向伟; 李将渊; 马曾燕
制备了多壁碳纳米管修饰玻碳电极(MWNT/GCE),研究了维生素B2、B6、B12和维生素C共存时在该电极上的电化学行为.实验发现,在HAc-NaAc缓冲溶液中,该电极可同时测定以上四种维生素,线性范围分别为1.0×10-6～1.0×10-4 mol/L、5.0×10-5～2.0×10-3 mol/L、5.0×10-5～7.5×10-4 mol/L和5.0×10-5～2.0×10-3 mol/L,其检出限分别为7.0×10-7 mol/L、1.0×10-5 mol/L、2.5×10-5 mol/L和5.0×10-6 mol/L.样品分析的RSD分别为1.66%、1.71%、2.26%和1.46%.方法简便快捷,可用于四种维生素同时分析测定.
Full Text Available Okra is consumed as a vegetable by populations in Africa and Asia and particularly in Egypt. In this study, we investigated some nutritional components of okra grown in four different geographical locations of Egypt. A comparative analysis of water-soluble vitamins (B2, B3, B6, B12, and C and fat-soluble vitamins (E, K, D, A, and β-carotene in okra pods was carried out. Results of principal component analysis (PCA showed three clusters of varieties. The first cluster included the Dakahlia (D and Kafr El-Sheikh (K varieties. The second and the third clusters separated out the Suez (S and Mansoura (M varieties independently. The S pod showed the highest contents of vitamins B6 (49.81 μg/100 g and E (1.47 mg/100 g but contained the lowest contents of vitamins B3 (1.42 μg/100 g and B12 (undetected. The K pod showed the lowest vitamin C content (11.60 mg/100 g. The M pod showed the highest contents of vitamins B3 (22.70 μg/100 g, B12 (91.20 μg/100 g, C (27.14 mg/100 g, and K (0.21 mg/100 g. The D pod showed the lowest contents of vitamins E (0.15 mg/100 g, K (0.05 mg/100 g, and B6 (11.50 μg/100 g. These findings could help develop meal planning at the community level by incorporating okra varieties with high vitamin content.
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 ...
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...
Hvas, A M; Nexo, E; Nielsen, J B
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
Turgut, Burak; KAYA, Murat; ARSLAN, Sermal; Demir, Tamer; Güler, Mete; Kaya, Mehmet Kaan
Objective: To compare the levels of plasma homocysteine (Hcy), vitamin B6 (vit-B6), serum vitamin B12 (vit-B12), and folate in healthy individuals and in patients with normal tension glaucoma (NTG), pseudoexfoliative glaucoma (PXG), or primary open-angle glaucoma (POAG). Study design: A prospective controlled trial. Participants and methods: Forty healthy subjects, 48 patients with NTG, 38 patients with PXG, and 34 patients with POAG were included in the study. Those who used vitamin suppleme...
Lindqvist, Markus; Hellström, Anders; Henriksson, Anders E
Previous investigations have shown hyperhomocysteinemi in patients with abdominal aortic aneurysm (AAA). In the present study we evaluated the circulating level of homocysteine (Hcy) in relation to renal function, vitamins B6, B12 and folate status in AAA patients with special regard to aneurysm size, and rupture. Hcy, Creatinine, B6, B12 and folate were measured in 119 patients with AAA and 36 controls without aneurysm matched by age, gender and smoking habit. As expected there was a weak co...
Burak Turgut; Murat Kaya; Sermal Arslan; et al
Burak Turgut, Murat Kaya, Sermal Arslan, Tamer Demir, Mete Güler, Mehmet Kaan KayaFırat University School of Medicine, Department of Ophthalmology, Elazıg, TurkeyObjective: To compare the levels of plasma homocysteine (Hcy), vitamin B6 (vit-B6), serum vitamin B12 (vit-B12), and folate in healthy individuals and in patients with normal tension glaucoma (NTG), pseudoexfoliative glaucoma (PXG), or primary open-angle glaucoma (POAG).Study design: A prospective controlled trial.Participan...
Burak Turgut, Murat Kaya, Sermal Arslan, Tamer Demir, Mete Güler, Mehmet Kaan KayaFÄ±rat University School of Medicine, Department of Ophthalmology, ElazÄ±g, TurkeyObjective: To compare the levels of plasma homocysteine (Hcy), vitamin B6 (vit-B6), serum vitamin B12 (vit-B12), and folate in healthy individuals and in patients with normal tension glaucoma (NTG), pseudoexfoliative glaucoma (PXG), or primary open-angle glaucoma (POAG).Study design: A prospective controlled trial.Particip...
ÖZGÜR, Mahmure Üstün; KOYUNCU, İkbal
A new method for determining ternary mixtures of vitamin B1, B6 and B12 using second derivative spectrophotometry is described. The procedure is accurate, nondestructive and does not require any separation step or the solving of equations. Calibration graphs were linear up to 20 m gml-1 of vitamin B1 at 228.9 nm (r=0.9999), vitamin B6 at 309.6 nm (r=0.9999) and vitamin B12 at 361.7 nm (r=0.9998). The method was successfully applied for analyzing synthetic mixtures and c...
Despite their important role in cognitive function, the value of B vitamin supplementation is unknown. A systematic review of the effect of vitamins B6, B12, and folic acid supplementation on cognitive function was performed. Literature search conducted in MEDLINE with supplemental articles from re...
Feeding experiments with Ashbya gossypii followed by NMR analysis of the resulting riboflavin showed incorporation of deuterium from D-[2-2H]ribose at C-2' and from D-[1-2H]ribose in the pro-R position at C-1' of the ribityl side chain. The results rule out an Amadori rearrangement mechanism for the reduction of the ribosylamino to the ribitylamino linkage and point to formation of a Schiff base that is reduced stereospecifically opposite to the face from which the oxygen has departed. As prerequisite for the analysis, the 1H NMR signals for the pro-R and pro-S hydrogens at C-1' of riboflavin and its tetraacetate were assigned with the aid of synthetic stereospecifically deuteriated samples. Feeding experiments with Propionibacterium shermianii followed by NMR analysis of the resulting vitamin B12 showed: (1) 5-methylbenzimidazole (5MBI) incorporated and only one regioisomer (B6-demethylcyanocobalamin)formed. (2) 8-demethylriboflavin incorporated and the same regioisomer was obtained as 5MBI experiment. (3) [1'-13C, 5-15N]riboflavin incorporated and 13C-NMR showed that 13C at the B2 position of cyanocobalamin coupled to both adjacent nitrogen-15 atoms at about the same ratio
Full Text Available Burak Turgut, Murat Kaya, Sermal Arslan, Tamer Demir, Mete Güler, Mehmet Kaan KayaFırat University School of Medicine, Department of Ophthalmology, Elazıg, TurkeyObjective: To compare the levels of plasma homocysteine (Hcy, vitamin B6 (vit-B6, serum vitamin B12 (vit-B12, and folate in healthy individuals and in patients with normal tension glaucoma (NTG, pseudoexfoliative glaucoma (PXG, or primary open-angle glaucoma (POAG.Study design: A prospective controlled trial.Participants and methods: Forty healthy subjects, 48 patients with NTG, 38 patients with PXG, and 34 patients with POAG were included in the study. Those who used vitamin supplements or medications affecting Hcy and vitamin levels were excluded from the study. The levels of Hcy and vit-B6 were measured by High Performance Liquid Chromatography (HPLC. The levels of serum vit-B12 and folic acid were measured by competitive chemiluminescent enzyme immunoassay (CEI. One-way analysis if variance (ANOVA, analysis of covariance (ANCOVA, and the Tukey honestly significant difference test were used for statistical analysis.Results: The mean Hcy level of the PXG group was 15.46 ± 9.27 μmol/L which was significantly higher (P = 0.03 than that of the control group. There were no statistical differences in serum vit-B12 and folate levels among control subjects and NTG, PXG and POAG groups (P > 0.05. It was found that the mean plasma vit-B6 level was significantly higher in subjects with NTG (P = 0.03 and POAG (P = 0.025 versus controls. Mean vit-B6 levels in NTG and POAG were 30.50 ± 11.29 μg/L and 30 ± 12.15 μg/L, respectively.Conclusions: The plasma level of Hcy was found to be increased only in PXG patients and the plasma levels of vit-B6 were found to increase in the NTG and POAG sample groups. Using homocysteine and vit-B6 levels as the determinants of hyperhomocysteinemia still needs further research.Keywords: normal tension glaucoma, pseudoexfoliative glaucoma, primary open
van Wijk Nick; Watkins Carol J; Hageman Robert J J; Sijben John C W; Kamphuis Patrick G H J; Wurtman Richard J; Broersen Laus M
Abstract Background Folate, vitamin B-12, and vitamin B-6 are essential nutritional components in one-carbon metabolism and are required for methylation capacity. The availability of these vitamins may therefore modify methylation of phosphatidylethanolamine (PE) to phosphatidylcholine (PC) by PE-N-methyltransferase (PEMT) in the liver. It has been suggested that PC synthesis by PEMT plays an important role in the transport of polyunsaturated fatty acids (PUFAs) like docosahexaenoic acid (DHA...
Yang, Hui; Xiao, Xue; Zhao, Xuesong; Hu, Lan; Lv, Caofang; Yin, Zhangkun
This paper presents the intrinsic fluorescence characteristics of vitamin B1, B2 and B6 measured with 3D fluorescence Spectrophotometer. Three strong fluorescence areas of vitamin B2 locate at λex/λem=270/525nm, 370/525nm and 450/525nm, one fluorescence areas of vitamin B1 locates at λex/λem=370/460nm, two fluorescence areas of vitamin B6 locates at λex/λem=250/370nm and 325/370nm were found. The influence of pH of solution to the fluorescence profile was also discussed. Using the PARAFAC algorithm, 10 vitamin B1, B2 and B6 mixed solutions were successfully decomposed, and the emission profiles, excitation profiles, central wavelengths and the concentration of the three components were retrieved precisely through about 5 iteration times.
Tanaka, Toshiko; Scheet, Paul; Giusti, Betti; Bandinelli, Stefania; Piras, Maria Grazia; Usala, Gianluca; Lai, Sandra; Mulas, Antonella; Corsi, Anna Maria; Vestrini, Anna; Sofi, Francesco; Gori, Anna Maria; Abbate, Rosanna; Guralnik, Jack; Singleton, Andrew
The B vitamins are components of one-carbon metabolism (OCM) that contribute to DNA synthesis and methylation. Homocysteine, a by-product of OCM, has been associated with coronary heart disease, stroke and neurological disease. To investigate genetic factors that affect circulating vitamin B6, vitamin B12, folate and homocysteine, a genome-wide association analysis was conducted in the InCHIANTI (N = 1175), SardiNIA (N = 1115), and BLSA (N = 640) studies. The top loci were replicated in an in...
Full Text Available Background/Aim. Zeolites are the hydratised alumosilicates of alcali and earthalcali cations, which have a long three-dimensional crystal structure. Preparations on the basis of zeolites are used for adsorption of organic and nonorganic toxic substances and they, also, find more and more use in veterinary and human medicine and pharmacy. The aim of this study was to evaluate the possibilities of zeolite to adsorb vitamins B1, B2 and B6 in acid and neutral solutions, as well as the characteristics of the process (saturability, reversibility and competitivness. Methods. The specific and sensitive HPLC method with fluorescent detector was used for determination of vitamins B1, B2 and B6. Analyte separation and detection were carried out by applying the reverse-phase method on column C18. An in vitro experiment was done by testing the influence of pH value (2 and 7, concentration of vitamin solution (1, 2 and 5 mg/L, the lenght of contact with zeolite (10-180 min and cation competitiveness on the exchange capacity, which is achieved by media and zeolite contact, as well as a possible vitamins desorption through changing pH value of the solution at 37°C. Jon competitiveness was examined by adding commercial feed mixture (grower with a defined content of the examined vitamines in zeolite solutions the pH = 2 and pH = 7. Results. Vitamins B1, B2 and B6 were stable in both pH=2 and pH = 7 solutions at 37°C, in the defined time intervals. In acid solution concentrations of vitamins significantly declined in the first 10 min, with no significant decline in further 30 min for all the three concentrations testch. In neutral solution, after the addition of 1% zeolite, decrease in vitamins concentrations was slightly lower than in acid solution, but also significant in the first 10 min of the contact with zeolite. It was found that zeolite, which adsorbed vitamins in acid solution, transferred in the neutral one released a significant quantity of adsorbed
van Wijk Nick
Full Text Available Abstract Background Folate, vitamin B-12, and vitamin B-6 are essential nutritional components in one-carbon metabolism and are required for methylation capacity. The availability of these vitamins may therefore modify methylation of phosphatidylethanolamine (PE to phosphatidylcholine (PC by PE-N-methyltransferase (PEMT in the liver. It has been suggested that PC synthesis by PEMT plays an important role in the transport of polyunsaturated fatty acids (PUFAs like docosahexaenoic acid (DHA from the liver to plasma and possibly other tissues. We hypothesized that if B-vitamin supplementation enhances PEMT activity, then supplementation could also increase the concentration of plasma levels of PUFAs such as DHA. To test this hypothesis, we determined the effect of varying the combined dietary intake of these three B-vitamins on plasma DHA concentration in rats. Methods In a first experiment, plasma DHA and plasma homocysteine concentrations were measured in rats that had consumed a B-vitamin-poor diet for 4 weeks after which they were either continued on the B-vitamin-poor diet or switched to a B-vitamin-enriched diet for another 4 weeks. In a second experiment, plasma DHA and plasma homocysteine concentrations were measured in rats after feeding them one of four diets with varying levels of B-vitamins for 4 weeks. The diets provided 0% (poor, 100% (normal, 400% (enriched, and 1600% (high of the laboratory rodent requirements for each of the three B-vitamins. Results Plasma DHA concentration was higher in rats fed the B-vitamin-enriched diet than in rats that were continued on the B-vitamin-poor diet (P = 0.005; experiment A. Varying dietary B-vitamin intake from deficient to supra-physiologic resulted in a non-linear dose-dependent trend for increasing plasma DHA (P = 0.027; experiment B. Plasma DHA was lowest in rats consuming the B-vitamin-poor diet (P > 0.05 vs. normal, P . enriched and high and highest in rats consuming the
KANDUNGAN VITAMIN B6, B9, B12 DAN E BEBERAPA JENIS DAGING, TELUR, IKAN DAN UDANG LAUT DI BOGOR DAN SEKITARNYA (VITAMIN B6, B9, B12 AND E CONTENT OF SEVERAL TYPES OF MEATS, EGGS, FISHES AND MARINE SHRIMPS IN BOGOR AND SURROUNDING AREAS)
Heru Yuniati; Almasyhuri Almasyhuri
ABSTRACT Food Composition Table (DKBM) in Indonesia has not mentioned all types of nutrients available in the food, particularly vitamin B6, B9 (folic acid), B12, and vitamin E. Therefore this study aimed to analyze the content of vitamin B6, B9 (folic acid), B12, and vitamin E in several types of meat, eggs, fish and marine shrimps consumed in Bogor and surrounding areas. Vitamin B6, B9, B12, and vitamin E from three kinds of meat (chicken, beef, lamb), two types of eggs (chicken, duck), an...
Erickson, Kirk I.; Suever, Barbara L.; Shaurya Prakash, Ruchika; Colcombe, Stanley J.; McAuley, Edward; Arthur F Kramer
Previous studies have reported that high concentrations of homocysteine and lower concentrations of vitamin B6, B12, and folate increase the risk for cognitive decline and pathology in aging populations. In this cross-sectional study, high-resolution magnetic resonance imaging (MRI) scans and a 3-day food diary were collected on 32 community-dwelling adults between the ages of 59 and 79. We examined the relation between vitamin B6, B12, and folate intake on cortical volume using an optimized ...
Zhuo, Jia-Min; Praticò, Domenico
Epidemiological and clinical studies indicate that elevated circulating level of homocysteine (Hcy) is a risk factor for developing Alzheimer's disease (AD). Dietary deficiency of folate, vitamin B6 and B12 results in a significant increase of Hcy levels, a condition also known as hyperhomocysteinemia (HHcy).
采用循环伏安法研究了维生素B6在维生素B12修饰玻碳电极上的电化学行为,建立了测定痕量维生素B6的新方法.在pH 8.6的NH3-NH4Cl缓冲溶液中,维生素B6在修饰电极上产生一个灵敏的氧化峰,采用差分脉冲伏安法测定,其氧化峰电流与维生素B6的浓度在8.0×10-7～2.0×10-4 mol/L范围内呈良好的线性关系,检出限为2.0×10-7 mol/L.该修饰电极具有良好的选择性、灵敏度及稳定性,用于片剂中维生素B6的定量分析,结果令人满意.%A Vitamin B,2 modified glassy carbon electrode was prepared. The electrochemical behavior of Vitamin B6 (VB6) was studied at the prepared electrode by cyclic voltammetry. The modified electrode showed an excellent electrocatalytical effect on oxidation of VB6. In NH3-NH4C1 buffer solution(pH 8.6), the anodic peak current had a linear relationship with VB6 concentration in the range of 8.0×10-7 -2.0×10-4 mol / L by differential pulse voltammetry. The detection limit was 2.0×10-7mol / L. The modified electrode had good selectivity and sensitivity. The proposed method had been applied to the determination of VB6 in tablets with satisfactory results.
Full Text Available Vitamins B6, B12 and folate play crucial metabolic roles especially during the reproductive years for women. There is limited reporting of within-subject variability of these vitamins. This study aimed to determine the within and between subject variability in serum vitamins B6, B12, folate and erythrocyte folate concentrations in young women; identify factors that contribute to variability; and determine dietary intakes and sources of these vitamins. Data were obtained from the control group of a trial aimed at investigating the effect of iron on the nutritional status of young women (age 25.2 ± 4.2 year; BMI 21.9 ± 2.2 kg/m2. The coefficients of variability within-subject (CVI and between-subject (CVG for serum vitamins B6, B12 and folate, and erythrocyte folate were calculated. Food frequency questionnaires provided dietary data. CVI and CVG were in the range 16.1%–25.7% and 31.7%–62.2%, respectively. Oral contraceptive pill (OCP use was associated (P = 0.042 with lower serum vitamin B12 concentrations. Initial values were 172 ± 16 pmol/L and 318 ± 51 pmol/L for OCP and non-OCP users, respectively; with differences maintained at four time points over 12 weeks. BMI, age, physical activity, alcohol intake and haematological variables did not affect serum or erythrocyte vitamin concentrations. Vitamin B12 intakes were derived from traditional and unexpected sources including commercial energy drinks. Young women using OCP had significantly lower serum vitamin B12 concentrations. This should be considered in clinical decision making and requires further investigation.
Erickson, Kirk I; Suever, Barbara L; Prakash, Ruchika Shaurya; Colcombe, Stanley J; McAuley, Edward; Kramer, Arthur F
Previous studies have reported that high concentrations of homocysteine and lower concentrations of vitamins B6, B12, and folate increase the risk for cognitive decline and pathology in aging populations. In this cross-sectional study, high resolution magnetic resonance imaging (MRI) scans and a 3-day food diary were collected on 32 community-dwelling adults between the ages of 59 and 79. We examined the relation between vitamins B6, B12, and folate intake on cortical volume using an optimized voxel-based morphometry (VBM) method and global gray and white matter volume after correcting for age, sex, body mass index, calorie intake, and education. All participants met or surpassed the recommended daily intake for these vitamins. In the VBM analysis, we found that adults with greater vitamin B6 intake had greater gray matter volume along the medial wall, anterior cingulate cortex, medial parietal cortex, middle temporal gyrus, and superior frontal gyrus, whereas people with greater B12 intake had greater volume in the left and right superior parietal sulcus. These effects were driven by vitamin supplementation and were negated when only examining vitamin intake from diet. Folate had no effect on brain volume. Furthermore, there was no relationship between vitamins B6, B12, or folate intake on global brain volume measures, indicating that VBM methods are more sensitive for detecting localized differences in gray matter volume than global measures. These results are discussed in relation to a growing literature on vitamin intake on age-related neurocognitive deterioration. PMID:18281020
In 108 breast cancer, 63 cervix carcinoma, 35 corpus carcinoma and 15 ovarial cancer patients the erythrocyte transketolase, gluthathione reductase and aspartate aminotransferase activity were determined as parameters for the supply with vitamin B1, B2 and B6 before and after radiotherapy. The effects of thiamine pyrophosphate determined in cancer patients were normal but the effects of flavin adenine dinucleotide and pyridoxal-5-phosphate were significantly increased compared to the controls. These results revealed radiation-induced disorders in the B2 metabolism and tumor-induced disorders in the B6 metabolism. Both disorders can be avoided by treatment with vitamin B complex. (author)
Mona Yossef EL-Toweissy; Nema Abdel-Hameed Mohamed; Wessam Mohamed Abdel-Wahab
This study was undertaken to determine the modulating effects of intramuscular administration of melatonin (MT)(1mg/ kg) and/or Tri-B (B 1 , B 6 and B 12 ) (20mg/kg) on body weight and some biochemical changes in rats induced by Epinephrine (Epi) injection. The data showed that MT and/or Tri-B treatment effectively improved the changes in malondialdehyde, lipid profile, blood sugar level and insulin. MT and/or Tri-B administration following Epi improved partially the decrease in body weight a...
Ollilainen, V.; Finglas, P.M.; Berg, H. van den; Froidmont-Görtz, I. de
In 1989, the Community Bureau of Reference started a research program to improve the quality of vitamin analysis in food. To achieve this task, vitamin methodology was evaluated and tested by interlaboratory studies and the preparation of certified reference materials, which will be used for quality
Rajdl, Daniel; Racek, Jaroslav; Trefil, Ladislav; Stehlik, Pavel; Dobra, Jana; Babuska, Vaclav
Moderate regular consumption of alcoholic beverages is believed to protect against atherosclerosis but can also increase homocysteine or dimethylglycine, which are putative risk factors for atherosclerosis. We aimed (1) to investigate the effect of alcohol consumption on vitamins and several metabolites involved in one-carbon metabolism; and (2) to find the most effective way of decreasing homocysteine during moderate alcohol consumption. Methods: Male volunteers (n = 117) were randomly divided into five groups: the wine-only group (control, 375 mL of white wine daily for one month) and four groups combining wine consumption with one of the supplemented substances (folic acid, betaine, and vitamins B12 or B6). Significant lowering of homocysteine concentration after the drinking period was found in subjects with concurrent folate and betaine supplementation. Vitamin B12 and vitamin B6 supplementation did not lead to a statistically significant change in homocysteine. According to a multiple linear regression model, the homocysteine change in the wine-only group was mainly determined by the interaction between the higher baseline homocysteine concentration and the change in dimethylglycine levels. Folate and betaine can attenuate possible adverse effects of moderate alcohol consumption. Dimethylglycine should be interpreted together with data on alcohol consumption and homocysteine concentration. PMID:26771632
Full Text Available Moderate regular consumption of alcoholic beverages is believed to protect against atherosclerosis but can also increase homocysteine or dimethylglycine, which are putative risk factors for atherosclerosis. We aimed (1 to investigate the effect of alcohol consumption on vitamins and several metabolites involved in one-carbon metabolism; and (2 to find the most effective way of decreasing homocysteine during moderate alcohol consumption. Methods: Male volunteers (n = 117 were randomly divided into five groups: the wine-only group (control, 375 mL of white wine daily for one month and four groups combining wine consumption with one of the supplemented substances (folic acid, betaine, and vitamins B12 or B6. Significant lowering of homocysteine concentration after the drinking period was found in subjects with concurrent folate and betaine supplementation. Vitamin B12 and vitamin B6 supplementation did not lead to a statistically significant change in homocysteine. According to a multiple linear regression model, the homocysteine change in the wine-only group was mainly determined by the interaction between the higher baseline homocysteine concentration and the change in dimethylglycine levels. Folate and betaine can attenuate possible adverse effects of moderate alcohol consumption. Dimethylglycine should be interpreted together with data on alcohol consumption and homocysteine concentration.
KANDUNGAN VITAMIN B6, B9, B12 DAN E BEBERAPA JENIS DAGING, TELUR, IKAN DAN UDANG LAUT DI BOGOR DAN SEKITARNYA (VITAMIN B6, B9, B12 AND E CONTENT OF SEVERAL TYPES OF MEATS, EGGS, FISHES AND MARINE SHRIMPS IN BOGOR AND SURROUNDING AREAS
Full Text Available ABSTRACT Food Composition Table (DKBM in Indonesia has not mentioned all types of nutrients available in the food, particularly vitamin B6, B9 (folic acid, B12, and vitamin E. Therefore this study aimed to analyze the content of vitamin B6, B9 (folic acid, B12, and vitamin E in several types of meat, eggs, fish and marine shrimps consumed in Bogor and surrounding areas. Vitamin B6, B9, B12, and vitamin E from three kinds of meat (chicken, beef, lamb, two types of eggs (chicken, duck, and four species of fish (snapper, bloating, carp and tuna and crayfish are analyzed using High-Performance Liquid Chromatography (HPLC. The samples used are raw and taken from three locations in Bogor and surrounding areas. Fishes, meats and eggs contain high levels of folic acid, however the amount of folic acid content in meat varies depending on which part of meat the samples are taken, types of organ, and the fat content of the meat. The folic acid content in chicken wings is different with those in thigh. In fatty mutton the folic acid is higher than in those lean meat, and in yolk is higher than those in egg white. Vitamin E content of snapper is the highest amongs other types of fishes (6.54 µg/100 g.Chicken eggs contain a higher amount of vitamin E than duck eggs, while the yolk contains ahigher amount of vitamin E than those egg white. Keywords: animal foods, vitamin B6, vitamin B9 (folic Acid, vitamin B12, vitamin E ABSTRAK Daftar Komposisi Bahan Makanan (DKBM yang ada di Indonesia belum memuat semua jenis zat gizi dalam makanan, khususnya vitamin B6, B9 (asam folat, B12 dan vitamin E. Menganalisis kandungan vitamin B6, B9 (asam folat, B12, dan vitamin E dalam beberapa jenis daging, telur, ikan dan udang laut yang dikonsumsi masyarakat di Bogor dan sekitarnya. Kandungan vitamin B6, B9, B12 dan vitamin E dari tiga jenis daging (ayam, sapi, kambing, dua jenis telur (ayam, itik, serta empat jenis ikan (kakap, kembung, mas, tongkol dan udang laut
... 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. ...
We derive an analytical equation of state for the hard-sphere fluid that is within 0.01% of computer simulations for the whole range of the stable fluid phase. In contrast, the commonly used Carnahan-Starling equation of state deviates by up to 0.3% from simulations. The derivation uses the functional form of the isothermal compressibility from the Percus-Yevick closure of the Ornstein-Zernike relation as a starting point. Two additional degrees of freedom are introduced, which are constrained by requiring the equation of state to (i) recover the exact fourth virial coefficient B4 and (ii) involve only integer coefficients on the level of the ideal gas, while providing best possible agreement with the numerical result for B5. Virial coefficients B6 to B10 obtained from the equation of state are within 0.5% of numerical computations, and coefficients B11 and B12 are within the error of numerical results. We conjecture that even higher virial coefficients are reliably predicted.
Mona Yossef EL-Toweissy
Full Text Available This study was undertaken to determine the modulating effects of intramuscular administration of melatonin (MT(1mg/ kg and/or Tri-B (B 1 , B 6 and B 12 (20mg/kg on body weight and some biochemical changes in rats induced by Epinephrine (Epi injection. The data showed that MT and/or Tri-B treatment effectively improved the changes in malondialdehyde, lipid profile, blood sugar level and insulin. MT and/or Tri-B administration following Epi improved partially the decrease in body weight and liver glycogen levels. Tri B injection following Epi partialy improved all the tested parameters except malondialdehyde and blood sugar level that completely improved in stressed rats. It was evident that a combination of MT and vitamin B complex had protective actions and further it was better than either of them introduced alone in stressed rats. The possible interaction between MT and Tri B provided further support to MT synergistic actions with the aim of advocating MT and Tri B as a possible synergistic therapy.
Rejnmark, L; Vestergaard, P; Hermann, A P;
Folate, vitamin B(2) (riboflavin), and vitamin B(12 )may affect bone directly or through an effect on plasma homocysteine levels. Previously, a positive association has been found between plasma levels and bone mineral density (BMD) as well as risk of fracture. However, there are limited data...
陈泽忠; 冯锋; 林洁刁; 廖雪明
The effects of ionizing radiation on erythrocytic transketolase, glutathion reductase, and aspartate-aminotransferase activities with and without addition of coenzymes were studied in 152 Wistar rats, six beagles, and 225 carcinoma patients, as a measure for vitamin B1, B2, and B6 supplies. Examinations of 108 patients with mammary carcinoma and 117 patients with cervical, corpus, and ovarian carcinomas were undertaken prior to, during, and after termination of radiotherapy. Two check-up series were run, the first without vitamin B complex therapy, and the second with three daily applications of one dragee each, beginning on the first day of irradiation. The TPP effects recorded indicated no impairment of vitamin B1 supply. FAD and PLP effects, on the other hand, were significantly increased, which suggested B2 and B6 deficits. Vitamin B2 metabolism was causally impaired by radiation, while the disordes in vitamin B6 metabolism were attributed to tumour-related causes. The results obtained revealed that both types of disorders can be avoided by prophylactic vitamin B complex treatment. (author)
SONG Chun-rong; ZHAO Jian-jun; LIU Jin
The phase-matching for nonlinear optical crystal,the nonlinear phase matching angle, effective nonlinear coefficient, walk-off angles, permitted angle, and permitted wavelength are obtained in type-Ⅰ and type-Ⅱ phase matching in ultraviolet (UV) nonlinear optical crystals CsLiB6O10(CLBO) and K2Al2B2O7 (KABO) by detailed theoretical simulation. Through analysis and comparison, the phase matching characteristics of the second harmonic generation in the crystals are discussed when the wavelengths of the basic frequency lights turn continually.
Sitler, Steven; Hill, Cody; Raja, Krishnan S.; Charit, Indrajit
Transition metal borides are being considered for use as potential electrode coating materials in magnetohydrodynamic direct power extraction plants from coal-fired plasma. These electrode materials will be exposed to aggressive service conditions at high temperatures. Therefore, high-temperature oxidation resistance is an important property. Consolidated samples containing an equimolar solid solution of ZrB2-HfB2 with and without the addition of 1.8 mol pct LaB6 were prepared by ball milling of commercial boride material followed by spark plasma sintering. These samples were oxidized at 1773 K (1500 °C) in two different conditions: (1) as-sintered and (2) anodized (10 V in 0.1 M KOH electrolyte). Oxidation studies were carried out in 0.3 × 105 and 0.1 Pa oxygen partial pressures. The anodic oxide layers showed hafnium enrichment on the surface of the samples, whereas the high-temperature oxides showed zirconium enrichment. The anodized samples without LaB6 addition showed about 2.5 times higher oxidation resistance in high-oxygen partial pressures than the as-sintered samples. Addition of LaB6 improved the oxidation resistance in the as-sintered condition by about 30 pct in the high-oxygen partial pressure tests.
Sitler, Steven; Hill, Cody; Raja, Krishnan S.; Charit, Indrajit
Transition metal borides are being considered for use as potential electrode coating materials in magnetohydrodynamic direct power extraction plants from coal-fired plasma. These electrode materials will be exposed to aggressive service conditions at high temperatures. Therefore, high-temperature oxidation resistance is an important property. Consolidated samples containing an equimolar solid solution of ZrB2-HfB2 with and without the addition of 1.8 mol pct LaB6 were prepared by ball milling of commercial boride material followed by spark plasma sintering. These samples were oxidized at 1773 K (1500 °C) in two different conditions: (1) as-sintered and (2) anodized (10 V in 0.1 M KOH electrolyte). Oxidation studies were carried out in 0.3 × 105 and 0.1 Pa oxygen partial pressures. The anodic oxide layers showed hafnium enrichment on the surface of the samples, whereas the high-temperature oxides showed zirconium enrichment. The anodized samples without LaB6 addition showed about 2.5 times higher oxidation resistance in high-oxygen partial pressures than the as-sintered samples. Addition of LaB6 improved the oxidation resistance in the as-sintered condition by about 30 pct in the high-oxygen partial pressure tests.
目的 建立高效液相色谱法测定复合维生素B片中维生素B1、维生素B2、维生素B6的含量.方法 色谱柱:Wondasil C18色谱柱,流动相为醋酸-醋酸钠缓冲液(pH 4.5)-甲醇(65∶35),流速为1.0 mL·min-1,检测波长为270 nm.结果 维生素B1、维生素B2、维生素B6浓度分别在0.6 μg·mL-1～0.75 mg·mL-1、0.3 μg·mL-1～0.62 mg·mL-1、80～415 μg·mL1范围内与峰面积线性关系良好.结论 该方法简便、快速、准确可靠,可用于复合维生素B片中维生素B1、维生素B2、维生素B6的含量测定.
The microstructure and low-temperature magnetization of nanocrystalline Fe87-xZr7B6Cux and Fe81-xZr7B12Cux alloys (x = 0,1 and 2 at.%) have been studied using a combination of differential scanning calorimetry, x-ray diffraction analysis, transmission electron microscopy and superconducting quantum interference device magnetometry. The results show that the substitution of 1 at.% copper for iron in both low- and high-boron-content alloys has significant effects on the microstructure and magnetic properties, while increasing the copper content to 2 at.% does not cause any further significant change in the microstructure and magnetic properties. For the low-boron-content alloys, the addition of 1 at.% copper promotes a uniform distribution of α-Fe grains, decreases the grain size without changing the phase structure, and decreases the exchange stiffness constant from 180±6 to 122±2 meV A2. For the high-boron-content alloys with the addition of 1 at.% copper, the constitutional crystalline phase changes from a metastable phase with the cubic 'Fe12Si2ZrB' structure to the equilibrium phase α-Fe. For the nanocrystalline Fe81Zr7B12 alloy with the metastable phase after being heated to 893 K at 20 K min-1, the saturation magnetization σs(0)=115±1 emu g-1, and the exchange stiffness constant D=86±2 meV A2, confirming that the metastable phase is a weaker ferromagnetic phase
Ni Luh Kasih Ariani
Full Text Available ABSTRAK: Vitamin B terutama B1 (Tiamin, B2 (Riboflavin, dan B6 (Piridoksin sering terkandung dalam sirup multivitamin sehingga diperlukan analisis untuk mendeteksi secara simultan dalam campuran. Tujuan penelitian ini adalah membandingkan analisis vitamin B1, B2, dan B6 dalam sirup multivitamin secara simultan dengan kromatografi cair kinerja tinggi eluasi gradien dan isokratik, menggunakan kolom C18, panjang 15 cm, dan dengan pelarut campuran metanol: air : asam asetat glasial (10:90:1. Fase gerak adalah campuran natrium heksan sulfonat 5 mM dalam asam asetat glasial 0,5% dengan metanol yang dicampur secara gradien. Kondisi optimum metode gradien diperoleh pada laju alir 2,0 mL/menit, panjang gelombang 280 nm dengan waktu retensi 3,441 menit untuk piridoksin; 4,985 menit untuk riboflavin dan 7,393 menit untuk tiamin dengan resolusi 2,272 antara riboflavin dan piridoksin. Hasil uji presisi riboflavin dan piridoksin menggunakan metode isokratik (campuran natrium heksan sulfonat 5 mM dengan metanol dengan perbandingan 70 : 30 masing-masing dengan RSD adalah 1,377 dan 1,376 sedangkan metode gradien adalah 0,693 dan 0,825. Uji linearitas ketiga vitamin menggunakan dua metode isokratik dan gradien memenuhi persyaratan dengan R2 = 0,999. Kata kunci : Vitamin B, sirup multivitamin, kromatografi cair kinerja tinggi ABSTRACT: The aim of this research is to compare the simultaneous analytical results of B1 (Tiamin, B2 (Riboflavin, and B6 (Piridoxin in multivitamin syrup between gradient and isocratic methods using high performance liquid chromatography (HPLC. The separation was performed on 15 cm length of C18 column and a mixture of methanol, water and glacial acetate acid with ratio of 10:90:1 was used as solvent. The eluent was a mixture of methanol and 5 mM sodium hexane sulfonate in 0.5% glacial acetate acid and gradually mixed using 2 different pumps. The optimal analytical conditions for gradient method were found to be 2,0 mL/min of flow rate and
Validação de métodos cromatográficos por clae para análise das vitaminas B1, B2, B6 e niacina naturalmente presentes em farinha de cereais Validation of hplc methods for analysis of vitamins B1, B2, B6 and niacin naturally present in cereal flours
Ana Elisa Ferreira Presoto
Full Text Available Complex B vitamins are present in some cereal foods and the ingestion of enriched products contributes to the recommended dietary intake of these micronutrients. To adapt the label of some products, it is necessary to develop and validate the analytical methods. These methods must be reliable and with enough sensitivity to analyze complex B vitamins naturally present in food at low concentration. The purpose of this work is to evaluate, with validated methods, the content of vitamins B1, B2, B6 and niacin in five cereal flours used in food industry (oat, rice, barley, corn and wheat.
Preditores sócio-demográficos, de estilo de vida e gineco-obstétricos das concentrações séricas ou plasmáticas de homocisteína, ácido fólico e vitaminas B12 e B6 em mulheres de baixa renda de São Paulo, Brasil Socio-demographic, lifestyle, gynecological, and obstetric predictors of serum or plasma concentrations of homocysteine, folic acid, and vitamins B12 and B6 among low-income women in São Paulo, Brazil
Lana Carneiro Almeida
Full Text Available O presente estudo investigou fatores sócio-demográficos, de estilo de vida e gineco-obstétricos associados às concentrações séricas ou plasmáticas de homocisteína, ácido fólico, vitaminas B12 e B6 em mulheres de baixa renda de São Paulo, Brasil. Concentrações séricas de ácido fólico e vitamina B12 foram analisadas por fluoroimunoensaio; concentrações plasmáticas de homocisteína e vitamina B6, por cromatografia líquida de alta performance em fase reversa. Variáveis independentes foram inicialmente selecionadas segundo pressupostos teóricos, correlação de Pearson ou teste Kruskal-Wallis (p This study examined the socio-demographic, lifestyle, gynecological, and obstetric factors associated with serum or plasma concentrations of homocysteine, folic acid, and vitamins B12 and B6 among low-income women in São Paulo, Brazil. Serum concentrations of folic acid and vitamin B12 were measured by fluoroimmunoassay, while plasma vitamin B6 and homocysteine levels were measured by reversed-phase high performance liquid chromatography. Independent variables were initially selected by Pearson correlation or Kruskal-Wallis test (p < 0.20. Based on cut-off values, altered concentrations of homocysteine, folic acid, and vitamins B12 and B6 were found in 20%, 6%, 11%, and 67% of participants, respectively. Age was positively correlated with vitamin B6 and homocysteine plasma concentrations (p < 0.001. Body mass index was positively correlated with vitamin B6 plasma concentration (p < 0.001. Multiple linear regression models accounted for 10.2%, 5.8%, 14.4%, and 9.4% of folic acid, vitamins B12 and B6, and homocysteine plasma or serum concentrations, respectively. In this study, socio-demographic, lifestyle, gynecological, and obstetric variables showed important predictive value for serum or plasma levels of the biochemical indicators assessed.
A novel ternary lithium strontium borate Li2Sr4B12O23 crystal with size up to 20 mm×10 mm×4 mm has been grown via the top-seeded solution growth method below 730 °C. Single-crystal XRD analyses showed that Li2Sr4B12O23 crystallizes in the monoclinic space group P21/c with a=6.4664(4) Å, b=8.4878(4) Å, c=15.3337(8) Å, β=102.02(3)°, Z=2. The crystal structure is composed of [B10O18]6− network and isolated [B2O5]4− unit. The IR spectrum further confirmed the presence of both BO3 and BO4 groups. TG-DSC and Transmission spectrum were reported. Band structures and density of states were calculated. - Graphical abstract: A new phase, Li2Sr4B12O23, has been discovered in the ternary M2O–M′O–B2O3 (M=alkali-metal, M′=alkalineearth metal) system. The crystal structure consists of [B10O18]6− network and isolated [B2O5]4− unit. Highlights: ► Li2Sr4B12O23 is a a novel borate discovered in the M2O–M′O–B2O3 (M=alkali-metal, M′=alkaline-earth metal) system. ► Li2Sr4B12O23 crystal structure has a three-dimensional crystal structure with [B10O18]6− network and isolated [B2O5]4− unit. ► Sr1 and Sr2 are located in two different channels constructed by 3∞[B10O18] network.
王伟姣; 唐湘伟; 黄莉
目的:建立高效液相色谱法测定多维元素胶囊(15)中的烟酰胺、维生素B1、维生素B2、维生素B6的含量.方法:采用Boston Green ODS C18柱(250 mm×4.6 mm,5 μm);流动相:庚烷磺酸钠溶液(取庚烷磺酸钠0.941 g,加冰乙酸10 ml,加水1 000 ml溶解,用NaOH试液调节pH至3.8)-甲醇(70:30);进样量:20 μl;检测波长为280 nm;柱温:30℃;流速1.0 ml·min-1.结果:烟酰胺、维生素B1、维生素B2、维生素B6分别在38.83～349.44,9.88～88.94,4.03～36.25,3.97～35.77 μg·ml-1范围内线性关系良好(r≥0.999 6);平均回收率分别为98.7%(RSD=0.89%),98.7%(RSD=1.03%),99.0%(RSD=1.03%),99.8%(RSD=1.49%).结论:该方法准确,灵敏度高,重复性好,可作为多维元素胶囊(15)的质量控制方法之一.%Objective: To develop an HPLC method for the determination of nicotinamide, vitamin B, , vitamin B2 and vitamin B6 in Duoweiyuansu capsules ( 15 ). Method: The separation was preformed on a Boston Green ODS C18 column ( 250 mm ×4. 6 mm,5 μm ) and the mobile phase consisted of sodium heptanesulfonate solution ( containing 0. 941 g sodium heptanesulfonate and 10ml glacial acetic acid in 1000ml water, and adjusting Ph to 3. 80 with NaOH test solution )-methanol ( 70: 30 ). The detection wavelength was set at 280nm. The flow rate was 1.0 ml ? Min-1 , and the column temperature was 30℃. Result: The calibration curve was linear within the range of 38. 83 ~349.44 μg ? Ml-1 for nicotinamide, 9. 88 ~ 88. 94 μg ? Ml-1 for vitamin B, , 4.03 ~36. 25 μg ? Ml-1 for vitamin B2 and3.97 -35.77 μg ? Ml-1 for vitamin B6. The average recovery was 98.7%( RSD =0. 89% ), 98.7%( RSD = 1.03% ), 99.0% ( RSD = 1. 03% ) and 99. 8%( RSD = 1. 49% ), respectively. Conclusion: This method is sensitive and accurate with good reproduc-ibility, and can be used for the quality control of Duoweiyuansu capsules ( 15 ) .
Boron reacted with ball milled boron oxide under pressures between 1 and 5 GPa and at temperatures between 1300 and 1700 oC to afford boron suboxide (B6O). Icosahedral B6O grains with diameters ranging from 100 nm to 1.3 μm were prepared. The factors that affect the synthesis of B6O are investigated. The best sample with crystal size up to 1.3 μm is obtained at 2 GPa and 1400 oC for 6 h. The indentation experiment gave an average Vickers hardness of 32.3 GPa for bulk B6O sample, which is consistent with previous reports. Bulk B6O sample exhibits oxidation resistance in air up to 1000 oC and mild oxidation in the temperatures of 1000-1200 oC, which is more oxidation resistant than diamond. It is possible that B6O could be used as a substitute for diamond in industry because of its relatively mild synthesis conditions, high thermal stability and high hardness. - Graphical abstract: Icosahedral B6O grains were prepared for mixtures of boron and ball milled boron oxide at 2 GPa and 1400 oC, a milder synthesis condition in comparison with previous works.
Eussen, S.J.; Vollset, S.E.; Hustad, S.; Midttun, O.; Meyer, K.; Fredriksen, A.; Ueland, P.M.; Jenab, M.; Slimani, N.; Ferrari, P.; Agudo, A.; Sala, N.; Capella, G.; Giudice, G. Del; Palli, D.; Boeing, H.; Weikert, C.; Bueno-De-Mesquita, H.B.; Buchner, F.L.; Carneiro, F.; Berrino, F.; Vineis, P.; Tumino, R.; Panico, S.; Berglund, G.; Manjer, J.; Stenling, R.; Hallmans, G.; Martinez, C.; Arrizola, L.; Barricarte, A.; Navarro, C.; Rodriguez, L.; Bingham, S.; Linseisen, J.; Kaaks, R.; Overvad, K.; Tjonneland, A.; Peeters, P.H.M.; Numans, M.E.; Clavel-Chapelon, F.; Boutron-Ruault, M.C.; Morois, S.; Trichopoulou, A.; Lund, E.; Plebani, M.; Riboli, E.; Gonzalez, C.A.
B vitamins and polymorphisms in genes coding for enzymes involved in one-carbon metabolism may affect DNA synthesis and methylation and thereby be implicated in carcinogenesis. Previous data on vitamins B2 and B6 and genetic polymorphisms other than those involving MTHFR as risk factors for gastric
Salvati, Louis M; McClure, Sean C; Reddy, Todime M; Cellar, Nicholas A
This method provides simultaneous determination of total vitamins B1, B2, B3, and B6 in infant formula and related nutritionals (adult and infant). The method was given First Action for vitamins B1, B2, and B6, but not B3, during the AOAC Annual Meeting in September 2015. The method uses acid phosphatase to dephosphorylate the phosphorylated vitamin forms. It then measures thiamine (vitamin B1); riboflavin (vitamin B2); nicotinamide and nicotinic acid (vitamin B3); and pyridoxine, pyridoxal, and pyridoxamine (vitamin B6) from digested sample extract by liquid chromatography-tandem mass spectrometry. A single-laboratory validation was performed on 14 matrixes provided by the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) to demonstrate method effectiveness. The method met requirements of the AOAC SPIFAN Standard Method Performance Requirement for each of the three vitamins, including average over-spike recovery of 99.6 ± 3.5%, average repeatability of 1.5 ± 0.8% relative standard deviation, and average intermediate precision of 3.9 ± 1.3% relative standard deviation. PMID:27297842
Validação de métodos cromatográficos por clae para análise das vitaminas B1, B2, B6 e niacina naturalmente presentes em farinha de cereais Validation of hplc methods for analysis of vitamins B1, B2, B6 and niacin naturally present in cereal flours
Ana Elisa Ferreira Presoto; Ligia Bicudo de Almeida-Muradian
Complex B vitamins are present in some cereal foods and the ingestion of enriched products contributes to the recommended dietary intake of these micronutrients. To adapt the label of some products, it is necessary to develop and validate the analytical methods. These methods must be reliable and with enough sensitivity to analyze complex B vitamins naturally present in food at low concentration. The purpose of this work is to evaluate, with validated methods, the content of vitamins B1, B2, ...
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 ...
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 ...
Ade, Martin; Hillebrecht, Harald
Single crystals of the ternary borides Cr2AlB2, Cr3AlB4, Cr4AlB6, MoAlB, WAlB, Mn2AlB2, and Fe2AlB2 were grown from the elements with an excess of Al. Structures were refined by X-ray methods on the basis of single crystal data. All compounds crystallize in orthorhombic space groups. In each case boron atoms show the typical trigonal prisms BM6. The BM6-units are linked by common rectangular faces forming B-B-bonds. Thus, zigzag chains of boron atoms are obtained for MoAlB, WAlB, and M2AlB2 (M = Cr, Mn, Fe); chains of hexagons for Cr3AlB4; and double chains of hexagons for Cr4AlB6. The same subunits are known for the binary borides CrB, Cr3B4, Cr2B3, and β-WB, too. The boride partial structures are separated by single layers of Al-atoms in the case of the chromium compounds and double layers for WAlB, i.e., W2Al2B2. All crystal structures can be described using a unified building set principle with quadratic 4(4)-nets of metal atoms. The different compositions and crystal structures are obtained by different numbers of metal layers in the corresponding parts according to the formula (MB)2Aly(MB2)x. This principle is an extension of a scheme which was developed for the boridecarbides of niobium. Furthermore, there is a close similarity to the group of ternary carbides MAl(MC)n, so-called MAX-phases. Therefore, they might be named as "MAB-phases". The pronounced two-dimensionality and the mixture of strong covalent and metallic interactions make MAB-phases to promising candidates for interesting material properties. All compositions were confirmed by EDX measurements. Additionally, microhardness measurements were performed. PMID:26069993
Mikawa, Yasuhito; Mizobuchi, Satoshi; Egi, Moritoki; Morita, Kiyoshi
Patients undergoing a panic attack (PA) or a hyperventilation attack (HVA) are sometimes admitted to emergency departments (EDs). Reduced serotonin level is known as one of the causes of PA and HVA. Serotonin is synthesized from tryptophan. For the synthesis of serotonin, vitamin B6 (Vit B6) and iron play important roles as cofactors. To clarify the pathophysiology of PA and HVA, we investigated the serum levels of vitamins B2, B6, and B12 and iron in patients with PA or HVA attending an ED. ...
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 ...
... Consumer Datos en español Health Professional Other Resources Vitamin B6 Fact Sheet for Consumers Have a question? ... ODS: ods.od.nih.gov/contact What is vitamin B6 and what does it do? Vitamin B6 ...
... 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: ...
... 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 | ...
Full Text Available Patients undergoing a panic attack (PA or a hyperventilation attack (HVA are sometimes admitted to emergency departments (EDs. Reduced serotonin level is known as one of the causes of PA and HVA. Serotonin is synthesized from tryptophan. For the synthesis of serotonin, vitamin B6 (Vit B6 and iron play important roles as cofactors. To clarify the pathophysiology of PA and HVA, we investigated the serum levels of vitamins B2, B6, and B12 and iron in patients with PA or HVA attending an ED. We measured each parameter in 21 PA or HVA patients and compared the values with those from 20 volunteers. We found that both Vit B6 and iron levels were significantly lower in the PA/HVA group than in the volunteer group. There was no significant difference in the serum levels of vitamins B2 or B12. These results suggest that low serum concentrations of Vit B6 and iron are involved in PA and HVA. Further studies are needed to clarify the mechanisms involved in such differences.
Mikawa, Yasuhito; Mizobuchi, Satoshi; Egi, Moritoki; Morita, Kiyoshi
Patients undergoing a panic attack (PA) or a hyperventilation attack (HVA) are sometimes admitted to emergency departments (EDs). Reduced serotonin level is known as one of the causes of PA and HVA. Serotonin is synthesized from tryptophan. For the synthesis of serotonin, vitamin B6 (Vit B6) and iron play important roles as cofactors. To clarify the pathophysiology of PA and HVA, we investigated the serum levels of vitamins B2, B6, and B12 and iron in patients with PA or HVA attending an ED. We measured each parameter in 21 PA or HVA patients and compared the values with those from 20 volunteers. We found that both Vit B6 and iron levels were significantly lower in the PA/HVA group than in the volunteer group. There was no significant difference in the serum levels of vitamins B2 or B12. These results suggest that low serum concentrations of Vit B6 and iron are involved in PA and HVA. Further studies are needed to clarify the mechanisms involved in such differences. PMID:23603926
... 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 ...
... used in combination with other B vitamins in vitamin B complex products. You may remember a prescription medication called ... Adermine Chlorhydrate, Adermine Hydrochloride, B Complex Vitamin, B6, Chlorhydrate ... Pyridoxal, Pyridoxal Phosphate, Pyridoxal 5 Phosphate, Pyridoxal-5- ...
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
Malouf, RM; Areosa Sastre, A
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...
... 29 Labor 9 2010-07-01 2010-07-01 false Maritime industry. 2530.200b-6 Section 2530.200b-6 Labor... Provisions § 2530.200b-6 Maritime industry. (a) General. Sections 202(a)(3)(D), 203(b)(2)(D) and 204(b)(3)(E... provisions applicable to the maritime industry. In general, those provisions permit statutory...
Hunger, Miriam; Mutti, Elena; Rieder, Alexander;
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...
Melike Sezgin Evim; Rahime Tüten; Birol Baytan; Selin Yakarışık; Adalet Meral Güneş
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.
Melike Sezgin Evim
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.
Pepper, M Reese; Black, Maureen M
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
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...
A new sample preparation and separation combination for precise, accurate, rapid, and simultaneous determination of vitamins B1, B2, B3, B5, B6, B7, and B9 in infant formula and related nutritionals by LC-MS/MS.
Cellar, Nicholas A; McClure, Sean C; Salvati, Louis M; Reddy, Todime M
An improved method was developed for simultaneous determination of the fortified forms of thiamine (B1), riboflavin (B2), nicotinamide and nicotinic acid (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), and folic acid (B9) in infant formulas and related nutritionals. The method employed a simple, effective, and rapid sample preparation followed by liquid chromatography tandem mass spectrometry (LC-MS/MS). It improved upon previous methodologies by offering facile and rugged sample preparation with improved chromatographic conditions, which culminated in a highly accurate and precise method for water-soluble vitamin determination in a wide range of formulas. The method was validated over six days in ten unique matrices with two analysts and on instruments in two different labs. Intermediate precision averaged 3.4 ± 2.6% relative standard deviation and over-spike recovery averaged 100.2 ± 2.4% (n = 160). Due to refinements in sample preparation, the method had high sample throughput capacity. PMID:27506358
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)
Vučijak Nevena Ž.
Full Text Available The importance of vitamin B6 has been known since its discovery in the 1940's. Chemical tests, elestrometric titration determinations, and absorption spectrum studies showed that this vitamin exists in three major chemical forms: pyridoxine (an alcohol, pyridoxal (an aldehyde, and pyridoxamine (a primary amine. Vitamin B6 is needed for more than 100 enzymes involved in protein metabolism, and it is assumed that this vitamin is cofactor of metabolic processes more important than any other substance. A deficiency of vitamin B6 in the human diet leads to severe disorders. Vitamin B6 is necessary for the proper function of the immune and nervous system, and helps the body convert protein to energy. This paper describes the history, properties and applications of vitamin B6, elucidation of chemical structure, and different procedures for synthesis of pyridoxine and pyridoxamine.
Sujol, Guillaume; Docquier, Aurélie; Boulahtouf, Abdelhay; Castet-Nicolas, Audrey; Cavaillès, Vincent
International audience Vitamin B6 is well-known for its role as a cofactor in many enzymatic reactions and recently, several epidemiological studies have highlighted the importance of this vitamin as a protective agent against various cancers: elevated vitamin B6 plasma levels were associated with a lower risk of colorectal cancer development, for example. In vivo studies have shown that vitamin B6 decreased cell proliferation and enhanced the immune response. At the cellular level, antiox...
Vučijak Nevena Ž.; Petrović Slobodan D.; Bezbradica Dejan I.; Knežević-Jugović Zorica D.; Mijin Dušan Ž.
The importance of vitamin B6 has been known since its discovery in the 1940's. Chemical tests, elestrometric titration determinations, and absorption spectrum studies showed that this vitamin exists in three major chemical forms: pyridoxine (an alcohol), pyridoxal (an aldehyde), and pyridoxamine (a primary amine). Vitamin B6 is needed for more than 100 enzymes involved in protein metabolism, and it is assumed that this vitamin is cofactor of metabolic processes more important than any other s...
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.)
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...
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 ...
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.
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.
... 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 ...
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Doets, Esmee; Groot, de C.P.G.M.
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.
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 ...
The powder method was used to investigate Lu5-Ni19B6 structure belonging to a new type: sp. g. P6/mmm, a=0.4943(1), c=1.7161(9) nm, N=30 (R=0.120). The L45Ni19B6 structure is a new representative of the homologous series based on CaCu5 and CeCo3B2 types; its elementary cell contains two layers of CaCu5 type structure and three layers of CeCo3B2 type structure. Structure of the new L45Ni19B6 type belongs to the class of structures with trigonal-prismatic coordination of smallest atoms
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
Meng-Fai Kuo; Huei-Shyong Wang
In some patients without vitamin B6 deficiency, epilepsy can not be controlled withoutan extra supplement of vitamin B6. The therapeutic role of pyridoxal phosphate (PLP), theactive form of vitamin B6, may not be replaced with other forms of vitamin B6 sometimes.Until now, four inborn errors of metabolism are known to affect vitamin B6 concentrationsin the brain. Three of them are hyperprolinemia type 2, antiquitin deficiency, and pyridoxinephosphate oxidase deficiency. The fourth disorder oc...
Krajcovicová-Kudlácková, M; Blazícek, P; Sebeková, K; Valachovicová, M
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
Dobson, Ruth; Alvares, Debie
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
Leischker, A H; Kolb, G F
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
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.
Haider, S.; Ahmad, N; Anaissie, E J; Abdel Karim, N.
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...
Russcher, Henk; Heil, Sandra G; Slobbe, Lennert; Lindemans, Jan
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
涂晓田; 杨为民; 胡伊乐
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.
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
Miller, A; Furlong, D; Burrows, B A; Slingerland, D W
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
Le Marchand, Loïc; Wang, Hansong; Selhub, Jacob; Vogt, Thomas M.; Yokochi, Lance; Decker, Robert
Circulating level of vitamin B6 has been inversely associated with colorectal cancer (CRC) risk but, unlike for folate, few studies have examined the relationship of vitamin B6 to colorectal adenoma, the precursor lesion to most CRCs. We measured plasma levels of folate, vitamin B6, and vitamin B12 in 241 patients with pathologically confirmed first occurrence of colorectal adenoma and 280 controls among Caucasians, Japanese Americans, and Native Hawaiians undergoing flexible sigmoidoscopy sc...
Anderson, Peter J.; Dueker, Stephen; Miller, Joshua; Green, Ralph; Roth, John; Carkeet, Colleen; Buchholz,; Bruce A.
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.
Lubis, Zulhaida; . Hardinsyah; Syarief, Hidayat; Jalal, Fasli; Muhilal
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...
Dawson, D. W.; Sawers, A H; Sharma, R. K.
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, ...
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.
Gonzalez Szwacki, Nevill; Tymczak, C. J.
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.
Friso, Simonetta; Lotto, V; Corrocher, R; Choi, Sang Woon
While overt vitamin B6 deficiency is not a frequent finding nowadays in medical practice, evidence suggests that insufficiency of this vitamin is rather widespread in a quite large portion of the population such as the elderly or in not unusual conditions such as that of alcohol addiction. Moreover, a mild deficiency in B6 vitamin is a state that may be associated with an increased risk of cardiovascular disease. Epidemiologic evidence from case control and prospective studies have suggested that low dietary intake or reduced blood concentrations of vitamin B6 is associated with an increased risk of cardiovascular disease, although most recent trials demonstrated the ineffectiveness of vitamin B6 supplementation on the prevention of cardiovascular events recurrence. Due to limited and somewhat inconsistent data together with the ample variety of critical functions in which vitamin B6 is involved in the human body, it is very challenging to attempt at establishing a cause and effect relationship between vitamin B6 and risk of cardiovascular disease as it is to delineate the exact mechanism(s) by which vitamin B6 may modulate such risk. In the present chapter we review the currently available knowledge deriving from both epidemiological and mechanistic studies designed to define potential candidate mechanisms for the association of vitamin B6 impairment and risk of cardiovascular disease development. PMID:22116704
Javid, Parva; Christensen, Erik
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
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 .
MOLLOY, ANNE MARIE; SCOTT, JOHN MARTIN
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 ...
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...
Ryan-Harshman, Milly; Aldoori, Walid
QUESTION A 42-year-old woman with carpal tunnel syndrome tells you she has started taking a vitamin B6 supplement to relieve her symptoms. Her work in an automotive parts department involves both lifting moderately heavy packages and typing at a computer terminal. What does the research indicate about vitamin B6 as a treatment option, and what health issues should you discuss with this patient?
Malcolm, D E; Yu, P H; Bowen, R.C.; O'Donovan, C.; Hawkes, J; Hussein, M
Plasma levels of the active form of vitamin B6 (pyridoxal phosphate) in 19 patients taking phenelzine were found to be reduced on the average to approximately 54% of the value in a control group. There was no correlation of pyridoxal phosphate level with phenelzine daily dosage over the range of 30 mg to 90 mg. No symptoms of vitamin B6 deficiency peripheral neuropathy were found.
Linnebank, M.; Moskau, S; Semmler, A; Widman, G; Weller, M.; Kallweit, U; Elger, C E
Treatment with several antiepileptic drugs (AED) is associated with lower serum concentrations of folate or vitamin B12. This prospective monocenter study analyzed vitamin B6 blood levels in 400 serial patients with epilepsy, AED-treated (n=385), untreated (n=15) and healthy controls (n=233). The mean plasma vitamin B6 levels of the AED-treated (12.1±10.1; p=0.093) and the untreated patients (15.6±12.4; p=0.664) were not significantly different from the controls (13.9±15.2). These observation...
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
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
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.)
... 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...
Maryam Valizadeh; Nasim Valizadeh
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.
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
Wang, Hui; Kong, Lingyao; Zhao, Xiaoyan; Lv, Zhenlong; Li, Tongwei; Ju, Wei Wei; You, Jinghan; Bai, Ying
K3B6O10Cl is a perovskite-like nonlinear optical (NLO) crystal, which exhibits large second harmonic generation (SHG) response. Based on density-functional theory, we investigate the influence of pressure on SHG tensor of K3B6O10Cl. At zero pressure, the non-centrosymmetric distortion of K3B6O10Cl from BO4 tetrahedron results in the similar SHG tensor to β-BaB2O4 (BBO). At 50 GPa, the ClK6 octahedron distortion of K3B6O10Cl becomes the main source of SHG and give similar SHG tensor to LiNbO3. Therefore, pressure induces K3B6O10Cl from a BBO-like NLO material to a LiNbO3-like NLO material.
Rasmussen, Heather E.; Gustashaw, Kristin A. R.; Tangney, Christy C; Breanna S. Oberlin
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...
Lumeng, L.; Lui, A; Li, T K
The plasma content of B6 vitamers is governed by, among other factors, dietary supply and metabolic interconversion. This study examines the effect of pyridoxine supplementation on the plasma content of B6 vitamers and pyridoxic acid in man, and the metabolic conversion and release of B6 compounds in isolated rat hepatocytes. Six healthy human subjects were given 100 mg pyridoxine-HCl/d orally for 1--3 wk. Before pyridoxine supplementation, the mean total plasma level of B6 vitamers was 114 +...
Ouyang, Lizhi; Ching, W. Y.; Randaccio, Lucio
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.
Clarke, Robert; Sherliker, Paul; Hin, Harold;
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...
The main goal of this bachelor thesis is to apply theoretical knowledge in B2B marketing to the example of marketing processes in a particular company, to evaluate the current situation of its activities with regard to B2B principles and to suggest relevant recommendations. The theoretical part focuses on specific characteristics of B2B marketing, describes its differences from marketing on consumer markets, deals with buying behaviour of organizations and specifies particular features of mar...
Heide, P.A.M. van der; Cate, H.W. ten; Dam, L.M. ten; Groot, R.A. de; Vroomen, A.R. de
The optical properties of LaB6 and CeB6 have been investigated using spectroscopic ellipsometry. The results were compared with band-structure calculations. The main features of the spectra of both materials originate from optical transitions starting at boron-derived levels of similar character. A
Reinstatler, Lael; Qi, Yan Ping; Williamson, Rebecca S.; Garn, Joshua V.; Oakley, Godfrey P
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...
Dietzfelbinger, Hermann; Hubmann, Max
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
Yuan, Yuan; Cheng, Longjiu
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.
The ENDF/B-6 Standards Library includes evaluated data for seven neutron reactions that are internationally recommended as reference standards for nuclear measurements. The reactions are H-1,(n,n), He-3(n,p), Li-6(n,t), B-10(n,α), C(n,n), Au(n,γ), U-235(n,f). The data are available on magnetic tape from the IAEA Nuclear Data Section, free of charge. (author)
Single crystals of LaB6 were prepared by float zone refining of hot pressed blocks of LaB6. The orientations studied were (001), (110), and a high index plane. The resulting crystals and the as-received material were chemically analyzed by vacuum fusion, combustion analysis, self-arc mass spectroscopy, and wet chemical analysis. The first two provided accurate analysis for O, N, H, and C. The remaining elements except for La and B were determined by mass spectroscopy. The wet chemical analyses determined the B/La ratio. Two batches of as-received material had B/La ratios of 6.0 and 5.8, respectively. Slightly lower B/La ratios were obtained in the single crystals grown by the float zone technique from these materials. The single crystals were further characterized by measurements of lattice parameter and density. Work function values were determined by the FERP method and the thermionic method. Work function measurements in conjunction with Auger analysis of the crystals provided insight into the electron emission character of LaB6. Results indicate that for maximum emission from a crystal plane a proper heat treatment is necessary. Brightness of the crystals was measured in a Cambridge S-4 scanning electron microscope using a Broers type gun. Results show that a brightness of 106 amp/cm2 steradian (20kV) may be achieved with a single crystal LaB6 cathode operating at a temperature of 19000K which corresponds to a lifetime greater than 500 hrs for 1 mm cathodes
The causes of the CsLiB6O10 (CLBO) crystal characteristics deterioration by storage identified. The CLBO monocrystals up to 60 x 40 x 20 mm in size were grown through seeding from the solution in the melt in the LiO2-Cs2O-B2O3-MoO3 system. The thermal analysis results are presented. It is shown, that crystallization process by the melt cooling does not occur. Practically there take place the processes of water penetration into the porous structure and washing out the Cs ions therefrom, i.e. the hydration and hydrolysis processes. To prevent water absorption it is necessary to keep the CLBO crystal in dry atmosphere
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.
... 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...
Agrawal, Sanwar; Nathani, Shweta
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...
Gian Maria Pacifici
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...
Ganjehei, Leila; Massumi, Ali; Razavi, Mehdi; James M Wilson
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.
Ayşe Tosun; Yusuf Ziya Aral; Emre Çeçen; Ayvaz Aydoğdu; Bilin Çetinkaya Çakmak
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...
@@ 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
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.)
Gian Maria Pacifici
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.
Nyholm, E.; Turpin, P; Swain, D; Cunningham, B.; Daly, S; P. Nightingale; Fegan, C
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...
Full Text Available Abstract Background Studies have shown a clear relationship between depressive disorders and vitamin B12 deficiency. Gastroenteritis and Helicobacter pylori infections can cause vitamin B12 deficiency. Helicobacter pylori infections are not uncommon among people of Turkish descent in The Netherlands. Aim To examine the frequency of vitamin B12 deficiency in depressive patients of Turkish descent and compare it to the frequency of vitamin B12 deficiency in depressive patients of Dutch descent. Methods The present study is a comparative cross-sectional study of 47 patients of Turkish descent and 28 of Dutch descent. The depressive disorder diagnosis and differential diagnosis were made using the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, fourth edition text revision (SCID. The severity of the depressive symptoms was determined using the Beck Depression Inventory (BDI and the 21-item Hamilton Depression Rating Scale (HAM-D-21. Serum baseline vitamin B6 and B12, folic acid and total serum homocysteine (tHcy levels were measured. Results The average ages of the patients of Turkish and Dutch descent were 40.57 and 44.75 years, respectively. There were no demonstrable differences between the serum vitamin B6, folic acid and tHcy levels in the two groups. The serum vitamin B12 levels were however clearly lower in the patients of Turkish descent than in those of Dutch descent. Vitamin B12 deficiency was however observed in 14 patients of Turkish descent and 1 of Dutch descent. This difference was significant. On the BDI, the patients of Turkish descent scored significantly higher than those of Dutch descent. Patients with vitamin B12 deficiency and those with hyperhomocysteinaemia had a significantly higher BDI score than patients with normal vitamin B12 and homocysteine levels. No relationship was observed with vitamin B12 and tHcy. Conclusion Vitamin B12 deficiency occurs more frequently in depressive
Bai, Hui; Zhai, Hua-Jin; Li, Si-Dian; Wang, Lai-Sheng
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
... 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...
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.)
Lildballe, Dorte L; Mutti, Elena; Birn, Henrik;
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...
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
KR Dholakia; TS Dharmarajan; D Yadav; S Oiseth; EP Norkus; CS Pitchumoni
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.
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)
Agrawal, Sanwar; Nathani, Shweta
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
Cheng, Zhuo; Yamamoto, Haruki; Bauer, Carl E
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
Albersen, Monique; Bosma, M.; Jans, Judith J M; Hofstede, FC; van Hasselt, PM; De Sain-van Der Velden, Monique G M; Visser, Gepke; Verhoeven-Duif, NM
Background Over the past years, the essential role of vitamin B6 in brain development and functioning has been recognized and genetic metabolic disorders resulting in functional vitamin B6 deficiency have been identified. However, data on B6 vitamers in children are scarce. Materials and Methods B6
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.
Schiller, N L; Roberts, R. B.
The growth rate of three vitamin B6-dependent Streptococcus mitior (B6DS) and two non-B6DS strains in Todd-Hewitt broth, with and without vitamin B6 supplementation, was examined. Even in optimally supplemented culture media, the growth rate of the three B6DS strains was much slower than that of comparable non-B6DS strains. Uptake studies with [3H] pyridoxine suggest that these B6DS strains cannot assimilate pyridoxine. Although not transported intracellularly, pyridoxine inhibited the growth...
Heather E. Rasmussen
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.
The thermal conductivities of stoichiometric CaB6, vacancy-doped Ca1-δB6, and EuB6 have been measured between 6 and 300 K. All our data may be rather well described across the entire temperature regime covered on the basis of a Debye-type relaxation-time approximation and by assuming the concurring influence of various scattering channels on the mean free path of the phonons. An unusual and strong resonance in the scattering rate of the phonons of all investigated materials is attributed to a strong interaction between acoustic itinerant and localized modes, the latter arising from oscillations of the metal cations around their equilibrium position
Cubic crystals of the Zn4O[B6O12] composition obtained from the ZnO-B2O3-Li2O(Na2O,K2O)-H2O system with the NnO addition are studied in the temperature range of 250-450 deg C and at the pressure of 1000 atm. It is established that stable crystallization zones are characteristic for the above compound. The crystals are colourless and possess luminescent properties. Interplane distances, cubic lattice parameters and interatomic distances in the Zn4O[B6O12] structure are determined
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.
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
Smith, Mark H.; Woods, Sandra L.
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...
Uwe Gröber; Klaus Kisters; Joachim Schmidt
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 ...
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
Hemlata Bhaskar; Rekha Chaudhary
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...
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
İNCECİK, Faruk; HERGÜNER, Mihriban Özlem; Altunbaşak, Şakir
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...
Milligan, D W; Quick, A; Barnard, D L
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 ...
Gopinath, Krishnamoorthy; Venclovas, Česlovas; Ioerger, Thomas R.; Sacchettini, James C.; McKinney, John D.; Mizrahi, Valerie; Warner, Digby F.
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...
KARLI, R.; Gül, A; UĞUR, B.
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...
Slack, G. A.; Morgan, K. E.
Electron deficient and non-deficient boron compounds are discussed as potential thermoelectric generator materials. Particular attention is paid to carbon-doped beta-boron, high-carbon boron carbide, and the alpha-boron derivative compound boron suboxide. Stoichiometric B6O shows some promise, and may have a higher ZT than the other two compounds. Carbon saturated beta-boron appears to have a higher ZT than undoped samples. Carbon saturated boron carbide at B12C3 does exist. Its thermoelectric behavior is unknown.
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
Doğan, Melike; Demirci, Serpil
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...
Sañudo-Wilhelmy, S. A.; Gobler, C. J.; Okbamichael, M.; Taylor, G. T.
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.
Htet, Min Kyaw; Fahmida, Umi; Thurnham, David I; Hlaing, Lwin Mar; Akib, Arwin; Utomo, Budi; Houghton, Lisa A
The aim of the present study was to assess the prevalence of deficiency of folate and vitamin B12 and, simultaneously, the nutrient intake adequacy of folate, vitamin B12, iron, vitamin A, vitamin C, vitamin B6 and calcium in 391 adolescent anaemic (Hbvitamin B12 concentrations were 6·5 (4·6, 8·5) nmol/l and 612·8 (443·2, 795·2) pmol/l, respectively. The prevalence of folate deficiency defined as vitamin B12 deficiency defined as vitamin A, vitamin C, vitamin B6 and calcium, ranging from 60 to 100 %. Red meat or poultry was rarely consumed, but fish was consumed on a daily basis. Green leafy vegetables were also consumed frequently but consumption of dairy products was uncommon. Folate deficiency was high, and the prevalence of inadequate intake of folate among other key micronutrients was relatively common in this sample of anaemic adolescent schoolgirls. Appropriate strategies such as food fortification and dietary diversification are needed to improve the micronutrient status of these young women to ensure optimal health and future reproductive success. PMID:26481660
Janak Rathod , Taral Shah , Manisha Gupta, Rajendra Mehta
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 ...
Roth, J R; Lawrence, J G; Bobik, T A
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
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.)
Prlainović Nevena Ž.
Full Text Available 3-Cyano-4-ethoxymethyl-6-methyl-2-pyridone is an important precursor in the synthesis of vitamin B6, obtained in the addition reaction between 2-cyanoacetamide and 1-ethoxy-2,4-pentanedione catalyzed by lipase from Candida rugosa (triacylglycerol ester hydrolases, EC 126.96.36.199. This work shows new experimental data and mathematical modeling of lipase catalyzed synthesis of 3-cyano-4-ethoxymethyl-6-methyl-2-pyridone, starting from 1-ethoxy-2,4-pentanedione and 2-cyanoacetamide. Kinetic measurements were done at 50 oC with enzyme concentration of 1.2 % w/v. Experimental results were fitted with two kinetic models: the ordered bi-ter and ping-pong bi-ter model, and the initial rates of the reaction were found to correlate best with a ping-pong bi-ter mechanism with inhibition by 2-cyanoacetamide. Obtained specificity constants indicated that lipase from C. rugosa had higher affinity towards 1-ethoxy-2,4-pentanedione and less bulky substrates. [Projekat Ministarstva nauke Republike Srbije, br. 172013, br. III 46010 and br. 172049
Janak Rathod , Taral Shah , Manisha Gupta, Rajendra Mehta
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
Woo, Kam S; Kwok, Timothy C Y; Celermajer, David S
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
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...
Kam S. Woo
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.
Delva, M. Dianne; Anderson, J E
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.
Chu, Colin; Scanlon, Peter
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.
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)
O'Gorman, P; Holmes, D; Ramanan, A V; Bose-Haider, B; Lewis, M J; Will, A
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
Monique Albersen; Marjolein Bosma; Jans, Judith J. M.; Hofstede, Floris C.; van Hasselt, Peter M.; de Sain-van der Velden, Monique G. M.; Gepke Visser; Verhoeven-Duif, Nanda M.
Background Over the past years, the essential role of vitamin B6 in brain development and functioning has been recognized and genetic metabolic disorders resulting in functional vitamin B6 deficiency have been identified. However, data on B6 vitamers in children are scarce. Materials and Methods B6 vitamer concentrations in simultaneously sampled plasma and cerebrospinal fluid (CSF) of 70 children with intellectual disability were determined by ultra performance liquid chromatography-tandem m...
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.)
Sordo Martínez, Lissette; Soto Mulet, Laritza; González Hernández, Rolando
Se desarrolló un método por espectrofotometría de derivadas de primer orden para la determinación de vitamina B12 en una formulación multivitamínica compuesta por vitamina B1, B6 y B12. La amplitud de la señal de la primera derivada se determinó a 378 nm. La validación prospectiva del método demostró que fue lineal (r=0,999), preciso (repetibilidad CV=0 y 132%; reproducibilidad CV=2,7 y 1,67 %), exacto y selectivo (se determinó B12 en presencia de las vitaminas B1, B6 y en presencia de los pr...
The kinetic studies indicate that riboflavin acts as a sensitizer in the photolysis of cyanocobalamin and in this way promotes the degradation of the molecule. Many microorganisms use light for pathogenesis.The present work describes the interaction of vitamin B2 and B12 at molecular level in bacterial enzymes which could delineate the possible mechanism of inhibiting the disease producing bacteria. Methodology: The molecular basis of interaction between the flavin derivatives and the B12- dependent enzymes was studied using molecular modeling software, the MVD. A series of nineteen flavin derivative sand three B12 containing enzymes; glutamate mutase, diol dehydratase and methionine synthase were taken for the study. The potential binding affinity between flavin derivatives and B12 enzymes was checked on the basis of lowest docking score, number of hydrogen bonds and favorable binding modes. Results: We found riboflavin, 2-ketoflavin and 4-ketoflavin as the best interacting compounds with each of the three enzymes taken. The regions containing lone pair of electrons are critical for the maximum number of binding conformations. Conclusion: It may be concluded that flavin derivatives may influence the activity of B12 enzymes. Therefore,the understanding of molecular basis of this interaction and the identification of the key factors involved,might be useful to design new molecules with enhanced selectivity towards B12 dependent enzymes. Thi scan lead to the screening and discovery of new compounds as useful antibiotics and the active natural drugs. (author)
Kumudha, Anantharajappa; Sarada, Ravi
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
Yoshio Hisaeda, Takahiro Masuko, Erika Hanashima and Takashi Hayashi
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.
樊蕴辉; 伊红丽; 李立群; 曹国富; 沈海涛
Objectives To investigate the relationship between plasma homocysteine (Hcy), folate,vitamin B12and vascular dementia (VaD). Methods: The plasma levels of Hey. folate. vitamin B12 and MMSE were measured in 86 VaD patients, 87 non-VaD cerebral vascular disease patients, and 90 age-matched normal controls of Affiliated Hospital, North China Coal Medical University. Results: The plasma Hey levels were significantly increased in the VaD group than non-VaD cerebral vascular disease group and normal controls (P<0. 01). The Hey level was negatively related with folate and VitB12 levels. They all significantly correlated with VaD and the MMSE score (P＜0. 01＝. Conclusion-. The levels of Hey. folate and vitamin B12were significantly correlated with VaD.%目的:探讨血浆同型半胱氨酸(Hcy)、叶酸(FA)、VitB12与血管性痴呆(VaD)的相关性.方法:检测VaD患者86例(VaD组),非VaD患者87例(非VaD组),健康体检正常者90例(正常组)血浆Hcy、FA、VitB 2浓度.并对3组受检者进行简易智能状态量表(MMSE)评定.结果:VaD组患者Hcy浓度显著高于非VaD组及正常组(P＜0.01).FA、VitB12浓度与Hcy浓度负相关.血浆Hcy、FA、VitB12水平与VaD、MMSE得分显著相关(P＜0.01).结论:VaD高危人群应定期检测Hcy浓度,推荐服用VitB12和FA可预防VaD的发生.
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
Roed, Casper; Skovby, Flemming; Lund, Allan Meldgaard
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
杨谊; 李兵; 史学慧
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%.
Gröber, Uwe; Kisters, Klaus; Schmidt, Joachim
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
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.
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.
VALDES SOCIN, Hernan Gonzalo
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...
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.
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...
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.
@@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。
Moretti Rita; Torre Paola; Antonello Rodolfo; Cattaruzza Tatiana; Cazzato Giuseppe; Bava Antonio
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...
Hjelt, K.; Krasilnikoff, P.A.
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%).
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%)
Butzin, Nicholas C.; Secinaro, Michael A.; Swithers, Kristen S.; Gogarten, J Peter; Noll, Kenneth M.
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...
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
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...
Arpita Patel; Chandan Chakrabarty; Arjun Singh; Jatin Patel; Hitesh Mewada; S L Sharma
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...
Vijay Kumar; Sandeep,; Sajjal; Shivraj B
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 ...
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.)
Gruber, Karl; Kräutler, Bernhard
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
Khodabandehloo, Niloofar; Vakili, Masoud; Hashemian, Zahra; Zare Zardini, Hadi
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
Rajsekhar, Putta; Reddy, Mugannagari Maheshwar; Vaddera, Sameeraja; Rajini, G; Tikeli, Vinil
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
Pawlak, Roman; Parrott, Scott James; Raj, Sudha; Cullum-Dugan, Diana; Lucus, Debbie
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
Full Text Available Background: Drugs with complex pharmacology are used in the management of drug use disorder (DUD and HIV/AIDS in Malaysia and in parts of South-East Asia. Their multiethnic populations suggest complexity due to the genetic polymorphism, such as CYP2B6 that metabolizes methadone and anti-retroviral. Aims: Our aim was to explore the genetic polymorphism of CYP2B6 among Malays, Chinese, Indians, and opiate-dependent individuals in Malaysia. Settings and Design: The study utilized DNA from our previous studies on CYPs and new recruitments from opiate-dependent individuals. Materials and Methods: For the new recruitment, after obtaining consent and baseline demography, 5 ml blood was obtained from patients attending methadone maintenance therapy (MMT Clinics. Genomic DNA was extracted using standard methods. 10 nucleotide changes associated with CYP2B6FNx0110, CYP2B6FNx012, CYP2B6FNx0117, CYP2B6FNx0111, CYP2B6FNx018, CYP2B6FNx0114, CYP2B6FNx019, CYP2B6FNx014, CYP2B6FNx016, CYP2B6FNx0127, and CYP2B6FNx0120 were determined using multiplex nested allele-specific PCR. Statistical Analysis: Descriptive statistics were used to summarize demographic data. Differences in allele frequencies between populations were tested using Chi-squared test and were corrected using the Bonferroni test. Results: CYP2B6 polymorphism in Malaysia is variable with trends that suggest an ethnic difference. Reduced activity CYP2B6FNx016 occurred in 13% to 26% among Malays, Chinese, Indians and opiate-dependent individuals. Another ′reduced activity′, CYP2B6FNx012 allele, was found at much lower percentages in the groups. Conclusions: The relative commonness of reduced-activity CYP2B6 alleles in our study called for attention in terms of dosage requirements for MMT and ARV in Malaysia. It also implored follow-up association studies to determine its relevance and consequences in personalized medicine for drug use disorder and HIV/AIDS.
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.
Bender, D A; Njagi, E. N.; Danielian, P. S.
Vitamin B6 deficiency was induced in mice by maintenance for 4 weeks on a vitamin B6-free diet. Tryptophan metabolism was assessed by determining the urinary excretion of tryptophan metabolites, the metabolism of [14C]tryptophan in vivo and the formation of tryptophan and niacin metabolites by isolated hepatocytes. The vitamin B6-deficient animals excreted more xanthurenic acid and 3-hydroxykynurenine, and less of the niacin metabolites N1-methyl nicotinamide and methyl-2-pyridone-4-carboxami...
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
Selhub, Jacob; Morris, Martha Savaria; Jacques, Paul F.; Rosenberg, Irwin H.
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 ...
Mera, Paola E.; Escalante-Semerena, Jorge C.
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...
Full Text Available Over the past years, the essential role of vitamin B6 in brain development and functioning has been recognized and genetic metabolic disorders resulting in functional vitamin B6 deficiency have been identified. However, data on B6 vitamers in children are scarce.B6 vitamer concentrations in simultaneously sampled plasma and cerebrospinal fluid (CSF of 70 children with intellectual disability were determined by ultra performance liquid chromatography-tandem mass spectrometry. For ethical reasons, CSF samples could not be obtained from healthy children. The influence of sex, age, epilepsy and treatment with anti-epileptic drugs, were investigated.The B6 vitamer composition of plasma (pyridoxal phosphate (PLP > pyridoxic acid > pyridoxal (PL differed from that of CSF (PL > PLP > pyridoxic acid > pyridoxamine. Strong correlations were found for B6 vitamers in and between plasma and CSF. Treatment with anti-epileptic drugs resulted in decreased concentrations of PL and PLP in CSF.We provide concentrations of all B6 vitamers in plasma and CSF of children with intellectual disability (±epilepsy, which can be used in the investigation of known and novel disorders associated with vitamin B6 metabolism as well as in monitoring of the biochemical effects of treatment with vitamin B6.
纪万里; 要辉; 沈定文
目的：建立维生素 B6凝胶剂中维生素 B6的含量测定方法。方法：采用卡波姆940为基质，以维生素 B6为主药，制备成维生素 B6凝胶剂，采用紫外分光光度法测定维生素 B6的含量。结果：卡波姆为基质制备的凝胶剂质地均匀细腻、质量稳定；采用紫外分光光度法，以291nm 作为维生素 B6检测波长，含量测定方法可行，维生素 B6在5～25μg／ml 浓度范围内，线性关系良好，平均回收率为98．79％，RSD 为0．46％。结论：采用紫外分光光度法测定维生素 B6凝胶剂中维生素 B6含量方法简单可行，结果准确。%Objective To establish the method for the content determination of vitamin B6 gels.Method Using the matrix of Car-bopol 940 and vitamin B6 -based medicine to prepare vitamin B6 gels,and using the UV to evaluate content determination of vitamin B6 .Results Using carbopol gels as matrix to prepare the gels which is uniform,exquisite and stable quality.Using the UV spectro-photometry to 291nm as wavelength to detect the content determination of vitamin B6 ,which is feasible and the calibration curve are linear within a well range of vitamin B6 in 5 -25μg/ml,the average recovery is 98.79%,RSD is 0.46%.Conclusion Using the UV spectrophotometry to detect the ointmen of vitamin B6 ,which is simple,feasible and accurate.
Akopov, Georgiy; Yeung, Michael T; Turner, Christopher L; Li, Rebecca L; Kaner, Richard B
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
von Castel-Roberts, Kristina M; Mørkbak, Anne Louise; Nexo, Ebba;
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...
Objective To study the status of the relevant domestic Vitamin B6. Methods Reviewing the domestic literature, summarizing and analyzing related data. Results The clinical Vitamin B6 had many new uses where we could draw lessons from. Conclusion Vitamin B6 has very good sight of clinical application and research.%目的：了解国内有关维生素B6的临床应用现状。方法复习国内文献，总结和分析相关资料。结果维生素B6有不少临新用途，可以借鉴。结论维生素B6有很好的临床应用和研究前景。
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.
Allen, Lindsay H
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
Chalouhi, Christel; Faesch, Sabine; Anthoine-Milhomme, Marie-Constance; Fulla, Yvonne; Dulac, Olivier; Chéron, Gérard
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
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
Nakos, M; Pepelanova, I; Beutel, S; Krings, U; Berger, R G; Scheper, T
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
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)
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
Månsson, Maria; Klejnstrup, Marie Louise; Phipps, Richard Kerry;
FBI and iso-FB1, having hydroxyl functions at C3, C4, and C5. Analysis of the NMR data for FB2 showed very similar chemical shift values when compared to an authentic Fusarium FB2 standard, strongly indicating identical molecules despite that an absolute stereochemical assignment of FB2 from A. niger...
A review of in vitro bioaccessibility and bioavailability methods for polyphenols and selected nutrients is presented. The review focuses on in vitro solubility, dialyzability, the dynamic gastrointestinal model (TIM)™, and Caco-2 cell models, the latter primarily for uptake and transport, and a discussion of how these methods have been applied to generate data for a range of nutrients, carotenoids and polyphenols. Recommendations are given regarding which methods are most justified for answ...
Full Text Available A review of in vitro bioaccessibility and bioavailability methods for polyphenols and selected nutrients is presented. The review focuses on in vitro solubility, dialyzability, the dynamic gastrointestinal model (TIM™, and Caco-2 cell models, the latter primarily for uptake and transport, and a discussion of how these methods have been applied to generate data for a range of nutrients, carotenoids and polyphenols. Recommendations are given regarding which methods are most justified for answering bioaccessibility or bioavailability related questions for specific nutrients. The need for more validation studies in which in vivo results are compared to in vitro results is also discussed.
Etcheverry, Paz; Grusak, Michael A.; Fleige, Lisa E.
A review of in vitro bioaccessibility and bioavailability methods for polyphenols and selected nutrients is presented. The review focuses on in vitro solubility, dialyzability, the dynamic gastrointestinal model (TIM)™, and Caco-2 cell models, the latter primarily for uptake and transport, and a discussion of how these methods have been applied to generate data for a range of nutrients, carotenoids, and polyphenols. Recommendations are given regarding which methods are most justified for answ...
A review of in vitro bioaccessibility and bioavailability methods for polyphenols and selected nutrients is presented. The review focuses on in vitro solubility, dialyzability, the dynamic gastrointestinal model (TIM), and Caco-2 cell models, the latter primarily for uptake and transport, and a disc...
Background: Breastmilk B-vitamin concentrations can fluctuate with maternal intake. Low maternal intake of B-vitamins may result in low B-vitamin breastmilk concentrations and consequently B-vitamin deficiency in their infants because infants 0–6 months are recommended to be exclusively breastfed. T...
Lildballe, Dorte L.; Mutti, Elena; Birn, Henrik; Nexo, Ebba
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...
Massey, Thomas H; Pickersgill, Trevor T; J Peall, Kathryn
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
Wang, Wei; Chen, Qiang; Wang, Ying-Jin; Bai, Hui; Gao, Ting-Ting; Li, Hai-Ru; Zhai, Hua-Jin; Li, Si-Dian
Considerable recent research effort has been devoted to the development of boronyl (BO) chemistry. Here we predict three perfectly planar boron boronyl clusters: C2v B6O4 (1, (1)A1), D2h B6O4(−) (2, (2)B3u), and D2h B6O4(2−) (3, (1)Ag). These are established as the global-minimum structures on the basis of the coalescence kick and basin hopping structural searches and electronic structure calculations at the B3LYP/aug-cc-pVTZ level, with complementary CCSD/6-311+G* and single-point CCSD(T)/6-311+G*//B3LYP/aug-cc-pVTZ calculations for 2. The C2v B6O4 neutral cluster features a hexagonal B4O2 ring with two terminal BO groups. The D2h B6O4(−/2−) clusters have ethylene-like structures and are readily formulated as B2(BO)4(−/2−), in which a B2 core with double bond character is bonded to four terminal BO groups. Chemical bonding analyses show that B6O4 (1) possesses an aromatic π bonding system with three delocalized, six-centered π bonds over the hexagonal ring, rendering it an inorganic analogue of benzene, whereas the B6O4(−/2−) (2 and 3) species closely resemble ethylene in terms of structures and bonding. This work provides new examples for the analogy between boron oxides and hydrocarbons. PMID:26166194
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.
Durand, C; Mary, S; Brazo, P; Dollfus, S
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
Martinez Estrada, K M; Cadabal Rodriguez, T; Miguens Blanco, I; García Méndez, L
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
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 ...
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)
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
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
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
Ebru Yilmaz Keskin; Basar Demir; Mahir igde; Banu Gulcan Oksuz
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...
Mutti, Elena; Ruetz, Markus; Birn, Henrik;
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...
Jang, Hyun-soon; Roh, Sook Young; Jeong, Eun Hye; Kim, Byung-Su; Sunwoo, Mun Kyung
Although ginkgo is commonly used as an alternative treatment for memory loss, Alzheimer’s dementia and peripheral circulatory disturbances, it is also known to cause neuronal symptoms due to ginkgotoxin (4′-methoxypyridoxine or B6 antivitamin). We experienced a case of a 51-year-old female patient with generalized tonic clonic seizure and postictal confusion after eating large amounts of ginkgo nuts. Blood vitamin B6 level was decreased. After conservative treatment and pyridoxine medication,...
Chiang, En-Pei; Smith, Donald E.; Selhub, Jacob; Dallal, Gerard; Wang, Yi-Cheng; Roubenoff, Ronenn
Previously we observed strong and consistent associations between vitamin B6 status and several indicators of inflammation in patients with rheumatoid arthritis. Clinical indicators, including the disability score, the length of morning stiffness, and the degree of pain, and biochemical markers, including the erythrocyte sedimentation rate and C-reactive protein levels, were found to be inversely correlated with circulating vitamin B6 levels. Such strong associations imply that impaired vitam...
Elske M. Brouwer-Brolsma
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.