body retention of vitamin B 12 absorption (WBC B12-58Co). After having validate the WBC B12-58Co, taking the Schilling test as reference, we have studied the feasibility to evaluate the intestinal contamination by measurement of the profile activity distribution of vitamin B12-58Co and by a double tracer technique (WBC B12-58Co/ WBC 51 Cr Cl3). Methodology: twenty five patients were studied for the setting up of the new methodology. For eleven of them the WBC B12-58 Co retention was measured at the 7th day after the oral administration of 37KBq of B12-58Co using a four detectors whole body counter. One week later, a Schilling test was performed after the oral absorption of 18,5 KBq B12-57Co. Results were expressed as %ID. In these patients, one single peak of hepatic activity was observed on the whole body profile and thus no further intestinal correction was needed. In order to evaluate the intestinal contribution, we made in nine other patients the profile of the whole body distribution of activity at 1 h, 1 week and two weeks after the oral administration of B12-58Co. For five other patients a double tracer technique was used for intestinal correction after the simultaneous oral administration of 37 KBq of B12-58Co and 1,85 MBq of 51 Cr Cl3. The B12-58Co absorption was evaluated after intestinal correction based on subtraction of the 51Cr Cl3 contribution after the formula: B12-58Co(%ID) = WBC B12-58Co - WBC 51 Cr Cl3/1 - WBC 51 Cr Cl3. Results: the correlation with the Schilling test was found excellent: r=0,94 (n=11). The normality for WBC retention (n=7) was define as 53,2 +-12,4% ID (SD). For nine patients studied at the 7th day, the presence of a double peak (hepatic and intestinal peaks) allowed the subtraction by exponential extrapolation; the correction range was 4,4% to 37,2%. With the exception of one observation there was no difference in the measure of vitamin

  2. Drugs and vitamin B12 and folate metabolism.

    Science.gov (United States)

    Lindenbaum, J

    1983-01-01

    Deficiency of either folic acid or vitamin B12 may interfere with DNA synthesis and result in megaloblastic anemia or other conditions. These 2 vitamins have dissimilar molecular structures and are present in different foods; they are also absorbed and metabolized differently. In 201 consecutive cases of megaloblastic anemia, for 90% the cause was alcoholism and poor diet; 0.5% (1 case) was related to oral contraceptives (OCs). Megaloblastic anemia due to folate deficiency has occasionally been reported in patients with inflammatory bowel disease and has been attributed to poor diet, impaired absorption, and increased tissue utilization of folate. Sulfasalazine, a compound containing a sulfa drug and a salicylate that is broken down to its active components by the gut flora, is widely used in the treatment of inflammatory bowel disease and has been shown to impair the absorption of folic acid, polyglutamyl folate, and methyl-tetrahydrofolic acid in patients with these disorders. There is also evidence suggesting an interaction between anticonvulsant drugs and folate balance. A number of cases of megaloblastic anemia due to folate deficiency have been reported in women taking OCs. While in some cases no apparent cause for the megaloblastic anemia other than contraceptive therapy was demonstrated, in many patients other underlying disorders that were likely to disturb folate balance such as celiac disease, decreased dietary vitamin intake, and the administration of other drugs known to affect folate status have also been present. There is no convincing evidence that sex steroids affect folate absorption; about 20% of women taking OCs were found to have mild megaloblastic changes on Papanicolaou smears. These changes disappered after folic acid therapy, suggesting that OCs may cause an increased demand for folate limited to the reproductive system. Another finding is of low serum cobalamin levels in women using OCs; this appears however to be a laboratory abnormality

  3. LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray B12

    Science.gov (United States)

    1990-01-01

    LDEF (Postflight), AO201 : Interplanetary Dust Experiment, Tray B12 The postflight photograph shows little change of the exposed surfaces when compared with the prelaunch photograph. Although not noticable in the photograph, a light coating of contamination was seen on all experiment surfaces in this location. The difference in colors of the IDE detectors, located on the right hand mounting plate, is a result of the reflected surroundings and not related to space exposure. A close observation of the detector surfaces reveal that some damage has occured from meteroid and/or debris impacts. One impact crater can be seen, upper right quadrant, on the detector located in the sixth (6th) row down from the top and the fifth (5th) row from the right. Other impacts, smaller in size, show as small white dots on the detector surface. The solar sensor seems to have changed little, if any. However, the color of the solar array baseplate, showing indications of contamination, appears to be darker than the detector mounting plate. The center section cover plate shows little change when compared with the pre-launch photograph. However, during inspection, a light coat of the brown contamination has been observed on all surfaces. The color of the bonding material (RTV) used to secure several thin specimen, sapphire, to individual mounting plates has changed from pink to gold. At one location, that of a single specimen, the bonding material is more gray than gold in color. This has been attributed to the specimen being considerably thicker. The EPDS thermal cover in the right hand side of the tray shows a light coating of brown contamination on the Chemglaze II A-276 white paint.

  4. RANGELAND SEQUESTRATION POTENTIAL ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    Lee Spangler; George F. Vance; Gerald E. Schuman; Justin D. Derner

    2012-03-31

    Rangelands occupy approximately half of the world's land area and store greater than 10% of the terrestrial biomass carbon and up to 30% of the global soil organic carbon. Although soil carbon sequestration rates are generally low on rangelands in comparison to croplands, increases in terrestrial carbon in rangelands resulting from management can account for significant carbon sequestration given the magnitude of this land resource. Despite the significance rangelands can play in carbon sequestration, our understanding remains limited. Researchers conducted a literature review to identify sustainably management practices that conserve existing rangeland carbon pools, as well as increase or restore carbon sequestration potentials for this type of ecosystem. The research team also reviewed the impact of grazing management on rangeland carbon dynamics, which are not well understood due to heterogeneity in grassland types. The literature review on the impact of grazing showed a wide variation of results, ranging from positive to negative to no response. On further review, the intensity of grazing appears to be a major factor in controlling rangeland soil organic carbon dynamics. In 2003, researchers conducted field sampling to assess the effect of several drought years during the period 1993-2002. Results suggested that drought can significantly impact rangeland soil organic carbon (SOC) levels, and therefore, carbon sequestration. Resampling was conducted in 2006; results again suggested that climatic conditions may have overridden management effects on SOC due to the ecological lag of the severe drought of 2002. Analysis of grazing practices during this research effort suggested that there are beneficial effects of light grazing compared to heavy grazing and non-grazing with respect to increased SOC and nitrogen contents. In general, carbon storage in rangelands also increases with increased precipitation, although researchers identified threshold levels of

  5. The soluble receptor for vitamin B12 uptake (sCD320) increases during pregnancy and occurs in higher concentration in urine than in serum

    DEFF Research Database (Denmark)

    Abuyaman, Omar; Andreasen, Birgitte H; Kronborg, Camilla;

    2013-01-01

    BACKGROUND: Cellular uptake of vitamin B12 (B12) demands binding of the vitamin to transcobalamin (TC) and recognition of TC-B12 (holoTC) by the receptor CD320, a receptor expressed in high quantities on human placenta. We have identified a soluble form of CD320 (sCD320) in serum and here we...... gestational weeks 17-41. sCD320, holoTC, total TC and complex formation between holoTC and sCD320 were measured by in-house ELISA methods, while creatinine was measured on the automatic platform Cobas 6000. Size exclusion chromatography was performed on a Superdex 200 column. RESULTS: Median (range) of serum...

  6. 维生素B12滴眼液中维生素B12有关物质方法学研究

    Institute of Scientific and Technical Information of China (English)

    张媛媛

    2015-01-01

    目的:建立维生素B12滴眼液中维生素B12有关物质的检测方法.方法:高效液相色谱法,乙腈-0.05mol/l磷酸二氢钾溶液(17:83),用磷酸调节PH值至3.0.检测波长361nm.结果:本方法能有效检测出维生素B12的有关物质.

  7. 根据血清维生素B12水平测定值诊断维生素B12缺乏症

    Institute of Scientific and Technical Information of China (English)

    Vinod; Devalia; 颜淑敏(译)

    2006-01-01

    当患者出现血液系统、神经系统及神经精神系统异常时,血清维生素B12水平被用价是否存在维生素B12的缺乏。及早给予维生素B12补充治疗可阻止不可逆性神经系统病变和认知功能障碍的发生。

  8. Megalin-mediated endocytosis of transcobalamin-vitamin-B12 complexes suggests a role of the receptor in vitamin-B12 homeostasis.

    OpenAIRE

    Moestrup, S K; Birn, H.; Fischer, P B; Petersen, C M; Verroust, P. J.; Sim, R. B.; Christensen, E I; Nexø, E.

    1996-01-01

    Kidney cortex is a main target for circulating vitamin B12 (cobalamin) in complex with transcobalamin (TC). Ligand blotting of rabbit kidney cortex with rabbit 125I-TC-B12 and human TC-57Co-B12 revealed an exclusive binding to megalin, a 600-kDa endocytic receptor present in renal proximal tubule epithelium and other absorptive epithelia. The binding was Ca2+ dependent and inhibited by receptor-associated protein (RAP). Surface plasmon resonance analysis demonstrated a high-affinity interacti...

  9. Vitamin B12 intake and status and cognitive function in elderly people.

    Science.gov (United States)

    Doets, Esmée L; van Wijngaarden, Janneke P; Szczecińska, Anna; Dullemeijer, Carla; Souverein, Olga W; Dhonukshe-Rutten, Rosalie A M; Cavelaars, Adrienne E J M; van 't Veer, Pieter; Brzozowska, Anna; de Groot, Lisette C P G M

    2013-01-01

    Current recommendations on vitamin B12 intake vary from 1.4 to 3.0 μg per day and are based on the amount needed for maintenance of hematologic status or on the amount needed to compensate obligatory losses. This systematic review evaluates whether the relation between vitamin B12 intake and cognitive function should be considered for underpinning vitamin B12 recommendations in the future. The authors summarized dose-response evidence from randomized controlled trials and prospective cohort studies on the relation of vitamin B12 intake and status with cognitive function in adults and elderly people. Two randomized controlled trials and 6 cohort studies showed no association or inconsistent associations between vitamin B12 intake and cognitive function. Random-effects meta-analysis showed that serum/plasma vitamin B12 (50 pmol/L) was not associated with risk of dementia (4 cohort studies), global cognition z scores (4 cohort studies), or memory z scores (4 cohort studies). Although dose-response evidence on sensitive markers of vitamin B12 status (methylmalonic acid and holotranscobalamin) was scarce, 4 of 5 cohort studies reported significant associations with risk of dementia, Alzheimer's disease, or global cognition. Current evidence on the relation between vitamin B12 intake or status and cognitive function is not sufficient for consideration in the development of vitamin B12 recommendations. Further studies should consider the selection of sensitive markers of vitamin B12 status. PMID:23221971

  10. Metabolic vitamin B12 deficiency: a missed opportunity to prevent dementia and stroke.

    Science.gov (United States)

    Spence, J David

    2016-02-01

    The purpose of this narrative review is to highlight insights into the importance and frequency of metabolic vitamin B12 (B12) deficiency, reasons why it is commonly missed, and reasons for the widespread but mistaken belief that treatment of B12 deficiency does not prevent stroke or improve cognitive function. Metabolic B12 deficiency is common, being present in 10%-40% of the population; is frequently missed; is easily treated; and contributes importantly to cognitive decline and stroke in older people. Measuring serum B12 alone is not sufficient for diagnosis; it is necessary to measure holotranscobalamin or functional markers of B12 adequacy such as methylmalonic acid or plasma total homocysteine. B-vitamin therapy with cyanocobalamin reduces the risk of stroke in patients with normal renal function but is harmful (perhaps because of thiocyanate accumulation from cyanide in cyanocobalamin) in patients with renal impairment. Methylcobalamin may be preferable in renal impairment. B12 therapy slowed gray matter atrophy and cognitive decline in the Homocysteine and B Vitamins in Cognitive Impairment Trial. Undiagnosed metabolic B12 deficiency may be an important missed opportunity for prevention of dementia and stroke; in patients with metabolic B12 deficiency, it would be prudent to offer inexpensive and nontoxic supplements of oral B12, preferably methylcobalamin or hydroxycobalamin. Future research is needed to distinguish the effects of thiocyanate from cyanocobalamin on hydrogen sulfide, and effects of treatment with methylcobalamin on cognitive function and stroke, particularly in patients with renal failure. PMID:26597770

  11. Relationship of blood folate, vitamin B12 levels with coronary artery disease

    International Nuclear Information System (INIS)

    To investigate the relationship of blood folate, vitamin B12 (Vit. B12) with coronary artery disease and the mechanism, whole blood folate, plasma folate and Vit. B12 in 94 patients with coronary heart disease (CHD) were measured and compared with normal controls. The relationship of folate, Vit. B12 levels with the number of coronary vessel stenosis was also studied. Homocysteine(Hcy) and lipid levels in 57 subjects randomly selected were measured and the correlation of whole blood folate, plasma folate and Vit. B12 with Hcy and lipid levels was analyzed. The results showed that whole blood folate, plasma folate and Vit. B12 concentrations in CHD patients were significantly lower than those in normal controls. There were no significant differences in whole blood folate, plasma folate and Vit. B12 levels between patients with different number of coronary vessel stenosis. There was negative correlation of whole blood folate, plasma folate and Vit. B12 with Hcy, but no significant correlation was found with lipid. The results demonstrated that low blood folate and Vit. B12 levels were associated with the coronary heart disease, and that high plasma Hcy caused by deficiency of folate and Vit. B12 may be an independent risk factor for coronary artery disease. (authors)

  12. Vitamin B12-loaded solid lipid nanoparticles as a drug carrier in cancer therapy.

    Science.gov (United States)

    Genç, Lütfi; Kutlu, H Mehtap; Güney, Gamze

    2015-05-01

    Nanostructure-mediated drug delivery, a key technology for the realization of nanomedicine, has the potential to improve drug bioavailability, ameliorate release deviation of drug molecules and enable precision drug targeting. Due to their multifunctional properties, solid lipid nanoparticles (SLNs) have received great attention of scientists to find a solution to cancer. Vitamin supplements may contribute to a reduction in the risk of cancer. Vitamin B12 has several characteristics that make it an attractive entity for cancer treatment and possible therapeutic applications. The aim of this study was to produce B12-loaded SLNs (B12-SLNs) and determine the cytotoxic effects of B12-SLNs on H-Ras 5RP7 and NIH/3T3 control cell line. Results obtained by MTT assay, transmission electron and confocal microscopy showed that B12-loaded SLNs are more effective than free vitamin B12 on cancer cells. In addition, characterization studies indicate that while the average diameter of the B12 was about 650 nm, B12-SLNs were about 200 nm and the drug release efficiency of vit. B12 by means of SLNs increased up to 3 h. These observations point to the fact that B12-SLNs could be used as carrier systems due to the therapeutic effects on cancer. PMID:24344935

  13. Vitamin B12 deficiency in resettled Bhutanese refugees--United States, 2008-2011.

    Science.gov (United States)

    2011-03-25

    Since 2008, approximately 30,000 Bhutanese refugees have been resettled in the United States. Routine medical examinations of refugees after arrival in resettlement states indicated hematologic and neurologic disorders caused by vitamin B12 deficiency. These cases were reported by examining physicians and state health departments to CDC, which initiated an investigation. This report summarizes the results of that investigation. Sera from overseas medical examinations, postarrival examinations in three state health departments (Minnesota, Utah, and Texas), and medical records and interviews at a health clinic in St. Paul, Minnesota, were evaluated. Vitamin B12 deficiency, defined as serum vitamin B12 concentration Bhutanese refugees screened for vitamin B12 deficiency at the St. Paul clinic. Although the deficiencies might be multifactorial, the main cause is thought to be the diet consumed by these refugees for nearly two decades in Nepal, which lacked meat, eggs, and dairy products, the major dietary sources of vitamin B12. Additionally, infection with Helicobacter pylori might play a role. Clinicians should be aware of the risk for vitamin B12 deficiency in Bhutanese refugees. All Bhutanese refugees should be given nutrition advice and should receive supplemental vitamin B12 upon arrival in the United States. In addition, refugees with clinical manifestations suggestive of deficiency should be tested for adequate serum vitamin B12 concentrations and, if found to have a B12 deficiency, screened for underlying causes, treated with parenteral vitamin B12 or high-dose oral supplements, and evaluated for response to therapy. PMID:21430638

  14. Association of B12 deficiency and clinical neuropathy with metformin use in type 2 diabetes patients

    Directory of Open Access Journals (Sweden)

    A K Singh

    2013-01-01

    Full Text Available Context: Long-term metformin use has been hypothesized to cause B12 deficiency and neuropathy in Type 2 diabetes patients. However, there is a paucity of Indian data regarding the same. Aim: To compare the prevalence of B12 deficiency and peripheral neuropathy in patients with Type 2 diabetes mellitus treated with or without metformin. Materials and Methods: We recruited patients with Type 2 diabetes and divided them into metformin exposed and nonmetformin exposed groups. We measured baseline demographic variables like age, sex, vegetarian status, and HbA1c levels in both groups. We compared vitamin B12 levels and severity of peripheral neuropathy (using Toronto Clinical Scoring System (TCSS in both groups. Definite B12 deficiency was defined as B12 <150 pg/ml and possible B12 deficiency as <220 pg/ml. The difference in vitamin B12 levels and TCSS was calculated in both groups using independent samples t-test. Spearman′s rank correlation between cumulative metformin use and B12 level was calculated. Odds ratio of vitamin B12 deficiency in metformin exposed group was also estimated. Results: Mean serum B12 levels was significantly lower in metformin exposed group (n=84 compared with nonmetformin exposed group (n=52 (410±230.7 versus 549.2±244.7, P=0.0011. Mean neuropathy score was significantly higher in metformin exposed group. (5.72±2.04 versus 4.62±2.12, P=0.0064. Odds ratio for possible B12 deficiency was 4.45 (95% CI 1.24-15.97. There was significant negative correlation between cumulative metformin dose and vitamin B12 level (r=−0.68, P<0.0001. Conclusion: Metformin use is associated with vitamin B12 deficiency and clinical neuropathy in Type 2 diabetes patients.

  15. Relation of Vitamin B12 Levels to Bone Mineral Density of Postmenopausal Women - Original Investigation

    Directory of Open Access Journals (Sweden)

    Nur Kesiktaş

    2009-04-01

    Full Text Available Aim: Although vitamin B12 (vit-B12 is known to influence the hemopoeitic and nervous systems, little is known about the skeletal effects of vit-B12. Researchs that demonstrated an association between serum vitamin B-12 concentration and osteoblastic function and its’ role in DNA synthesis, which suggesting a relationship between osteoporosis, this randomized controlled trial were planned. Material and Methods: Vit-B12 levels of 740 patients aged between 50-65 years, who were applied to our outpatient clinic because of chronic low back pain were examined and divided with vitamin B-12 levels over or below 400 pg/ml. 26 participant who met all inclusion criteria with vit-B12 level below 400pg/ml were assigned to case group. Among the patients that vit-B12 levels were over 400pg/ml, 20 participants were randomly selected to control group. Bone mineral density (BMD, biochemical measurements, causes of osteoporosis and vit-B12 defiencies were investigated. A computer program was used for statistic evaluation. Results: There was not statistically significant difference between BMD’s of case and control groups (p>0.05. When the vit-B12 levels were grouped with over 400 pg/ml, below 200 pg/ml and between 200-400 pg/ml, osteodensimetric examinations of femur neck BMD (p<0.05 were achieved statistically significant difference. Conclusion: The results of this trial highlight an association of vitamin B-12 status with osteoporosis. Vit-B12 defiency is an easy and cheap treatable condition so that reason we suggest that levels of vit-B12 should be investigated. (From the World of Osteoporosis 2009;15:1-6

  16. Interaction of conjugated bile acids and detergents with a radiosorbent assay of vitamin B-12

    International Nuclear Information System (INIS)

    The effect of conjugated bile acids and detergents on the radiosorbent technique for the determination of vitamin B-12 activity is reported. It is shown that whereas the non-ionic detergent Triton X-100 has no effect on the vitamin B-12-radiosorbent assay, the addition of ionic detergents, e.g. glycocholic acid, taurocholic acid or sodium lauryl sulfate, results in a falsely-elevated vitamin B-12 activity presumably due to the disruption of the binding of vitamin B-12 to the intrinsic factor-Sephadex complex. This effect may be of importance not only to the radiosorbent assaying of vitamin B-12, but to the in vivo intestinal absorption of vitamin B-12 as well

  17. Revisiting Metformin: Annual Vitamin B12 Supplementation may become Mandatory with Long-Term Metformin Use.

    Science.gov (United States)

    Mahajan, R; Gupta, K

    2010-10-01

    Monitoring of adverse drug reactions of a drug is a continuous process and runs through-out the life of a drug. Many rare adverse effects of a drug are documented after years of use; when a single case (signal generation) is reported leading subsequently to reporting of more cases. Deficiency of Vitamin B12 (vit B(12)) is a known sequel of prolonged metformin therapy. It was recommended to have annual measurement of serum vit B(12) levels in patients on long term metformin therapy way back in 1970 itself. After more than 50 years of use of metformin, we have come to know that metformin induced vit B(12) deficiency can cause neuropathy; forcing to change the recommendation from annual screening of vit B(12) levels to annual supplementation of vit B(12). PMID:21264109

  18. Update: vitamin B12 deficiency among Bhutanese refugees resettling in the United States, 2012.

    Science.gov (United States)

    Cuffe, Kendra; Stauffer, William; Painter, John; Shetty, Sharmila; Montour, Jessica; Zhou, Weigong

    2014-07-18

    In 2008, clinicians performing routine medical examinations in the United States reported high rates of hematologic and neurologic disorders caused by vitamin B12 deficiency in resettled Bhutanese refugees. To confirm this finding, CDC screened Bhutanese refugees' serum samples for vitamin B12 levels and found vitamin B12 deficiency in 64% (n = 99) of samples obtained before departure and 27% (n = 64) of samples obtained after arrival in the United States. In response, CDC recommended that arriving Bhutanese refugees receive oral vitamin B12 supplements and nutrition advice. In 2012, based on anecdotal reports of decreasing rates of vitamin B12 deficiency in this population, CDC worked with select domestic refugee health programs to determine if the recommendations had reduced the vitamin B12 deficiency rate among Bhutanese refugees. PMID:25029113

  19. CAUSES AND CONDITIONS ASSOCIATED WITH REDUCED LEVEL OF VITAMIN B12: A REVIEW

    Directory of Open Access Journals (Sweden)

    Chandrakant Belwal

    2012-10-01

    Full Text Available Vitamin B12 plays an important role in building of genetic material, in development of normal red blood cells and in maintenance of nervous system. Major deficiency symptoms of Vitamin B12 include anemia and neurological disorders. The daily recommended intake of vitamin B12 for an adult is 1.5μg a day. Eating a diet containing required amount of vitamin B12 is the best way to treat the conditions associated with its low level. Vitamin B12 found only in animal based foods such as meats, liver, kidney, fish, eggs, milk and milk products, oysters and shellfish. Hence, vegetarians are more likely to have low level of Vitamin B12.

  20. Briefing on geological sequestration

    Science.gov (United States)

    Geological sequestration (GS) is generally recognized as the injection and long-term (e.g., hundreds to thousands of years) trapping of gaseous, liquid or supercritical carbon dioxide (CO2) in subsurface media – primarily saline formations, depleted or nearly depleted oil and gas...

  1. Purification of rat intestinal receptor for intrinsic factor-vitamin B12 complex

    International Nuclear Information System (INIS)

    The intrinsic factor (IF) in a rat gastric mucosal extract was bound efficiently to vitamin B12-sepharose without significant change in its nature to produce IF-vitamin B12-sepharose. The purification of the intestinal receptor for the IF-vitamin B12 complex was performed by the affinity chromatography using the IF-vitamin B12-sepharose as the affinity adsorbent. As a result of admixing the gastric mucosal extract sample with B12-sepharose while stirring for 4 hours, the adsorption was performed without any break through. Further, it was recognized that the B12-bound protein purified by the affinity chromatography using B12-sepharose was not much changed as compared with that before purification. Furthermore, it was recognized that IF-B12-sepharose was able to be made by binding IF with B12-sepharose which was made by coupling B12 with the market-available AH-sepharose. The IF-B12-sepharose was washed with buffer solution, and then was loaded with the small intestine mucosal extract. Thereafter, the receptor was eluted by making di-valent cation inert with the buffer solution. After the removal of EDTA in the eluted solution by dialysis, the activity of the receptor was measured. 48.5% of the receptor activity loaded was recovered by the elution with EDTA. The specific activity of the receptor represented by the final amount of B12 (pg)/the amount of protein (mg) in the purified substance was 335 folds of the original activity. (Iwakiri, K.)

  2. Vitamin B12 Deficiency: An Important Reversible Co-Morbidity in Neuropsychiatric Manifestations

    OpenAIRE

    Thomas Gregor Issac; Soundararajan Soundarya; Rita Christopher; Sadanandavalli Retnaswami Chandra

    2015-01-01

    Background: Vitamin B12 deficiency is a common condition causing neurologic, cognitive, psychiatric, and mood symptoms. With varied religious, ethnic, and socioeconomic heterogeneity among the people in India greatly influencing their dietary habits and with the high prevalence of Helicobacter pylori infection, Vitamin B12 deficiency is not uncommon, but is often under recognized due to the lack of classical symptomatic presentation. Materials and Methods: Retrospective study on Vitamin B12 d...

  3. Do MCI patients with vitamin B12 deficiency have distinctive cognitive deficits?

    OpenAIRE

    Silva, Dina; Albers, Ulrike; Santana, Isabel; Vicente, Margarida; Martins, Isabel Pavão; Verdelho, Ana; Guerreiro, Manuela; de-Mendonça, Alexandre

    2013-01-01

    Background Vitamin B12 deficiency is common in older people, and may be responsible for reversible dementia. Low serum vitamin B12 levels were also observed in patients with Mild Cognitive Impairment (MCI). It is not known whether patients with vitamin B12 deficiency have a distinctive profile of cognitive impairment different from the episodic memory deficit usually observed in MCI. Results From a cohort of 310 patients with MCI followed in a memory clinic in Lisbon, only 10 cases with vitam...

  4. Influence of Co and B12 on the growth and nitrogen fixation of Trichodesmium

    OpenAIRE

    Irene B. Rodriguez; Ho, Tung-Yuan

    2015-01-01

    We investigated the influence of varying cobalt (Co) and B12 concentrations to growth and nitrogen fixation of Trichodesmium, a major diazotroph in the tropical and subtropical oligotrophic ocean. Here we show that sufficient inorganic Co, 20 pmol L-1, sustains the growth of Trichodesmium either with or without an additional B12 supply. We also found that in these culture conditions, nitrogen levels fixed by Trichodesmium were higher in treatments with insufficient B12 than in treatments with...

  5. 可改善维生素B12吸收的Eligen技术

    Institute of Scientific and Technical Information of China (English)

    范丽珠(摘)

    2008-01-01

    Emisphere Technologies报告,采用其Eligen配方技术能改善口服维生素B12的生物利用度。Eligen B12产品(I)可使需要补充维生素B12的患者避免多次注射或口服大剂量。

  6. A case of acute psychosis due to vitamin b12 deficiency

    OpenAIRE

    Sayın, Selim; Arslan, Erol; Demirbaş, Şeref; ESER, Mithat; Kenan SAĞLAM

    2014-01-01

    Patients with vitamin B12 deficiency may present with hematologic, neuropsychiatric and cardiovascular symptoms. A clinical Picture of acute psychosis can be seen in rare cases and if not corrected, vitamin B12 deficiency can lead to permanent demage. Acute psychosis and symptoms of anemia with sixty-year-old male patient was evaluated and found that vitamin B12 deficiency due to the terminal ileitis. The patient was healed without permanent damage with replacement therapy.The diagnosis and t...

  7. An audit to determine if vitamin b12 supplementation is necessary after sleeve gastrectomy

    OpenAIRE

    Eltweri, Amar M.; Bowrey, David J.; Christopher D Sutton; Graham, Lisa; Williams, Robert N

    2013-01-01

    Abstract Sleeve gastrectomy has increased in popularity over the last five years and it is likely to supersede gastric banding. Nevertheless, it is unclear whether vitamin B12 supplementation is required after surgery. The aim of this short report is to identify any vitamin B12 deficiency and highlight the necessity of post laparoscopic sleeve gastrectomy vitamin B12 monitoring. Patients and methods A review of 66 patients underwent LSG in our institution. 25 patients were excluded as they ha...

  8. Cerebral Atrophy in a Vitamin B12-deficient Infant of a Vegetarian Mother

    OpenAIRE

    Kocaoglu, Celebi; Akin, Fatih; Çaksen, Hüseyin; Böke, Saltuk Buğra; Arslan, Şükrü; Aygün, Serhat

    2014-01-01

    ABSTRACT In developed countries, vitamin B12 (cobalamin) deficiency usually occurs in children, exclusively breastfed ones whose mothers are vegetarian, causing low body stores of vitamin B12. The haematologic manifestation of vitamin B12 deficiency is pernicious anaemia. It is a megaloblastic anaemia with high mean corpuscular volume and typical morphological features, such as hyperlobulation of the nuclei of the granulocytes. In advanced cases, neutropaenia and thrombocytopaenia can occur, ...

  9. Vitamin B12: Unique Metalorganic Compounds and the Most Complex Vitamins

    OpenAIRE

    Lucio Randaccio; Silvano Geremia; Nicola Demitri; Jochen Wuerges

    2010-01-01

    The chemistry and biochemistry of the vitamin B12 compounds (cobalamins, XCbl) are described, with particular emphasis on their structural aspects and their relationships with properties and function. A brief history of B12, reveals how much the effort of chemists, biochemists and crystallographers have contributed in the past to understand the basic properties of this very complex vitamin. The properties of the two cobalamins, the two important B12 cofactors Ado- and MeCbl are described, wit...

  10. Long-term outcome in children with nutritional vitamin B12 deficiency

    OpenAIRE

    Melike Sezgin Evim; Şahin Erdöl; Özlem Özdemir; Birol Baytan; Adalet Meral Güneş

    2011-01-01

    Objective: Vitamin B12 deficiency is frequently observed in developing countries. Herein we report the long-term clinical and laboratory outcomes in 45 children presented with various symptoms of vitamin B12 deficiency.Materials and Methods: Symptoms and physical findings, and percentiles for weight, height, and head circumference at presentation were recorded. The educational level of the patients’ mothers, vitamin B12 deficiency-related diseases and family income data were collected. Compl...

  11. Is it time for vitamin B-12 fortification? What are the questions?1234

    OpenAIRE

    Green, Ralph

    2009-01-01

    Since the introduction of folic acid fortification of flour 10 y ago, an initiative to consider fortifying flour with vitamin B-12 has gained momentum in the United States. The impetus for this move stems from several considerations, including some evidence that a proportion of neural tube defect pregnancies may be the result of vitamin B-12 rather than folate deficiency. However, no interventional trials have taken place to show the efficacy of vitamin B-12 supplementation or fortification i...

  12. Imerslund-Gräsbeck syndrome (selective vitamin B12 malabsorption with proteinuria)

    OpenAIRE

    2006-01-01

    Imerslund-Gräsbeck syndrome (IGS) or selective vitamin B12 (cobalamin) malabsorption with proteinuria is a rare autosomal recessive disorder characterized by vitamin B12 deficiency commonly resulting in megaloblastic anemia, which is responsive to parenteral vitamin B12 therapy and appears in childhood. Other manifestations include failure to thrive and grow, infections and neurological damage. Mild proteinuria (with no signs of kidney disease) is present in about half of the patients. Anatom...

  13. Decreased Brain Levels of Vitamin B12 in Aging, Autism and Schizophrenia

    OpenAIRE

    Zhang Y; Hodgson N.W.; Trivedi M.S.; Abdolmaleky H.M.; Fournier M.; Cuenod M.; Do K.Q.; Deth R.C.

    2016-01-01

    Many studies indicate a crucial role for the vitamin B12 and folate-dependent enzyme methionine synthase (MS) in brain development and function, but vitamin B12 status in the brain across the lifespan has not been previously investigated. Vitamin B12 (cobalamin, Cbl) exists in multiple forms, including methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl), serving as cofactors for MS and methylmalonylCoA mutase, respectively. We measured levels of five Cbl species in postmortem human frontal...

  14. Biochemical Impedance on Intracellular Functions of Vitamin B12 in Chronic Toxigenic Mold Exposures

    OpenAIRE

    Ebere C. Anyanwu; Ijeoma Kanu

    2007-01-01

    A majority of patients with neurological disorders with chronic exposures to toxigenic molds and mycotoxins has vitamin B12 deficiency that is unrelated to dietary insufficiency. Vitamin B12 is a source of coenzymes, and participates in intracellular recycling of methionine, and in methionine synthase reactions. The biochemical processes that lead to B12 depletion and deficiency are not fully understood. This paper examines and assesses various most likely biochemical reasons that could imped...

  15. 维生素B12对抑郁症的辅助治疗%Vitamin B12 as Adjunctive Therapy in Patients with Major Depressive Disorder

    Institute of Scientific and Technical Information of China (English)

    杜春燕; 赵约翰; 徐广军

    2014-01-01

    目的:观察抑郁症患者血清维生素B12水平,探讨抗抑郁剂合并维生素B12治疗维生素B12缺乏抑郁症的疗效及安全性。方法对400名抑郁症患者进行血清维生素B12浓度测查,将筛查出的维生素B12缺乏的抑郁症患者70例,随机分为两组,各35例。对照组根据病情口服西酞普兰20~40 mg/次,每日1次,治疗8周;研究组根据病情口服西酞普兰20~40 mg/次,每日1次,同时合并使用维生素B12,治疗8周。研究组及对照组治疗前后1,2,4,8周末分别进行汉密尔顿抑郁量表( HAMD)评定;治疗后1,2,4,8周末分别评定副反应量表(TESS);治疗前及治疗后4,8周末分别查血清维生素B12浓度。结果抑郁症患者血清维生素B12平均水平(359.7±183.2)pg/ml,维生素B12缺乏发生率为19.5%,研究组与对照组第1周末汉密尔顿抑郁量表评分差异无显著性(P>0.05),治疗第2,4、8周末有显著性差异(P<0.01),研究组有效率为94.3%,对照组为74.3%,两组差异有显著性(P<0.01),血清维生素B12浓度治疗后4,8周末有显著性差异(P<0.01),且研究组汉密尔顿抑郁量表评分与血清维生素B12浓度负相关。两组不良反应均较轻微,TESS评分比较差异无显著性(P>0.05)。结论抑郁症患者血清维生素B12平均水平较正常明显降低,维生素B12缺乏发生率高,维生素B12辅助抗抑郁剂治疗可明显提高疗效,且不增加不良反应。%Objective To observe serum vitamin B 12 levels in patients with depression and explore the curative effects and safety of antidepressant combined with vitamine B 12 in the treatment of depression with vitamin B 12 deficiency.Methods Serum vitamin B12 lev-els in 400 patients with major depressive disorder were determined at baseline .70 depressive patients with vitamin B 12 deficiency were randomly divided into research

  16. A general review on vitamin B12 deficiency with focus on the situation in Jordan

    International Nuclear Information System (INIS)

    Vitamin B12 (cobalamin) is an essential nutrient that is only obtained from foods of animal origin, such as meat, eggs and dairy products. Vitamin B12 plays an important role in DNA synthesis and neurological function. Thus its deficiency can lead to several neurological symptoms such as memory loss, dizziness and in severe cases may lead to dementia. Many factors can cause or lead to vitamin B-12 deficiency. Among these are malabsorption, several gastron intestinal problems (i.e. celiac disease, Crobn's disease) and gastrointestinal surgeries. diagnosis of vitamin B-12 status depends commonly on serum vitamin B12 which is nonspecific tool for the deficiency. Other more specific tests, which reflect true deficiency, include serum and urine methylmalonic aci de, total serum homocysteine and serum holotranscobalamin. Vitamin B12 deficiency is a worldwide public health problem; epidemiological studies showed that its prevalence in industrialized countries ranges from 5-60% of the population depending on the used cutoff point of cobalamin level. In Jordan, many reports were published on vitamin B 12 deficiency. However, these reports gave different results of its prevalence ranging from 16-48% depending on the serum vitamin B12 cutoff point used. A recent study showed a prevalence of true deficiency of 32.7% based on measuring both serum vitamin B12 level and plasma methylmalonic acid. (authors).

  17. Light-dependent gene regulation by a coenzyme B12-based photoreceptor

    OpenAIRE

    Ortiz-Guerrero, Juan Manuel; Polanco, María Carmen; Murillo, Francisco J; Padmanabhan, S.; Elías-Arnanz, Montserrat

    2011-01-01

    Cobalamin (B12) typically functions as an enzyme cofactor but can also regulate gene expression via RNA-based riboswitches. B12-directed gene regulatory mechanisms via protein factors have, however, remained elusive. Recently, we reported down-regulation of a light-inducible promoter in the bacterium Myxococcus xanthus by two paralogous transcriptional repressors, of which one, CarH, but not the other, CarA, absolutely requires B12 for activity even though both have a canonical B12-binding mo...

  18. 血清活性维生素B12检测在维生素B12缺乏中的应用价值%The value of the serum active vitamin B12 in vitamin B12 deficiency

    Institute of Scientific and Technical Information of China (English)

    陈珊瑚; 张文辉; 周碧碧; 陈晓东

    2015-01-01

    目的 探讨血清中活性维生素B12检测在维生素B12缺乏中的应用价值.方法 采用酶免疫发光分析竞争法检测血清中维生素B12和叶酸的含量,及ELISA法检测血清活性维生素B12,通过ROC曲线分析活性维生素B12在诊断维生素B12缺乏中的特异度和敏感度;并且通过回归分析活性维生素B12水平与性别、年龄、总维生素B12及叶酸的相关性;统计分析各疾病组中活性维生素B12含量的累积百分比.结果 血清活性维生素B12判断维生素B12缺乏的ROC曲线下面积为0.983,敏感度为60.0%,特异性为99.2%;活性维生素B12与总维生素B12和叶酸存在良好的正相关,P<0.001,与年龄、性别不相关;各病例组中血液病组的活性维生素B12含量累计百分比最高,其次为神经系统疾病组.结论 血清活性维生素B12是用于临床维生素B12缺乏诊断较敏感、特异的指标,在血液病、神经系统疾病患者中,其临床应用价值更突出.

  19. Vitamin B 12 Deficiency and Multiple Sclerosis; Is there Any Association?

    Directory of Open Access Journals (Sweden)

    Mohamad Reza Najafi

    2012-01-01

    Full Text Available Background: Vitamin B 12 (Cobalamin deficiency can result in some clinical and paraclinical characteristics similar to what is seen in multiple sclerosis (MS patients. This study aimed to evaluate the controversial association between vitamin B 12 deficiency and MS. Methods: We measured serum vitamin B 12 in 60 patients with MS and 38 healthy controls. Clinical disability was evaluated according to the Extended Disability Status Scale (EDSS. Serum B 12 concentration was measured with Radioimmunoassay Dual Isotope method. The cutoff value for low serum vitamin B 12 concentrations was 75 pg/mL. Patients were in remission at the time of blood draw. Results: There were 13 (21.6% MS patients and 10 (26.3% controls with low serum B 12 concentration with no significant difference between the groups; P>0.05. The mean serum vitamin B 12 concentration in MS patients (108.9±45.3 pg/mL was not significantly different compared with controls (98.9±44.4 pg/mL; P=0.284. Likewise, there was no correlation between the concentration of serum vitamin B 12 and disease′ age of onset, duration, subtypes, or disability status. Conclusions: In contrast to some previous reports, our findings did not support any association between B 12 deficiency and MS.

  20. Transport of vitamin B12 in Escherichia coli: cloning of the btuCD region.

    OpenAIRE

    DeVeaux, L C; Kadner, R J

    1985-01-01

    The transport of vitamin B12 in Escherichia coli requires a specific vitamin B12 receptor protein in the outer membrane and the tonB gene product. In addition, the btuC gene, located at min 38 on the genetic map, has been found to influence vitamin B12 uptake or utilization. The btuC function is required for the growth response to vitamin B12 when the outer membrane transport process (btuB or tonB function) is defective. However, even in a wild-type strain, btuC is required for proper transpo...

  1. LDEF (Prelaunch), AO201 : Interplanetary Dust Experiment, Tray B12

    Science.gov (United States)

    1984-01-01

    LDEF (Prelaunch), AO201 : Interplanetary Dust Experiment, Tray B12 The prelaunch photograph shows the six (6) inch deep Interplanetary Dust Experiment (IDE) master control tray. The tray has three (3) mounting/cover plates elevated on fiberglass stand-offs to provide clearance and protection for hardware and electronics located underneath. The stand-offs also raise the plates to a level that minimizes shading of detectors by the tray sidewalls. The mounting plate located at the left hand end of the tray is populated with eighty (80) metaloxide-silicon (MOS) capacitor-type impact sensors and one (1) solar sensor that is located approximately in the center of the mounting plate. The IDE sensors are two (2) inch diameter MOS capacitor structures approximately 250 um thick. The detectors are formed by growing either 0.4um or 1.0um thick silicon oxide, SiO2, layer on the 250um thick, B-doped polished silicon wafer. The top metal contact, the visible surface, was formed by vapor deposition of 1000A of aluminum on the SiO2 surface. Aluminum was also vapor deposited on the backside to form the contact with the silicon substrate. Gold wires are bonded to the front and back aluminum layers for use in connecting the detectors to the circuits. The complete wafers, IDE detectors, are mounted on chromic anodized aluminum frames by bonding the detector backside to the aluminum frame with a space qualified RTV silicon adhesive, de-volatized RTV-511. The difference in colors of the detectors is caused by reflections in the metallized surfaces. A reflection of one of the technicians is visible in the three (3) rows of detector on the left hand side of the mounting plate. The solar sensor, located at the mounting plate center, consist of four (4) silicon solar cells connected in series and associated circuity bonded to an aluminum baseplate. The solar sensor registered each orbital sunrise independant of LDEF orientation at the time of sunrise. When IDE solar sensor data from the six

  2. Simplified Assay for Vitamin B12 in Plastic Tubes Coated with Intrinsic Factor

    International Nuclear Information System (INIS)

    Polymeric surfaces of some plastic test tubes can be firmly coated with protein solutions. Catt and Tregear have described a radioimmunoassay for polypeptide hormones using plastic tubes coated with specific antihormone antibody. We have developed a competitive binding assay for vitamin B12 using plastic tubes coated with intrinsic factor (I.F.). The method is simple and economical. I. F .-coated tubes are prepared by placing an I.F. solution in plastic test tubes overnight. After pouring out and rinsing twice with normal saline, the coated tubes are drained, dried and stored at 4°C until ready for use. The assay for serum B12 is run with a set of known B12 standard solutions in albumin. The B12 is liberated from protein binders by acidification and boiling. The freed B12 is then mixed with 1000 pg high specific activity 57Co B12 at pH 7.4 and poured into the I.F . -coated tubes. After standing for 24 h to allow for equilibration and competitive binding of hot and cold B12, the plastic tubes are emptied and rinsed twice with tap water. The wall-bound radioactivity is counted in a gamma counter. Tube counts/min are plotted for each B12 standard. An almost straight line curve is obtained. Tube counts/min of test sera are located on the standard curve and their B12 content read off. Serum B12 levels in 28 blood donors ranged from 400 to 2280 pg/m l with a mean of 1341 pg and a standard deviation of 503. Predicted B12 values for dilutions of normal sera agreed closely with levels experimentally determined. This test has proved stable and useful in clinical haematology. (author)

  3. Conformational Motions and Functionally Key Residues for Vitamin B12 Transporter BtuCD–BtuF Revealed by Elastic Network Model with a Function-Related Internal Coordinate

    OpenAIRE

    Ji-Guo Su; Xiao Zhang; Shu-Xin Zhao; Xing-Yuan Li; Yan-Xue Hou; Yi-Dong Wu; Jian-Zhuo Zhu; Hai-Long An

    2015-01-01

    BtuCD–BtuF from Escherichia coli is a binding protein-dependent adenosine triphosphate (ATP)-binding cassette (ABC) transporter system that uses the energy of ATP hydrolysis to transmit vitamin B12 across cellular membranes. Experimental studies have showed that during the transport cycle, the transporter undergoes conformational transitions between the “inward-facing” and “outward-facing” states, which results in the open–closed motions of the cytoplasmic gate of the transport channel. The ...

  4. If high folic acid aggravates vitamin B12 deficiency what should be done about it?

    Science.gov (United States)

    Johnson, Mary Ann

    2007-10-01

    The most common cause of vitamin B12 deficiency in older people is malabsorption of food-bound vitamin B12. Thus, it is suggested that the recommended daily allowance of 2.4 microg/d be met primarily with crystalline vitamin B12, which is believed to be well absorbed in individuals who have food-bound malabsorption. There is concern that high intakes of folic acid from fortified food and dietary supplements might mask the macrocytic anemia of vitamin B12 deficiency, thereby eliminating an important diagnostic sign. One recent study indicates that high serum folate levels during vitamin B12 deficiency exacerbate (rather than mask) anemia and worsen cognitive symptoms. Another study suggests that once vitamin B12 deficiency is established in subjects with food-bound malabsorption, 40 microg/d to 80 microg/d of oral crystalline vitamin B12 for 30 d does not reverse the biochemical signs of deficiency. Together, these studies provide further evidence that public health strategies are needed to improve vitamin B12 status in order to decrease the risk of deficiency and any potentially adverse interactions with folic acid. PMID:17972439

  5. Low vitamin B-12 status and risk of cognitive decline in older adults

    DEFF Research Database (Denmark)

    Clarke, Robert; Birks, Jacqueline; Nexo, Ebba;

    2007-01-01

    BACKGROUND: Elevated total homocysteine (tHcy) concentrations have been associated with cognitive impairment, but it is unclear whether low vitamin B-12 or folate status is responsible for cognitive decline. OBJECTIVE: We examined the associations of cognitive decline with vitamin B-12 and folate...

  6. Acute Reversible Mania as a Presenting Feature Of Vitamin B12 Deficiency

    Directory of Open Access Journals (Sweden)

    Kumar S

    2004-01-01

    Full Text Available Vitamin B12 deficiency usually presents with hematological or neuropsychiatric manifestations. The common clinical presentations include pernicious anemia, myelopathy (Subacute combined degeneration of the cord, myeloneuropathy, optic atrophy, dementia and psychosis. An uncommon manifestation of Vitamin B12 deficiency-acute onset mania-in a 25-years old man that responded to treatment is reported. Relevant literature is also reviewed.

  7. Acute Reversible Mania as a Presenting Feature Of Vitamin B12 Deficiency

    OpenAIRE

    Kumar S

    2004-01-01

    Vitamin B12 deficiency usually presents with hematological or neuropsychiatric manifestations. The common clinical presentations include pernicious anemia, myelopathy (Subacute combined degeneration of the cord), myeloneuropathy, optic atrophy, dementia and psychosis. An uncommon manifestation of Vitamin B12 deficiency-acute onset mania-in a 25-years old man that responded to treatment is reported. Relevant literature is also reviewed.

  8. Vitamin B12 intake and status and cognitive function in elderly people

    NARCIS (Netherlands)

    Doets, E.L.; Wijngaarden, van J.P.; Szczecinska, A.; Dullemeijer, C.; Souverein, O.W.; Dhonukshe-Rutten, R.A.M.; Cavelaars, A.J.E.M.; Veer, van 't P.; Brzozowska, A.M.; Groot, de C.P.G.M.

    2013-01-01

    Current recommendations on vitamin B12 intake vary from 1.4 to 3.0 µg per day and are based on the amount needed for maintenance of hematologic status or on the amount needed to compensate obligatory losses. This systematic review evaluates whether the relation between vitamin B12 intake and cogniti

  9. Research Intensity Synthesis of Propionic Acid and Vitamin B12 Propionibacteria

    Directory of Open Access Journals (Sweden)

    Kuznetsova Tatyana

    2015-10-01

    Full Text Available Conducted the selection and breeding of strains of Propionibacterium shermanii ability to synthesize vitamin B12 and propionic acid. Dedicated 9 propionibacteria strains synthesize vitamin B12 (180-1200 mcgr/ml and propionic acid (0,63- 2,53 g/l.

  10. Vitamin B12 Levels in Rat Organs - No Change Following Prolonged Treatment with Metformin

    DEFF Research Database (Denmark)

    Thagaard, Mikkel Svankjær; Nexø, Ebba; Greibe, Eva

    2015-01-01

    Aim: Few studies have explored vitamin B12 (B12) distribution in control rats and in rats treated with metformin, an anti-diabetic drug known to decrease the plasma level of B12 in humans. Here we report B12 levels in both control rats and in rats treated by two different methods of delivering...... metformin. Methods: Male Wistar rats aged 16 weeks at sacrifice was treated for 6 weeks with daily subcutaneous injections of either saline (n = 10) or metformin (n = 10). We collected plasma and organs for analyses of B12, and we explored the fraction of protein-bound B12 in selected organs. In addition we...... examined the effect of four weeks administration of metformin (n = 10= or sline (n = 10) by intra-peritoneal osmotic pumps on levels of B12 in plasma, liver, and kidneys of rats aged 14 weeks at sacrifice. Results: Median concentration of B12 in the 16 weeks old control rats was highest in the kidney (1350...

  11. Interventions with vitamins B6, B12 and C in pregnancy

    Science.gov (United States)

    The water-soluble vitamins B6, B12 and C play important roles in maternal health as well as fetal development and physiology during gestation. This systematic review evaluates the risks and benefits of interventions with vitamins B6, B12 and C during pregnancy on maternal, neonatal and child health ...

  12. Atopy, asthma, and lung function in relation to folate and vitamin B(12) in adults

    DEFF Research Database (Denmark)

    Thuesen, B H; Husemoen, L L N; Ovesen, L;

    2010-01-01

    Recent studies suggested low serum folate and impaired folate metabolism as potential risk factors for development of asthma and atopic disease, but the results are inconsistent. The aim of this study was to investigate the relations of markers of folate and vitamin B12 (B12) deficiency with...

  13. Relationship between vitamin B12 and sensory and motor peripheral nerve function in older adults.

    NARCIS (Netherlands)

    Leishear, K.; Boudreau, R.M.; Studenski, S.A.; Ferrucci, L.; Rosano, C.; Rekeneire, N. de; Houston, D.K.; Kritchevsky, S.B.; Schwartz, A.V.; Vinik, A.I.; Hogervorst, E.; Yaffe, K.; Harris, T.B.; Newman, A.B.; Strotmeyer, E.S.

    2012-01-01

    OBJECTIVES: To examine whether deficient B12 status or low serum B12 levels are associated with worse sensory and motor peripheral nerve function in older adults. DESIGN: Cross-sectional. SETTING: Health, Aging and Body Composition Study. PARTICIPANTS: Two thousand two hundred and eighty-seven adult

  14. Folate and vitamin B12 status in Latin America and the Caribbean: An update

    Science.gov (United States)

    Background: The current magnitude of folate and vitamin B12 deficiency in Latin America and the Caribbean is uncertain. Objective: To summarize data on plasma or serum vitamin B12 and folate concentrations in Latin America and the Caribbean reported since 1990, a period that covers the era before an...

  15. Oral Vitamin B12 Replacement for the Treatment of Pernicious Anemia.

    Science.gov (United States)

    Chan, Catherine Qiu Hua; Low, Lian Leng; Lee, Kheng Hock

    2016-01-01

    Many patients with pernicious anemia are treated with lifelong intramuscular (IM) vitamin B12 replacement. As early as the 1950s, there were studies suggesting that oral vitamin B12 replacement may provide adequate absorption. Nevertheless, oral vitamin B12 replacement in patients with pernicious anemia remains uncommon in clinical practice. The objective of this review is to provide an update on the effectiveness of oral vitamin B12 for the treatment of pernicious anemia, the recommended dosage, and the required frequency of laboratory test and clinical monitoring. Relevant articles were identified by PubMed search from January 1, 1980 to March 31, 2016 and through hand search of relevant reference articles. Two randomized controlled trials, three prospective papers, one systematic review, and three clinical reviews fulfilled our inclusion criteria. We found that oral vitamin B12 replacement at 1000 μg daily was adequate to replace vitamin B12 levels in patients with pernicious anemia. We conclude that oral vitamin B12 is an effective alternative to vitamin B12 IM injections. Patients should be offered this alternative after an informed discussion on the advantages and disadvantages of both treatment options. PMID:27602354

  16. Competitive chemiluminescent enzyme immunoassay for vitamin B12 analysis in human milk

    Science.gov (United States)

    BACKGROUND Few accurate data exist on the concentration of vitamin B12 in human milk. Binding of the vitamin to haptocorrin (HC) can interfere with the assay if not removed by pretreatment, and very low values can occur in women with poor B12 status. This study evaluated two competitive enzyme bind...

  17. Development of radiolabelled vitamin B12 and derivatives on oncology and tumor therapy

    International Nuclear Information System (INIS)

    Current study and clinical application of the radiolabelled Vitamin B12 and derivative are summarized. The biological activity of Vitamin B12 and the application of 111In, 10B, 99Tcm (Re) labelling derivatives on oncology and tumor therapy are mainly reviewed

  18. The complete coenzyme B12 biosynthesis gene cluster of Lactobacillus reuteri CRL 1098

    NARCIS (Netherlands)

    Santos, dos F.; Vera, J.L.; Heijden, van der R.; Valdez, G.F.; Vos, de W.M.; Sesma, F.; Hugenholtz, J.

    2008-01-01

    The coenzyme B12 production pathway in Lactobacillus reuteri has been deduced using a combination of genetic, biochemical and bioinformatics approaches. The coenzyme B12 gene cluster of Lb. reuteri CRL1098 has the unique feature of clustering together the cbi, cob and hem genes. It consists of 29 OR

  19. The complete coenzyme B12 biosynthesis gene cluster of Lactobacillus reuteri CRL1098

    NARCIS (Netherlands)

    F. Santos; J.L. Vera; R. van der Heijden; G. Valdez; W.M. de Vos; F. Sesma; J. Hugenholtz

    2008-01-01

    The coenzyme B12 production pathway in Lactobacillus reuteri has been deduced using a combination of genetic, biochemical and bioinformatics approaches. The coenzyme B12 gene cluster of Lb. reuteri CRL1098 has the unique feature of clustering together the cbi, cob and hem genes. It consists of 29 OR

  20. 17 CFR 270.8b-12 - Requirements as to paper, printing and language.

    Science.gov (United States)

    2010-04-01

    ..., printing and language. 270.8b-12 Section 270.8b-12 Commodity and Securities Exchanges SECURITIES AND... Requirements as to paper, printing and language. (a) Registration statements and reports shall be filed on good... and reports shall be in the English language. If any exhibit or other paper or document filed with...

  1. De diagnostiek van vitamine-B12-deficiëntie herzien

    NARCIS (Netherlands)

    Wiersinga, W J; de Rooij, S E J A; Huijmans, J G M; Fischer, C; Hoekstra, Joost B. L.

    2005-01-01

    Vitamin B12 (cobalamin) deficiency is a common disorder with potential irreversible haematological and neurological consequences. Currently used diagnostic tests such as the evaluation of serum vitamin B12 and the Schilling test are insufficient, e.g. the positive predictive value of a low serum vit

  2. Vitamin B12 in Obese Adolescents with Clinical Features of Insulin Resistance

    Directory of Open Access Journals (Sweden)

    Mandy Ho

    2014-12-01

    Full Text Available Emerging evidence indicates an association between obesity, metformin use and reduced vitamin B12 status, which can have serious hematologic, neurologic and psychiatric consequences. This study aimed to examine B12 status in obese adolescents with pre-diabetes and/or clinical features of insulin resistance. Serum B12 was measured using chemiluminescence immunoassay in 103 (43 male, 60 female obese (mean body mass index (BMI z-score ± SD (2.36 ± 0.29, adolescents aged 10 to 17 years, median (range insulin sensitivity index of 1.27 (0.27 to 3.38 and 13.6% had pre-diabetes. Low B12 (<148 pmol/L was identified in eight (7.8% and borderline status (148 to 221 pmol/L in an additional 25 (24.3% adolescents. Adolescents with borderline B12 concentrations had higher BMI z-scores compared to those with normal concentrations (2.50 ± 0.22 vs. 2.32 ± 0.30, p = 0.008 or those with low B12 concentration (2.50 ± 0.22 vs. 2.27 ± 0.226, p = 0.041. In conclusion, nearly a third of obese adolescents with clinical insulin resistance had a low or borderline serum B12 status. Therefore, further investigations are warranted to explore the cause and the impact of low B12 status in obese pediatric populations.

  3. 17 CFR 240.12b-12 - Requirements as to paper, printing and language.

    Science.gov (United States)

    2010-04-01

    ..., if the filing is an HTML document, as defined in Regulation S-T Rule 11 (17 CFR 232.11). (e) Where a..., printing and language. 240.12b-12 Section 240.12b-12 Commodity and Securities Exchanges SECURITIES AND... paper, printing and language. (a) Statements and reports shall be filed on good quality, unglazed...

  4. Inhibition of the vitamin B12 binding capacity of proteins by the hydrolysis product of cyclophosphamide

    International Nuclear Information System (INIS)

    The inhibitory effect of cyclophosphamide hydrolysis product (CPHP) on vitamin B12 binding ability to proteins has been established. The ester N-(2-chloroethyl)-N'-(3-phosphopropyl)-etheylenediamine hydrochloride is probably responsible, in vitro, for blocking the protein binding sites. Preincubation of proteins with vitamin B12 prevents the inhibitory effect of CPHP. (au)

  5. Vitamin B-12 and homocysteine status among vegetarians: a global perspective.

    Science.gov (United States)

    Elmadfa, Ibrahim; Singer, Ingrid

    2009-05-01

    Evidence exists that well-planned vegetarian diets provide numerous health benefits and are appropriate for all stages of the life cycle. It is also known that animal foods provide micronutrients that are nonexistent or available only in limited amounts in plant foods. Restriction or exclusion of all animal foods may therefore result in low intake of certain micronutrients such as vitamin B-12, thereby affecting vitamin B-12 status and elevating plasma homocysteine concentrations. Overall, the studies we reviewed showed reduced mean vitamin B-12 status and elevated mean homocysteine concentrations in vegetarians, particularly among vegans. Low vitamin B-12 intake may lead to decreased bioavailability and functional deficiency of cobalamin. Although early noticeable symptoms of vitamin B-12 deficiency are nonspecific (unusual fatigue, digestion problems, frequent upper respiratory infections), the best-known clinical manifestations of cobalamin malabsorption are hematologic (pernicious anemia) and neurologic symptoms. Hyperhomocysteinemia is associated with an increased risk of atherosclerosis and cardiovascular disease. Given these health concerns, vegetarians, particularly vegans, must be advised to carefully plan their diets, to monitor their plasma vitamin B-12 on a regular basis to facilitate early detection of low cobalamin status, and to use vitamin B-12-fortified foods or take vitamin B-12 supplements if necessary. PMID:19357223

  6. FRACTION OF TOTAL PLASMA VITAMIN B12 BOUND TO TRANSCOBALAMIN CORRELATES WITH COGNITIVE FUNCTION IN ELDERLY LATINOS WITH DEPRESSIVE SYMPTOMS

    Science.gov (United States)

    Background: The fraction of total plasma vitamin B12 bound to transcobalamin (holoTC/B12 ratio) may reflect tissue levels of the vitamin, but its clinical relevance is unclear. Methods: associations between cognitive function and total B12, holoTC, and holoTC/B12 ratio were assessed in a cohort of ...

  7. Vitamin B-12 treatment of asymptomatic, deficient, elderly Chileans improves conductivity in myelinated periphreal nerves, but high serum folate impairs vitamin B-12 status response assessed by the combined indicator of...

    Science.gov (United States)

    Since 2005 the National Feeding Program for the Elderly (PACAM) in Chile has provided a B12 fortified milk drink (1.7 µg B12/d) which is insufficient to ensure B12 adequacy in many individuals. The objective was to evaluate effects of adding 1 mg B12/d to PACAM vs 1 mg B12/d as a pill with PACAM on ...

  8. Genetic architecture of vitamin B12 and folate levels uncovered applying deeply sequenced large datasets

    DEFF Research Database (Denmark)

    Grarup, Niels; Sulem, Patrick; Sandholt, Camilla H;

    2013-01-01

    the underlying biology of human traits and diseases. Here, we used a large Icelandic whole genome sequence dataset combined with Danish exome sequence data to gain insight into the genetic architecture of serum levels of vitamin B12 (B12) and folate. Up to 22.9 million sequence variants were analyzed...... in combined samples of 45,576 and 37,341 individuals with serum B12 and folate measurements, respectively. We found six novel loci associating with serum B12 (CD320, TCN2, ABCD4, MMAA, MMACHC) or folate levels (FOLR3) and confirmed seven loci for these traits (TCN1, FUT6, FUT2, CUBN, CLYBL, MUT......, MTHFR). Conditional analyses established that four loci contain additional independent signals. Interestingly, 13 of the 18 identified variants were coding and 11 of the 13 target genes have known functions related to B12 and folate pathways. Contrary to epidemiological studies we did not find...

  9. 60岁后要补维生素B12

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    据统计,美国60岁以上的老年人当中,1/5缺乏维生素B12。因此,医学家建议:素食者和老年人尤其要注意多吃富含维生素B12的食物,以弥补膳食中维生素B12不足的缺陷。维生素B12对于维持缝康的神经经胞和红细胞非常关键。缺乏维生素B12轻则导致疲劳、眩晕.重则会引起神经损伤、贫血和痴呆。

  10. Novel method for bioproduction labelled vitamin B12 with cobalt-57

    International Nuclear Information System (INIS)

    In the first stage of project 'investigation for preparation and production of radio-kit vitamin B12 with med-grade', isolation and purification of solution containing vitamin B12 after fermentation by using different resins such as XAD-4, XAD7 was achieved. After extensive researches on Amberlite-XAD and eluation of the column by different solvents, the purified cyanocobalamin was prepared. The second stage of this research concerns with the bioproduction of radioactive form of vitamin B12 in which the nonradioactive cobalt atom present in the vitamin B12 molecule is replaced by a radioactive isotope of cobalt, usually cobalt-57 which is generated in 30 MeV p-Cyclotron. Such radioactive form of vitamin is used extensively in the diagnosis of vitamin B12 deficiency states in nuclear medicine

  11. Subhyaloid haemorrhage in a patient with vitamin B12 deficiency: a unique presentation

    Directory of Open Access Journals (Sweden)

    Z.A. Wadood Khan

    2013-07-01

    Full Text Available Vitamin B12 deficiency causes pancytopenia and also is also assocciated with platelet dysfunction. We report the case of a 17-year-old girl, who presented with fatigue and sudden painless, non-progressive loss of vision in the left eye. An ophthalmologic evaluation revealed bilateral subhyaloid haemorrhage, with macular involvement on the left eye. Earlier Bone marrow aspiration and biopsy were suggestive of partially treated vitamin B12 deficiency with pancytopenia. The patient had received four doses of vitamin B12 injections. She was given a complete course of vitamin B12 injections. Both the pancytopenia and subhyaloid haemorrhage improved completely with restoration of normal vision. This case documents the rare occurrence of subhyaloid haemorrhage in vitamin B12 deficiency.

  12. Genetic Variation in Vitamin B-12 Content of Bovine Milk and Its Association with SNP along the Bovine Genome

    OpenAIRE

    Rutten, Marc J. M.; Bouwman, Aniek C; R Corinne Sprong; van Arendonk, Johan A M; Visker, Marleen H. P. W.

    2013-01-01

    Vitamin B-12 (also called cobalamin) is essential for human health and current intake levels of vitamin B-12 are considered to be too low. Natural enrichment of the vitamin B-12 content in milk, an important dietary source of vitamin B-12, may help to increase vitamin B-12 intake. Natural enrichment of the milk vitamin B-12 content could be achieved through genetic selection, provided there is genetic variation between cows with respect to the vitamin B-12 content in their milk. A substantial...

  13. Efficacy and safety of fortification and supplementation with vitamin B12: biochemical and physiological effects.

    Science.gov (United States)

    Carmel, Ralph

    2008-06-01

    Long known as an uncommon but serious medical disorder requiring medical management, vitamin B12 deficiency is now seen to be common worldwide, but it is in a quite different form than traditionally envisioned. Most of the newly recognized deficiency is subclinical in nature, its health impact and natural history are uncertain, and its prevalence has been greatly inflated by also including persons with "low-normal" vitamin B12 levels, few of whom are deficient. The spread of folic acid fortification has also introduced concerns about folate's potentially adverse neurologic consequences in persons with undetected vitamin B12 deficiency. Fortification with vitamin B12 may prove more complicated than fortification with folic acid, however, because the bioavailability of vitamin B12 is limited. Bioavailability for those who need the vitamin B12 the most is especially poor, because they often have malabsorption affecting either classical intrinsic factor-mediated absorption or food-vitamin B12 absorption. Moreover, new evidence shows that many elderly persons respond poorly to daily oral doses under 500 microg (1 microg = 0.74 nmol), even if they do not have classical malabsorption, which suggests that proposed fortification with 1 to 10 microg may be ineffective. Those least in need of vitamin B12 usually have normal absorption and are thus at greatest risk for whatever unknown adverse effects of high-dose fortification might emerge, such as the effects of excess accumulation of cyanocobalamin. Studies are needed to define the still unproven health benefits of vitamin B12 fortification, the optimal levels of fortification, the stability of such fortification, interactions with other nutrients, and any possible adverse effects on healthy persons. The answers will permit formulation of appropriately informed decisions about mandatory fortification or (because fortification may prove a poor choice) about targeted supplementation in subpopulations with special needs for

  14. The Folate-Vitamin B12 Interaction, Low Hemoglobin, and the Mortality Risk from Alzheimer's Disease.

    Science.gov (United States)

    Min, Jin-Young; Min, Kyoung-Bok

    2016-03-21

    Abnormal hemoglobin levels are a risk factor for Alzheimer's disease (AD). Although the mechanism underlying these associations is elusive, inadequate micronutrients, particularly folate and vitamin B12, may increase the risk for anemia, cognitive impairment, and AD. In this study, we investigated whether the nutritional status of folate and vitamin B12 is involved in the association between low hemoglobin levels and the risk of AD mortality. Data were obtained from the 1999-2006 National Health and Nutrition Examination Survey (NHANES) and the NHANES (1999-2006) Linked Mortality File. A total of 4,688 participants aged ≥60 years with available baseline data were included in this study. We categorized three groups based on the quartiles of folate and vitamin B12 as follows: Group I (low folate and vitamin B12); Group II (high folate and low vitamin B12 or low folate and high vitamin B12); and Group III (high folate and vitamin B12). Of 4,688 participants, 49 subjects died due to AD. After adjusting for age, sex, ethnicity, education, smoking history, body mass index, the presence of diabetes or hypertension, and dietary intake of iron, significant increases in the AD mortality were observed in Quartile1 for hemoglobin (HR: 8.4, 95% CI: 1.4-50.8), and the overall risk of AD mortality was significantly reduced with increases in the quartile of hemoglobin (p for trend = 0.0200), in subjects with low levels of both folate and vitamin B12 at baseline. This association did not exist in subjects with at least one high level of folate and vitamin B12. Our finding shows the relationship between folate and vitamin B12 levels with respect to the association between hemoglobin levels and AD mortality. PMID:27003215

  15. Vitamin B12 deficiency in Caenorhabditis elegans results in loss of fertility, extended life cycle, and reduced lifespan ☆

    OpenAIRE

    Bito, Tomohiro; Matsunaga, Yohei; Yabuta, Yukinori; Kawano, Tsuyoshi; Watanabe, Fumio

    2013-01-01

    Vitamin B12 (B12) deficiency has been linked to developmental disorders, metabolic abnormalities, and neuropathy; however, the mechanisms involved remain poorly understood. Caenorhabditis elegans grown under B12-deficient conditions for five generations develop severe B12 deficiency associated with various phenotypes that include decreased egg-laying capacity (infertility), prolonged life cycle (growth retardation), and reduced lifespan. These phenotypes resemble the consequences of B12 defic...

  16. Enhanced Peptide Stability Against Protease Digestion Induced by Intrinsic Factor Binding of a Vitamin B12 Conjugate of Exendin-4

    OpenAIRE

    Bonaccorso, Ron L.; Chepurny, Oleg G.; Becker-Pauly, Christoph; HOLZ, GEORGE G.; Doyle, Robert P.

    2015-01-01

    Peptide digestion from proteases is a significant limitation in peptide therapeutic development. It has been hypothesized that the dietary pathway of vitamin B12 (B12) may be exploited in this area, but an open question is whether B12-peptide conjugates bound to the B12 gastric uptake protein intrinsic factor (IF) can provide any stability against proteases. Herein, we describe a new conjugate of B12 with the incretin peptide exendin 4 that demonstrates picomolar agonism of the glugacon-like ...

  17. Mielopatia por deficiência de vitamina B12 apresentando-se como mielite transversa Myelopathy due to vitamin B12 deficiency presenting as transverse myelitis

    Directory of Open Access Journals (Sweden)

    Luiz Felipe Rocha Vasconcellos

    2002-03-01

    Full Text Available As manifestações neurológicas associadas à deficiência de vitamina B12 incluem polineuropatia, mielopatia, demência e neuropatia óptica. O diagnóstico laboratorial é feito através da dosagem sérica de cianocobalamina ou homocisteína e da excreção urinária de ácido metilmalônico. No estudo anatomopatológico observa-se na microscopia a destruição da mielina e de axônios vistos na substância branca. A região mais comumente afetada é o cordão posterior cervical e/ou torácico. O acometimento da coluna lateral é raro, ocorrendo em casos graves e avançados. O tratamento consiste na reposição de vitamina B12 e a resposta depende da gravidade do quadro e do tempo transcorrido entre o inicio dos sintomas e inicio do tratamento. Relatamos o caso de um paciente que apresentou, como manifestação de deficiência de vitamina B12, mielite transversa. O estudo morfológico da medula demonstrou comprometimento dos tractos cortico-espinhais lateral e anterior, da coluna dorsal e ainda do tracto espino-talâmico.Vitamin B12 deficiency may induce neuropathy, myelopathy, dementia and optic neuropathy. The diagnosis is established by vitamin B12, homocysteine and methylmalonic acid measurements. Myelin and axon destruction in the white matter of the spinal cord are observed. The posterior column of the cervical and thoracic level is the most common involved area. The involvement of the anterior column is restricted to advanced and relatively severe cases. Treatment is based on vitamin B12 injections, and the prognosis depends on the stage of vitamin deficiency and deterioration at treatment onset. We report a case with transverse myelitis due to vitamin B12 deficiency. This picture is relatively uncommon, however, we believe patients with transverse myelitis should have vitamin B12 studies as part of the diagnosis work up.

  18. Intestinal synthesis and absorption of vitamin B-12 in channel catfish

    International Nuclear Information System (INIS)

    A feeding experiment conducted in a controlled environment and using a vitamin B12-deficient, but otherwise nutritionally complete, purified diet revealed that intestinal microorganisms in channel catfish synthesized approximately 1.4 ng of vitamin B12 per gram of bodyweight per day. Removal of cobalt from the diet or supplementation with an antibiotic (succinylsulfathiazole) significantly reduced the rate of intestinal synthesis and liver stores of vitamin B12. Radiolabeled vitamin B12 in the blood, liver, kidneys, and spleen of fish fed 60Co in the diet indicated that the intestinally synthesized vitamin was absorbed by the fish. The primary route of absorption was directly from the digestive tract into the blood because coprophagy was prevented in the rearing aquariums and the amount of vitamin B12 dissolved in the aquarium water was too low for gill absorption. Dietary supplementation of vitamin B12 was not necessary for normal growth and erythrocyte formation in channel catfish in a 24-week feeding period. A longer period, however, may have caused a vitamin deficiency since liver-stored vitamin B 12 decreased between the 2nd and 24th weeks

  19. Possible undercompensation effect in the Kondo insulator (Yb,Tm)B12

    Science.gov (United States)

    Alekseev, P. A.; Nemkovski, K. S.; Mignot, J.-M.; Clementyev, E. S.; Ivanov, A. S.; Rols, S.; Bewley, R. I.; Filipov, V. B.; Shitsevalova, N. Yu.

    2014-03-01

    The effects of Tm substitution on the dynamical magnetic response of Yb1-xTmxB12 (x=0, 0.08, 0.15, and 0.75) and Lu0.92Tm0.08B12 compounds have been studied using time-of-flight inelastic neutron scattering. Major changes were observed in the spectral structure and temperature evolution of the Yb contribution to the inelastic response for a rather low content of magnetic Tm ions. A sizable influence of the RB12 host (YbB12, as compared to LuB12 or pure TmB12) on the crystal-field splitting of the Tm3+ ion is also reported. The results point to a specific effect of impurities carrying a magnetic moment (Tm, as compared to Lu or Zr) in a Kondo insulator, which is thought to reflect the "undercompensation" of Yb magnetic moments, originally Kondo screened in pure YbB12. A parallel is made with the strong effect of Tm substitution on the temperature dependence of the Seebeck coefficient in Yb1-xTmxB12, which was reported previously.

  20. High vitamin B12 level and good treatment outcome may be associated in major depressive disorder

    Directory of Open Access Journals (Sweden)

    Tanskanen Antti

    2003-12-01

    Full Text Available Abstract Background Despite of an increasing body of research the associations between vitamin B12 and folate levels and the treatment outcome in depressive disorders are still unsolved. We therefore conducted this naturalistic prospective follow-up study. Our aim was to determine whether there were any associations between the vitamin B12 and folate level and the six-month treatment outcome in patients with major depressive disorder. Because vitamin B12 and folate deficiency may result in changes in haematological indices, including mean corpuscular volume, red blood cell count and hematocrit, we also examined whether these indices were associated with the treatment outcome. Methods Haematological indices, erythrocyte folate and serum vitamin B12 levels were determined in 115 outpatients with DSM-III-R major depressive disorder at baseline and serum vitamin B12 level again on six-month follow-up. The 17-item Hamilton Depression Rating Scale was also compiled, respectively. In the statistical analysis we used chi-squared test, Pearson's correlation coefficient, the Student's t-test, analysis of variance (ANOVA, and univariate and multivariate linear regression analysis. Results Higher vitamin B12 levels significantly associated with a better outcome. The association between the folate level and treatment outcome was weak and probably not independent. No relationship was found between haematological indices and the six-month outcome. Conclusion The vitamin B12 level and the probability of recovery from major depression may be positively associated. Nevertheless, further studies are suggested to confirm this finding.

  1. Voltammetry of Vitamin B12 on a thin self-assembled monolayer modified electrode

    International Nuclear Information System (INIS)

    Vitamin B12 showed three reduction waves at a thin self-assembled monolayer of mercaptoacetic acid modified gold electrode at 0.21, 0.16, -0.41 V in a 0.01 mol l-1 HCl solution at a scan rate of 100 mV s-1. The overall electrode reaction followed an ECE mechanism, leading to a total two-electron exchange. The predominant Co(III) form was reduced directly at 0.21 V by a one-electron transfer accomplished by CN- cleavage into the cyanocob(II)alamin. The latter species then equilibrated with the base-off B12r, which was immediately reduced into B12s at 0.16 V. The wave at -0.41 V might be a catalytic hydrogen wave. The cathodic peak currents at 0.21 V were controlled by the diffusion of Vitamin B12. On the base of its diffusion behavior, the semi-derivate voltammetric method for the detection of Vitamin B12 was presented. The semi-derivate voltammetric peak current of the wave at 0.21 V was linear with the content of Vitamin B12 in the range of 4.0 x 10-9 to 4.0 x 10-5 mol l-1. The detection limit was 1.0 x 10-9 mol l-1. The proposed method was applied successfully to determine the content of Vitamin B12 in pharmaceutical preparations

  2. Measurement of FA and VitB12 in serum by TRFIA and its clinical application

    International Nuclear Information System (INIS)

    To investigate the correlation between diseases and the quantity of folic acid(FA) and vitamine B12 (VitB12) in serum, the quantity of FA and VitB12 in serum was measured by TR- FIA. The results showed that the levels of FA and VitB12 in 68 controlled subjects were 20.13±5.72 nmol/L and 240.45±58.23 pmol/L respectively. The levels of FA and VitB12 in 6 patients with megaloblastic anemia, 26 with medium-terminal gestation femineity, 7 with liver cirrhosis, 10 with gastric ulcerand 31 with cerebral infarction were significant lower than those in the control group. The level of FA in 24 with malignant hematopathy and 57 with malignant tumor was significantly lower but VitB12 between the 31 patients with iron deficiency anemia and 12 with CAA and the control group. The amount of the FA in 9 patients with chronic atrophic gastritis and 42 blood donors were lower than that in the control. The determination of FA and VitB12 levels may be quite significant in the diagnosis, therapy and prognosis of diseases. Laboratories should establish the reference values which fit the locals specifically. (authors)

  3. [Vitamin B12, folic acid and mental function in the elderly].

    Science.gov (United States)

    Meertens, Lesbia; Solano, Liseti

    2005-03-01

    Elderly people is a vulnerable population group to specific nutrient deficiencies as vitamin B12 and folic acid, which are closely related to mental functions deterioration, especially of cognitive functions. This study was aimed to measure B12 vitamin and folic acid indicators and to establish relationships to mental function. 53 elderly, older than 60 years, living in a geriatric home were assessed. The dietary intake was evaluated by the direct weighed method, serum B12 vitamin and folic acid by radioimmunoanalysis and mental function by Foltein's mini-mental test. Dietary intake for Vit B12 was adequate and deficient for folic acid while serum levels were within normal range. Vitamin B12 levels were at marginal or deficiency values in 26,4% of the elderly and folic acid deficiency was present in 43.4%. 49% of the elderly had mental function alterations and B12 vitamin levels were significantly lower in this group. A positive association between age and mental function (elderly below 80 years had lower risk of mental impairment) and between serum B12 and mental function were found. Elderly were at risk of deficiency for both vitamins and age and mental function were associated to this risk. Further evaluation including other nutrients should be performed. PMID:15782537

  4. Neurology of Nutritional Vitamin B12 Deficiency in Infants: Case Series From India and Literature Review.

    Science.gov (United States)

    Goraya, Jatinder Singh; Kaur, Sukhjot; Mehra, Bharat

    2015-11-01

    We studied 27 infants aged 6 to 27 months with vitamin B12 deficiency also known as "infantile tremor syndrome" in India. All were exclusively breast-fed by vegetarian mothers. Developmental delay or regression, pallor, skin hyperpigmentation, and sparse brown hair were present in all. Majority were hypotonic and involuntary movements were encountered in 18. Anemia and macrocytosis was found in 83% and 71% infants, respectively. Low serum vitamin B12 was present in 12 of 21 infants. Seven of the 9 infants with normal serum vitamin B12 had received vitamin B12 before referral. Twelve mothers had low serum vitamin B12. Cerebral atrophy was present in all the 9 infants who underwent neuroimaging. Treatment with vitamin B12 resulted in dramatic improvement in general activity and appetite within 48 to 72 hours followed by return of lost milestones. Tremors resolved in all by 3 to 4 weeks. Nutritional vitamin B12 deficiency is a treatable cause of neurologic dysfunction in infants. PMID:25953825

  5. Is vitamin B12 deficiency a risk factor for cardiovascular disease in vegetarians?

    Science.gov (United States)

    Pawlak, Roman

    2015-06-01

    The goal of this paper is to describe the role of vitamin B12 deficiency in cardiovascular disease development among vegetarians. Vegetarians have a high prevalence of vitamin B12 deficiency. Deficiency of this vitamin is associated with a variety of atherogenic processes that are mainly, but not exclusively, due to vitamin B12 deficiency-induced hyperhomocysteinemia. Each 5-μmol/L increase above 10 μmol/L of serum homocysteine is associated with a 20% increased risk of circulatory health problems. Mean homocysteine concentration >10 μmol/L among vegetarians was reported in 32 of 34 reports. Macrocytosis associated with vitamin B12 deficiency is also associated with fatal and non-fatal coronary disease, myocardial infarction, stroke, and other circulatory health problems. Compared with non-vegetarians, vegetarians have an improved profile of the traditional cardiovascular disease risk factors, including serum lipids, blood pressure, serum glucose concentration, and weight status. However, not all studies that assessed cardiovascular disease incidence among vegetarians reported a protective effect. Among studies that did show a lower prevalence of circulatory health problems, the effect was not as pronounced as expected, which may be a result of poor vitamin B12 status due to a vegetarian diet. Vitamin B12 deficiency may negate the cardiovascular disease prevention benefits of vegetarian diets. In order to further reduce the risk of cardiovascular disease, vegetarians should be advised to use vitamin B12 supplements. PMID:25998928

  6. Fisiopatologia da deficiência de vitamina B12 e seu diagnóstico laboratorial Physiopathology of vitamin B12 deficiency and its laboratorial diagnosis

    Directory of Open Access Journals (Sweden)

    Clóvis Paniz

    2005-10-01

    Full Text Available INTRODUÇÃO: A vitamina B12 é hidrossolúvel, não-sintetizada pelo organismo humano, presente em alimentos de origem animal. Sua deficiência é muito freqüente entre idosos, vegetarianos e indivíduos que adotam baixa dieta protéica ou apresentam problemas de absorção gastrintestinal. FISIOPATOLOGIA: A deficiência de vitamina B12 leva a transtornos hematológicos, neurológicos e cardiovasculares, principalmente, por interferir no metabolismo da homocisteína (Hcy e nas reações de metilação do organismo. Muitas vezes a deficiência pode permanecer assintomática por longos períodos, desencadeando uma deficiência crônica que, se mantida, pode levar a manifestações neurológicas irreversíveis. METODOLOGIAS: Metodologias eficientes que permitam um diagnóstico precoce são imprescindíveis. Porém um método considerado padrão-ouro ainda não é consensual. A dosagem sérica de vitamina B12 sofre algumas restrições pelos problemas de sensibilidade e especificidade, podendo ocorrer sintomas de deficiência mesmo com vitamina B12 sérica dentro dos níveis normais ou, de outro modo, ocorrendo baixos níveis de vitamina B12 sérica sem, contudo, apresentar baixos níveis da fração de vitamina realmente disponível para as células e sem apresentar sintomatologia. Novas alternativas vêm surgindo, como a dosagem de transcobalamina II (Tc II, a única fração de vitamina B12 disponível para as células, ou a dosagem de ácido metilmalônico (MMA e Hcy, metabólitos que aumentam quando ocorre diminuição de vitamina B12 intracelular. Estes testes apresentam algumas vantagens, mas também limitações importantes para uso rotineiro. CONCLUSÃO: Em casos subclínicos, um diagnóstico correto e precoce representa ainda um desafio, e futuros estudos são necessários para definir um método padrão para diagnóstico laboratorial da deficiência de vitamina B12.INTRODUCTION: The vitamin B12 is a water soluble vitamin, not

  7. Therapeutic role of Vitamin B12 in patients of chronic tinnitus: A pilot study

    Directory of Open Access Journals (Sweden)

    Charu Singh

    2016-01-01

    Full Text Available True tinnitus is a phantom auditory perception arising from a source or trigger in the cochlea, brainstem, or at higher centers and has no detectable acoustic generator. The most accepted is the famous neurophysiologic model of Jastreboff, which stresses that tinnitus, is a subcortical perception and results from the processing of weak neural activity in the periphery. The aim of this study is to determine the role of Vitamin B12 in treatment of chronic tinnitus. In this randomized, double-blind pilot study, total 40 patients were enrolled, of which 20 in Group A (cases received intramuscular therapy of 1 ml Vitamin B12 (2500 mcg weekly for a period of 6 weeks and Group B (20 patients received placebo isotonic saline 01 ml intramuscular. The patients were subjected to Vitamin B12 assay and audiometry pre- and post-therapy. Of the total patients of tinnitus, 17 were Vitamin B12 deficient that is 42.5% showed deficiency when the normal levels were considered to be 250 pg/ml. A paired t-test showed that in Group A, patients with Vitamin B12 deficiency showed significant improvement in mean tinnitus severity index score and visual analog scale (VAS after Vitamin B12 therapy. This pilot study highlights the significant prevalence of Vitamin B12 deficiency in North Indian population and improvement in tinnitus severity scores and VAS in cobalamin-deficient patients receiving intramuscular Vitamin B12 weekly for 6 weeks further provides a link between cobalamin deficiency and tinnitus thereby suggestive of a therapeutic role of B12 in cobalamin-deficient patients of tinnitus.

  8. Therapeutic role of Vitamin B12 in patients of chronic tinnitus: A pilot study.

    Science.gov (United States)

    Singh, Charu; Kawatra, Rahul; Gupta, Jaya; Awasthi, Vishnu; Dungana, Homnath

    2016-01-01

    True tinnitus is a phantom auditory perception arising from a source or trigger in the cochlea, brainstem, or at higher centers and has no detectable acoustic generator. The most accepted is the famous neurophysiologic model of Jastreboff, which stresses that tinnitus, is a subcortical perception and results from the processing of weak neural activity in the periphery. The aim of this study is to determine the role of Vitamin B12 in treatment of chronic tinnitus. In this randomized, double-blind pilot study, total 40 patients were enrolled, of which 20 in Group A (cases) received intramuscular therapy of 1 ml Vitamin B12 (2500 mcg) weekly for a period of 6 weeks and Group B (20) patients received placebo isotonic saline 01 ml intramuscular. The patients were subjected to Vitamin B12 assay and audiometry pre- and post-therapy. Of the total patients of tinnitus, 17 were Vitamin B12 deficient that is 42.5% showed deficiency when the normal levels were considered to be 250 pg/ml. A paired t-test showed that in Group A, patients with Vitamin B12 deficiency showed significant improvement in mean tinnitus severity index score and visual analog scale (VAS) after Vitamin B12 therapy. This pilot study highlights the significant prevalence of Vitamin B12 deficiency in North Indian population and improvement in tinnitus severity scores and VAS in cobalamin-deficient patients receiving intramuscular Vitamin B12 weekly for 6 weeks further provides a link between cobalamin deficiency and tinnitus thereby suggestive of a therapeutic role of B12 in cobalamin-deficient patients of tinnitus. PMID:26960786

  9. 食品中维生素B12的测定

    Institute of Scientific and Technical Information of China (English)

    姜淑云; 徐兰

    2004-01-01

    维生素B12——氰钴胺,是人体必需的微量营养成分之一,可助人体对铁的代谢及对血红蛋白的合成具有重要的生理功能和临床意义。还有些专业人士认为维生素B12可以防止心血管疾病和白癜风疾病的发生。研究维生素B12检测方法,可用于检

  10. Revisiting Metformin: Annual Vitamin B12 Supplementation may become Mandatory with Long-Term Metformin Use

    OpenAIRE

    Mahajan, R; Gupta, K.

    2010-01-01

    Monitoring of adverse drug reactions of a drug is a continuous process and runs through-out the life of a drug. Many rare adverse effects of a drug are documented after years of use; when a single case (signal generation) is reported leading subsequently to reporting of more cases. Deficiency of Vitamin B12 (vit B12) is a known sequel of prolonged metformin therapy. It was recommended to have annual measurement of serum vit B12 levels in patients on long term metformin therapy way back in 197...

  11. DETECTION OF VITAMIN B12 IN DIFFERENT COW MILK USING ELISA TECHNIQUE

    OpenAIRE

    TERZİ, Göknur; KAMBER, Ufuk; NİSBET, Cevat; ÇENESİZ, Sena

    2012-01-01

    ABSTRACT Vitamin B12 is a member of the vitamin B complex. It contains cobalt, and is also known as cobalamin. It is exclusively synthesised by bacteria and is found primarily in fish, meat, poultry, eggs, milk and milk products. Vitamin B12 deficiency have an underlying stomach or intestinal disorder that limits the absorption of vitamin B12 and might be caused to megaloblastic anemia. In this study cow milk samples were collected from in two different region in Turkey. In milk samples the a...

  12. Vitamin B12 Deficiency in Persons with Intellectual Disability in a Vegetarian Residential Care Community

    OpenAIRE

    Mohammed Morad; Mark Gringols; Isack Kandel; Joav Merrick

    2005-01-01

    The goal of this study was to determine the prevalence of vitamin B12 deficiency among intellectually disabled persons in a vegetarian remedial community in Israel. In this community, 47 individuals with intellectual disability (ID) live in 7 enlarged families in a kibbutz style agricultural setting. These 47 individuals and 17 of their caregivers were screened for vitamin B12 deficiency. There were 25.5% of the disabled vs. 11.8% of the caregivers found to have levels of vitamin B12 lower th...

  13. Neonatal Hyperbilirubinemia in a Turkish Cohort: Association of Vitamin B12

    OpenAIRE

    Eroglu, Nilgun; Kandur, Yasar; Kalay, Salih; Kalay, Zuhal; Guney, Ozgur

    2015-01-01

    Background Deficiency of vitamin B12 (VitB12) causes failure of erytrocyte maturation leading to cell lysis. Red blood cell lysis causes excess heme production that ends with hyperbilirubinemia. In this study, we aimed to evaluate the role of VitB12 in neonatal hyperbilirubinemia (NNH) with prolonged jaundice and to compare patients with control group who did not develop hyperbilirubinemia. Methods A total of 20 patients (M/F = 13/7) with jaundice and 20 healthy controls (M/F = 11/9) were inc...

  14. Svaer vitamin B12-mangel hos spaedbørn brysternaeret af veganere

    DEFF Research Database (Denmark)

    Roed, Casper; Skovby, Flemming; Lund, Allan Meldgaard

    2009-01-01

    Weight loss and reduction of motor skills resulted in paediatric evaluation of a 10-month-old girl and a 12-month-old boy. Both children suffered form anaemia and delayed development due to vitamin B12 deficiency caused by strict maternal vegan diet during pregnancy and nursing. Therapy with...... cyanocobalamin was instituted with remission of symptoms. Since infants risk irreversible neurologic damage following severe vitamin B12 deficiency, early diagnosis and treatment are mandatory. Vegan and vegetarian women should take vitamin B12 supplementation during the pregnancy and nursing period...

  15. Hyperhomocysteinaemia And Vitamin B12 Deficiency In Ischaemic Strokes In India

    OpenAIRE

    Wadia R S; Edul N C; Bhagat S; Bandishti S; Kulkarni R; Sontakke S; Barhadi S; Shah M

    2004-01-01

    Hyperhomocysteinemia is a recognised risk factor for stroke and ischemic heart disease (HID). Vit B12 Folate and pyridoxine deficiency are important causes of raised serum homocysteine. As a vegetarian diet is very poor in Vit B12 we sought to study the incidence of hyperhomocysteinaemia in our stroke populating and to measure Vit B12 and folate in these cases. Consecutive cases of ischaemic stroke, either arterial or venous, admitted over a period of 2 1/2 years were studied. Embolic strokes...

  16. Towards the synthesis of light-stable coenzyme B12 analogs

    OpenAIRE

    S. Gallo; E. Freisinger; Sigel, R. K. O.

    2007-01-01

    The organometallic complex coenzyme B12 (adenosyl cobalamin, AdoCbl) is not only an essential coenzyme in many biochemical reactions of most if not all living organisms but has lately been shown to play a crucial role in the regulation of B12 related genes. As a consequence, coenzyme B12 has been a target of intense research. However, the investigations of AdoCbl have often been hampered due to its high light-sensitivity leading to decomposition of the compound within a few seconds. Here, we ...

  17. A pediatric patient with recurrent pseudotumor cerebri and vitamin B12 deficiency.

    Science.gov (United States)

    Yetgin, Sevgi; Derman, Orhan; Dogan, Muhsin

    2006-01-01

    Pseudotumor cerebri is a syndrome of increased intracranial pressure, normal cerebrospinal fluid values, and a normal cerebral ventricles on brain imaging studies. A patient with a diagnosis of pseudotumor cerebri was admitted to the authors' hospital twice within a 2.5-year interval and treated with vitamin B12 (vit-B12). At the second admission she also presented with a cerebral venous thrombosis that might have been explained by vit-B12 deficiency, homocysteinemia, and an increased level of lipoprotein-a. PMID:16326411

  18. Link between vitamin B12, type 2 diabetes mellitus, and bone mineral density in elderly patients

    OpenAIRE

    Moatassem S. Amer, MD; Randa Ali-Labib, MD; Tamer M. Farid, MD; Doha Rasheedy, MD; Mohammad F. Tolba, MSc

    2015-01-01

    Background/Purpose: There have been many conflicting reports on the effects of type 2 diabetes mellitus (DM) and the level of vitamin B12 on bone mineral density (BMD) in elderly patients. Moreover, conflicting data exists regarding the prevalence of vitamin B12 deficiency among elderly diabetics. The aim of this study was to investigate the link between vitamin B12 levels, type 2 DM, and BMD in elderly patients. Methods: A case–control study was conducted on 61 participants, ≥60 years of ...

  19. TD-DFT Insight into Photodissociation of Co-C Bond in Coenzyme B12

    OpenAIRE

    PawelMichalKozlowski; PiotrLodowski

    2014-01-01

    Coenzyme B12 (AdoCbl) is one of the most biologically active forms of vitamin B12, and continues to be a topic of active research interest. The mechanism of Co-C bond cleavage in AdoCbl, and the corresponding enzymatic reactions are however, not well understood at the molecular level. In this work, time-dependent density functional theory (TD-DFT) has been applied to investigate the photodissociation of coenzyme B12. To reduce computational cost, while retaining the major spectroscopic featu...

  20. Intrinsic factor van castle en resorptie van vitamine B12 : een klinisch en experimenteel onderzoek met behulp van radioaktieve vitamine B12.

    NARCIS (Netherlands)

    Abels, Johannes

    1959-01-01

    Hoofdstuk I bevat enkele opmerkingen over de werking van vit.B12 met radioactieve kobalt isolopen. Bij toediening aan de mens geven wij voorkeur aan Co56 en Co58 op grond van hun relatief korte haveringstijden t.o.v. Co60. De vier gangbare metoden voor het meten van de resorptie van radioaktieve vit

  1. Bread cofortified with folic acid and vitamin B-12 improves the folate and vitamin B-12 status of healthy older people: a randomized controlled trial

    NARCIS (Netherlands)

    Winkels, R.M.; Brouwer, I.A.; Clarke, R.; Katan, M.B.; Verhoef, P.

    2008-01-01

    Background: Mandatory fortification of flour with folic acid has reduced the number of neural tube defects in North America. Concerns that high intakes of folic acid might mask vitamin B-12 deficiency in older persons have delayed the introduction of fortification in many European countries. Coforti

  2. Carbon Sequestration in Agricultural Soils

    OpenAIRE

    World Bank

    2009-01-01

    The purpose of this report is to improve the knowledge base for facilitating investments in land management technologies that sequester soil organic carbon. While there are many studies on soil carbon sequestration, there is no single unifying volume that synthesizes knowledge on the impact of different land management practices on soil carbon sequestration rates across the world. A meta-a...

  3. Combined indicator of vitamin B 12 status: modification for missing biomarkers and folate status and recommendations for revised cut-points

    Science.gov (United States)

    Background: A novel approach to determine vitamin B 12 status is to combine four blood markers: total B 12 (B 12 ), holotranscobalamin (holoTC), methylmalonic acid (MMA) and total homocysteine (tHcy). This combined indicator of B 12 status is expressed as cB 12 = log 10 [(holoTC · B 12 )/ (MMA · Hcy...

  4. Combined indicator of vitamin B12 status: modification for missing biomarkers and folate status, and recommendations for revised cut-points

    Science.gov (United States)

    Background: We propose a novel approach to diagnose B12 status by combining four blood markers: total B12 (B12), holo-transcobalamin (holoTC), methylmalonic acid (MMA) and total homocysteine (tHcy). Combined B12 status is expressed as cB12=log10[(holoTC•B12)/(MMA•Hcy)]–(reference, age function). Her...

  5. Masking of vitamin B12 deficiency associated neuropathy by folic acid

    NARCIS (Netherlands)

    van Amsterdam JGC; Opperhuizen A; Jansen EHJM; TOX

    2005-01-01

    Het Ministerie van VWS overweegt om bepaalde voedselbestanddelen te verrijken met foliumzuur. Foliumzuurverrijking houdt echter een gezondheidsrisico in, omdat het vitamine B12 deficientie maskeert, waardoor het de incidentie van megaloblastische anemie en perifere neuropathie kan verhogen. Dit ra

  6. 辅酶B12及其模型化合物

    Institute of Scientific and Technical Information of China (English)

    陈慧兰

    1989-01-01

    辅酶B12,即5’-脱氧腺苷钴胺素,是一个天然存在的有机金属化合物。它与维生素B12,即氰钴胺素组成和结构相似,但生理功能不同,维生素B12是一种抗恶性贫血的药物,而辅酶B12在生物体内多种代谢过程中起着重要作用,其中研究得最多的是与分子内重排有关的酶反

  7. 维生素B12的保健作用

    Institute of Scientific and Technical Information of China (English)

    王华

    2012-01-01

    一、维生素B12的生理功能1提高叶酸利用率维生素B12与叶酸一起合成甲硫氨酸(由高半胱氨酸合成)和胆碱,在产生嘌呤和嘧啶的过程中合成甲基钴胺和辅酶B12,参与许多重要化合物的甲基化过程.维生素B12缺乏时,使叶酸变成不能利用的形式,导致叶酸缺乏症.

  8. 素食者及老人应补充维生素B12

    Institute of Scientific and Technical Information of China (English)

    马因

    2005-01-01

    维生素B12对维持健康的神经细胞和血红细胞至关重要,缺乏维生素B12会导致很多疾病,轻者出现疲劳和轻微头晕,重则神经受损、贫血和痴呆。目前维生素B12缺乏现象比医生认为的更普遍,而那些最容易缺乏维生素B12的人群是素食者及老人们。

  9. 维生素B12与老年痴呆

    Institute of Scientific and Technical Information of China (English)

    严段梅(译)

    2006-01-01

    美国营养学掌调查了马萨诸塞州一家族的后裔,从26岁到83岁的男女共5000人的难生素B12血浆冰平。结果表明,39%的人体内B12水平居于正常偏低,近25%的人维生素B12水平处于不足状态。研究者认为,在一般人中还有很多维生素B12缺乏的患者未被发现。

  10. 维生素B12与二甲双胍

    Institute of Scientific and Technical Information of China (English)

    汪经平

    2010-01-01

    @@ 二甲双胍是治疗2型糖尿病最常用的一线药物.根据新英格兰杂志的最新研究:2型糖尿病患者长期使用二甲双胍会增加维生素B12缺乏的风险,换句话说,维生素B12随着用药时间较长而流失.众所周知,二甲双胍能引起维生素B12缺乏,这与叶酸浓度降低有关,最终导致同型半胱氨酸的水平升高,这是维生素B12和叶酸缺乏的标记.

  11. Magnetic properties of Ho1- x Lu x B12 solid solutions

    Science.gov (United States)

    Gabáni, S.; Gaz̆o, E.; Pristás̆, G.; Takác̆ová, I.; Flachbart, K.; Shitsevalova, N.; Siemensmeyer, K.; Sluchanko, N.

    2013-05-01

    Magnetic properties of the geometrically frustrated antiferromagnet HoB12 (with T N = 7.4 K) modified by substitution of magnetic Ho atoms through non-magnetic Lu ones are presented and discussed. In this case, in Ho1- x Lu x B12 solid solutions, both chemical pressure resulting from different Lu3+ and Ho3+ radii and magnetic dilution take place with increasing Lu content ( x) that change properties of the system. The received results show strong indication for the existence of a quantum critical point near x = 0.9, which separates the region of magnetic order (starting with HoB12 for x = 0) and the nonmagnetic region (ending with superconducting LuB12 for x = 1).

  12. Metabolic network rewiring of propionate flux compensates vitamin B12 deficiency in C. elegans.

    Science.gov (United States)

    Watson, Emma; Olin-Sandoval, Viridiana; Hoy, Michael J; Li, Chi-Hua; Louisse, Timo; Yao, Victoria; Mori, Akihiro; Holdorf, Amy D; Troyanskaya, Olga G; Ralser, Markus; Walhout, Albertha Jm

    2016-01-01

    Metabolic network rewiring is the rerouting of metabolism through the use of alternate enzymes to adjust pathway flux and accomplish specific anabolic or catabolic objectives. Here, we report the first characterization of two parallel pathways for the breakdown of the short chain fatty acid propionate in Caenorhabditis elegans. Using genetic interaction mapping, gene co-expression analysis, pathway intermediate quantification and carbon tracing, we uncover a vitamin B12-independent propionate breakdown shunt that is transcriptionally activated on vitamin B12 deficient diets, or under genetic conditions mimicking the human diseases propionic- and methylmalonic acidemia, in which the canonical B12-dependent propionate breakdown pathway is blocked. Our study presents the first example of transcriptional vitamin-directed metabolic network rewiring to promote survival under vitamin deficiency. The ability to reroute propionate breakdown according to B12 availability may provide C. elegans with metabolic plasticity and thus a selective advantage on different diets in the wild. PMID:27383050

  13. Cerebral atrophy in a vitamin B12-deficient infant of a vegetarian mother.

    Science.gov (United States)

    Kocaoglu, Celebi; Akin, Fatih; Caksen, Hüseyin; Böke, Saltuk Buğra; Arslan, Sükrü; Aygün, Serhat

    2014-06-01

    In developed countries, vitamin B12 (cobalamin) deficiency usually occurs in children, exclusively breastfed ones whose mothers are vegetarian, causing low body stores of vitamin B12. The haematologic manifestation of vitamin B12 deficiency is pernicious anaemia. It is a megaloblastic anaemia with high mean corpuscular volume and typical morphological features, such as hyperlobulation of the nuclei of the granulocytes. In advanced cases, neutropaenia and thrombocytopaenia can occur, simulating aplastic anaemia or leukaemia. In addition to haematological symptoms, infants may experience weakness, fatigue, failure to thrive, and irritability. Other common findings include pallor, glossitis, vomiting, diarrhoea, and icterus. Neurological symptoms may affect the central nervous system and, in severe cases, rarely cause brain atrophy. Here, we report an interesting case, a 12-month old infant, who was admitted with neurological symptoms and diagnosed with vitamin B12 deficiency. PMID:25076673

  14. Is metformin-induced vitamin B12 deficiency responsible for cognitive decline in type 2 diabetes?

    Directory of Open Access Journals (Sweden)

    Deepti Khattar

    2016-01-01

    Full Text Available Introduction: Diabetes mellitus has its deleterious effects on various aspects of cognition such as memory function, executive function, and information-processing speed. The present study aims to assess cognition in diabetes patients and also tries to find its association with Vitamin B12 deficiency induced by metformin. Materials and Methods: Thirty diabetics taking metformin and thirty nondiabetic controls were enrolled. Event-related potentials (ERPs and serum Vitamin B12 levels were evaluated in them. Results: Vitamin B12 levels were found to be deficient, and latencies of waves P200 and P300 were prolonged in the diabetics as compared to the controls. The dose and duration of metformin had no association with the ERPs. Conclusions: Although the Vitamin B12 levels were deficient in diabetics on metformin, this is not the reason behind the cognitive impairment found in them.

  15. Pigmentation in vitamin B12 deficiency masquerading Addison′s pigmentation: A rare presentation

    Directory of Open Access Journals (Sweden)

    Ritesh Kumar Agrawala

    2013-01-01

    Full Text Available A 35-year-female presented with generalized weakness, weight loss, and progressive pigmentation was worked up for suspicion of Addisons disease. On examination hyper pigmentation was noted on both palmar and dorsal aspect of hands involving knuckles, creases, feet, tongue, oral mucosa and gluteal region. There was no evidence of hypocortisolemia as initially suspected, and literature search revealed a possibility of vitamin B12 deficiency. She had megaloblastic anemia with a low serum vitamin B12, mostly due to poor dietary intake. Her hyper pigmentation resolved with vitamin B12 supplementation. Skin biopsy showed increased pigmentation at stratum spinosum and basal-layer. The mechanism of hyper pigmentation in vitamin B12 deficiency was due to an increase in melanin synthesis.

  16. Lifestyle and genetic determinants of folate and vitamin B12 levels in a general adult population

    DEFF Research Database (Denmark)

    Thuesen, Betina H; Husemoen, Lise Lotte N; Ovesen, Lars;

    2009-01-01

    Danish legislation regarding food fortification has been very restrictive resulting in few fortified food items on the Danish market. Folate and vitamin B12 deficiency is thought to be common due to inadequate intakes but little is known about the actual prevalence of low serum folate and vitamin B......12 in the general population. The aim of the present study was to evaluate the folate and vitamin B12 status of Danish adults and to investigate associations between vitamin status and distinct lifestyle and genetic factors. The study included a random sample of 6784 individuals aged 30-60 years....... Information on lifestyle factors was obtained by questionnaires and blood samples were analysed for serum folate and vitamin B12 concentrations and several genetic polymorphisms. The overall prevalence of low serum folate (

  17. Vitamin B12 Deficiency in Persons with Intellectual Disability in a Vegetarian Residential Care Community

    Directory of Open Access Journals (Sweden)

    Mohammed Morad

    2005-01-01

    Full Text Available The goal of this study was to determine the prevalence of vitamin B12 deficiency among intellectually disabled persons in a vegetarian remedial community in Israel. In this community, 47 individuals with intellectual disability (ID live in 7 enlarged families in a kibbutz style agricultural setting. These 47 individuals and 17 of their caregivers were screened for vitamin B12 deficiency. There were 25.5% of the disabled vs. 11.8% of the caregivers found to have levels of vitamin B12 lower than 157 pg/ml. It is concluded that persons with ID in this vegetarian residential care community seemed to be at a higher risk for vitamin B12 deficiency.

  18. [Folate metabolism--epigenetic role of choline and vitamin B12 during pregnancy].

    Science.gov (United States)

    Drews, Krzysztof

    2015-12-01

    Adequate choline intake during pregnancy is essential for proper fetal development. Nowadays studies suggest that even in high income countries regular pregnant women diet does not provide the satisfactory amount of choline. Choline demand during pregnancy is high and it seems to exceed present choline intake recommendations. Moreover lactation period also demands choline supplementation because of its high concentration in female milk. Numerous studies on animal model proved correlation between choline supplementation during pregnancy and proper fetal cognitive function development. Despite increased synthesis in maternal liver during pregnancy choline demand is much higher than common dietary uptake. Nowadays studies as to the nutritional recommendations during pregnancy concern also vitamin B12 supplementation. Vitamin B12 deficiency may be an important risk factor of neural tube defects development. Presented article contains a review of data on proper choline and vitamin B12 uptake during pregnancy and lactation and potential results of choline and vitamin B12 poor maternal status. PMID:26995945

  19. Effect of vitamin B12 deficiency on neurodevelopment in infants: current knowledge and possible mechanisms

    Science.gov (United States)

    Severe vitamin B12 deficiency produces a cluster of neurological symptoms in infants, including irritability, failure to thrive, apathy, anorexia, and developmental regression, which respond remarkably rapidly to supplementation. The underlying mechanisms may involve delayed myelination or demyelina...

  20. Serum Homocysteine, Vitamin B12, Folic Acid Levels and Methylenetetrahydrofolate Reductase (MTHFR) Gene Polymorphism in Vitiligo

    OpenAIRE

    Ali Yasar; Kamer Gunduz; Ece Onur; Mehmet Calkan

    2012-01-01

    The aim of this study was to determine serum vitamin B12, folic acid and homocysteine (Hcy) levels as well as MTHFR (C677, A1298C) gene polymorphisms in patients with vitiligo, and to compare the results with healthy controls. Forty patients with vitiligo and 40 age and sex matched healthy subjects were studied. Serum vitamin B12 and folate levels were determined by enzyme-linked immunosorbent assay. Plasma Hcy levels and MTHFR polymorphisms were determined by chemiluminescence and real time ...

  1. MEASUREMENT OF VITAMIN B12 CONCENTRATION: A REVIEW ON AVAILABLE METHODS

    OpenAIRE

    Karmi O et al

    2011-01-01

    Vitamin B12 is a water-soluble vitamin. It is one of the eight vitamins of vitamin B complex, needed for blood and cell maturation. It helps maintain healthy nerve cells and red blood cells, and it is needed in DNA replication. Its deficiency may cause megaloblastic anemia (amidst others health issues). For these and many similar reasons, it sometimes becomes necessary to measure its concentration. This article has carefully reviewed the different methods used for measuring vitamin B12 concen...

  2. Low vitamin B-12 status and risk of cognitive decline in older adults.

    OpenAIRE

    MOLLOY, ANNE MARIE

    2007-01-01

    PUBLISHED PubMed ID: 17991650 BACKGROUND: Elevated total homocysteine (tHcy) concentrations have been associated with cognitive impairment, but it is unclear whether low vitamin B-12 or folate status is responsible for cognitive decline. OBJECTIVE: We examined the associations of cognitive decline with vitamin B-12 and folate status in a longitudinal cohort study performed from 1993 to 2003 in Oxford, United Kingdom. DESIGN: Cognitive function was assessed with the Mini-Mental State Exa...

  3. Vitamin B12 deficiency among patients with diabetes mellitus: is routine screening and supplementation justified?

    OpenAIRE

    Kibirige, Davis; Mwebaze, Raymond

    2013-01-01

    Vitamin B12 is an essential micronutrient required for optimal hemopoetic, neuro-cognitive and cardiovascular function. Biochemical and clinical vitamin B12 deficiency has been demonstrated to be highly prevalent among patients with type 1 and type 2 diabetes mellitus. It presents with diverse clinical manifestations ranging from impaired memory, dementia, delirium, peripheral neuropathy, sub acute combined degeneration of the spinal cord, megaloblastic anemia and pancytopenia. This review ar...

  4. Vitamin B12 Status in a Tertiary Care Center in Central Gujarat

    Directory of Open Access Journals (Sweden)

    Andrews Liggy, Tintu Thomas , Haridas Nambudiri

    2012-09-01

    Full Text Available Introduction: Vitamin B12 deficiency usually presents with pernicious anemia or various neuropsychiatric manifestations such as neuropathy, myelopathy, dementia, cerebellar ataxia, optic atrophy, pscyhosis and mood disorders. Hence vitamin B12 deficiency should be identified. The local population in our area mainly comprises of vegetarians, this study was initiated with a view to assess their B12 status early, to rule out its deficiency and help to prevent further complications. Methodology: We analyzed serum B12 levels in 396 cases by competitive chemiluminescent immunometric method using Immulite instrument. Result: It was found that B12 levels were significantly low in 260(65.6% patients (P<0.000. Majority 225 (86.5% of the deficient patients were vegetarians and the deficiency was found less in non vegetarians (P<0.000. The B12 deficiency was evident more in patients below 50years (199 out of 396 i.e. 76.5% of age as compared to those who are above 51 years of age (60 out of 396 i.e. 23.4%, with a P value <0.000. The deficiency was prevalent more in females 179 (68.8% in comparison to males 81(31.1% and the P<0.000. Our study found that B12 deficiency is quiet prevalent in local population (65.6%, the condition being worse in females. And it was also noticed that deficiency was relatively more in vegetarians. Conclusion: The early detection of B12 deficiency could help in warding off the resultant complications.

  5. Association of vitamin B12, folate, homocysteine and cognition in the elderly

    OpenAIRE

    Lökk, Johan

    2003-01-01

    Normal and subnormal serum levels of vitamin B12 and/or folate do not exclude functional deficiency, and elderly people are specifically exposed to deficiency owing to impaired nutrition, malabsorption, accompanying diseases and current medication. Several studies report that low levels of vitamin B12 are more common in people with Alzheimer’s disease (AD) than in non-demented people. Low levels of folate are also correlated with other types of dementia. Current studies suggest that low level...

  6. Vitamin B12 deficiency presenting with an acute reversible extrapyramidal syndrome

    OpenAIRE

    Joy M.

    2005-01-01

    Vitamin B12 deficiency usually presents with pernicious anemia or various neuropsychiatric manifestations. Commonly seen neuropsychiatric manifestations include large fiber neuropathy, myelopathy (subacute combined degeneration of the spinal cord), dementia, cerebellar ataxia, optic atrophy, psychosis and mood disorders. The present report highlights an unusual presentation of vitamin B12 deficiency- acute onset extrapyramidal syndrome in a 55-year-old man. The patient presented with a 10-day...

  7. Absorption and transport of radioactive 57Co-vitamin B12 in experimental giardiasis in rats

    International Nuclear Information System (INIS)

    Giardiasis was produced in weanling albino rats by feeding suspension of Giardia lamblia cysts isolated from human stool. Experiments were carried out to assess the absorption and transport through intestinal wall of 57Co-vitamin B12 in these rats. The results showed a significant impairment of the absorption of the vitamin in the rats with experimental giardiasis. However, the transport of the vitamin B12 was unimpaired. (author)

  8. Vitamin B12 deficiency. Prevalence among South Asians at a Toronto clinic.

    OpenAIRE

    Gupta, Anil K.; Damji, Alkarim; Uppaluri, Aparna

    2004-01-01

    OBJECTIVE: To estimate the prevalence of vitamin B12 deficiency in adult South Asian patients. DESIGN: Retrospective chart review. SETTING: Family practice clinic in Toronto, Ont. PARTICIPANTS: Records of 988 South Asian patients. INTERVENTION: Of 1000 randomly selected records, we found 988 charts. From charts with at least one documented B12 level, we extracted data on age, mean corpuscular volume (MCV), hemoglobin and ferritin levels, and diet (if available). Descriptive and analytic stati...

  9. Masking of vitamin B12 deficiency associated neuropathy by folic acid

    OpenAIRE

    van Amsterdam JGC; Opperhuizen A; Jansen EHJM; TOX

    2005-01-01

    The Dutch authorities consider fortifying certain foods with folic acid. Folic acid supplementation may, however, mask vitamin B12 deficiency and increase the incidence of peripheral neuropathy. This literature review outlines published studies to the potential masking of vitamin B12 deficiency related pernicious anaemia by folic acid. aggravate neurological manifestations comes from publications in the mid-1940s, when folic acid was first used to treat patients with pernicious anaemia. This ...

  10. The role of holotranscobalamin in examination of vitamin B12 status

    OpenAIRE

    Čabarkapa Velibor; Stošić Zoran; Uzurov Vera; Sakač Vladimir; Đerić Mirjana

    2008-01-01

    Introduction. Holotranscobalamin contains biologically available cobalamin because only holotranscobalamin promotes the uptake of the cobalamin therein by all cells, via specific receptors. Therefore holotranscobalamin has been proposed as a potentially useful alternative indicator of vitamin B12 status. The aim of the present study was to assess usefulness of holotranscobalamin in the evaluation of vitamin B12 status. Material and methods. We examined serum level of holotranscobalamin in 135...

  11. The complete coenzyme B12 biosynthesis gene cluster of Lactobacillus reuteri CRL 1098

    OpenAIRE

    Santos, dos, T.C.; Vera, J.L.; Heijden, van der, C.A.M.; G. F. VALDEZ; De Vos; Sesma, F.; Hugenholtz, J

    2008-01-01

    The coenzyme B12 production pathway in Lactobacillus reuteri has been deduced using a combination of genetic, biochemical and bioinformatics approaches. The coenzyme B12 gene cluster of Lb. reuteri CRL1098 has the unique feature of clustering together the cbi, cob and hem genes. It consists of 29 ORFs encoding the complete enzymic machinery necessary for de novo biosynthesis. Transcriptional analysis showed it to be expressed as two tandem transcripts of approximately 22 and 4 kb, carrying co...

  12. Vitamin B12, folate and folate-binding proteins in dairy products

    OpenAIRE

    Arkbåge, Karin

    2003-01-01

    Vitamin B12 and folate are two important B vitamins for maintaining good health, being involved in amino acid metabolism and DNA synthesis. Milk and dairy products are good sources of vitamin B12 and folate. Moreover, they are of interest due to their content of folate-binding proteins (FBP), since it was hypothesised that these promote folate bioavailability. Furthermore, fermentation of milk is a way to increase the content of both vitamins. Vitamin analysis in fermented dairy products is c...

  13. Effects of vitamin B12 and folate deficiency on brain development in children

    OpenAIRE

    Black, Maureen M.

    2008-01-01

    Folate deficiency in the periconceptional period contributes to neural tube defects; deficits in vitamin B12 (cobalamin) have negative consequences on the developing brain during infancy; and deficits of both vitamins are associated with a greater risk of depression during adulthood. This review examines two mechanisms linking folate and vitamin B12 deficiency to abnormal behavior and development in infants: disruptions to myelination and inflammatory processes. Future investigations should f...

  14. Association of B12 deficiency and clinical neuropathy with metformin use in type 2 diabetes patients

    OpenAIRE

    Singh, A.K.; Kumar, A.; D Karmakar; R K Jha

    2013-01-01

    Context: Long-term metformin use has been hypothesized to cause B12 deficiency and neuropathy in Type 2 diabetes patients. However, there is a paucity of Indian data regarding the same. Aim: To compare the prevalence of B12 deficiency and peripheral neuropathy in patients with Type 2 diabetes mellitus treated with or without metformin. Materials and Methods: We recruited patients with Type 2 diabetes and divided them into metformin exposed and nonmetformin exposed groups. We measured baseline...

  15. Is metformin-induced vitamin B12 deficiency responsible for cognitive decline in type 2 diabetes?

    OpenAIRE

    Deepti Khattar; Farah Khaliq; Neelam Vaney; Madhu, S.V.

    2016-01-01

    Introduction: Diabetes mellitus has its deleterious effects on various aspects of cognition such as memory function, executive function, and information-processing speed. The present study aims to assess cognition in diabetes patients and also tries to find its association with Vitamin B12 deficiency induced by metformin. Materials and Methods: Thirty diabetics taking metformin and thirty nondiabetic controls were enrolled. Event-related potentials (ERPs) and serum Vitamin B12 levels were eva...

  16. Serum folate, vitamin B-12 and cognitive function in middle and older age: The HAPIEE study

    OpenAIRE

    Horvat, Pia; Gardiner, Julian; Kubinova, Ruzena; Pajak, Andrzej; Tamosiunas, Abdonas; Schöttker, Ben; Pikhart, Hynek; Peasey, Anne; Jansen, Eugene; Bobak, Martin

    2016-01-01

    Background Nutrient status of B vitamins, particularly folate and vitamin B-12, may be related to cognitive ageing but epidemiological evidence remains inconclusive. Objective The aim of this study was to estimate the association of serum folate and vitamin B-12 concentrations with cognitive function in middle-aged and older adults from three Central and Eastern European populations. Methods Men and women aged 45–69 at baseline participating in the Health, Alcohol and Psychosocial factors in ...

  17. The effects of exercise training and acute exercise duration on plasma folate and vitamin B12

    OpenAIRE

    Kim, Young-Nam; Hwang, Ji Hyeon; Cho, Youn-Ok

    2016-01-01

    BACKGROUND/OBJECTIVES Energy production and the rebuilding and repair of muscle tissue by physical activity require folate and vitamin B12 as a cofactor. Thus, this study investigated the effects of regular moderate exercise training and durations of acute aerobic exercise on plasma folate and vitamin B12 concentrations in moderate exercise trained rats. MATERIALS/METHODS Fifty rats underwent non-exercise training (NT, n = 25) and regular exercise training (ET, n = 25) for 5 weeks. The ET gro...

  18. Premarital screening of 466 Mediterranean women for serum ferritin, vitamin B12, and folate concentrations

    OpenAIRE

    Karabulut, Aysun; GÜLER, ÖMER TOLGA; KARAHAN, HATİCE TUBA; ÖZKAN, SEVGİ; KOYUNCU, HASAN; DEMİRCİLER, İBRAHİM

    2015-01-01

    Background/aim: Iron, folate, and vitamin B12 serum levels are closely related with dietary habits and have an essential role in the healthy development of a fetus. We aimed to investigate hemoglobin, ferritin, folate, and vitamin B12 levels in preconceptional women in an area where a plant-based diet referred to as Mediterranean cuisine is commonly used. Materials and methods: The study population included 466 women between the ages of 18 and 45 years admitted for thalassemia screening. So...

  19. Biosynthesis of poly(3-hydroxypropionate) from glycerol using engineered Klebsiella pneumoniae strain without vitamin B12

    OpenAIRE

    Feng, Xinjun; Xian, Mo; Liu, Wei; Xu, Chao; Zhang, Haibo; Zhao, Guang

    2015-01-01

    Poly(3-hydroxypropionate) (P3HP) is a biodegradable and biocompatible thermoplastic. Previous studies demonstrated that engineered Escherichia coli strains can produce P3HP with supplementation of expensive vitamin B12. The present study examined the production of P3HP from glycerol in the recombinant Klebsiella pneumoniae strain, which naturally synthesizes vitamin B12. The genes glycerol dehydratase and its reactivation factor (dhaB123, gdrA, and gdrB from K. pneumoniae), aldehyde dehydroge...

  20. Correlations of folic acid, vitamin B12, homocysteine, and thrombopoietin to platelet count in HCV infection

    OpenAIRE

    Somayh S. Eissa; Olfat M. Hendy; Fatma Younis; Aziza K. Omar Samy; Ayat R. Abdallah; Laila A. Ahmed

    2012-01-01

    IntroductionThe platelet count is known to decrease in proportion to the advancement of the stage of liver disease in chronic hepatitis C (CHC) viral infection. The platelet count is currently used as an index for fibrosis staging. The pathophysiology of thrombocytopenia (TCP) in patients with hepatitis C virus (HCV) infection is not completely understood. PurposeThis work aimed to study the correlations of folic acid (FA), vitamin B12 (Vit B12), homocysteine (Hcy), and thrombopoietin to t...

  1. Quantitative Evaluation of Cobalamins (Vit.B12) Produced by Native Propionibacteria

    OpenAIRE

    H.kazemi fard; N. Mozami; Jalali, M.

    1995-01-01

    in order to prepare cobalamins (Vit. B12) using microbial culture method, the strains of Genus propionibacteriun have been chosen in preference to other species because of their rapid growth and high productivity of selected mutants."nIn the present research we examined the quantitative evaluation of cobalamins (Vit.B12) produced by native propionibacteria and results have been compared to other reports in this subject."nThe native propionibacteria were isolated from Iranien dairy p...

  2. AB156. Homocysteine and vitamin B12: risk factors for erectile dysfunction

    OpenAIRE

    Lu, Zheng; Mo, Zengnan

    2014-01-01

    Background Increasing levels of homocysteine (Hcy) is associated with cardiovascular disease, and erectile dysfunction (ED) has close relation with cardiovascular disease, therefore, high homocysteine may be one of the risk factors of ED. During the metabolism of homocysteine, vitamin B12 plays an important role and could be the main factor in causing erectile dysfunction as well. Purpose To investigate the relationship between Hcy, vitamin B12 and ED in sample. Methods The study included 1,4...

  3. Vitamin B12–dependent taurine synthesis regulates growth and bone mass

    OpenAIRE

    Roman-Garcia, Pablo; Quiros-Gonzalez, Isabel; Mottram, Lynda; Lieben, Liesbet; Sharan, Kunal; Wangwiwatsin, Arporn; Tubio, Jose; Lewis, Kirsty; Wilkinson, Debbie; Santhanam, Balaji; Sarper, Nazan; Clare, Simon; Vassiliou, George S; Velagapudi, Vidya R.; Dougan, Gordon

    2014-01-01

    Both maternal and offspring-derived factors contribute to lifelong growth and bone mass accrual, although the specific role of maternal deficiencies in the growth and bone mass of offspring is poorly understood. In the present study, we have shown that vitamin B12 (B12) deficiency in a murine genetic model results in severe postweaning growth retardation and osteoporosis, and the severity and time of onset of this phenotype in the offspring depends on the maternal genotype. Using integrated p...

  4. Visual Evoked Potentials in Vitamin B12 Deficiency: Results of a Preliminary Study

    OpenAIRE

    Değirmenci, Yıldız; Örs, Ceyda Hayretdağ; Yılmaz, Yeliz; Karaman, Handan Işın Özışık

    2012-01-01

    Objective: Aim of this study was to investigate the possible relationship between serum vitamin B12 levels and P100 latency and amplitudes with visual evoked potentials (VEP) in patients with B12 vitamin deficiency without optic neuritis (ON). Material and Methods: Patients who presented to the outpatient neurology clinic of Çanakkale Onsekiz Mart University Research Hospital underwent initial evaluation. Among those, complete blood count, full biochemistry (blood glucose, liver and kidne...

  5. Response to Vitamin B12 and Folic Acid in Myalgic Encephalomyelitis and Fibromyalgia

    OpenAIRE

    Björn Regland; Sara Forsmark; Lena Halaouate; Michael Matousek; Birgitta Peilot; Olof Zachrisson; Carl-Gerhard Gottfries

    2015-01-01

    Background Patients with myalgic encephalomyelitis (ME, also called chronic fatigue syndrome) may respond most favorably to frequent vitamin B12 injections, in vital combination with oral folic acid. However, there is no established algorithm for individualized optimal dosages, and rate of improvement may differ considerably between responders. Objective To evaluate clinical data from patients with ME, with or without fibromyalgia, who had been on B12 injections at least once a week for six m...

  6. Associations between Homocysteine, Folic Acid, Vitamin B12 and Alzheimer's Disease: Insights from Meta-Analyses.

    Science.gov (United States)

    Shen, Liang; Ji, Hong-Fang

    2015-01-01

    The associations between homocysteine (Hcy), folic acid, and vitamin B12 and Alzheimer's disease (AD) have gained much interest, while remaining controversial. We aim to perform meta-analyses to evaluate comprehensively: i) Hcy, folic acid, and vitamin B12 levels in AD patients in comparison with controls; and ii) the association between Hcy, folic acid, and vitamin B12 levels and risk of AD. A literature search was performed using Medline and Scopus databases. A total of 68 studies were identified and included in the meta-analyses. Stata 12.0 statistical software was used to perform the meta-analyses. First, AD patients may have higher level of Hcy, and lower levels of folate and vitamin B12 in plasma than controls. Further age-subgroup analysis showed no age effect for Hcy levels in plasma between AD patients and matched controls, while the differences in folate and vitamin B12 levels further enlarged with increased age. Second, data suggests that high Hcy and low folate levels may correlate with increased risk of AD occurrence. The comprehensive meta-analyses not only confirmed higher Hcy, lower folic acid, and vitamin B12 levels in AD patients than controls, but also implicated that high Hcy and low folic acid levels may be risk factors of AD. Further studies are encouraged to elucidate mechanisms linking these conditions. PMID:25854931

  7. Serum homocysteine, vitamin B12, folic acid levels and methylenetetrahydrofolate reductase (MTHFR) gene polymorphism in vitiligo.

    Science.gov (United States)

    Yasar, Ali; Gunduz, Kamer; Onur, Ece; Calkan, Mehmet

    2012-01-01

    The aim of this study was to determine serum vitamin B12, folic acid and homocysteine (Hcy) levels as well as MTHFR (C677, A1298C) gene polymorphisms in patients with vitiligo, and to compare the results with healthy controls. Forty patients with vitiligo and 40 age and sex matched healthy subjects were studied. Serum vitamin B12 and folate levels were determined by enzyme-linked immunosorbent assay. Plasma Hcy levels and MTHFR polymorphisms were determined by chemiluminescence and real time PCR methods, respectively. Mean serum vitamin B12 and Hcy levels were not significantly different while folic acid levels were significantly lower in the control group. There was no significant relationship between disease activity and vitamin B12, folic acid and homocystein levels. No significant difference in C677T gene polymorphism was detected. Heterozygote A1298C gene polymorphism in the patient group was statistically higher than the control group. There was no significant relationship between MTHFR gene polymorphisms and vitamin B12, folic acid and homocysteine levels. In conclusion, vitamin B12, folate and Hcy levels are not altered in vitiligo and MTHFR gene mutations (C677T and A1298C) do not seem to create susceptibility for vitiligo. PMID:22846211

  8. Serum Homocysteine, Vitamin B12, Folic Acid Levels and Methylenetetrahydrofolate Reductase (MTHFR Gene Polymorphism in Vitiligo

    Directory of Open Access Journals (Sweden)

    Ali Yasar

    2012-01-01

    Full Text Available The aim of this study was to determine serum vitamin B12, folic acid and homocysteine (Hcy levels as well as MTHFR (C677, A1298C gene polymorphisms in patients with vitiligo, and to compare the results with healthy controls. Forty patients with vitiligo and 40 age and sex matched healthy subjects were studied. Serum vitamin B12 and folate levels were determined by enzyme-linked immunosorbent assay. Plasma Hcy levels and MTHFR polymorphisms were determined by chemiluminescence and real time PCR methods, respectively. Mean serum vitamin B12 and Hcy levels were not significantly different while folic acid levels were significantly lower in the control group. There was no significant relationship between disease activity and vitamin B12, folic acid and homocystein levels. No significant difference in C677T gene polymorphism was detected. Heterozygote A1298C gene polymorphism in the patient group was statistically higher than the control group. There was no significant relationship between MTHFR gene polymorphisms and vitamin B12, folic acid and homocysteine levels. In conclusion, vitamin B12, folate and Hcy levels are not altered in vitiligo and MTHFR gene mutations (C677T and A1298C do not seem to create susceptibility for vitiligo.

  9. Vitamin B12: one carbon metabolism, fetal growth and programming for chronic disease.

    Science.gov (United States)

    Rush, E C; Katre, P; Yajnik, C S

    2014-01-01

    This review brings together human and animal studies and reviews that examine the possible role of maternal vitamin B12 (B12) on fetal growth and its programming for susceptibility to chronic disease. A selective literature review was undertaken to identify studies and reviews that investigate these issues, particularly in the context of a vegetarian diet that may be low in B12 and protein and high in carbohydrate. Evidence is accumulating that maternal B12 status influences fetal growth and development. Low maternal vitamin B12 status and protein intake are associated with increased risk of neural tube defect, low lean mass and excess adiposity, increased insulin resistance, impaired neurodevelopment and altered risk of cancer in the offspring. Vitamin B12 is a key nutrient associated with one carbon metabolic pathways related to substrate metabolism, synthesis and stability of nucleic acids and methylation of DNA which regulates gene expression. Understanding of factors regulating maternal-fetal one carbon metabolism and its role in fetal programming of non communicable diseases could help design effective interventions, starting with maternal nutrition before conception. PMID:24219896

  10. Validity of transcobalamin II-based radioassay for the determination of serum vitamin B12 concentrations

    International Nuclear Information System (INIS)

    A valid radioassay for the estimation of serum vitamin B12 in the presence of naturally occurring vitamin B12 (= cobalamin) analogues can be operated if serum transcobalamin II (TC II) is used as the binding protein. Serum samples that gave diagnostically discrepant results when their vitamin B12 content was analysed (i) by a commercial radioassay known to be susceptible to interference from cobalamin analogues, and (ii) by microbiological assay, were further analysed by an alternative radioassay which uses the transcobalamins (principally TC II) of diluted normal serum as the assay binding protein. Concordance between the results from microbiological assay and the TC II-based radioassay was found in all cases. In an extended study over a three-year period, all routine serum samples sent for vitamin B12 analysis that had a vitamin B12 content of less than 320 ng/l by the TC II-based radioassay (reference range 200-850 ng/l) were reanalysed using an established microbiological method. Over 1000 samples were thus analysed. The data are presented to demonstrate the validity of the TC II-based radioassay results in this group of patients, serum samples from which are most likely to produce diagnostically erroneous vitamin B12 results when analysed by a radioassay that is less specific for cobalamins. (author)

  11. Cyanobacteria and Eukaryotic Algae Use Different Chemical Variants of Vitamin B12.

    Science.gov (United States)

    Helliwell, Katherine Emma; Lawrence, Andrew David; Holzer, Andre; Kudahl, Ulrich Johan; Sasso, Severin; Kräutler, Bernhard; Scanlan, David John; Warren, Martin James; Smith, Alison Gail

    2016-04-25

    Eukaryotic microalgae and prokaryotic cyanobacteria are the major components of the phytoplankton. Determining factors that govern growth of these primary producers, and how they interact, is therefore essential to understanding aquatic ecosystem productivity. Over half of microalgal species representing marine and freshwater habitats require for growth the corrinoid cofactor B12, which is synthesized de novo only by certain prokaryotes, including the majority of cyanobacteria. There are several chemical variants of B12, which are not necessarily functionally interchangeable. Cobalamin, the form bioavailable to humans, has as its lower axial ligand 5,6-dimethylbenzimidazole (DMB). Here, we show that the abundant marine cyanobacterium Synechococcus synthesizes only pseudocobalamin, in which the lower axial ligand is adenine. Moreover, bioinformatic searches of over 100 sequenced cyanobacterial genomes for B12 biosynthesis genes, including those involved in nucleotide loop assembly, suggest this is the form synthesized by cyanobacteria more broadly. We further demonstrate that pseudocobalamin is several orders of magnitude less bioavailable than cobalamin to several B12-dependent microalgae representing diverse lineages. This indicates that the two major phytoplankton groups use a different B12 currency. However, in an intriguing twist, some microalgal species can use pseudocobalamin if DMB is provided, suggesting that they are able to remodel the cofactor, whereas Synechococcus cannot. This species-specific attribute implicates algal remodelers as novel and keystone players of the B12 cycle, transforming our perception of the dynamics and complexity of the flux of this nutrient in aquatic ecosystems. PMID:27040778

  12. B12 Vitamin and Folat Prevelance of Children and Adolescents in Diyarbakır

    Directory of Open Access Journals (Sweden)

    Kahraman Öncel

    2006-01-01

    Full Text Available The most common cause of megaloblastic anemia in childhood are vitamin B12 and folat deficiency. Folat and vitamin B12 play a role in DNA synthessis in gastrointestinal, urogenital,nerves and hemotopoetic cells. The diagnosis of megaloblastic anemia is easy and the treatment cost is low.In this study, the prevalence of vitamin B12 and folat deficiencies in 889 students were determined. Vitamin B12 and folat levels in blood samples were measured via RİAThe average age were betwen 12 and 22 years. Of this students 294(%33,1 were female and 595 (%66,9 were male. The incidence of vitamin B12 deficiency was found to be 2.2%, while folat deficiency was 21.8%. The mean vitamin B12 level was 331,51±144,05 pg/mL (325,60±138,91 in pg/mL male, 343,48±153,48 pg/mL in female, the mean folat level was 5,42±2,12 ng/ml (5,23±2,11 ng/ml in male, 5,80±2,10 ng/ml in female.The prevelance of folat deficiency in our region was higher than other countries, possibly due to low socioeconomical status, improper or inadequate food intake and low educational status.

  13. Cyanobacteria and Eukaryotic Algae Use Different Chemical Variants of Vitamin B12

    Science.gov (United States)

    Helliwell, Katherine Emma; Lawrence, Andrew David; Holzer, Andre; Kudahl, Ulrich Johan; Sasso, Severin; Kräutler, Bernhard; Scanlan, David John; Warren, Martin James; Smith, Alison Gail

    2016-01-01

    Summary Eukaryotic microalgae and prokaryotic cyanobacteria are the major components of the phytoplankton. Determining factors that govern growth of these primary producers, and how they interact, is therefore essential to understanding aquatic ecosystem productivity. Over half of microalgal species representing marine and freshwater habitats require for growth the corrinoid cofactor B12, which is synthesized de novo only by certain prokaryotes, including the majority of cyanobacteria. There are several chemical variants of B12, which are not necessarily functionally interchangeable. Cobalamin, the form bioavailable to humans, has as its lower axial ligand 5,6-dimethylbenzimidazole (DMB). Here, we show that the abundant marine cyanobacterium Synechococcus synthesizes only pseudocobalamin, in which the lower axial ligand is adenine. Moreover, bioinformatic searches of over 100 sequenced cyanobacterial genomes for B12 biosynthesis genes, including those involved in nucleotide loop assembly, suggest this is the form synthesized by cyanobacteria more broadly. We further demonstrate that pseudocobalamin is several orders of magnitude less bioavailable than cobalamin to several B12-dependent microalgae representing diverse lineages. This indicates that the two major phytoplankton groups use a different B12 currency. However, in an intriguing twist, some microalgal species can use pseudocobalamin if DMB is provided, suggesting that they are able to remodel the cofactor, whereas Synechococcus cannot. This species-specific attribute implicates algal remodelers as novel and keystone players of the B12 cycle, transforming our perception of the dynamics and complexity of the flux of this nutrient in aquatic ecosystems. PMID:27040778

  14. Genetic variation in vitamin B-12 content of bovine milk and its association with SNP along the bovine genome.

    Directory of Open Access Journals (Sweden)

    Marc J M Rutten

    Full Text Available Vitamin B-12 (also called cobalamin is essential for human health and current intake levels of vitamin B-12 are considered to be too low. Natural enrichment of the vitamin B-12 content in milk, an important dietary source of vitamin B-12, may help to increase vitamin B-12 intake. Natural enrichment of the milk vitamin B-12 content could be achieved through genetic selection, provided there is genetic variation between cows with respect to the vitamin B-12 content in their milk. A substantial amount of genetic variation in vitamin B-12 content was detected among raw milk samples of 544 first-lactation Dutch Holstein Friesian cows. The presence of genetic variation between animals in vitamin B-12 content in milk indicates that the genotype of the cow affects the amount of vitamin B-12 that ends up in her milk and, consequently, that the average milk vitamin B-12 content of the cow population can be increased by genetic selection. A genome-wide association study revealed significant association between 68 SNP and vitamin B-12 content in raw milk of 487 first-lactation Dutch Holstein Friesian cows. This knowledge facilitates genetic selection for milk vitamin B-12 content. It also contributes to the understanding of the biological mechanism responsible for the observed genetic variation in vitamin B-12 content in milk. None of the 68 significantly associated SNP were in or near known candidate genes involved in transport of vitamin B-12 through the gastrointestinal tract, uptake by ileum epithelial cells, export from ileal cells, transport through the blood, uptake from the blood, intracellular processing, or reabsorption by the kidneys. Probably, associations relate to genes involved in alternative pathways of well-studied processes or to genes involved in less well-studied processes such as ruminal production of vitamin B-12 or secretion of vitamin B-12 by the mammary gland.

  15. Dual isotope Schilling test for measuring absorption of food-bound and free vitamin B12 simultaneously

    International Nuclear Information System (INIS)

    A prototype food-bound vitamin B12 (food-B12) absorption test has been developed in which 57Co-B12 was incorporated in vitro into egg yolk (yolk-B12) and served to volunteers in 50-g cooked portions together with toast and coffee for breakfast. Six hours later, 1 mg nonlabeled B12 was given intramuscularly and 24-hour urine was collected for radioactivity measurement. In separate tests, the absorption of yolk-B12 and crystalline 57Co-B12 was equally poor in patients with pernicious anemia. However, in patients with simple gastric achlorhydria and those who had undergone gastric surgery, the assimilation of yolk-B12 was impaired greatly, whereas the absorption of crystalline radio-B12 was normal. Egg yolk labeled with 58Co-B12 was administered together with crystalline 57Co-B12 in a dual isotope test with results similar to those obtained when the tests were prepared separately. This yolk-58Co-B12 test with its ability to detect malabsorption of food-B12 may be considered as an addition to the first part of the Schilling test

  16. Effect of oral vitamin B-12 with or without folic acid on cognitive function in older people with mild vitamim B-12 deficiency: a randomized, placebo-controlled trial

    OpenAIRE

    Eussen, S.J.; Groot, de, H.L.F.; Joosten, L.W.; Bloo, R.; Clarke, R.; Ueland, P.M.; Schneede, J.; Blom, H. J.; Hoefnagels, W. H.; Staveren, van, W.A.

    2006-01-01

    Background: Vitamin B-12 deficiency is associated with cognitive impairment in older people. However, evidence from randomized trials of the effects of vitamin B-12 supplementation on cognitive function is limited and inconclusive. Objective: The objective was to investigate whether daily supplementation with high doses of oral vitamin B-12 alone or in combination with folic acid has any beneficial effects on cognitive function in persons aged 70 y with mild vitamin B-12 deficiency. Design: I...

  17. The usefulness of holotranscobalamin in predicting vitamin B12 status in different clinical settings.

    Science.gov (United States)

    Herrmann, Wolfgang; Obeid, Rima; Schorr, Heike; Geisel, Jürgen

    2005-02-01

    Serum concentrations of homocysteine (Hcy) and methylmalonic acid (MMA) become increased in B12-deficient subjects and are therefore, considered specific markers of B12 deficiency. Serum level of holotranscobalamin (holoTC) becomes decreased before the development of the metabolic dysfunction. We investigated the usefulness of holoTC in diagnosing B12 deficiency in some clinical settings. We measured serum concentrations of holoTC, MMA, Hcy and total B12 in omnivores, vegetarians, elderly people and haemodialysis patients. Our results indicated that the incidence of holoTC vegans (76%). Low holoTC and elevated MMA were detected in 64% of the vegans and 43% of the lacto- and lacto-ovovegetarians. An elevated MMA and a low holoTC were found in subjects with total serum B12 as high as 300 pmol/L. The distribution of holoTC in elderly people was similar to that in younger adults (median holoTC 55 pmol/L in both groups). A low holoTC and an elevated MMA were found in 16% of the elderly group. An elevated MMA and a normal holoTC were found in 20% of the elderly group who had a relatively high median serum concentration of creatinine (106.1 micromol/L). Serum concentrations of holoTC in dialysis patients were considerably higher than all other groups (median 100 pmol/L). This was also associated with severely increased serum levels of MMA (median 987 nmol/L). From these results it can be concluded that serum concentration of holoTC is a much better predictor of B12 status than total B12. This was particularly evident in case of dietary B12 deficiency. Serum concentrations of holoTC as well as MMA can be affected by renal dysfunction. Elevated MMA and normal holoTC in patients with renal insufficiency may not exclude vitamin B12 deficiency. HoloTC seems not to be a promising marker in predicting B12 status in renal patients. PMID:15720207

  18. [Vitamin B 12 deficiency in strict vegetarian diet. Why do some people choose such a diet, and what will they do in case of vitamin B 12 deficiency].

    Science.gov (United States)

    Johnsen, J B; Fønnebø, V

    1991-01-10

    Nine persons in the county of Troms, Norway, were interviewed on their strict vegetarian diet. Improved health was indicated as the main reason for their choice of diet, but religion was a contributing reason for some. Most of the study persons would increase the intake of vitamin B12 if a deficiency state were to occur. One person reported, however, that she would not regard vitamin B12 deficiency as a health problem. The interviews disclosed beliefs regarding human physiology that are very far removed from standard scientific knowledge. The article indicates that communication between patient and the health care system may be difficult in such circumstances. Problems of communication would probably be minimized if the patient had a thorough understanding of human physiology and the health worker a thorough understanding of the reasons for the patient's choice of diet. PMID:2000592

  19. Vitamin B12 Phosphate Conjugation and Its Effect on Binding to the Human B12 -Binding Proteins Intrinsic Factor and Haptocorrin.

    Science.gov (United States)

    Ó Proinsias, Keith; Ociepa, Michał; Pluta, Katarzyna; Chromiński, Mikołaj; Nexo, Ebba; Gryko, Dorota

    2016-06-01

    The binding of vitamin B12 derivatives to human B12 transporter proteins is strongly influenced by the type and site of modification of the cobalamin original structure. We have prepared the first cobalamin derivative modified at the phosphate moiety. The reaction conditions were fully optimized and its limitations examined. The resulting derivatives, particularly those bearing terminal alkyne and azide groups, were isolated and used in copper-catalyzed alkyne-azide cycloaddition reactions (CuAAC). Their sensitivity towards light revealed their potential as photocleavable molecules. The binding abilities of selected derivatives were examined and compared with cyanocobalamin. The interaction of the alkylated derivatives with haptocorrin was less affected than the interaction with intrinsic factor. Furthermore, the configuration of the phosphate moiety was irrelevant to the binding process. PMID:27120016

  20. Bile acid sequestrants

    DEFF Research Database (Denmark)

    Hansen, Morten; Sonne, David P; Knop, Filip K

    2014-01-01

    Bile acids are synthesized in the liver from cholesterol and have traditionally been recognized for their role in absorption of lipids and in cholesterol homeostasis. In recent years, however, bile acids have emerged as metabolic signaling molecules that are involved in the regulation of lipid and...... glucose metabolism, and possibly energy homeostasis, through activation of the bile acid receptors farnesoid X receptor (FXR) and TGR5. Bile acid sequestrants (BASs) constitute a class of drugs that bind bile acids in the intestine to form a nonabsorbable complex resulting in interruption of the...... enterohepatic circulation. This increases bile acid synthesis and consequently reduces serum low-density lipoprotein cholesterol. Also, BASs improve glycemic control in patients with type 2 diabetes. Despite a growing understanding of the impact of BASs on glucose metabolism, the mechanisms behind their glucose...

  1. Algorithm for the early diagnosis of vitamin B12 deficiency in elderly people

    Directory of Open Access Journals (Sweden)

    Gonzalo Palacios

    2013-10-01

    Full Text Available Background: The elderly population is particularly at risk for developing vitamin B12-deficiency. Serum cobalamin does not necessarily reflect a normal B12 status. The determination of methylmalonic acid is not available in all laboratories. Issues of sensitivity for holotranscobalamin and the low specificity of total homocysteine limit their utility. The aim of the present study is to establish a diagnostic algorithm by using a combination of these markers in place of a single measurement. Methods: We compared the diagnostic efficiency of these markers for detection of vitamin B12 deficiency in a population (n = 218 of institutionalized elderly (median age 80 years. Biochemical, haematological and morphological data were used to categorize people with or without vitamin B12 deficiency. Results: In receiver operating curves characteristics for detection on vitamin B12 deficiency using single measurements, serum folate has the greatest area under the curve (0.87 and homocysteine the lowest (0.67. The best specificity was observed for erythrocyte folate and methylmalonic acid (100% for both but their sensitivity was very low (17% and 53%, respectively. The highest sensitivity was observed for homocysteine (81% and serum folate (74%. When we combined these markers, starting with serum and erythrocyte folate, followed by holotranscobalamin and ending by methylmalonic acid measurements, the overall sensitivity and specificity of the algorithm were 100% and 90%, respectively. Conclusion: The proposed algorithm, which combines erythrocyte folate, serum folate, holotranscobalamin and methylmalonic acid, but eliminate B12 and tHcy measurements, is a useful alternative for vitamin B12 deficiency screening in an elderly institutionalized cohort.

  2. Vitamin B12 deficiency and depression in elderly: cross-sectional study in Eastern Croatia

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    Maja Miškulin

    2014-12-01

    Full Text Available Introduction: Vitamin B12 deficiency occurs frequently among elderly patients and it has recently been connected with the occurrence of depressive symptoms in this population. The aim of this study was to determine the frequency of vitamin B12 deficiency among elderly patients from Eastern Croatia and to evaluate whether there is a connection between this deficiency and the occurrence of depressive symptoms among them.Methods: This cross-sectional study was conducted from April to June 2013, among 140 elderly patients from Vukovar-Srijem County (47.9%, 67/140 males and 52.1%, 73/140 females; mean age 71.0±6.7 years. The anonymous questionnaire was used to obtain demographic data, data regarding socio-economic status and personal history of diseases of study participants as well as data pertaining to the existence of depressive symptoms among them. The competitive immunoassay vitamin B12 kit was used to determine serum levels of vitamin B12.Results: Among all study participants there were 7.1% (10/140 of them with B12 deficiency and 70.0% (98/140 of them with the symptoms of depression. Depressive symptoms occurred in 100.0% (10/10 patients with the vitamin B12 deficiency and 67.7% (88/130 of patients without it.Conclusion: The study showed positive connection between the existence of depressive symptoms and vitamin B12 deficiency among elderly patients. This finding points to the need for frequent vitamin status evaluation in this age group and its consequent correction that could improve overall health of this population subgroup.

  3. Evaluation of Mean Platelet Volume Before and After Cobalamin Treatment in Patients with Vitamin B12 Deficiency

    OpenAIRE

    Suleyman Yuce; Medine Cumhur Cure; Erkan Cure; Sefa Kiztanir; Abdulkadir Basturk; Hasan Efe

    2014-01-01

    Purpose: Megaloblastic anemia due to vitamin B12 deficiency is common in the population. Vitamin B12 therapy may stimulate all cell types in the bone marrow. We investigated whether young, active and large platelets are released into the peripheral blood during vitamin B12 treatment and measured the level of mean platelet volume (MPV), an indicator of the presence of these platelets. Materials and Methods: A total of 204 patients (40 males, 160 females) with vitamin B12 deficiency were in...

  4. Effects of vitamin B-12 supplementation on neurologic and cognitive function in older people: a randomized controlled trial.

    OpenAIRE

    Dangour, AD; Allen, E; Clarke, R.; Elbourne, D; Fletcher, Ae; Letley, L.; Richards, M; Whyte, K.; Uauy, R.; Mills, K

    2015-01-01

    BACKGROUND: Moderate vitamin B-12 deficiency is relatively common in older people. However, there is little robust evidence on the effect of vitamin B-12 supplementation on neurologic and cognitive outcomes in later life. OBJECTIVE: We investigated whether vitamin B-12 supplementation benefits neurologic and cognitive function in moderately vitamin B-12-deficient older people. DESIGN: We conducted a double-blind, randomized, placebo-controlled trial in 7 general practices in South East Englan...

  5. Transcobalamin C776G genotype modifies the association between vitamin B12 and homocysteine in older hispanics

    Science.gov (United States)

    Background: A common polymorphism, C776G, in the plasma B12 transport protein transcobalamin (TC), encodes for either proline or arginine at codon 259. This polymorphism may affect the affinity of TC for B12 and subsequent delivery of B12 to tissues. Methods: TC genotype and its associations with i...

  6. Transcobalamin C776G genotype modifies the association between vitamin B12 and homocysteine in older Hispanics

    Science.gov (United States)

    Background: A common polymorphism, C776G, in the plasma B12 transport protein transcobalamin (TC), encodes for either proline or arginine at codon 259. This polymorphism may affect the affinity of TC for B12 and subsequent delivery of B12 to tissues. Methods: TC genotype and its associations with i...

  7. Serum vitamin B12, folic acid and ferritin levels in patients with migraine

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    Abdullah Acar

    2011-09-01

    Full Text Available OBJECTIVE: It has been reported that disability due to migraine may be reduced with homocysteine-lowering treatment including folic acid and vitamin B12. In addition, recently the periaqueductal gray matter iron deposits have been found to be increased in migraine patients. There are few studies regarding vitamin B12, folic acid, ferritin and transferrin levels in patients with migraine. The aims of this study was to measure vitamin B12, folic acid, ferritin and transferrin levels in patients with migraine and compare them with the control group. METHODS: Fifty-one consecutive newly diagnosed migraine patients who did not receive any vitamin supplement medication were enrolled. The study group consisted of 51 patients, suffering from migraine with aura (n= 23 and migraine without aura (n= 28. The control group consisted of 28 healthy participants without history of headache, anemia and vitamin supplement. Serum vitamin B12, folic acid, ferritin and transferin levels were measured using a chemiluminescence method. RESULTS: Migraine patients had significantly lower concentrations of vitamin B12 and folic acid compared with the healthy controls (for vitamin B12; 215.6±133.7 pg/ml vs. 289.9±12 pg/ml, respectively, p=0.005; for folic acid; 6.74 ± 4.31 pg/ml vs. 8.47 ± 1.85 pg/ml, respectively, p=0.048. The vitamin B12 levels were found to be significantly lower during attacks in migraine patients than in interictal periods (177.3 ± 139.2 pg/ml vs 252.5 ± 119.5 pg/ml, p=0.043. There were no differences in folic acid, ferritin, and transferritin levels between during attacks and in interictal period of patients with migraine (p>0.05. The ferritin levels were found to be significantly lower during attacks in migraine patients than in interictal periods (43.4 ± 41.1 mg/ml, vs 75.4 ± 51.7, mg/ml, p=0.018. CONCLUSION: Migraine patients had lower serum vitamin B12 and folic acid levels than healthy subjects. These findings supported that vitamin B12

  8. Plasma Folate and Vitamin B12 Levels in Patients with Hepatocellular Carcinoma.

    Science.gov (United States)

    Cui, Lian-Hua; Quan, Zhen-Yu; Piao, Jin-Mei; Zhang, Ting-Ting; Jiang, Meng-Hui; Shin, Min-Ho; Choi, Jin-Su

    2016-01-01

    Folate and vitamin B12 involved in the one-carbon metabolism may play a key role in carcinogenesis and progression of hepatocellular carcinoma (HCC) through influencing DNA integrity. The purpose of this study is to evaluate the association of plasma folate and vitamin B12 levels with HCC in a case-control study on 312 HCC patients and 325 cancer-free controls. Plasma concentrations of folate and vitamin B12 in all the subjects were measured by electrochemiluminescence immunoassay. Meanwhile, the information of HCC patients' clinical characteristics including tumor-node-metastasis (TNM) stage, tumor size and tumor markers were collected. The patients of HCC had significantly lower folate levels than those of controls; there was no significant difference in the mean of plasma vitamin B12 levels. We also observed an inverse association between the levels of plasma folate and HCC: the adjusted odds ratios (OR) (95% confidence intervals (CI)) of HCC from the highest to lowest quartile of folate were 0.30 (0.15-0.60), 0.33 (0.17-0.65), and 0.19 (0.09-0.38). Compared to the subjects in the lowest quartile of plasma vitamin B12, only the subjects in the highest quartile of vitamin B12 exhibited a significant positive relationship with HCC, the adjusted OR was 2.01 (95% CI, 1.02-3.98). HCC patients with Stage III and IV or bigger tumor size had lower folate and higher vitamin B12 levels. There was no significant difference in the mean plasma folate levels of the HCC cases in tumor markers status (AFP, CEA and CA19-9 levels), whereas patients with higher CEA or CA19-9 levels retained significantly more plasma vitamin B12 than those with normal-CEA or CA19-9 level. In conclusion, plasma folate and vitamin B12 levels could be associated with HCC, and might be used as predictors of clinical characteristics of HCC patients. However, further prospective studies are essential to confirm the observed results. PMID:27376276

  9. Stability of added and in situ-produced vitamin B12 in breadmaking.

    Science.gov (United States)

    Edelmann, Minnamari; Chamlagain, Bhawani; Santin, Marco; Kariluoto, Susanna; Piironen, Vieno

    2016-08-01

    Vitamin B12 exists naturally in foods of animal origin and is synthesised only by certain bacteria. New food sources are needed to ensure vitamin B12 intake in risk groups. This study aimed to investigate the stability of added cyanocobalamin (CNCbl, chemically modified form) and hydroxocobalamin (OHCbl, natural form) and in situ-synthesised vitamin B12 in breadmaking. Samples were analysed both with a microbiological (MBA) and a liquid chromatographic (UHPLC) method to test applicability of these two methods. Proofing did not affect CNCbl and OHCbl levels. By contrast, 21% and 31% of OHCbl was lost in oven-baking steps in straight- and sponge-dough processes, respectively, whereas CNCbl remained almost stable. In sourdough baking, 23% of CNCbl and 44% of OHCbl were lost. In situ-produced vitamin B12 was almost as stable as added CNCbl and more stable than OHCbl. The UHPLC method showed its superiority to the MBA in determining the active vitamin B12. PMID:26988471

  10. A case of vitamin B12 deficiency with involuntary movements and bilateral basal ganglia lesions.

    Science.gov (United States)

    Kitamura, Taisuke; Gotoh, Seiji; Takaki, Hayato; Kiyuna, Fumi; Yoshimura, Sohei; Fujii, Kenichiro

    2016-07-28

    An 86-year-old woman with a one-year history of dementia was admitted to our hospital complaining of loss of appetite, hallucinations, and disturbance of consciousness. She gradually presented with chorea-like involuntary movements of the extremities. Diffusion-weighted magnetic resonance imaging (MRI) showed bilateral symmetrical hyperintense signals in the basal ganglia. The serum vitamin B12 level was below the lower detection limit of 50 pg/ml. The homocysteine level was markedly elevated at 115.8 nmol/ml. Anti-intrinsic factor and anti-parietal cell antibody tests were positive. Gastrointestinal endoscopy revealed atrophic gastritis. The patient was diagnosed with encephalopathy due to vitamin B12 deficiency caused by pernicious anemia. Involuntary movements and MRI abnormalities improved with parenteral vitamin B12 supplementation. Bilateral basal ganglia lesions are rare manifestations of adult vitamin B12 deficiency. The present case is considered valuable in identifying the pathophysiology of involuntary movement due to vitamin B12 deficiency. PMID:27356735

  11. 叶酸、Vitamin B12与血管性痴呆

    Institute of Scientific and Technical Information of China (English)

    王树华; 单培彦

    2005-01-01

    自从十九世纪五十年代Addison(英国)第一次描述恶性贫血伴有的神经精神症状,经用Vit B12、叶酸(folicacid)可逆转之后人们逐渐认识到叶酸、Vit B12缺乏可造成神经系统的损伤。近年来的研究发现叶酸、Vit B12与脑功能障碍尤其与老年人认知障碍有关。从近十几年发表的有关血管性痴呆(Vascular dementia,VD)文献来看,叶酸、Vit B12水平下降或缺乏与VD及认知障碍有关,并研究探讨了其作用机制和叶酸、Vit B12对VD及认知功能的改善效果。

  12. 营养元素大盘点维生素B12

    Institute of Scientific and Technical Information of China (English)

    永军

    2014-01-01

    维生素B12存在于肉食中,通常在蔬菜中难以找到它的踪迹,因此以素食为主的人往往缺乏维生素B12。维生素B12是一种水溶性维生素,它对于神经细胞的正常活动、DNA的复制以及某些具有调节睛绪作用的化学物质的分泌是必不可少的。正因如此,癌症、抑郁症的发生都与维生素B12缺乏有着密切关系。此外,维生素B12对于维护神经系统健康,促进儿童生长发育以及红细胞的生成具有重要的作用。

  13. Associations between Vitamin B-12 Status and Oxidative Stress and Inflammation in Diabetic Vegetarians and Omnivores.

    Science.gov (United States)

    Lee, Yau-Jiunn; Wang, Ming-Yang; Lin, Mon-Chiou; Lin, Ping-Ting

    2016-03-01

    Diabetes is considered an oxidative stress and a chronic inflammatory disease. The purpose of this study was to investigate the correlations between vitamin B-12 status and oxidative stress and inflammation in diabetic vegetarians and omnivores. We enrolled 154 patients with type 2 diabetes (54 vegetarians and 100 omnivores). Levels of fasting glucose, glycohemoglobin (HbA1c), lipid profiles, oxidative stress, antioxidant enzymes activity, and inflammatory makers were measured. Diabetic vegetarians with higher levels of vitamin B-12 (>250 pmol/L) had significantly lower levels of fasting glucose, HbA1c and higher antioxidant enzyme activity (catalase) than those with lower levels of vitamin B-12 (≤ 250 pmol/L). A significant association was found between vitamin B-12 status and fasting glucose (r = -0.17, p = 0.03), HbA1c (r = -0.33, p = 0.02), oxidative stress (oxidized low density lipoprotein-cholesterol, r = -0.19, p = 0.03), and antioxidant enzyme activity (catalase, r = 0.28, p = 0.01) in the diabetic vegetarians; vitamin B-12 status was significantly correlated with inflammatory markers (interleukin-6, r = -0.33, p vegetarian diet. PMID:26927168

  14. Urinary levels of early kidney injury molecules in children with vitamin B12 deficiency.

    Science.gov (United States)

    Güneş, Ali; Aktar, Fesih; Tan, İlhan; Söker, Murat; Uluca, Ünal; Balık, Hasan; Mete, Nuriye

    2016-10-01

    The aim of this study was to investigate urine early kidney injury molecules, including human kidney injury molecule-1 (KIM-1), liver-type fatty-acid binding protein (L-FABP), N-acetyl-b-D-glucosaminidase A (NAG), and neutrophil gelatinase-associated lipocalin (NGAL) in children with vitamin B12 (cobalamin) deficiency (CD). Twelve children with vitamin B12 deficiency and 20 healthy matched controls were included. Hematologic parameters, serum urea, creatinine (Cr), electrolytes, B12 and folate levels were recorded. Estimated glomerular filtration rate (eGFR) was calculated. Urine protein, electrolytes, andurinary early markers were measured. Patients with CD had significantly higher urine electrolyte/Cr ratios (p L-FABP/Cr, NAG/Cr and NGAL/Cr were found in CD group (p <0.05). Significant negative correlations were found between levels of serum B12 and urinary markers in the patients (p <0.05). Increased urinary kidney injury molecules and electrolytes in children with B12 deficiency suggest a possible subclinical renal dysfunction, which cannot be determined by conventional kidney function tests. PMID:27606644

  15. Effect of calcium deficiency on vitamin B12 absorption in rats.

    Science.gov (United States)

    Bergesen, O; Schjønsby, H; Schjerven, L

    1990-03-01

    The influence of calcium on vitamin B12 absorption was investigated in two experiments. In the first we investigated whether B12 malabsorption in rats with biliary diversion through choledochocolic fistula is caused by deficiency of calcium in the small intestine. Calcium concentrations were measured in 10 fistula- and 10 sham-operated rats. Fistula rats had steatorrhea, but the concentration of calcium in the intestinal lumen was increased. In the second experiment we studied the effect of calcium deficiency on B12 absorption. Ten young rats were fed a low-calcium diet and 10 rats a control diet for 4 weeks. Rats on the low-calcium diet had moderately reduced calcium concentration in the blood and in the intestinal juice but unaltered calcium concentration in the cytosol fraction of intestinal mucosal scrapings. The absorption of 57CoB12 was unimpaired. This suggests that moderate calcium deficiency does not influence the intestinal absorption of vitamin B12 in the rat. PMID:2320946

  16. Localised Skin Hyperpigmentation as a Presenting Symptom of Vitamin B12 Deficiency Complicating Chronic Atrophic Gastritis.

    Science.gov (United States)

    El-Shafie, Kawther; Samir, Nafisa; Lakhtakia, Ritu; Davidson, Robin; Al-Waili, Ahmed; Al-Mamary, Muna; Al-Shafee, Mohammed

    2015-08-01

    Vitamin B12 deficiency is common in developing countries and should be suspected in patients with unexplained anaemia or neurological symptoms. Dermatological manifestations associated with this deficiency include skin hyper- or hypopigmentation, angular stomatitis and hair changes. We report a case of a 28-year-old man who presented to the Sultan Qaboos University Hospital in Muscat, Oman, in November 2013 with localised hyperpigmentation of the palmar and dorsal aspects of both hands of two months' duration. Other symptoms included numbness of the hands, anorexia, weight loss, dizziness, fatigability and a sore mouth and tongue. There was no evidence of hypocortisolaemia and a literature search revealed a possible B12 deficiency. The patient had low serum B12 levels and megaloblastic anaemia. An intrinsic factor antibody test was negative. A gastric biopsy revealed chronic gastritis. After B12 supplementation, the patient's symptoms resolved. Family physicians should familiarise themselves with atypical presentations of B12 deficiency. Many symptoms of this deficiency are reversible if detected and treated early. PMID:26357561

  17. Localised Skin Hyperpigmentation as a Presenting Symptom of Vitamin B12 Deficiency Complicating Chronic Atrophic Gastritis

    Directory of Open Access Journals (Sweden)

    Kawther El-Shafie

    2015-08-01

    Full Text Available Vitamin B12 deficiency is common in developing countries and should be suspected in patients with unexplained anaemia or neurological symptoms. Dermatological manifestations associated with this deficiency include skin hyper- or hypopigmentation, angular stomatitis and hair changes. We report a case of a 28-year-old man who presented to the Sultan Qaboos University Hospital in Muscat, Oman, in November 2013 with localised hyperpigmentation of the palmar and dorsal aspects of both hands of two months’ duration. Other symptoms included numbness of the hands, anorexia, weight loss, dizziness, fatigability and a sore mouth and tongue. There was no evidence of hypocortisolaemia and a literature search revealed a possible B12 deficiency. The patient had low serum B12 levels and megaloblastic anaemia. An intrinsic factor antibody test was negative. A gastric biopsy revealed chronic gastritis. After B12 supplementation, the patient’s symptoms resolved. Family physicians should familiarise themselves with atypical presentations of B12 deficiency. Many symptoms of this deficiency are reversible if detected and treated early.

  18. Vitamin B12 levels of subjects aged 0-24 year(s) in Konya, Turkey.

    Science.gov (United States)

    Akin, Fatih; Yavuz, Haluk; Bodur, Said; Kiyici, Aysel

    2014-12-01

    Research reports indicate that vitamin B12 levels show racial differences, which suggests that using the reference ranges of varied populations may lead to inaccurate results. This study aimed to determine normal serum levels of vitamin B12 among children and young people in the Konya region of Turkey. It evaluated 1,109 samples; 54 were from cord-blood and 1,055 were from healthy subjects aged 0-24 year(s), who were admitted to primary healthcare centres. The normal reference levels obtained for vitamin B12 at 2.5-97.5 percentile (P2.5-P97.5) range were 127-606 pg/mL for girls, 127-576 pg/mL for boys, and 127-590 pg/mL for the entire study group. The reported reference values for vitamin B12 in other studies were higher than the current results. Vitamin B12 levels vary from country to country; comparisons between countries may not be valid, and normal levels for each population should be obtained. PMID:25895195

  19. Theoretical study of hydrogen adsorption on Ca-decorated C48B12 clusters

    International Nuclear Information System (INIS)

    The hydrogen adsorption on Ca-decorated C48B12 clusters is studied using density functional theory. The favorable binding site for Ca atom is the hexagonal C4B2 rings. The strong interaction between Ca atoms and C48B12 cluster hinders the aggregation of Ca atoms on the cluster surface. C48B12 is an electron deficient system with a large electron affinity of 2.952 eV. The decorated Ca atoms transfer their electrons to the cluster easily. The net charges on the Ca atoms are in the range of 1.101 to 1.563 e. When H2 molecules approach the Ca atoms, they are moderately polarized and adsorbed around the Ca atoms in molecular form. The adsorption strength can reach up to 0.133 eV/H2. Each Ca atom in the Ca-decorated C48B12 complexes can adsorb three H2 molecules. The fully decorated C48B12Ca6 can hold up to 18 H2 molecules

  20. Enhancing vitamin B12 content in soy-yogurt by Lactobacillus reuteri.

    Science.gov (United States)

    Gu, Qing; Zhang, Chen; Song, Dafeng; Li, Ping; Zhu, Xuan

    2015-08-01

    More attention from the aged and vegetarians has been paid to soy-product due to its taste, easy digestibility, as well as the association with health. However, soy-product has a defect of low vitamin content, mainly the water-soluble vitamin B12. This study was to investigate co-fermentation of glycerol and fructose in soy-yogurt to enhance vitamin B12 production by Lactobacillus reuteri. After a serial combination experiments, the co-fermentation was confirmed to enhance the production of vitamin B12 up to 18 μg/100mL. Both supplementations induced the expression of cobT and cbiA and functioned to balance the redox reaction. Meanwhile, high content of fructose supplementation reduced the production of vitamin B12 and suppressed expression of cobT in bacteria. It was proved that the vitamin B12 content of this soy-yogurt is higher than other fermented soybean based food and thus can be served as an alternative food for the aged and vegetarians. PMID:25955289

  1. Treatment of radiation skin lesions in various stages with different preparations of vitamin B12

    International Nuclear Information System (INIS)

    Since the aqueous solution of Vit. B12 was firstly used to treat efficaciously the acute radiation injury of skin and superficial second-degree skin burn, we have successfully treated radiation skin lesions in acute, chronic and recovering stages with the cream or oil preparation of Vit. B12. In the period of ten years (1979-1988), altogether 418 cases of radiation or non-radiation skin injury were observed and 48 out of 49 cases with acute radiation skin ulcer treated with aqueous solution of Vit. B12 were healed with an effective rate of 97.95% and average healing time of 12.6 days. All of 37 cases with chronic radiation skin injury treated with oil preparation of Vit. B12 were healed or improved with an effective rate of 100% and average healing time of 21.49 days. However, in the control group, of 18 cases treated with conventional drugs only 13 were healed, the effective rate being 72.22% and healing time 63.5 days, and both of these indices were of significant difference, as compared with those treated with Vit. B12

  2. Clinical Significances of Serum Vitamin B12, Folate and Ferritin Levels in Patients with Malignant Tumors

    International Nuclear Information System (INIS)

    In order to evaluate the clinical significances of the serum vitamin B12, folate and ferritin levels in patients with malignant tumors, the levels were measured in 10 normal control subjects, 70 patients with malignant tumors, 7 patients with liver cirrhosis and 25 patients with other benign diseases. The results are as follows: 1) In normal control subjects, mean serum values for vitamin B12, folate and ferritin level were 588.80±131.58 pg/ml, 5.59±1.52 ng/ml and 89.22±42.78 ng/ml retrospectively. 2) There was no significant difference in serum levels between patients with benign diseases and normal control subjects. 3) The serum vitamin B12 and ferritin levels in patients with liver cirrhosis were significantly higher than in normal control, and the serum folate levels in these patients were lower than in normal control subjects. 4) The serum vitamin B12 and ferritin levels in patients with malignant tumors were significantly higher than in normal control subjects, and the serum folate levels in these patients were significantly lower than in normal control subjects. The above results suggest that the serum vitamin B12 and ferritin may be useful as tumor markers in patients with malignant tumors.

  3. The Schilling test cannot be replaced by an absorption test with unlabeled vitamin B12.

    Science.gov (United States)

    Henze, E; Männer, S; Clausen, M; Malfertheiner, P; Hellwig, D; Ditschuneit, H; Kornhuber, H; Adam, W E

    1988-04-15

    It was the purpose of this study to evaluate the diagnostic usefulness of an oral absorption test using nonlabeled Vit B12 suggested by a commercial distributor as an alternative for the more expensive Schilling test (ST). Plasma levels of Vit B12 were measured with a commercial kit before and 4 h after oral administration of 1 mg Vit B12 in 32 normals, in 16 patients with normal ST, and in 14 patients with abnormal ST for determination of sensitivity and specificity with the ST as golden standard. In normals, a mean of 767 +/- 404 pg/ml before and 1096 +/- 776 pg/ml after oral Vit B12 with a mean increase of 331 +/- 453 pg/ml was measured. Because of the obvious large variation, no meaningful range for normal absorption could be established. In the two patient subsets, there was no Gaussian distribution of the results, with a meridian of Vit B12 increase after absorption of 142 pg/ml, range 27-2668 pg/ml, in the group with normal ST and a meridian of 244 pg/ml ranging from 40 to 2453 pg/ml in the group with abnormal ST. Statistical nonparametric analysis did not reveal any difference between the two groups. Assuming a minimum required increase of 100 pg/ml, as suggested by the kit distributor, a sensitivity of only 27% and a specificity of 75% was obtained.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3392890

  4. Neurological Manifestations Of Vitamin B12 (Coblamin Deficiency with a Re-appraisal of its Etiology

    Directory of Open Access Journals (Sweden)

    Divate p

    2003-01-01

    Full Text Available We undertook a study 25 patients, all clinically suspected to have vitamin B12 deficiency; they were investigated hematologically, biochemically, & by gastric biopsy and MRI. Most of the patients were more than 40 years of age, were either vegetarian or non-vegetarian; 21 patients were belonging to the middle-income group. The total number of males in the study was 22 and there were three females. The clinical features of vitamin B12 deficiency are described. Clinical evidence of pyramidal tract involvement was found in six patients (24%. MRI confirmed cord involvement in 12 of the 17 patients (70.5%: follow up MRI of two patients showed marked reductions in signals after one year of treatment. These patients showed improvement after receiving injectable vitamin b12. Nerve conduction studies (N.C.V showed evidence of neuropathy in fifteen of eighteen (83% patients. Gastric biopsy was abnormal in all except one in the 20 patients in whom it was conducted. Anti intrinsic factor blocking antibodies (AIFBA were elevated in 11/24 (45.8% and anti parietal cell antibodies (APCAB were elevated in 19/24 patients (79%. The possible etiological factors responsible for vitamin B12 deficiency are age and pernicious anemia. As concluded in this study, diet was not found to be a contributory factor in the causation of cobalamin deficiency. We conclude that pernicious anemia is probably an important etiological factor as a cause of vitamin B12 deficiency in Indians. The male predominance is intriguing.

  5. Determination of vitamin B12 (cobalamine) absorption by means of a simple double-isotope technique

    International Nuclear Information System (INIS)

    The background, practical instruction and clinical results of a simplified method of determining the absorption of cobalamine (vitamin B12) are presented. The simultaneous administration of 57CO-CN-cobalamine, a non-absorbable marker (51CrCl3), and red carmine tablets enable quantitative assessments of the cobalamine absorption by collection of a small red feaces sample. In contrast to the classical Schilling-test, this vitamin B12 absorption test (B12-ABS-test) or faeces-spot-test is, independent of fasting, flushing dose, renal function and diurnal urinary collection. This is documented in a series of clinical studies. The B12-ABS-test provides accurate and precise results compared to the reference method (whole-body-counting). The Schilling test, on the contrary, gives approximately 50% false low values in a reference group of elderly hospitalized patients. A modification of the B12-ABS-test, has been used to determine the cobalamine absorption in children, and a set of age-related reference intervals have been established, together with quantitative measurements of the cobalamine absorption in children with small bowel diseases. Based on several years of practical experience, we recommend replacement of the Schilling test by this simple double-isotope technique. (author)

  6. Bile acid sequestrants for cholesterol

    Science.gov (United States)

    ... ency/patientinstructions/000787.htm Bile acid sequestrants for cholesterol To use the sharing features on this page, ... are medicines that help lower your LDL (bad) cholesterol . Too much cholesterol in your blood can stick ...

  7. The impact of vegan diet on B-12 status in healthy omnivores: five-year prospective study

    OpenAIRE

    Edyta Mądry; Aleksandra Lisowska; Philip Grebowiec; Jarosław Walkowiak

    2012-01-01

    Background. There are no long-term prospective studies assessing the impact of the vegan diet on vitamin B-12 (B-12) status. Many vegans take B-12 supplements irregularly or refuse to adopt them at all, considering them to be “unnatural” products. The use of B-12 fortifi ed food may be an alternative. Therefore, we aimed to estimate the long-term effect of a vegan diet on serum B-12 concentrations in healthy omnivore adults, comparing the infl uence of natural products con...

  8. Hyperhomocysteinaemia And Vitamin B12 Deficiency In Ischaemic Strokes In India

    Directory of Open Access Journals (Sweden)

    Wadia R S

    2004-01-01

    Full Text Available Hyperhomocysteinemia is a recognised risk factor for stroke and ischemic heart disease (HID. Vit B12 Folate and pyridoxine deficiency are important causes of raised serum homocysteine. As a vegetarian diet is very poor in Vit B12 we sought to study the incidence of hyperhomocysteinaemia in our stroke populating and to measure Vit B12 and folate in these cases. Consecutive cases of ischaemic stroke, either arterial or venous, admitted over a period of 2 1/2 years were studied. Embolic strokes and those on vitamin supplements were excluded. cases were divided into vegetarian (including those taking milk and / Or eggs, those who took non-vegetarian 4 or less times a month, and frequent non-vegetarians taking 5 or more times a month. Serum total homocysteine, serum B12 and folate levels were studied along with all other routine parameters. For comparison we examined 101 controls without HID, stroke, peripheral vascular disease, rental failure or recent vitamin intake. With the international norm for homocysteine given as 5-15 umol/litre (1we called serum homocysteine 16 umol/litre or more as raised. There were 147 cases of ischcmic stroke :119 arterial and 28 venous infarcts. In the arterial strokes 99 of 119 cases (83.19% had raised serum Homocysteine including 25 of 27 (92.5% of those with arterial stroke before age 45. Of 28 cases with venous infarct 21 (75% had raised homocysteine (HCY. Hyperhomocysteinemia was the commonest risk factor for stroke in our populations. Out of the total 147 cases the exact dietary intake was not known for ten cases., 58 were vegetarians, 54 were occasional non vegetarians (NV and 25 were frequent NV. In the 58 vegetarians, 55 had serum HCY> 16 umol/1 (94.8% and of those vegetarians with HCY> 16, serum B12 <200pg/ml was seen in 44 (75.8% and between 200-300 pg/ml in five (8.6%. Of the 54 occasional NV, 46 had HCY>16umo/1 (85.2% Of those with HCY >16, serum B12 level of <200 pg/ ml was seen in 28 (51.85% occ. NV and

  9. HPLC法测定维生素B12片的含量

    Institute of Scientific and Technical Information of China (English)

    张静; 刘志杰; 李东辉

    2011-01-01

    目的为了建立HPLC法测定维生素B12片含量的方法。方法采用WatersC18色谱柱,流动相为乙腈-0.05mol/L磷酸二氢钾(pH3.0)(13:87),流速1.0mL/min,检测波长237nm。结果维生素B12在0.255~0.765μg/ml范围内呈良好线性关系,回收率(n=3)为98.5%。结论该方法简便、快捷,可作为维生素B12片的质量控制方法之一。

  10. Vitamin B12-catalyzed synthesis of some peracetylated alkyl b-D-xylopyranosides

    Directory of Open Access Journals (Sweden)

    LJILJANA STEVANOVIC

    2003-10-01

    Full Text Available The vitamin B12-catalyzed glycosylation reaction of brominated b-D-xylose peracetate with alkanols ROH (C1-C8 has been studied. The catalytically active species in this reaction was cob(Ialamin, obtained by chemical reduction of Vitamin B12 with NaBH4 (Co(III to Co(I. The reaction was carried out with 2 mol% of vitamin B12, with respect to xylosyl bromide 1, under argon at room temperature. Under these conditions, peracetylated C1-C8-alkyl b-D-xylopyranosides (3a–3f were obtained in moderate yield (55–70 %. In all cases 3,4-di-O-acetyl-D-xylal (4 was obtained, as the product of reductive elimination of peracetylated xylosyl bromide (15–25 %.

  11. Vitamin B12 and folate levels in normal population of northern Pakistan

    International Nuclear Information System (INIS)

    Diagnosis of vitamin B12 or folate deficiency can not be made unless reference ranges of these vitamins in a given population are known. These serum levels depend upon the dietary intake of these vitamins which in turn depends upon the availability of foods containing these vitamins and the methods of cooking/processing. The latter vary in different populations. Therefore serum level of these vitamins would vary in different populations. Serum levels of vitamin B12 and folate were estimated by radioimmunoassay technique in 30 normal subjects of different age groups. The levels of vitamin B12 were found to be 215.2 pg/ml and that of folate 3.9 ng/ml. These values are much lower than those described for European population. It is therefore concluded that the cut off point of the levels of these vitamins should be different than the European figures. (author)

  12. Iron, folacin, vitamin B12 and zinc status and immune response in the elderly

    International Nuclear Information System (INIS)

    The relationships of iron, folacin, vitamin B12 and zinc status to cell-mediated immune response were investigated among 125 healthy, elderly persons (60-87 years of age). Plasma ferritin, plasma and red cell folate, and plasma vitamin B12 levels were assayed immuno-radiometrically. Plasma and hair zinc levels were determined by atomic absorption spectroscopy. Immune response was determined by transformation of peripheral blood lymphocytes after stimulation with phytohemagglutinin (PHA) and concanavalin A (con A), and in mixed lymphocyte reaction. Deficiencies of iron, folacin vitamin B12 and zinc were each associated (independently) with significantly lower lymphocyte responses to PHA and con A, and mixed lymphocyte reaction (P 12 or zinc. Further, they suggest that deficiencies of these nutrients may play a role in the depression of cell-mediated immunity with age, which in turn may lead to increased susceptibility to infectious diseases and cancer in the elderly

  13. Diagnosis of SDAT by HMPAO SPECT and vitamin B12 serum concentration

    International Nuclear Information System (INIS)

    It is quite difficult to confirm the diagnosis of demential disorders, including senile dementia of the Alzheimer type (SDAT) by clinical means only. Through the combination of 99mTc-HMPAO brain SPECT and serum vitamin B12 determination it was hoped to speed up and improve the diagnosis of SDAT. 116 patients who had been divided into four groups according to their defect pattern in the 99mTc-HMPAO brain SPECT 17 very probably had SDAT; of these 15 showed a defect pattern with brain SPECT which could be associated to SDAT. The majority of SDAT patients had serum vitamin B12 levels in the lower normal range or pathologically below that range. Both investigations contributed to establishing the SDAT diagnosis without replacing other investigations. The determination of serum vitamin B12 does not require any major additional effort. (orig.)

  14. The relationship between cerebrovascular disease and homocysteine, folate and vitamin B12 in serum

    International Nuclear Information System (INIS)

    To investigate the relationship between cerebrovascular disease and the serum levels of homocysteine(Hcy), folate and vitamin B12, the serum levels of Hcy, folate and vitamin B12 in 148 patients with cerebrovascular disease were measured by fluorescence polarization immuno- assay and chemiluminescence and were compared with those in healthy controls. The result showed that the serum Hcy levels in patients with cerebral infarction, cerebral hemorrhage and vertebrobasilar ischemiay were significantly higher than those in healthy controls (P12 levels were signifieantly lower (P0.05). No significantly higher ratio of increased Hcy levels was observed in patient with complications (P> 0.05). Our conclusion is that hyperhomocysteinemia may be a new and an independent risk factor for cerebrovascular disease. The serum Hcy level is correlated with decreased levels of folate and vitamin B12 but not obviously correlated with hypertension, diabetes and coronary heart disease. (authors)

  15. Genetic architecture of vitamin B12 and folate levels uncovered applying deeply sequenced large datasets.

    Science.gov (United States)

    Grarup, Niels; Sulem, Patrick; Sandholt, Camilla H; Thorleifsson, Gudmar; Ahluwalia, Tarunveer S; Steinthorsdottir, Valgerdur; Bjarnason, Helgi; Gudbjartsson, Daniel F; Magnusson, Olafur T; Sparsø, Thomas; Albrechtsen, Anders; Kong, Augustine; Masson, Gisli; Tian, Geng; Cao, Hongzhi; Nie, Chao; Kristiansen, Karsten; Husemoen, Lise Lotte; Thuesen, Betina; Li, Yingrui; Nielsen, Rasmus; Linneberg, Allan; Olafsson, Isleifur; Eyjolfsson, Gudmundur I; Jørgensen, Torben; Wang, Jun; Hansen, Torben; Thorsteinsdottir, Unnur; Stefánsson, Kari; Pedersen, Oluf

    2013-06-01

    Genome-wide association studies have mainly relied on common HapMap sequence variations. Recently, sequencing approaches have allowed analysis of low frequency and rare variants in conjunction with common variants, thereby improving the search for functional variants and thus the understanding of the underlying biology of human traits and diseases. Here, we used a large Icelandic whole genome sequence dataset combined with Danish exome sequence data to gain insight into the genetic architecture of serum levels of vitamin B(12) (B12) and folate. Up to 22.9 million sequence variants were analyzed in combined samples of 45,576 and 37,341 individuals with serum B(12) and folate measurements, respectively. We found six novel loci associating with serum B(12) (CD320, TCN2, ABCD4, MMAA, MMACHC) or folate levels (FOLR3) and confirmed seven loci for these traits (TCN1, FUT6, FUT2, CUBN, CLYBL, MUT, MTHFR). Conditional analyses established that four loci contain additional independent signals. Interestingly, 13 of the 18 identified variants were coding and 11 of the 13 target genes have known functions related to B(12) and folate pathways. Contrary to epidemiological studies we did not find consistent association of the variants with cardiovascular diseases, cancers or Alzheimer's disease although some variants demonstrated pleiotropic effects. Although to some degree impeded by low statistical power for some of these conditions, these data suggest that sequence variants that contribute to the population diversity in serum B(12) or folate levels do not modify the risk of developing these conditions. Yet, the study demonstrates the value of combining whole genome and exome sequencing approaches to ascertain the genetic and molecular architectures underlying quantitative trait associations. PMID:23754956

  16. HPLC determination of vitamin B12 and inositol in Lysine,Inositol and Vitamin B12 Oral Solution%高效液相色谱法测定赖氨肌醇维B12口服溶液中维生素B12及肌醇的含量

    Institute of Scientific and Technical Information of China (English)

    刘珊珊; 吴琼珠

    2007-01-01

    目的:建立赖氨肌醇维B12口服溶液中维生素B12和肌醇的含量测定方法.方法:采用高效液相色谱法,紫外及示差折光检测器,ODS柱和氨基柱分别测定维生素B12和肌醇含量.流动相分别为乙腈-0.05 mol·L-1磷酸二氢钾溶液(13∶87)用磷酸调节pH至3.0,乙腈-水(70∶30);检测波长分别为 361 nm 和 210 nm;流量:1.0 mL·min-1;进样体积:20 μL.结果:维生素B12和肌醇浓度分别在1.52~6.08 μg·mL-1和5.02~20.06 mg·mL-1范围内与峰面积呈良好的线性关系,平均回收率(n=9)分别为99.5%(RSD=0.76%)和99.4%(RSD=1.39%).结论:本法专属性强,结果准确,重现性好,适用于赖氨肌醇维B12口服溶液中维生素B12和肌醇的含量测定.

  17. Effects of vitamin B12 on the corneal nerve regeneration in rats.

    Science.gov (United States)

    Romano, Maria Rosaria; Biagioni, Francesca; Carrizzo, Albino; Lorusso, Massimo; Spadaro, Angelo; Micelli Ferrari, Tommaso; Vecchione, Carmine; Zurria, Monia; Marrazzo, Giuseppina; Mascio, Giada; Sacchetti, Benedetto; Madonna, Michele; Fornai, Francesco; Nicoletti, Ferdinando; Lograno, Marcello Diego

    2014-03-01

    The study was designed to investigate the effects of a new ophthalmic solution containing 0.05% vitamin B12 0.05% on corneal nerve regeneration in rats after corneal injury. Eyes of anesthetized male Wistar rats were subjected to corneal injury by removing the corneal epithelium with corneal brush (Algerbrush). After the epithelial debridement, the right eye of each animal received the instillation of one drop of the ophthalmic solution containing vitamin B12 0.05% plus taurine 0.5% and sodium hyaluronate 0.5% four time per day for 10 or 30 days. Left eyes were used as control and treated with solution containing taurine 0.5% and sodium hyaluronate 0.5% alone following the same regimen. Fluorescein staining by slit-lamp and morphological analysis was used to determine corneal wound healing. Immunohistochemistry, immunoblot and confocal microscopy were used to examine corneal re-innervation. Slit-lamp and histological analyses showed that re-epithelization of the corneas was accelerated in rats treated with vitamin B12. A clear-cut difference between the two groups of rats was seen after 10 days of treatment, whereas a near-to-complete re-epithelization was observed in both groups at 30 days. Vitamin B12 treatment had also a remarkable effect on corneal re-innervation, as shown by substantial increased in the expression of neurofilament 160 and β-III tubulin at both 10 and 30 days. The presence of SV2A-positive nerve endings suggests the presence of synapse-like specialized structures in corneal epithelium of the eye treated with vitamin B12. Our findings suggest that vitamin B12 treatment represents a powerful strategy to accelerate not only re-epithelization but also corneal re-innervation after mechanical injury. PMID:24486457

  18. NutriPhone: vitamin B12 testing on your smartphone (Conference Presentation)

    Science.gov (United States)

    Lee, Seoho; O'Dell, Dakota; Hohenstein, Jessica; Colt, Susannah; Mehta, Saurabh; Erickson, David

    2016-03-01

    Vitamin B12 deficiency is the leading cause of cognitive decline in the elderly and is associated with increased risks of several acute and chronic conditions including anemia. The deficiency is prevalent among the world population, most of whom are unaware of their condition due to the lack of a simple diagnostics system. Recent advancements in the smartphone-enabled mobile health can help address this problem by making the deficiency tests more accessible. Previously, our group has demonstrated the NutriPhone, a smartphone platform for the accurate quantification of vitamin D levels. The NutriPhone technology comprises of a disposable test strip that performs a colorimetric reaction upon collecting a sample, a reusable accessory that interfaces with the smartphone camera, and a smartphone app that stores the algorithm for analyzing the test-strip reaction. In this work, we show that the NutriPhone can be expanded to measure vitamin B12 concentrations by developing a lateral flow assay for B12 that is compatible with our NutriPhone system. Our novel vitamin B12 assay incorporates blood sample processing and key reagent storage on-chip, which advances it into a sample-in-answer-out format that is suitable for point-of-care diagnostic applications. In order to enable the detection of pM levels of vitamin B12 levels, silver amplification of the initial signal is used within the total assay time of less than 15 minutes. We demonstrate the effectiveness of our NutriPhone system by deploying it in a resource-limited clinical setting in India where it is used to test tens of participants for vitamin B12 deficiency.

  19. Serum folate, vitamin B-12 and cognitive function in middle and older age: The HAPIEE study

    Science.gov (United States)

    Horvat, Pia; Gardiner, Julian; Kubinova, Ruzena; Pajak, Andrzej; Tamosiunas, Abdonas; Schöttker, Ben; Pikhart, Hynek; Peasey, Anne; Jansen, Eugene; Bobak, Martin

    2016-01-01

    Background Nutrient status of B vitamins, particularly folate and vitamin B-12, may be related to cognitive ageing but epidemiological evidence remains inconclusive. Objective The aim of this study was to estimate the association of serum folate and vitamin B-12 concentrations with cognitive function in middle-aged and older adults from three Central and Eastern European populations. Methods Men and women aged 45–69 at baseline participating in the Health, Alcohol and Psychosocial factors in Eastern Europe (HAPIEE) study were recruited in Krakow (Poland), Kaunas (Lithuania) and six urban centres in the Czech Republic. Tests of immediate and delayed recall, verbal fluency and letter search were administered at baseline and repeated in 2006–2008. Serum concentrations of biomarkers at baseline were measured in a sub-sample of participants. Associations of vitamin quartiles with baseline (n = 4166) and follow-up (n = 2739) cognitive domain-specific z-scores were estimated using multiple linear regression. Results After adjusting for confounders, folate was positively associated with letter search and vitamin B-12 with word recall in cross-sectional analyses. In prospective analyses, participants in the highest quartile of folate had higher verbal fluency (p < 0.01) and immediate recall (p < 0.05) scores compared to those in the bottom quartile. In addition, participants in the highest quartile of vitamin B-12 had significantly higher verbal fluency scores (β = 0.12; 95% CI = 0.02, 0.21). Conclusions Folate and vitamin B-12 were positively associated with performance in some but not all cognitive domains in older Central and Eastern Europeans. These findings do not lend unequivocal support to potential importance of folate and vitamin B-12 status for cognitive function in older age. Long-term longitudinal studies and randomised trials are required before drawing conclusions on the role of these vitamins in cognitive decline. PMID:26808046

  20. [Determination of serum vitamin B12 and folic acid by non boil (new standard) radioassay].

    Science.gov (United States)

    Ishiwata, Y; Tuchii, K; Endo, N; Ikeda, R; Yasuda, K

    1994-06-01

    On purpose to study the radioassay of serum vitamin B12 and folic acid using non boil methods in with these two vitamins were released from their endogenous binding proteins with alkaline denaturation and separated the bound vitamins from the free ones with the magnetic iron particles coated these vitamin binders (purified hog intrinsic factor and beta-lactoglobulin from cow milk) were evaluated on precision and accuracy, compared with boil radioassay. 1. The reproducibilities of non boil method were 4.5 +/- 2.5% on vit. B12 and 3.5 +/- 0.2% on folate (n = 10), respectively. 2. The recovery test of the two serum vitamins with the use of cyanocobalamin and pteroylglutamic acid (J.P.) were finely showed the rations of 95.2-99.0% for vit. B12 and 101.0-108.0% for folic acid. And that of folic acid use of 5-methyl-tetrahydro-pteroylglutamic acid was showed the ratios of 101.0-104.0%. The values of folic acid measured by this method were found slightly higher than non boil method using conventional standard. 3. The correlation coefficient between non boil method and boil method were 0.987 and regression equation was showed y = 0.97x + 73.59 for vit. B12 (n = 75) and r = 0.932, y = 1.02x-0.08 (n = 78) for folic acid. 4. Normal range of serum total vit. B12 concentration was 210-920 (484 +/- 160 pg/ml, n = 259) and that of folic acid was 2.5-9.2 (5.2 +/- 1.4 ng/ml, n = 257), as well as boil method. 5. Accordingly it was considered that non boil (new standard) method was excellent for estimation of vitamin B12 and folic acid clinical status. PMID:8072237

  1. [A case of subacute combined degeneration with normal serum vitamin B12 level].

    Science.gov (United States)

    Nagaishi, Akiko; Takashima, Hiroshi; Fukuda, Yasuo; Kuroda, Yasuo

    2003-09-01

    A 40-year-old woman was admitted to our hospital because of pancytopenia with megaloblastic anemia. Two months later she complained of rapidly progressive gait disturbance and numbness in the distal part of limbs. She also told that her hair had turned totally gray in the third decade. Neurologically, mental state, cranial nerves and cerebellar functions were normal. Superficial sensations were impaired below the lower thoracic level and deep sensations were completely lost in the lower limbs. Moderate weakness was found in the lower limbs, symmetrically. Deep tendon reflexes were diminished in the upper limbs and absent in the lower limbs. Babinski's reflex was positive bilaterally. MR images of the spinal cord showed hyperintensity in the posterior column below the thoracic cord. Although the serum level of vitamin B12 was within normal range, serum homocysteine level was elevated markedly. Under the diagnosis of subacute combined degeneration (SCD) due to possible vitamin B12 deficiency, the treatment with intravenous injections of 500 micrograms/day of mecobalamin was undertaken. Muscle strength and sensory impairment improved progressively and she became able to walk with a cane. The coloration of her gray hair was also noted. After treatment, pancytopenia and megaloblastic anemia also markedly improved. Vitamin B12 became high in serum concentration and the serum level of homocysteine became normal. These clinical and laboratory findings support the diagnosis of SCD with normal serum level of vitamin B12 in our case, suggesting that the level of vitamin B12 in serum does not always correlate with that in tissue and, therefore, SCD should not be excluded just only by the reason of normal serum vitamin B12 level. PMID:14727562

  2. The impact of vegan diet on B-12 status in healthy omnivores: five-year prospective study

    Directory of Open Access Journals (Sweden)

    Edyta Mądry

    2012-06-01

    Full Text Available Background. There are no long-term prospective studies assessing the impact of the vegan diet on vitamin B-12 (B-12 status. Many vegans take B-12 supplements irregularly or refuse to adopt them at all, considering them to be “unnatural” products. The use of B-12 fortifi ed food may be an alternative. Therefore, we aimed to estimate the long-term effect of a vegan diet on serum B-12 concentrations in healthy omnivore adults, comparing the infl uence of natural products consumption and B-12 fortifi ed food. Material and methods. A fi ve year prospective study was carried out comprising 20 omnivore healthy adult subjects, who moved to strict vegan diet for 5 years. Ten volunteers followed vegan diet based entirely on natural products, while the remaining ten subjects consumed food fortifi ed in B-12. In all subjects serum vitamin B-12 concentration was determined before and 6, 12, 24 and 60 months after the implementation of the diet. Results. A signifi cant decrease (p < 0.0002 of serum B-12 concentrations in the whole studied group was noted after 60 months of vegan diet. However, observed changes were in fact limited to the subgroup consuming exclusively natural products (p < 0.0001. Conclusions. Transition from omnivore to vegan diet is associated with the risk of vitamin B-12 defi ciency. B-12 fortifi ed products might constitute a valuable alternative in vegans refusing to take vitamin supplements.

  3. Vitamin B12, folate, and homocysteine levels in patients with obsessive–compulsive disorder

    Directory of Open Access Journals (Sweden)

    Türksoy N

    2014-09-01

    Full Text Available Nuray Türksoy,1 Rabia Bilici,2 Altan Yalçiner,3 Y Özay Özdemir,2 Ibrahim Örnek,4 Ali Evren Tufan,5 Ayşe Kara6 1Simurg Psychiatry and Psychotherapy Center, Istanbul, 2Erenköy State Hospital for Psychiatric and Neurological Diseases, Istanbul, 3Düzen Laboratories, Istanbul, 4Florence Nightingale Hospital, Istanbul, 5Department of Child and Adolescent Psychiatry, Abant Izzet Baysal University, Bolu, 6Bakırköy State Hospital for Psychiatric and Neurological Diseases, Istanbul, Turkey Abstract: It is known that elevated serum homocysteine, decreased folate, and low vitamin B12 serum levels are associated with poor cognitive function, cognitive decline, and dementia. Current literature shows that some psychiatric disorders, mainly affective and psychotic ones, can be related to the levels of vitamin B12, folate, and homocysteine. These results can be explained by the importance of vitamin B12, folate, and homocysteine in carbon transfer metabolism (methylation, which is required for the production of serotonin as well as for other monoamine neurotransmitters and catecholamines. Earlier studies focused on the relationship between folate deficiency, hyperhomocysteinemia, and depressive disorders. Although depressive and anxiety disorders show a common comorbidity pattern, there are few studies addressing the effect of impaired one-carbon metabolism in anxiety disorders – especially in obsessive–compulsive disorder (OCD. This study aimed to measure the levels of vitamin B12, folate, and homocysteine specifically in order to see if eventual alterations have an etiopathogenetic significance on patients with OCD. Serum vitamin B12, folate, and homocysteine concentrations were measured in 35 patients with OCD and 22 controls. In addition, the Structured Clinical Interview for the Diagnostic and Statistical Manual for Mental Disorders, Fourth Edition, Text Revision, Yale–Brown Obsessive Compulsive Scale, Hamilton Rating Scale for Depression

  4. 维生素B12的临床应用现状

    Institute of Scientific and Technical Information of China (English)

    杨梦洁

    2014-01-01

    目的:了解维生素B12的临床应用现状。方法复习、分析和整理国内相关文献。结果维生素B12在一些领域有了不少的临床应用进展。结论这些临床应用有推广和继续深入研究的价值。

  5. 维生素总动员之七——维生素B12

    Institute of Scientific and Technical Information of China (English)

    朱雨

    2010-01-01

    食物来源维生素B12基本不存在于植物中,但鱼、蛋、肉、肝中含量丰富,肠道细菌可以合成,故一般情况下人体不缺乏、但维生素B12是素食者容易缺乏的维生素,也是红细胞生成不可缺少的重要元素。

  6. 维生素B12(钻胺素)

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    了解维生素B12维生素B12被认为是“红色维生素”,它本身不能通过胃肠很好地分解吸收,需要与钙结合才能吸收;可能会受到酸性或碱性物质、水、阳光、酒精和某些药物的破坏。

  7. Biosynthesis of vitamin B12: concerning the origin of the methine protons of the corrin nucleus

    International Nuclear Information System (INIS)

    13C NMR spectroscopy has been used to locate six deuterium atoms incorporated biosynthetically on the periphery of the corrin nucleus of vitamin B12 (cyanocobalamin) derived from cells of Propionibacterium shermanii grown in a medium containing 50% 2H2O and 13C-enriched delta-aminolevulinic acid. The implications of these results for the mechanism of vitamin B12 biosynthesis are discussed, and it is concluded that the same oxidation level of the intermediates is maintained throughout the biosynthetic pathway, from delta-aminolevulinic acid to corrin

  8. Probing Reversible Chemistry in Coenzyme B12-Dependent Ethanolamine Ammonia Lyase with Kinetic Isotope Effects

    OpenAIRE

    Rentergent, Julius; Scruton, Nigel S; Hay, Sam; Jones, Alex R.

    2015-01-01

    Coenzyme B12-dependent enzymes such as ethanolamine ammonia lyase have remarkable catalytic power and some unique properties that enable detailed analysis of the reaction chemistry and associated dynamics. By selectively deuterating the substrate (ethanolamine) and/or the β-carbon of the 5′-deoxyadenosyl moiety of the intrinsic coenzyme B12, it was possible to experimentally probe both the forward and reverse hydrogen atom transfers between the 5′-deoxyadenosyl radical and substrate duri...

  9. Metabolic engineering of cobalamin (vitamin B12) production in Bacillus megaterium

    OpenAIRE

    Biedendieck, Rebekka; Malten, Marco; Barg, Heiko; Bunk, Boyke; Martens, Jan‐Henning; Deery, Evelyne; Leech, Helen; Warren, Martin J.; Jahn, Dieter

    2009-01-01

    Summary Cobalamin (vitamin B12) production in Bacillus megaterium has served as a model system for the systematic evaluation of single and multiple directed molecular and genetic optimization strategies. Plasmid and genome‐based overexpression of genes involved in vitamin B12 biosynthesis, including cbiX, sirA, modified hemA, the operons hemAXCDBL and cbiXJCDETLFGAcysGAcbiYbtuR,and the regulatory gene fnr, significantly increased cobalamin production. To reduce flux along the heme branch of t...

  10. Long-term outcome in children with nutritional vitamin B12 deficiency

    Directory of Open Access Journals (Sweden)

    Melike Sezgin Evim

    2011-12-01

    Full Text Available Objective: Vitamin B12 deficiency is frequently observed in developing countries. Herein we report the long-term clinical and laboratory outcomes in 45 children presented with various symptoms of vitamin B12 deficiency.Materials and Methods: Symptoms and physical findings, and percentiles for weight, height, and head circumference at presentation were recorded. The educational level of the patients’ mothers, vitamin B12 deficiency-related diseases and family income data were collected. Complete blood count, serum vitamin B12, folate, iron, iron binding capacity and ferritin, and plasma homocysteine levels were recorded measured at presentation. The patients were treated with vitamin B12, as follows: 1 mg/d IM for 1 week, followed by 1 mg IM QWK for 2 weeks, and then monthly 1mg injections. Patients were neurologically and hematologically re-evaluated after treatment. The visual evoked potential (VEP test was used to examine the integrity and function of the visual pathway. Brainstem evoked potential (BAEP responses were used to analyze auditory function. Neuromotor development was assessed using Denver II Development Screening Test. Results: The mean age of 20 male and 25 female patients was 5.6±5.9 years (range: 1.4 months-17 years. The most common symptoms at presentation were weakness, failure to thrive, and hematologic manifestations (pallor, petechiae, ecchymosis. Abnormal neurologic findings at presentation were observed in 20% of the patients, and were more commonly observed in those <2 years. VEP, BAEP, and Denver II Development tests were performed in 66% of the patients one year after vitamin B12 replacement was started. VEP and BAEP interval prolongation was observed in 37% and 17% of the cases, respectively. Denver II Development Test results showed developmental delay in 20% of the patients tested.Conclusion: All the patients achieved full hematologic recovery within 1 month of treatment onset. Neurological symptoms resolved

  11. Congenital disorders of vitamin B12 transport and their contributions to concepts. II.

    OpenAIRE

    Hall, C. A.

    1981-01-01

    Congenital deficiencies of Transcobalamin II (TC II) and R binders of vitamin B12 (B12, cobalamin, Cbl) have been described in several families. The deficiency of TC II exists as at least three variants. The deficiency of TC II is expressed by a profound megaloblastic pancytopenia during the first few weeks of life, but the serum Cbl is normal. In contrast, the deficiency of R binder is asymptomatic, tissues are replete in Cbl, but the serum Cbl is low. All of the R binder in the several body...

  12. Vitamin B(12) dependent changes in mouse spinal cord expression of vitamin B(12) related proteins and the epidermal growth factor system

    DEFF Research Database (Denmark)

    Mutti, Elena; Lildballe, Dorte L; Kristensen, Lise;

    2013-01-01

    Chronic vitamin B(12) (cobalamin) deficiency in the mammalian central nervous system causes degenerative damage, especially in the spinal cord. Previous studies have shown that cobalamin status alters spinal cord expression of epidermal growth factor (EGF) and its receptor in rats. Employing a...... cobinamide (4.25nmol/h), saline or cobalamin (1.75nmol/h) the spinal cords were analyzed for cobalamin and for the mRNA levels of cobalamin related proteins and members of the EGF system using quantitative reverse transcription PCR. The median spinal cord cobalamin content was 17, 32, and 52pmol/gr of...

  13. Vitamin B12 deficiency: An important reversible co-morbidity in neuropsychiatric manifestations

    Directory of Open Access Journals (Sweden)

    Thomas Gregor Issac

    2015-01-01

    Full Text Available Background: Vitamin B12 deficiency is a common condition causing neurologic, cognitive, psychiatric, and mood symptoms. With varied religious, ethnic, and socioeconomic heterogeneity among the people in India greatly influencing their dietary habits and with the high prevalence of Helicobacter pylori infection, Vitamin B12 deficiency is not uncommon, but is often under recognized due to the lack of classical symptomatic presentation. Materials and Methods: Retrospective study on Vitamin B12 deficiency with neuropsychiatric symptoms in patients who attended neurology, psychiatry, and geriatric OPDs for a period of 1 year in a specialized neuropsychiatric institute in South India. Results: Out of 259 patients who had Vitamin B12 deficiency (<220 pmol/L, 60 had neuropsychiatric symptoms. Among them the Vitamin B12 levels were <150 (severe, 150-200 (moderate, and 201-220 pmol/L (mild in 19, 24, 17 patients, respectively. Twenty one were diagnosed with Posterior dementias, 20 with frontotemporal dementia, 7 with Schizophrenia, 4 each with Parkinson′s disease and alcohol-dependent syndromes (ADS, 3 with bipolar affective disorder, and 1 with Creutzfeldt-Jakob disease. Eight patients also had hypothyroidism. First symptom of presentation was behavioral disturbances in 30 (50%, memory loss in 20 (33.9%, and sensorimotor and movement disorders in 9 (15.3%, and 56.7% were vegetarians while 43.3% were nonvegetarians. In our study, Vitamin B12 deficiency was more prevalent in elderly males (56.67% and was associated with increased severity of behavioral disturbances (P = 0.043 which was the most common presentation. Memory loss was present in 16 (84.2% patients of severe Vitamin B12 deficiency. Hindi mental status examination (HMSE score was graded as <20, 20-24, 24-31 in 37 (61.7%, 10 (16.7%, and 13 (21.7% patients, respectively. Cognitive decline in Vitamin B12 deficiency was significantly associated with increased serum cholesterol (P = 0.019 and was

  14. Effects of divalent cations on vitamin B12 adsorption to brush borders of rat intestine

    International Nuclear Information System (INIS)

    A brush border preparation from rat intestine was incubated with rat intrinsic factor-vitamin B12 complex in 0.01M Tris-HCl buffer, pH 7.4. The 57Co-B12 uptake to brush borders was proportional to the amount of protein or to alkaline phosphatase activity in the preparations. The uptake increased with time of incubation. At 370C, the uptake after incubation for 15 min. was 80-85% of that for one hr. The uptake at 4 0C was approximately 70% of that at 37 0C. There was no difference as a result of adding glucose to the incubation medium. The uptake was observed in the alkaline environment above pH 6.3. Maximum uptake occurred at pH 8.0. Brush borders washed with Krebs-Ringer bicarbonate buffer (pH 7.4) exhibited no difference in B12 uptake, whether in the presence of absence of calcium ion. But brush borders washed with ethylenediaminetetraacetate exhibited no uptake when incubated in calcium-free medium. The uptake reached a maximum by addition of calcium ion at a concentration of 0.3 mM, and was not alter up to 10 mM. Addition of magnesium ion exhibited no uptake. Calcium-dependent B12 uptake was markedly inhibited by manganese ion. Magnesium ion seemed to slightly inhibit the calcium-dependent uptake. (auth.)

  15. Perturbed angular correlation studies of Hf binding to cyanocobalamin (vitamin B12)

    International Nuclear Information System (INIS)

    Gamma ray perturbed angular correlation (PAC) experiments have been carried out with 181Hf labeled cyanocobalamin. Evidence is presented which strongly indicates that Hf binds to vitamin B12 at the phosphate group linking the sugar residue to a side chain of the corrin ring system. Analysis of the time-differential PAC spectra for the crystalline Hf--B12 complex indicates a static electric quadrupole interaction at the Hf nucleus, corresponding to the electric field gradient generated by the chemical bonding. The magnitudes of the derived interaction parameters are similar to those found in Hf phosphate compounds. In aqueous solution, the Hf--B12 complex exhibits PAC spectra which appear to originate from two sources. Approximately 3/4 of the Hf nuclei experience a static electric quadrupole interaction with the same characteristic interaction frequency as in the solid, but with an increased asymmetry parameter. Approximately 1/4 of the Hf signal strength is attributable to a time-dependent quadrupole interaction with a relaxation constant indicative of an effective molecular entity comparable in size to the B12 molecule. This effect may be related to molecular motion in the solution. These results demonstrate the utility of the PAC experimental method for the study of macromolecular species in both the solid and solution forms, and opens possibilities for obtaining new information concerning the structure, orientation, and behavior of macromolecules

  16. Vitamin B12 Replacement Therapy and Its Rehabilitative Effects on Psychiatric and Neurologic Symptoms

    OpenAIRE

    Amador, Nelly

    1998-01-01

    Vitamin b12 (cobalamin) deficiency has been associated with multiple neurological and psychiatric symptoms such as peripheral neuropathy, myelopathy, altered mental status, depression and dementia. Potentially irreversible neuropsychiatric changes due to low cobalamin levels are avoidable. Despite some controversy over the effectiveness of cobalamin therapy, there is growing evidence that subjects with low serum cobalamin levels suffering from dementia, displayed significant cognitive improve...

  17. Vitamin B12 deficiency presenting with an acute reversible extrapyramidal syndrome

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    Kumar Sudhir

    2004-10-01

    Full Text Available Vitamin B12 deficiency usually presents with pernicious anemia or various neuropsychiatric manifestations. Commonly seen neuropsychiatric manifestations include large fiber neuropathy, myelopathy (subacute combined degeneration of the spinal cord, dementia, cerebellar ataxia, optic atrophy, psychosis and mood disorders. The present report highlights an unusual presentation of vitamin B12 deficiency- acute onset extrapyramidal syndrome in a 55-year-old man. The patient presented with a 10-day history of slowness of all activities including a slow gait, mild tremors of hands and low volume speech. On examination, he had features of mask-like facies, reduced blink rate and cogwheel rigidity. He was investigated for the possible causes and was found to have laboratory features of vitamin B12 deficiency. Other causes for acute onset parkinsonism were excluded by appropriate investigations. He showed a dramatic improvement following treatment with intramuscular vitamin B12 injections. At a five-year follow up, he was found to be functionally independent with no neurological deficits.

  18. Platelet MAO-B activity and vitamin B12 in old age dementias.

    Science.gov (United States)

    Parnetti, L; Mecocci, P; Reboldi, G P; Santucci, C; Brunetti, M; Gaiti, A; Cadini, D; Senin, U

    1992-01-01

    Platelet MAO-B activity, serum vitamin B12 levels, and plasma folate were measured in patients suffering from presenile (AD) and senile (SDAT) dementia of Alzheimer-type, and vascular dementia (VD). MAO-B was higher in the SDAT group than in AD and controls. An inverse relationship between MAO-B activity and vit. B12 levels was documented in the whole group and in each category studied; furthermore, MAO-B was positively related to age. All the patients were then divided into two groups, according to vit. B12 levels (Group I: less than 200 pg/mL; Group II: greater than or equal to 200 pg/mL); Group I showed a significantly higher MAO-B activity with respect to Group II. The results indicate the existence of a negative association between platelet MAO-B activity and serum levels of vitamin B12 and confirm the existence of biological differences between presenile and senile dementia of Alzheimer type. PMID:1520404

  19. Transport properties of Ho1- x Lu x B12 solid solutions

    Science.gov (United States)

    Gabáni, S.; Bat'ko, I.; Bat'ková, M.; Flachbart, K.; Gaz̆o, E.; Pristás̆, G.; Takác̆ová, I.; Bogach, A. V.; Sluchanko, N. E.; Shitsevalova, N. Yu.

    2013-05-01

    Our studies of Ho1- x Lu x B12 solid solutions have shown that the temperature of antiferromagnetic (AF) order in geometrically frustrated system of HoB12 ( T N = 7.4 K) is linearly suppressed to zero temperature, i.e. T N → 0, as lutetium concentration increases to x→ x c ≈ 0.9. In this contribution, we present original results of electrical resistivity measurements on Ho1- x Lu x B12 single crystalline samples with x = 0, 0.2, 0.5, 0.7, 0.9, 1 in the temperature range 0.06-300 K and in magnetic fields ( B) up to 8 T. Complex B vs T N phase diagrams were received from precise temperature ρ( T) and field ρ( B) dependences of resistivity with several AF phases for x ≤ 0.5 pointing to a possibility of quantum critical point at x c ≈ 0.9. The scattering of conduction electrons in the AF phase and in the paramagnetic phase as well as Hall effect results are analyzed and discussed for various concentrations x, when magnetic dilution increases with the increasing content of nonmagnetic Lu ions in the Ho1- x Lu x B12 system.

  20. Expeditious synthesis of noble metal nanoparticles using Vitamin B12 under microwave irradiation

    Science.gov (United States)

    A greener synthesis protocol for noble nanometals is developed using vitamin B12 as a reducing and capping agent in conjunction with the use of microwaves. Successful assembly of nanoparticles or microparticles with varied shapes and sizes have been demonstrated. The synthesized ...

  1. Brief Report: Childhood Disintegrative Disorder as a Likely Manifestation of Vitamin B12 Deficiency

    Science.gov (United States)

    Malhotra, Savita; Subodh, B. N.; Parakh, Preeti; Lahariya, Sanjay

    2013-01-01

    Childhood disintegrative disorder is a rare disorder, characterized by regression of acquired skills after a period of normal development. The case of childhood disintegrative disorder presented here was found to have vitamin B12 deficiency and hyperhomocysteinemia on extensive evaluation to find a probable cause for regression. This case…

  2. Review of the magnitude of folate and vitamin B12 deficiencies worldwide

    Science.gov (United States)

    Human deficiencies of folate and vitamin B12 result in adverse effects which may be of public health significance, but the magnitude of these deficiencies is unknown. Therefore, we examine the prevalence data currently available, assess global coverage of surveys, determine the frequency with which...

  3. Structural basis for receptor recognition of vitamin-B(12)-intrinsic factor complexes

    DEFF Research Database (Denmark)

    Andersen, Christian Brix Folsted; Madsen, Mette; Storm, Tina;

    2010-01-01

    Cobalamin (Cbl, vitamin B(12)) is a bacterial organic compound and an essential coenzyme in mammals, which take it up from the diet. This occurs by the combined action of the gastric intrinsic factor (IF) and the ileal endocytic cubam receptor formed by the 460-kilodalton (kDa) protein cubilin and...

  4. Competitive chemiluminescent anzyme immunoassay for vitamin B12 analysis in human milk.

    Science.gov (United States)

    Recent discoveries of matrix interferences by haptocorrin (HC) in human milk and serum show that past analyses of vitamin B12 in samples with high HC content might have been inaccurate (Lildballe et al., 2009; Carmel & Agrawal, 2012). We evaluated two competitive enzyme-binding immunoassays for seru...

  5. Elevated plasma vitamin B12 levels and cancer prognosis: A population-based cohort study

    DEFF Research Database (Denmark)

    Arendt, Johan Frederik Håkonsen; Farkas, Dora Kormendine; Pedersen, Lars;

    2015-01-01

    BACKGROUND: Elevated plasma vitamin B12 levels (cobalamin, Cbl) are associated with increased short-term cancer risk among patients referred for this laboratory measurement. We aimed to assess prognosis in cancer patients with elevated plasma Cbl. METHODS: We conducted a population-based cohort...

  6. Total serum homocysteine as an indicator of vitamin B12 and folate status

    International Nuclear Information System (INIS)

    Presented is a modification of an assay for total serum homocysteine (Hcy) in which the Hcy plus radioactive adenosine is converted enzymatically to labeled S-adenosylhomocysteine (AdoHcy). The modifications included a commerical source for the AdoHcy hydrolase, adenosine labeled with either 14C or 3H, and separation of the AdoHcy by thin layer chromatography. The assay was sensitive to 25 pmol. Hcy levels in sera from 18 controls ranged from 6.9 to 12.1 mumol/L with a mean of 9.1 and a SD of 1.5 mumol/L. The total serum Hcy was increased in vitamin B12 and folate deficiency. The level was high in congenital defects of vitamin B12 metabolism, blocking the methylation of Hcy regardless of the serum vitamin B12 levels, but was normal in the absence of tissue deficiency even if the serum vitamin B12 levels were low. The procedure has been found practical in two years of use and requires only 0.1 mL of serum

  7. Vitamin B complex and vitamin B12 levels after peripheral nerve injury

    Science.gov (United States)

    Altun, Idiris; Kurutaş, Ergül Belge

    2016-01-01

    The aim of the present study was to evaluate whether tissue levels of vitamin B complex and vitamin B12 were altered after crush-induced peripheral nerve injury in an experimental rat model. A total of 80 male Wistar rats were randomized into one control (n = 8) and six study groups (1, 6, 12, 24 hours, 3, and 7 days after experimental nerve injury; n = 12 for each group). Crush-induced peripheral nerve injury was performed on the sciatic nerves of rats in six study groups. Tissue samples from the sites of peripheral nerve injury were obtained at 1, 6, 12, 24 hours, 3 and 7 days after experimental nerve injury. Enzyme-linked immunosorbent assay results showed that tissue levels of vitamin B complex and vitamin B12 in the injured sciatic nerve were significantly greater at 1 and 12 hours after experimental nerve injury, while they were significantly lower at 7 days than in control group. Tissue level of vitamin B12 in the injured sciatic nerve was significantly lower at 1, 6, 12 and 24 hours than in the control group. These results suggest that tissue levels of vitamin B complex and vitamin B12 vary with progression of crush-induced peripheral nerve injury, and supplementation of these vitamins in the acute period may be beneficial for acceleration of nerve regeneration.

  8. Vitamin B complex and vitamin B12 levels after peripheral nerve injury

    Institute of Scientific and Technical Information of China (English)

    Idiris Altun; Ergl Belge Kuruta

    2016-01-01

    The aim of the present study was to evaluate whether tissue levels of vitamin B complex and vitamin B12 were altered after crush-induced peripheral nerve injury in an experimental rat model. A total of 80 male Wistar rats were randomized into one control (n = 8) and six study groups (1, 6, 12, 24 hours, 3, and 7 days after experimental nerve injury;n = 12 for each group). Crush-induced peripheral nerve injury was per-formed on the sciatic nerves of rats in six study groups. Tissue samples from the sites of peripheral nerve injury were obtained at 1, 6, 12, 24 hours, 3 and 7 days after experimental nerve injury. Enzyme-linked immunosorbent assay results showed that tissue levels of vitamin B complex and vitamin B12 in the injured sciatic nerve were signiifcantly greater at 1 and 12 hours after experimental nerve injury, while they were signiifcantly lower at 7 days than in control group. Tissue level of vitamin B12 in the injured sciatic nerve was signiifcantly lower at 1, 6, 12 and 24 hours than in the control group. These results suggest that tissue levels of vitamin B complex and vitamin B12 vary with progression of crush-induced peripheral nerve injury, and supplementation of these vitamins in the acute period may be beneficial for acceleration of nerve regeneration.

  9. Disappearance of cerebral cortical atrophy following replacement therapy with vitamin B12 in an infant

    Directory of Open Access Journals (Sweden)

    Ebru Yilmaz Keskin

    2016-03-01

    Full Text Available Vitamin B12 (cobalamin deficiency during infancy is seen most commonly in exclusively breast-fed infants born to mothers with inadequate vitamin B12 stores. In addition to megaoblastic anemia, physical, social and neuromotor retardation may be seen in affected patients. In severe cases, thrombocytopenia and neutropenia may accompany anemia mimicking leukemia or aplastic anemia. Patients may rarely develop cerebral cortical atrophy evident on neuroimaging. In this article, a 12-month-old female infant with psychomotor developmental retardation who was referred to our hospital with the initial diagnosis of leukemia due to the finding of pancytopenia is presented. Further investigations revealed severe nutritional vitamin B12 deficiency in this case. Cranial magnetic resonance imaging (MRI showed cerebral cortical atrophy. Replacement therapy with vitamin B12 resulted in marked improvement of psychomotor status, and cranial MRI performed 7 months following the diagnosis and treatment initiation revealed resolution of cortical atrophy. [Cukurova Med J 2016; 41(1.000: 152-160

  10. Low-temperature heat capacity and thermodynamic functions of vitamin B12

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Temperature dependence of heat capacity of vitamin B12 has been measured by precision adiabatic vacuum calorimetry. • The thermodynamic functions of the vitamin B12 have been determined for the range from T → 0 to 343 K. • The character of heterodynamics of structure was detected. • The thermal stability of cyanocobalamin was studied by differential scanning calorimetry. - Abstract: In the present work temperature dependence of heat capacity of vitamin B12 (cyanocobalamin) has been measured for the first time in the range from 6 to 343 K by precision adiabatic vacuum calorimetry. Based on the experimental data, the thermodynamic functions of the vitamin B12, namely, the heat capacity, enthalpy H°(T) − H°(0), entropy S°(T) − S°(0) and Gibbs function G°(T) − H°(0) have been determined for the range from T → 0 to 343 K. The value of the fractal dimension D in the function of multifractal generalization of Debye's theory of the heat capacity of solids was estimated and the character of heterodynamics of structure was detected. The thermal stability of cyanocobalamin was also studied by differential scanning calorimetry

  11. Quantifying the Electrocatalytic Turnover of Vitamin B12-Mediated Dehalogenation on Single Soft Nanoparticles.

    Science.gov (United States)

    Cheng, Wei; Compton, Richard G

    2016-02-12

    We report the electrocatalytic dehalogenation of trichloroethylene (TCE) by single soft nanoparticles in the form of Vitamin B12 -containing droplets. We quantify the turnover number of the catalytic reaction at the single soft nanoparticle level. The kinetic data shows that the binding of TCE with the electro-reduced vitamin in the Co(I) oxidation state is chemically reversible. PMID:26806226

  12. Phylogenetic analysis of vitamin B12-related metabolism in Mycobacterium tuberculosis

    OpenAIRE

    Young, Douglas B.; Comas, Iñaki; de Carvalho, Luiz P. S.

    2015-01-01

    Comparison of genome sequences from clinical isolates of Mycobacterium tuberculosis with phylogenetically-related pathogens Mycobacterium marinum, Mycobacterium kansasii, and Mycobacterium leprae reveals diversity amongst genes associated with vitamin B12-related metabolism. Diversity is generated by gene deletion events, differential acquisition of genes by horizontal transfer, and single nucleotide polymorphisms (SNPs) with predicted impact on protein function and transcriptional regulation...

  13. Genomic Sequence of Klebsiella pneumoniae IIEMP-3, a Vitamin B12-Producing Strain from Indonesian Tempeh

    OpenAIRE

    Yulandi, Adi; Sugiokto, Febri Gunawan; Febrilina,; Suwanto, Antonius

    2016-01-01

    Klebsiella pneumoniae strain IIEMP-3, isolated from Indonesian tempeh, is a vitamin B12-producing strain that exhibited a different genetic profile from pathogenic isolates. Here we report the draft genome sequence of strain IIEMP-3, which may provide insights on the nature of fermentation, nutrition, and immunological function of Indonesian tempeh.

  14. Genomic Sequence of Klebsiella pneumoniae IIEMP-3, a Vitamin B12-Producing Strain from Indonesian Tempeh.

    Science.gov (United States)

    Yulandi, Adi; Sugiokto, Febri Gunawan; Febrilina; Suwanto, Antonius

    2016-01-01

    Klebsiella pneumoniae strain IIEMP-3, isolated from Indonesian tempeh, is a vitamin B12-producing strain that exhibited a different genetic profile from pathogenic isolates. Here we report the draft genome sequence of strain IIEMP-3, which may provide insights on the nature of fermentation, nutrition, and immunological function of Indonesian tempeh. PMID:26950331

  15. Effects of Formulation Variables and Storage Conditions on Light Protected Vitamin B12 Mixed Parenteral Formulations

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    Farnaz Monajjemzadeh

    2014-12-01

    Full Text Available Purpose: In this research the effect of vitamin B1 and B6 on cyanocobalamin stability in commercial light protected parenteral formulations and upon adding stabilizing agents will be investigated and best formulation composition and proper storage condition will be introduced. Methods: In this research some additives such as co solvents and tonicity adjusters, surfactants, antioxidants and chelating agents as well as buffer solutions, were used to improve the stability of the parenteral mixed formulations of B12 in the presence of other B vitamins (B1 and B6. Screening tests and accelerated stability tests were performed according to ICH guidelines Q1A (R2. Results: Shelf life evaluation revealed the best formulation and the proper storage condition. The results indicated the first kinetic models for all tested formulations and the optimum pH value was determined to be 5.8. There was no evidence of B12 loss when mixed with B1 and B6 in a medical syringe at room temperature for maximum of 8 hours. Conclusion: It is necessary to formulate vitamin B12 mixed parenteral solutions using proper phosphate buffers (pH=5.8 and to indicate “Store in refrigerator” on the mixed parenteral formulations of vitamin B12 with other B vitamins, which has not been expressed on the label of tested Brand formulations at the time of this study.

  16. Effect of combined folic acid, Vitamin B6, and Vitamin B12 on colorectal adenoma

    Science.gov (United States)

    Folic acid, vitamin B(6), and vitamin B(12) act in concert in the one-carbon metabolism and may protect against colorectal neoplasia. We examined the effect of combined B-vitamin treatment on the occurrence of colorectal adenoma. The Women's Antioxidant and Folic Acid Cardiovascular Study was a rand...

  17. The nutritional status of iron, folate, and vitamin B-12 of Buddhist vegetarians.

    Science.gov (United States)

    Lee, Yujin; Krawinkel, Michael

    2011-01-01

    Nutritional status of iron, folate, and vitamin B-12 in vegetarians were assessed and compared with those of non- vegetarians in Korea. The vegetarian subjects were 54 Buddhist nuns who ate no animal source food except for dairy products. The non-vegetarians were divided into two groups: 31 Catholic nuns and 31 female college students. Three-day dietary records were completed, and the blood samples were collected for analyzing a complete blood count, and serum levels of ferritin, folate, and vitamin B-12. There was no difference in hemoglobin among the diet groups. The serum ferritin and hematocrit levels of vegetarians did not differ from that of non- vegetarian students with a high intake of animal source food but low intake of vitamin C, and the levels were lower than that of non-vegetarian Catholic nuns with a modest consumption of animal source food and a high intake of vitamin C. The serum vitamin B-12 levels of all subjects except one vegetarian and the serum folate levels of all subjects except one non-vegetarian student fell within a normal range. In vegetarians, there was a positive correlation between the vitamin C intake and serum ferritin levels as well as between the laver intake and serum vitamin B-12 levels. In order to achieve an optimal iron status, both an adequate amount of iron intake and its bioavailability should be considered. Sufficient intake of vegetables and fruits was reflected in adequate serum folate status. Korean laver can be a good source of vitamin B-12 for vegetarians. PMID:21393109

  18. [Vitamin B(12) deficiency anaemia in a 7.5 months old girl].

    Science.gov (United States)

    Jarosz, Malgorzata; Irga, Ninela; Wierzba, Jolanta

    2004-01-01

    Vitamin B(12) stores at birth are adequate for infants until the end of the first year of life even if it 's concentration in maternal breast milk is low. However, there are some situations in which infants have depleted vitamin B(12) stores and in addition have a low dietary intake of cobalamin. Vitamin B(12) depletion occurs in infants who are exclusively breastfed by mothers who have unrecognized pernicious anemia or are strict vegetarians for many years. In those infants symptoms of bone marrow disfunction and impaired development of the central nervous system appear already in the first months of life. Unrecognized cobalamin deficiency may lead to serious neurologic consequences, and even to the death of the child. The authors present a case of a 7.5 month old girl admitted to the Department of Paediatrics, Haematology, Oncology and Endocrinology. Gdańsk Medical University suspected of acute leukaemia. Based on a detailed diagnostic procedure a final diagnosis of vitamin B(12) deficiency anaemia was established. The child was exclusively breast-fed. Results of investigations into the reason for cobalamin deficiency in the patient s organism. Led to the diagnosis of pernicious anaemia in the mother. Such a suspicion had been made during pregnancy, but no continuation of investigations nor appropriate treatment were implemented. After treatment with vitamin B(12) supplements and modification of the diet the patient improved quickly and remarkably. A few months follow-up was enough to observe remarkable improvement of psychomotor development of this child. PMID:15738604

  19. Comparative genomic analyses of nickel, cobalt and vitamin B12 utilization

    Directory of Open Access Journals (Sweden)

    Gelfand Mikhail S

    2009-02-01

    Full Text Available Abstract Background Nickel (Ni and cobalt (Co are trace elements required for a variety of biological processes. Ni is directly coordinated by proteins, whereas Co is mainly used as a component of vitamin B12. Although a number of Ni and Co-dependent enzymes have been characterized, systematic evolutionary analyses of utilization of these metals are limited. Results We carried out comparative genomic analyses to examine occurrence and evolutionary dynamics of the use of Ni and Co at the level of (i transport systems, and (ii metalloproteomes. Our data show that both metals are widely used in bacteria and archaea. Cbi/NikMNQO is the most common prokaryotic Ni/Co transporter, while Ni-dependent urease and Ni-Fe hydrogenase, and B12-dependent methionine synthase (MetH, ribonucleotide reductase and methylmalonyl-CoA mutase are the most widespread metalloproteins for Ni and Co, respectively. Occurrence of other metalloenzymes showed a mosaic distribution and a new B12-dependent protein family was predicted. Deltaproteobacteria and Methanosarcina generally have larger Ni- and Co-dependent proteomes. On the other hand, utilization of these two metals is limited in eukaryotes, and very few of these organisms utilize both of them. The Ni-utilizing eukaryotes are mostly fungi (except saccharomycotina and plants, whereas most B12-utilizing organisms are animals. The NiCoT transporter family is the most widespread eukaryotic Ni transporter, and eukaryotic urease and MetH are the most common Ni- and B12-dependent enzymes, respectively. Finally, investigation of environmental and other conditions and identity of organisms that show dependence on Ni or Co revealed that host-associated organisms (particularly obligate intracellular parasites and endosymbionts have a tendency for loss of Ni/Co utilization. Conclusion Our data provide information on the evolutionary dynamics of Ni and Co utilization and highlight widespread use of these metals in the three

  20. Vitamin B12 and vitamin B6 supplementation is needed among adults with phenylketonuria (PKU).

    Science.gov (United States)

    Hvas, A M; Nexo, E; Nielsen, J B

    2006-02-01

    Phenylketonuria (PKU) is caused by an autosomal recessive deficiency of the enzyme phelnylalanine hydroxylase leading to a failure to convert phenylalanine to tyrosine. To avoid irreversible neurological damage because of increased phenylalanine, treatment is instituted rapidly after birth. We examined 31 adult PKU patients living on a less protein-restricted diet. Theoretically, these PKU patients had an increased risk of developing vitamin B(12) and B(6) deficiency because of a limited intake of animal products. Besides laboratory tests (n = 31) we obtained clinical information (n = 30) and detailed information on food consumption (n = 28). Three-quarters of the patients had early biochemical signs of vitamin B(12) deficiency. In spite of a normal folate status, 9 (29%) had a plasma homocysteine above 12 micromol/L. In accord with these findings, the food questionnaires indicated that 11 (39%) patients received less than the recommended daily vitamin B(12), and 20 (71%) received less vitamin B(6) than recommended. A significant association was found between reduced vitamin B(12) intake and both reduced serum cobalamins (p = 0.04) and reduced serum transcobalamin saturation (p = 0.03). Eleven patients took a vitamin pill daily, and these patients had a significantly lower plasma homocysteine compared to the rest. The present study suggests that adult PKU patients were at increased risk of developing vitamin B(12) deficiency, and their intake of vitamin B(6) was below the recommended daily intake. In conclusion PKU patients need continuing dietary guidance throughout adult life, and considering the risks, costs and potential benefits, daily vitamin supplementation seems justified in these patients. PMID:16601867

  1. Enhanced pharmacological activity of Vitamin B12 and Penicillin as nanoparticles

    Directory of Open Access Journals (Sweden)

    Yariv I

    2015-05-01

    Full Text Available Inbar Yariv,1 Anat Lipovsky,2 Aharon Gedanken,2,3 Rachel Lubart,4 Dror Fixler11Faculty of Engineering and the Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan, Israel; 2Department of Chemistry, Kanbar Laboratory for Nanomaterials, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan, Israel; 3Department of Materials Science and Engineering, National Cheng Kung University, Tainan, Taiwan; 4Physics and Chemistry Department, Bar-Ilan University, Ramat-Gan, IsraelAbstract: Sonochemistry has become a well-known technique for fabricating nanomaterials. Since one of the advantages of nanomaterials is that they have higher chemical activities compared with particles in the bulk form, efforts are being made to produce nano organic compounds with enhanced biological activities that could be exploited in the medical area. This study uses the sonication technique to prepare nano Vitamin B12 and nano Penicillin, and demonstrates their enhanced biological and pharmacological activity. The size and morphology of the nano Penicillin and nano Vitamin B12 were investigated using electron microscopy as well as dynamic light scattering techniques. The sizes of Penicillin and Vitamin B12 nanoparticles (NPs were found to be 70 and 120–180 nm, respectively. The bactericidal effect of nano Penicillin was studied and found to be higher than that of the bulk form. Reducing the size of Vitamin B12 resulted in their enhanced antioxidative activity as observed using the electron paramagnetic spectroscopy technique. The penetration depth of these organic NPs can be detected by an optical iterative method. It is believed that nano organic drugs fabrication will have a great impact on the medical field.Keywords: sonochemistry, antibacterial, antioxidant, Vitamin B12, Penicillin, nanomaterials

  2. Response to vitamin B12 and folic acid in myalgic encephalomyelitis and fibromyalgia.

    Directory of Open Access Journals (Sweden)

    Björn Regland

    Full Text Available Patients with myalgic encephalomyelitis (ME, also called chronic fatigue syndrome may respond most favorably to frequent vitamin B12 injections, in vital combination with oral folic acid. However, there is no established algorithm for individualized optimal dosages, and rate of improvement may differ considerably between responders.To evaluate clinical data from patients with ME, with or without fibromyalgia, who had been on B12 injections at least once a week for six months and up to several years.38 patients were included in a cross-sectional survey. Based on a validated observer's rating scale, they were divided into Good (n = 15 and Mild (n = 23 responders, and the two groups were compared from various clinical aspects.Good responders had used significantly more frequent injections (p<0.03 and higher doses of B12 (p<0.03 for a longer time (p<0.0005, higher daily amounts of oral folic acid (p<0.003 in good relation with the individual MTHFR genotype, more often thyroid hormones (p<0.02, and no strong analgesics at all, while 70% of Mild responders (p<0.0005 used analgesics such as opioids, duloxetine or pregabalin on a daily basis. In addition to ME, the higher number of patients with fibromyalgia among Mild responders was bordering on significance (p<0.09. Good responders rated themselves as "very much" or "much" improved, while Mild responders rated "much" or "minimally" improved.Dose-response relationship and long-lasting effects of B12/folic acid support a true positive response in the studied group of patients with ME/fibromyalgia. It's important to be alert on co-existing thyroid dysfunction, and we suspect a risk of counteracting interference between B12/folic acid and certain opioid analgesics and other drugs that have to be demethylated as part of their metabolism. These issues should be considered when controlled trials for ME and fibromyalgia are to be designed.

  3. 维生素B12与腔隙性脑梗塞后抑郁的关联研究%Association of Vitamin B12 with Depression after Lacunar Stroke

    Institute of Scientific and Technical Information of China (English)

    李中春; 呙登俊; 江霞

    2013-01-01

    OBJECTIVE To explore the association of serum vitamin B12 with depression after lacunar stroke.METHODS Between June 2009 and June 2012,829 patients with lacunar stroke,according to Hamilton depression scale score,were divided into two groups:group with depression and group without depression.The concentration of serum vitamin B 12 and the ratio of vitamin B12 deficiency were compared.The relationship between Hamilton depression scale score and the concentration of serum vitamin B 12 in the group with depression was analyzed by the curve-fitting method.RESULTS The group without depression contained 750 cases and the mean concentration of serum vitamin B12 of this group was (172.5±20.4)pmol·L-1.There were 212 cases in the group without depression which were considered as vitamin B 12 deficiency.The group with depression contained 79 cases and the mean concentration of serum vitamin B12 of this group was (139.1±18.2)pmol·L-1.There were 53 cases in the group with depression which were considered as vitamin B12 deficiency.There were significant differences in the concentration of serum vitamin B 12 and the ratio of vitamin B 12 deficiency(P<0.000 1).Inverse curve reflected the relationship between Hamilton depression scale score and the concentration of serum vitamin B 12 in the group with depression.CONCLUSION Depression after lacunar stroke is related to vitamin B12 deficiency.%目的 探讨血清维生素B12与腔隙性脑梗塞后抑郁之间关系.方法 2009年6月—2012年6月腔隙性脑梗塞患者共829例,使用汉密尔顿抑郁量表将患者分为两组:无抑郁组和抑郁组,比较两组间血清维生素B12浓度和维生素B12缺乏者的比例.在抑郁组内对汉密尔顿抑郁量表评分和血清维生素B12浓度进行曲线拟合.结果 无抑郁组患者750例,血清维生素B12平均浓度为(172.5±20.4)pmol·L-1,其中维生素B12缺乏者212例.抑郁组79例,血清维生素B12平均浓度为(139.1± 18.2)pmol·L-1,其中维生素B

  4. Experimental evidence of orbital order in α-B12 and γ-B28 polymorphs of elemental boron

    Science.gov (United States)

    Mondal, Swastik; van Smaalen, Sander; Parakhonskiy, Gleb; Prathapa, Siriyara Jagannatha; Noohinejad, Leila; Bykova, Elena; Dubrovinskaia, Natalia; Chernyshov, Dmitry; Dubrovinsky, Leonid

    2013-07-01

    The electron density of the α form of boron has been obtained by multipole refinement against high-resolution, single-crystal x-ray diffraction data measured on a high-quality single crystal at a temperature of 100 K. Topological properties of this density have been used to show that all chemical bonds between B12 clusters in α-B12 are formed due to one orbital on each boron atom that is oriented perpendicular to the surface of the cluster. It is shown that the same orbital order on B12 clusters persists in both α-B12 and γ-B28 polymorphs and in several dodecaboranes, despite the fact that in every case the B12 clusters participate in entirely different kinds of exocluster bonds. It is likely that the same orbital order of B12 clusters can explain bonding in other boron polymorphs and boron-rich solids.

  5. OLDER ADULT PSYCHIATRIC INPATIENTS WITH NON-COGNITIVE DISORDERS SHOULD BE SCREENED FOR VITAMIN B12 DEFICIENCY

    Science.gov (United States)

    LACHNER, C.; MARTIN, C.; JOHN, D.; NEKKALAPU, S.; SASAN, A.; STEINLE, N.; REGENOLD, W.T.

    2016-01-01

    Objective Vitamin B12 (B12) deficiency is most prevalent among older adults. Practice guidelines recommend screening older adults with symptoms of cognitive disorder for B12 deficiency. However, guidelines for non-cognitive psychiatric disorders typically do not mention screening older adults for B12 deficiency. The purpose of this study was to determine whether routine screening of older adult psychiatric inpatients for B12 deficiency, regardless of cognitive symptoms, is clinically justified. Design We conducted a retrospective chart-review study of consecutive inpatient admissions. Setting Older Adult Acute Psychiatric Inpatient Unit at the University of Maryland Medical Center from 10/2007-4/2010. Participants Acute psychiatric inpatients aged ≥50 years who met inclusion criteria (N=374). Measurements Mean (SD) B12 levels and percentages of probable (<180pg/mL) and possible (180–350pg/mL) B12 deficiency as well as characteristics of patients with probable and possible B12 deficiency compared to patients with optimal B12 levels. Results Mean (SD) B12 levels and percentages of probable and possible B12 deficiency, respectively, for cognitive disorder patients [468 (284) pg/mL, 7.8 % (n=5) and 29.7% (n=19)] and for non-cognitive disorder patients [481(268) pg/mL, 4.8 %(n=15) and 33.2%(n=103)] were not significantly different (t=0.339, df=372, P=0.735; χ2=1.084, df=2, P=0.582, respectively). Conclusion Considering the potential benefits and low costs of screening and treatment, we conclude that it is justified to routinely screen older adult psychiatric inpatients for B12 deficiency whether or not cognitive disorder symptoms are present. PMID:24522476

  6. A Study of the Prevalence of Serum Vitamin B12 and Folic Acid Deficiency in Western Maharashtra

    OpenAIRE

    Mahajan, Sanket K.; Aundhakar, Swati C.

    2015-01-01

    Context: This study summarizes the prevalence of vitamin B12 and folic acid deficiency in the population coming to tertiary care center in Western Maharashtra along with the main presenting symptom routinely misinterpreted in daily practice. Aims and Objectives: 1. To study the prevalence of vitamin B12 and folic acid deficiency in the population of western Maharashtra. 2. To correlate the symptoms with serum vitamin B12 and folic acid levels. Materials and Methods: The present study is a cro...

  7. Low vitamin B12 levels among newly-arrived refugees from Bhutan, Iran and Afghanistan: a multicentre Australian study.

    Directory of Open Access Journals (Sweden)

    Jill Benson

    Full Text Available BACKGROUND: Vitamin B12 deficiency is prevalent in many countries of origin of refugees. Using a threshold of 5% above which a prevalence of low Vitamin B12 is indicative of a population health problem, we hypothesised that Vitamin B12 deficiency exceeds this threshold among newly-arrived refugees resettling in Australia, and is higher among women due to their increased risk of food insecurity. This paper reports Vitamin B12 levels in a large cohort of newly arrived refugees in five Australian states and territories. METHODS: In a cross-sectional descriptive study, we collected Vitamin B12, folate and haematological indices on all refugees (n = 916; response rate 94% of eligible population who had been in Australia for less than one year, and attended one of the collaborating health services between July 2010 and July 2011. RESULTS: 16.5% of participants had Vitamin B12 deficiency (<150 pmol/L. One-third of participants from Iran and Bhutan, and one-quarter of participants from Afghanistan had Vitamin B12 deficiency. Contrary to our hypothesis, low Vitamin B12 levels were more prevalent in males than females. A higher prevalence of low Vitamin B12 was also reported in older age groups in some countries. The sensitivity of macrocytosis in detecting Vitamin B12 deficiency was only 4.6%. CONCLUSION: Vitamin B12 deficiency is an important population health issue in newly-arrived refugees from many countries. All newly-arrived refugees should be tested for Vitamin B12 deficiency. Ongoing research should investigate causes, treatment, and ways to mitigate food insecurity, and the contribution of such measures to enhancing the health of the refugee communities.

  8. The effect of 5,6-dimethylbenzimidazole on vitamin B12 synthesis and protein production in Propionibacterium freudenreichii ssp. freudenreichii

    OpenAIRE

    Ishchenko, Tatiana

    2014-01-01

    Propionibacterium freudenreichii is commonly known as a Swiss-type cheese ripening culture, and is also frequently applied in the industrial production of vitamin B12 (cobalamin). One way to increase vitamin B12 productivity is the supplementation of medium with 5,6-dimethylbenzimidazole (DMBI), the lower ligand of cobalamin. The aim of this thesis was to investigate the effect of exogenous DMBI on vitamin B12 synthesis and protein production in type strain of P. freudenreichii ssp. freudenre...

  9. Clinical and laboratory features and response to treatment in patients presenting with vitamin B12 deficiency-related neurological syndromes

    OpenAIRE

    Aaron S; Kumar Sudhir; Vijayan J; Jacob J; Alexander M; Gnanamuthu C

    2005-01-01

    AIMS AND OBJECTIVES: To study the clinical and laboratory features of patients admitted with vitamin B12 deficiency-related (B12def) neurological syndromes. SETTINGS AND DESIGN: A hospital-based retrospective and prospective study conducted at a referral teaching hospital. MATERIALS AND METHODS: Consecutive patients admitted with vitamin B12 deficiency-related neurological disorders during a three-year period from June 2000 to May 2003 were included. Data regarding clinical and laboratory fea...

  10. Stability and aromaticity of nH2@B12N12 (n=1–12) clusters

    OpenAIRE

    Pratim K. Chattaraj; Arindam Chakraborty; Santanab Giri

    2011-01-01

    Standard ab initio and density functional calculations are carried out to determine the structure, stability, and reactivity of B12N12 clusters with hydrogen doping. To lend additional support, conceptual DFT-based reactivity descriptors and the associated electronic structure principles are also used. Related cage aromaticity of this B12N12 and nH2@B12N12 are analyzed through the nucleus independent chemical shift values.

  11. Indicators for assessing folate and vitamin B-12 status and for monitoring the efficacy of intervention strategies123

    OpenAIRE

    Green, Ralph

    2011-01-01

    Deficiencies of folate or of vitamin B-12 are widespread and constitute a major global burden of morbidity that affect all age groups. Detecting or confirming the presence of folate or vitamin B-12 deficiency and distinguishing one from the other depends, ultimately, on laboratory testing. Tests to determine the presence of folate or vitamin B-12 deficiency are used singly or in combination to establish the nutritional status and prevalence of deficiencies of the vitamins in various populatio...

  12. Mielopatia por deficiência de vitamina B12 apresentando-se como mielite transversa Myelopathy due to vitamin B12 deficiency presenting as transverse myelitis

    OpenAIRE

    Luiz Felipe Rocha Vasconcellos; Rosalie Branco Corrêa; Leila Chimelli; Fernanda Nascimento; Adriane Baptista Fonseca; Janaina Nagel; Sergio Augusto Pereira Novis; Maurice Vincent

    2002-01-01

    As manifestações neurológicas associadas à deficiência de vitamina B12 incluem polineuropatia, mielopatia, demência e neuropatia óptica. O diagnóstico laboratorial é feito através da dosagem sérica de cianocobalamina ou homocisteína e da excreção urinária de ácido metilmalônico. No estudo anatomopatológico observa-se na microscopia a destruição da mielina e de axônios vistos na substância branca. A região mais comumente afetada é o cordão posterior cervical e/ou torácico. O acometimento da co...

  13. Plasma levels of vitamin B12, epidermal growth factor and tumor necrosis factor alpha in patients with alzheimer dementia

    OpenAIRE

    Hatice Ferhan Komurcu; Nedret Kilic; Melike Erol Demirbilek; Kadir Okhan Akin

    2016-01-01

    Background: It was previously reported that vitamin B12 (Vit B12) has the regulatory effects on epidermal growth factor (EGF) and tumor necrosis factor alpha (TNF- and #945;). The role of Vit B12, EGF and TNF- and #945; in the pathogenesis of alzheimer dementia has not been elucidated yet. In this study the plasma Vit B12, EGF and TNF- and #945; level were examined in individuals, between 65-99 years old with and without alzheimer dementia (AD). Methods: The study group comprised 47 pati...

  14. Low Vitamin B12 Levels among Newly-Arrived Refugees from Bhutan, Iran and Afghanistan: A Multicentre Australian Study

    OpenAIRE

    Benson, Jill; Phillips, Christine; Kay, Margaret; Murray T Webber; Alison J Ratcliff; Correa-Velez, Ignacio; Lorimer, Michelle F.

    2013-01-01

    Background Vitamin B12 deficiency is prevalent in many countries of origin of refugees. Using a threshold of 5% above which a prevalence of low Vitamin B12 is indicative of a population health problem, we hypothesised that Vitamin B12 deficiency exceeds this threshold among newly-arrived refugees resettling in Australia, and is higher among women due to their increased risk of food insecurity. This paper reports Vitamin B12 levels in a large cohort of newly arrived refugees in five Australian...

  15. Electrochemistry and catalytic properties of amphiphilic vitamin B12 derivatives in nonaqueous media.

    Science.gov (United States)

    Giedyk, M; Shimakoshi, H; Goliszewska, K; Gryko, D; Hisaeda, Y

    2016-05-17

    The reduction pathway of cobalester (CN)Cble, an amphiphilic vitamin B12 derivative, was investigated in organic solvents under electrochemical conditions and compared with mono- and dicyanocobyrinates. The redox characteristics were determined using cyclic voltammetry and spectroelectrochemical methods. The presence of a nucleotide moiety in B12-derivative impedes the in situ formation of dicyano-species thus facilitating the (CN)Co(iii) to Co(i) reduction. The (CN)Cble shows stepwise reduction to Co(i) via (CN)Co(ii). The reduction of (CN)Co(ii)/Co(i) was found to depend on cyanide-solvent exchange equilibrium with weakly coordinating solvents and bulky peripheral chains promoting intact (CN)Co(ii) species existence. The studied complexes were also utilized as catalysts in bulk electrolysis of benzyl bromide affording bibenzyl in very good yield. PMID:26974051

  16. Acute Myocardial Infarction in a Young Lady due to Vitamin B12 Deficiency Induced Hyperhomocysteinemia

    Science.gov (United States)

    Shamkani, Warkaa Al; Jafar, Nagham Saeed; Narayanan, Sunil Roy; Rajappan, Anil Kumar

    2015-01-01

    Hyper-homocysteinemia is a risk factor for coronary artery disease in young patients. A 32 years old female without any conventional risk factors except obesity presented with acute anterior wall myocardial infarction (MI). Her echocardiography showed anterior wall hypokinesia with moderate left ventricular dysfunction. Angiography showed tight stenosis of the proximal left anterior descending (LAD) and borderline lesion in left circumflex coronary artery (LCX). She underwent percutaneous coronary intervention (PCI) to LAD with good result. Her blood tests showed low vitamin B12, folate and serum iron levels and elevated serum homocysteine level. She was given folic acid and vitamin B12 and her homocysteine levels normalized. This case demonstrates that hyperhomocysteinemia caused by nutritional deficiency of vitamin co factors may lead to MI. Hyperhomocysteinemia should be considered in the evalauation of young people with MI, especially those without conventional risk factors. PMID:25838876

  17. Radioisotope dilution technique for determination of vitamin B12 in foods

    International Nuclear Information System (INIS)

    A radioisotope dilution (RID) method for the determination of vitamin B12 is presented. The method combines a standard extraction procedure (AOAC 43.108, 12th ed.) with a commercially available RID assay kit. The method was evaluated on a wide range of fortified and unfortified food products. Recovery studies on both groups yielded average recoveries of 98.1 and 95.8%, respectively. Reproducibility data generated from replicate analysis on both groups gave a relative standard deviation of 6.9% for the fortified group and 9.2% for the unfortified group. For the samples studied, the mean vitamin B12 content determined by the RID method was 8.01 μ/100 g vs a mean of 7.54 μg/100 g by the AOAC microbiological method; the correlation coefficient was r = 0.983

  18. Phylogenetic analysis of vitamin B12-related metabolism in Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Douglas B. Young

    2015-03-01

    Full Text Available Comparison of genome sequences from clinical isolates of Mycobacterium tuberculosis with phylogenetically-related pathogens Mycobacterium marinum, Mycobacterium kansasii and Mycobacterium leprae reveals diversity amongst genes associated with vitamin B12-related metabolism. Diversity is generated by gene deletion events, differential acquisition of genes by horizontal transfer, and single nucleotide polymorphisms with predicted impact on protein function and transcriptional regulation. Differences in the B12 synthesis pathway, methionine biosynthesis, fatty acid catabolism, and DNA repair and replication are consistent with adaptations to different environmental niches and pathogenic lifestyles. While there is no evidence of further gene acquisition during expansion of the M. tuberculosis complex, the emergence of other forms of genetic diversity provides insights into continuing host-pathogen co-evolution and has the potential to identify novel targets for disease intervention.

  19. Thermoelectric properties of the Kondo semiconductor: Yb1-x LuxB12

    International Nuclear Information System (INIS)

    We have measured electrical resistivity ρ, thermal conductivity κ, and thermopower S of the Kondo semiconductor Yb1-xLuxB12 (0≤x≤1). On increasing x to 0.05, both the semiconducting increase in ρ(T) and the enhancement of κ below 60 K are strongly suppressed. A giant negative peak in S(T) for x=0 at 10 K vanishes already at x=0.01, whereas a broad peak stays at 30 K for x≤0.25 and shifts to 100 K for x≥0.75. These results suggest that the energy gap in YbB12 is filled up by the development of a mid-gap state at the Fermi level with Lu substitution

  20. Radio-isotopic assays of vitamin B12: interest of Kappa index in a multicentric study

    International Nuclear Information System (INIS)

    Owing to the lack of a reference technique and of an international cobalamin (vitamin B12) standard, and the large discrepancy between laboratory norms, the authors performed a multicentric study to compare five RIA kits usually used. First, classical tests were used to evaluate the analytical performances of each kit. Results did not demonstrate any superiority of one kit over another. Secondly, B12 values were classified among three categories (low, normal and high) characterized by laboratory and then manufacturer norms. The concordance between these two ''judgments'' was evaluated with the Kappa coefficient. In addition, the Kappa index proved that the norms supplied by the manufacturer were better than those of laboratories. But mean Kappa coefficient established for each norm gave us an insatisfactory result. Third, clinical informations allowed to improve the classification of the patients. New limits were defined for each technique and should be tested further, routinely in each laboratory. (author)

  1. Misdiagnosed vitamin B12 deficiency a challenge to be confronted by use of modern screening markers

    International Nuclear Information System (INIS)

    Vitamin B12 deficiency is one of the common conditions in the elderly population leading to confusion, depression, memory loss and balance problems. Unfortunately there is no gold standard test for the diagnosis of cobalamin deficiency and a wide range of variation in reference levels according to country, and laboratory assay used. This poses a problem in diagnosing this condition making it a commonly misdiagnosed medical entity. There is current emphasis on need for clearer guidelines and much research is still being done to pave ways to determine better reference values for serum B12 and other screening tests. It is advised that screening methods are used adjunctively for the purpose of screening individuals. (author)

  2. Diffusion of Vitamin B12 Across a Mesoporous Metal Organic Framework

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    Veronica Valencia

    2013-01-01

    Full Text Available We measure the rate of uptake and the rate of release of a Vitamin B12 solution (dissolved in water at 2 different temperatures (room temperature and 37°C by the mesoporous metal organic framework TbMOF-100 at 1-hour intervals using a spectrophotometer. Using the Beer-Lambert law, we calculate the concentration of the stock solution based on the absorbance values obtained with the spectrophotometer. These values allow for the quantification of the initial rate of uptake and the rate of uptake at a random incubation time of the Vitamin B12 by the TbMOF-100. We also calculate the value of the coefficient of diffusion for this 2-phase system using Fick’s laws of diffusion.

  3. Effect of dispersity on dissolution of α-AlB12 powder in different media

    International Nuclear Information System (INIS)

    Chemical stability of aluminium dodecaboride of different dispersity is studied in different corrosive media: hydrochloric, sulphuric, nitric acids and alkali of different concentration, hydrogen peroxide. Behaviour of boride and different boron modifications in air and during heating is investigated. It is shown that concentrated acids-nonoxidants (hydrochloric, sulphuric) at room temperature and during heating do not affect α-AlB12 irrespective of the powder dispersity. Aluminium boride behaves differently in the concentrated HNO3 depending on the powder dispersity. During oxidation of aluminium boride and different boron modifications a complete oxidation of specimens has not been observed as the protective oxide coating was formed on the surface of the powder particles. α-AlB12 exceeds amorphous and crystalline boron as to the resistance to scaling

  4. Synthesis and crystal structure of Pb(Bipy)2B12H12

    International Nuclear Information System (INIS)

    Lead complex with B12H122- anion and 2,2' bipyridine-lead(2) dodecahydro-closo-dodecaborate di(2,2' bipyridine) is synthesized and characterized by IF, UV and NMR spectrography methods. According to roentgen-structural analysis the crystals belong to monoclinic syngony, sp.gr. C2/m,a=17.872(4), b=18.672(5), c=9.228(7)A, β=109.11(4), V=2910(2)A3, Z=4. The structure consists of Pb2(Bipy)4(B12H12)2 dimeric units. The Pb-B distances are within the limits of 3.313-3.514A. 11 refs.; 2 figs.; 2 tabs

  5. Does B12 vitamin limit phytoplankton growth in the new Iberian Peninsula?

    Directory of Open Access Journals (Sweden)

    Esther Barber Lluch

    2014-07-01

    Surface autotrophic microbial populations were monthly collected and exposed to known nutrient concentrations and incubated under in situ light and temperature conditions. The experimental addition treatments included: a inorganic nutrients (nitrate, ammonium and phosphate; b B12 vitamin (cobalamin and c inorganic nutrients and cobalamin. On two occasions, four additional treatments were included: d organic nutrients (glucose and amino acids; e a combination of inorganic and organic nutrients; f organic nutrients and cobalamin; g inorganic and organic nutrients plus cobalamin. Amendment experiments lasted 4 days. Samples were collected every 24h for Chlorophyll-a concentration, pico- and nanoplankton abundance and heterotrophic bacterial abundance determination. Our results suggest that phytoplankton growth is co-limited by inorganic nutrients and B12-vitamin. This co-limitation varied along the study period likely related to changes in community composition and ambient nutrient and B-vitamins concentrations.

  6. Theory of Linear Optical Absorption in B_12 Clusters: Role of the geometry

    CERN Document Server

    Sahu, Sridhar

    2009-01-01

    Boron clusters have been widely studied theoretically for their geometrical properties and electronic structure using a variety of methodologies. An important cluster of boron is the B$_{12}$ cluster whose two main isomers have distinct geometries, namely, icosahedral ($I_{h}$) and quasi planar ($C_{3v}$). In this paper we investigate the linear optical absorption spectrum of these two B$_{12}$ structures with the aim of examining the role of geometry on the optical properties of clusters. The optical absorption calculations are performed using both the semi-empirical and the ab initio approaches. The semi-empirical approach uses a wave function methodology employing the INDO model Hamiltonian, coupled with large-scale configuration interaction (CI) calculations, to account for the electron-correlation effects. The \\emph{ab initio} calculations are performed within a time-dependent-density-functional-theory (TDDFT) methodology. The results for the two approaches are in very good qualitative agreement with eac...

  7. Quantitative Evaluation of Cobalamins (Vit.B12 Produced by Native Propionibacteria

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    H.kazemi fard

    1995-08-01

    Full Text Available in order to prepare cobalamins (Vit. B12 using microbial culture method, the strains of Genus propionibacteriun have been chosen in preference to other species because of their rapid growth and high productivity of selected mutants."nIn the present research we examined the quantitative evaluation of cobalamins (Vit.B12 produced by native propionibacteria and results have been compared to other reports in this subject."nThe native propionibacteria were isolated from Iranien dairy products and transferred to cobalamins productive medium."nAmount of cobalamins produced by these strains were measured by radioimmunoassay method. Our results showed that native propionibacteria produced 100 to 420 pg cobalamins per ml of the medium.

  8. Theoretical analysis of electronic absorption spectra of vitamin B12 models

    Science.gov (United States)

    Andruniow, Tadeusz; Kozlowski, Pawel M.; Zgierski, Marek Z.

    2001-10-01

    Time-dependent density-functional theory (TD-DFT) is applied to analyze the electronic absorption spectra of vitamin B12. To accomplish this two model systems were considered: CN-[CoIII-corrin]-CN (dicyanocobinamide, DCC) and imidazole-[CoIII-corrin]-CN (cyanocobalamin, ImCC). For both models 30 lowest excited states were calculated together with transition dipole moments. When the results of TD-DFT calculations were directly compared with experiment it was found that the theoretical values systematically overestimate experimental data by approximately 0.5 eV. The uniform adjustment of the calculated transition energies allowed detailed analysis of electronic absorption spectra of vitamin B12 models. All absorption bands in spectral range 2.0-5.0 eV were readily assigned. In particular, TD-DFT calculations were able to explain the origin of the shift of the lowest absorption band caused by replacement of the-CN axial ligand by imidazole.

  9. MEASUREMENT OF VITAMIN B12 CONCENTRATION: A REVIEW ON AVAILABLE METHODS

    Directory of Open Access Journals (Sweden)

    Karmi O et al

    2011-01-01

    Full Text Available Vitamin B12 is a water-soluble vitamin. It is one of the eight vitamins of vitamin B complex, needed for blood and cell maturation. It helps maintain healthy nerve cells and red blood cells, and it is needed in DNA replication. Its deficiency may cause megaloblastic anemia (amidst others health issues. For these and many similar reasons, it sometimes becomes necessary to measure its concentration. This article has carefully reviewed the different methods used for measuring vitamin B12 concentration, and the unique principles involved. The principles, basically, depend on the molecular structure of Vitamin B12 and its reactions with other substances. The methods include microbiological assay and spectrophotometric methods – these are old methods: they were the first available methods, but they are still in use for reference purposes. Another method is electroluminescent (ECL which involves highly reactive materials. However, inductive-coupled plasma-mass spectrometry (ICP-MS is a very important method, which is used routinely, even in many research. On the other hand, atomic absorption spectroscopy depends on measuring the amount of energy involved in the reaction; while radioimmunoassay (RIA is a highly sensitive immunoassay technique. In addition, there are different techniques for separating and preparing samples to be used in the various measurement methods. High-performance liquid chromatography (HPLC is used for non-validate analyst, while capillary-electrophoresis (CE that have high resolving power than traditional electrophoresis, which when they are coupled with certain detectors they afford us another principle for measuring this vitamin. Choosing the best method for measuring vitamin B12 concentration depends on many factors – including the type of sample, purpose of the test, necessity of pre-processing, time limitations, cost, sensitivity, specificity.

  10. Ultrafast electronic relaxation of excited state vitamin B12 in the gas phase

    International Nuclear Information System (INIS)

    The time evolution of electronically excited vitamin B12 (cyanocobalamin) has been observed for the first time in the gas phase. It reveals an ultrafast decay to a state corresponding to metal excitation. This decay is interpreted as resulting from a ring to metal electron transfer. This opens the observation of the excited state of other complex biomimetic systems in the gas phase, the key to the characterisation of their complex evolution through excited electronic states

  11. Folate, Vitamin B12, and Homocysteine as Risk Factors for Cognitive Decline in the Elderly

    OpenAIRE

    Kim, Jae-Min; Kim, Sung-Wan; Shin, Il-Seon; Yang, Su-Jin; Park, Woo-Young; Kim, Sung-Jin; Shin, Hee-Young; Yoon, Jin-Sang

    2008-01-01

    Objective Cross-sectional studies have shown that the dysregulation of one-carbon metabolism is associated with cognitive impairment. However, the findings of longitudinal studies investigating this association have been inconsistent. This study investigated the prospective associations between cognitive decline and the levels of folate, vitamin B12 and homocysteine both at baseline and over course of the study period. Methods A total of 607 (83%) elderly individuals were selected from a grou...

  12. COGNITIVE IMPAIRMENTS IN VITAMIN B12 AND FOLIC ACID DEFICIENCIES AND HYPERHOMOCYSTEINEMIA

    OpenAIRE

    P. R. Kamchatnov; I.V. Damulin

    2015-01-01

    Vitamin metabolic disorders can cause diverse dysfunctions of both the peripheral and central nervous systems. There is conclusive evidence that cyanocobalamin (vitamin B12) and folic acid deficiencies may lead to diminished cognitive functions even to the extent of developing dementia. Cognitive impairments may be accompanied by involvement of other regions of the central nervous system, the corticospinal tract in particular, less frequently by brainstem and cerebellar disorders. Changes in ...

  13. Immunohistochemical localisation of vitamin B12 R-binder in the human digestive tract.

    OpenAIRE

    Kudo, H; Inada, M; Ohshio, G; Wakatsuki, Y; Ogawa, K; Hamashima, Y.; Miyake, T

    1987-01-01

    The distribution of vitamin B12 R-binder in the human digestive tract was studied using an indirect immunoperoxidase technique. Positive staining for R-binder was found in the mucous cells and ductal epithelial cells of the salivary glands and the oesophageal glands. In normal gastric mucosa, no positive staining for R-binder was found, but in the area with intestinal metaplasia, the columnar epithelial cells and goblet cells showed positive staining. Epithelial cells of the gallbladder, intr...

  14. Serum Levels of Zinc, Copper, Vitamin B12, Folate and Immunoglobulins in Individuals with Giardiasis

    Directory of Open Access Journals (Sweden)

    M Zarebavani

    2012-12-01

    Full Text Available Background: Giardia lamblia is one of the most important intestinal parasites. The aim of this study was to measure serum levels of IgA, IgE, zinc, copper, vitamin B12 and folate in individuals with giardiasis in comparison to normal subjects.Methods: The study was carried out among 49 Giardia positive and 39 age and sex matched healthy volunteers. Examination of stool samples was done by direct wet smear and formol-ether concentration method. Serum samples were obtained for further laboratory examination. IgA levels were measured by Single Radial Immune Diffusion (SRID. IgE levels were measured by ELISA kit. Zinc and copper levels was measured by Ziestchem Diagnostics Kit and colorimetric endpoint-method respectively. Vitamin B12 and folate levels were measured by DRG Diagnostics Kit and Enzyme Immunoassay method respectively. All data were analyzed using SPSS version 17.Results: There was a statistically significant difference in IgA, IgE, copper and zinc levels between positive and negative groups (P<0.05. There was no significant difference between vitamin B12 and folate levels between the two groups. Mean values of Giardia positive and negative groups for IgA were 309.26 and 216.89 mg/dl, IgE 167.34 and 35.49 IU/ml, copper 309.74 and 253.61 µg/dl and zinc 69.41 and 144.75 µg/dl respectively.Conclusion: The results showed levels of IgA may correlate more closely with giardiasis than IgE. Regarding trace elements, giardiasis elevated serum copper levels, while it decreased serum zinc. Finally, there was no significant difference in serum levels of vitamin B12 and folic acid between the two groups.

  15. Localised Skin Hyperpigmentation as a Presenting Symptom of Vitamin B12 Deficiency Complicating Chronic Atrophic Gastritis

    OpenAIRE

    Kawther El-Shafie; Nafisa Samir; Ritu Lakhtakia; Robin Davidson; Ahmed Al-Waili; Muna Al-Mamary; Mohammed Al-Shafee

    2015-01-01

    Vitamin B12 deficiency is common in developing countries and should be suspected in patients with unexplained anaemia or neurological symptoms. Dermatological manifestations associated with this deficiency include skin hyper- or hypopigmentation, angular stomatitis and hair changes. We report a case of a 28-year-old man who presented to the Sultan Qaboos University Hospital in Muscat, Oman, in November 2013 with localised hyperpigmentation of the palmar and dorsal aspects of both hands of two...

  16. Basal Gnathostomes Provide Unique Insights into the Evolution of Vitamin B12 Binders

    OpenAIRE

    Lopes-Marques, Mónica; Ruivo, Raquel; Delgado, Inês; Wilson, Jonathan M.; Aluru, Neelakanteswar; L Filipe C Castro

    2014-01-01

    The uptake and transport of vitamin B12 (cobalamin; Cbl) in mammals involves a refined system with three evolutionarily related transporters: transcobalamin 1 (Tcn1), transcobalamin 2 (Tcn2), and the gastric intrinsic factor (Gif). Teleosts have a single documented binder with intermediate features to the human counterparts. Consequently, it has been proposed that the expansion of Cbl binders occurred after the separation of Actinopterygians. Here, we demonstrate that the diversification of t...

  17. Characterization of the cobalamin (vitamin B12) biosynthetic genes of Salmonella typhimurium.

    OpenAIRE

    Roth, J R; Lawrence, J. G.; Rubenfield, M; Kieffer-Higgins, S; Church, G M

    1993-01-01

    Salmonella typhimurium synthesizes cobalamin (vitamin B12) de novo under anaerobic conditions. Of the 30 cobalamin synthetic genes, 25 are clustered in one operon, cob, and are arranged in three groups, each group encoding enzymes for a biochemically distinct portion of the biosynthetic pathway. We have determined the DNA sequence for the promoter region and the proximal 17.1 kb of the cob operon. This sequence includes 20 translationally coupled genes that encode the enzymes involved in part...

  18. Intergenotypic variation of Vitamin B12 and Folate in AD: In north Indian population

    OpenAIRE

    Neelam Chhillar; Neeraj Kumar Singh; Basu Dev Banerjee; Kiran Bala; Mitra Basu; Deepika Sharma

    2014-01-01

    Objectives: Changes in lifestyle habits such as diet modification or supplementation have been indicated as probable protective factors for a number of chronic conditions including Alzheimer's disease (AD). With this background, we aim to hypothesize that whether C677T polymorphism of methylenetetrahydrofolate reductase (MTHFR) gene contributes towards the risk of developing AD and its association with vitamin B12 and folate levels. Materials and Methods: A case-control study comprising of to...

  19. LES ANEMIES MEGALOBLASTIQUES PAR CARENCE EN ACIDE FOLIQUE ET OU VIT B12

    OpenAIRE

    BELBACHIR, Elhadj Lotfi

    2013-01-01

    Les anémies mégaloblastique par carence en acide folique et bu en vit B12 constituent un réel problème de santé dans notre pays Cette étude qui comporte 106 cas nous a permis de mieux cerner les caractéristiques épidémiologiques cliniques paracliniques, et proposer une stratégie de prise en charge.

  20. Long term treatment with metformin in patients with type 2 diabetes and vitamin B 12

    Directory of Open Access Journals (Sweden)

    Yu V Pankratova

    2012-12-01

    Full Text Available Реферат по статье: De Jager J, Kooy A, Lehert P, Wulffelé MG, van der Kolk J, Bets D, Verburg J, Donker AJ, Stehouwer CD. Long term treatment with metformin in patients with type 2 diabetes and risk of vitamin B-12 deficiency: randomised placebo controlled trial. BMJ. 2010 May 20;340:c2181.