scholarly journals Vitamin B-6 Intake Is Modestly Associated with Arsenic Methylation in Uruguayan Children with Low-Level Arsenic Exposure

2020 ◽  
Vol 150 (5) ◽  
pp. 1223-1229 ◽  
Author(s):  
Gauri Desai ◽  
Marie Vahter ◽  
Elena I Queirolo ◽  
Fabiana Peregalli ◽  
Nelly Mañay ◽  
...  

ABSTRACT Background Detoxification of inorganic arsenic (iAs) occurs when it methylates to form monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). Lower proportions of urinary iAs and MMA, and higher proportions of DMA indicate efficient methylation. The role of B-vitamins in iAs methylation in children with low-level arsenic exposure is understudied. Objectives Our study objective was to assess the association between B-vitamin intake and iAs methylation in children with low-level arsenic exposure (<50 µg/L in water; urinary arsenic 5–50 µg/L). Methods We conducted a cross-sectional study in 290 ∼7-y-old children in Montevideo. Intake of thiamin, riboflavin, niacin, vitamin B-6, and vitamin B-12 was calculated by averaging 2 nonconsecutive 24-h recalls. Total urinary arsenic concentration was measured as the sum of urinary iAs, MMA, and DMA, and adjusted for urinary specific gravity; iAs methylation was measured as urinary percentage As, percentage MMA, and percentage DMA. Arsenic concentrations from household water sources were assessed. Linear regressions tested the relationships between individual energy-adjusted B-vitamins and iAs methylation. Results Median (range) arsenic concentrations in urine and water were 9.9 (2.2–48.7) and 0.45 (0.1–18.9) µg/L, respectively. The median (range) of urinary percentage iAs, percentage MMA, and percentage DMA was 10.6% (0.0–33.8), 9.7% (2.6–24.8), and 79.1% (58.5–95.4), respectively. The median (range) intake levels of thiamin, riboflavin, niacin, and vitamin B-6 were 0.81 (0.19–2.56), 1.0 (0.30–2.24), 8.6 (3.5–23.3), and 0.67 (0.25–1.73) mg/1000 kcal, respectively, whereas those of folate and vitamin B-12 were 216 (75–466) and 1.7 (0.34–8.3) µg/1000 kcal, respectively. Vitamin B-6 intake was inversely associated with urinary percentage MMA (β = −1.60; 95% CI: −3.07, −0.15). No other statistically significant associations were observed. Conclusions Although vitamin B-6 intake was inversely associated with urinary percentage MMA, our findings suggest limited support for a relation between B-vitamin intake and iAs methylation in children exposed to low-level arsenic.

2018 ◽  
Vol 39 (2) ◽  
pp. 281-289 ◽  
Author(s):  
Tyler J. Titcomb ◽  
Samantha T. Schmaelzle ◽  
Emily T. Nuss ◽  
Jesse F. Gregory ◽  
Sherry A. Tanumihardjo

Background: Hidden hunger affects individuals who chronically consume an inadequate intake of at least 1 micronutrient and is associated with low dietary diversity. Little data are available on dietary intake or status assessment of B vitamins among preschool children in Zambia. Objectives: The aim of this study was to assess 24-hour dietary recall records obtained from Zambian children aged 3 to 7 years for B vitamin intake in relation to adequacy and change over time in the same community. Methods: Twenty-four-hour dietary recalls were collected from 2 studies that were 2 years apart in the same district of Zambia. Data were retrospectively analyzed for B vitamin intake, that is, biotin, vitamin B12, folate, niacin, pantothenic acid, vitamin B6, riboflavin, and thiamin. The estimated average requirement (EAR) cut point method was used to assess inadequacy prevalence for EARs established by the Institute of Medicine in the United States. Results: For all B vitamins, mean values were below the EARs established for children 4 to 8 years old. Relative to the EAR, children had the highest intakes of vitamin B6 with inadequacies of 77.9% and 60.1% in 2010 and 2012, respectively. The highest prevalence of inadequate intake was associated with folate, where ≥95% of the children had intakes below the EAR in both studies. Conclusions: All median vitamin B intakes were inadequate among these young children in rural Zambia. Future researchers and policy makers may need to consider B vitamin status in resource-poor areas of the country.


2020 ◽  
Vol 124 (8) ◽  
pp. 865-873
Author(s):  
Takehiro Michikawa ◽  
Hiroshi Nitta ◽  
Makiko Sekiyama ◽  
Tatsuo Kuroda ◽  
Shoji F. Nakayama ◽  
...  

AbstractThe occurrence of anorectal malformations (ARM) is thought to be reduced with sufficient folate intake. However, there is no apparent evidence. We focused on enzyme cofactors for one-carbon metabolism, including folate (vitamin B9), vitamin B6 and vitamin B12, and explored the association between maternal combined intake of these B vitamins and the risk of ARM. Using baseline data from a Japanese nationwide birth cohort study between 2011 and 2014, we analysed data of 89 235 women (mean age at delivery = 31·2 years) who delivered singleton live births without chromosomal anomalies. Information on dietary intake was obtained via a FFQ focused on early pregnancy and used to estimate B vitamin intake. We also collected information on the frequency of folic acid supplement use. ARM occurrence was ascertained from medical records. We identified forty-three cases of ARM diagnosed up to the first month after birth (4·8 per 10 000 live births). In terms of individual intake of the respective B vitamins, high vitamin B6 intake was non-significantly associated with reduced odds of ARM. Compared with women in the low combined B vitamin intake group, the OR of having an infant with ARM was 0·4 (95 % CI 0·2, 1·0) in the high intake group (folate ≥400 μg/d, and upper half of vitamin B6 and/or vitamin B12). In conclusion, our cohort analysis suggested an inverse association between the combined intake of one-carbon metabolism-related B vitamins in early pregnancy and ARM occurrence.


2006 ◽  
Vol 16 (5) ◽  
pp. 453-484 ◽  
Author(s):  
Kathleen Woolf ◽  
Melinda M. Manore

The B-vitamins (thiamin, ribofavin, vitamin B-6) are necessary in the energy-producing pathways of the body, while folate and vitamin B-12 are required for the synthesis of new cells, such as the red blood cells, and for the repair of damaged cells. Active individuals with poor or marginal nutritional status for a B-vitamin may have decreased ability to perform exercise at high intensities. This review focuses on the B-vitamins and their role in energy metabolism and cell regeneration. For each vitamin, function related to physical activity, requirement, and status measures are given. Research examining dietary intakes and nutritional status in active individuals is also presented. Current research suggests that exercise may increase the requirements for ribofavin and vitamin B-6, while data for folate and vitamin B-12 are limited. Athletes who have poor diets, especially those restricting energy intakes or eliminating food groups from the diet, should consider supplementing with a multivitamin/mineral supplement.


2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Agata Muzsik ◽  
Agata Chmurzynska

AbstractIt has been hypothesized that insufficiency of one-carbon metabolism may aggravate lipid metabolism disturbances. Lipid metabolism abnormalities and metabolic syndrome (MetS)—which is associated with abnormally high levels of triglycerides (TG) and low levels of high-density lipoproteins (HDL)—often occur in postmenopausal women. The purpose of this study was thus to determine the relationships between amino acid and B vitamin intake, MTHFR genotype, lipid profile, and atherogenic indices in postmenopausal women.131 postmenopausal women were enrolled for the study. The mean macronutrient, amino acid, and B vitamin intake was evaluated using dietary records. Lipid profile and concentrations of apolipoprotein A1 (ApoA1) and B (ApoB) in serum were measured using the colorimetric method. The total homocysteine (tHcy) and glutathione (GSH) level in plasma were measured using high-performance liquid chromatography. MTHFR genotype (rs1801133) was determined using a single tube TaqMan SNP Genotyping Assay. We calculated atherogenic indices, such as Castelli's risk index I and II (CRI-I and CRI-II), the atherogenic coefficient (AC), and the TG/HDL ratio.No association was found between MetS and tHcy or GSH concentrations. MTHFR genotype and folate intake also did not affect tHcy, GSH, lipid profile, or atherogenic indices. Subjects with tHcy levels over the median had lower total protein intake, lower animal protein/plant protein ratio, lower protein/carbohydrates ratio, and higher amino acid intake (methionine, lysine, arginine, glycine, and tryptophan) than did subjects with lower tHcy levels. Women who failed to meet their vitamin B12 intake needs had almost 40% higher levels of tHcy than women who did met those needs.MTHFR genotype, folate intake, and tHcy levels in plasma are not associated with lipid metabolism in postmenopausal women. tHcy levels may depend on the intake of vitamin B12, and of protein or particular amino acids.The project was financed by the National Science Centre, Poland (grant number 2015/17/N/NZ9/04133).


2020 ◽  
Vol 223 (1) ◽  
pp. 124-131 ◽  
Author(s):  
Gauri Desai ◽  
Gabriel Barg ◽  
Marie Vahter ◽  
Elena I. Queirolo ◽  
Fabiana Peregalli ◽  
...  

2005 ◽  
Vol 85 (3) ◽  
pp. 389-399 ◽  
Author(s):  
D. E. Santschi ◽  
J. Chiquette ◽  
R. Berthiaume ◽  
R. Martineau ◽  
J. J. Matte ◽  
...  

Two studies were undertaken to verify the effect of the forage to concentrate ratio of the diet on B-vitamin concentrations in ruminal contents. In Study 1, eight primiparous and eight multiparous cows were used in a cross-over design, and concentrations of biotin, folates and vitamin B12 were determined in ruminal fluid and plasma of cows fed a high-forage (HF; 58:42 forage to concentrate ratio; DM basis) or a low-forage (LF; 37:63 forage to concentrate ratio; DM basis) diet. In Study 2, six ruminally cannulated lactating cows were used in a cross-over design to evaluate the effects of forage to concentrate ratio (HF = 60:40; LF = 40:60; DM basis) on concentrations of seven B-vitamins in the particle-free fluid and in both liquid- and solid-associated bacteria. Results showed that B-vitamins were present mainly in the bacterial fractions of the ruminal content, while only limited amounts were found in the surrounding fluid. A change in the forage to concentrate ratio had a greater effect on vitamin concentration in the bacteria associated with the solid fraction than in those present in the liquid portion of the rumen. The most noticeable effects of a low forage diet were an increase in riboflavin, but a decrease in true vitamin B12 concentrations in solid-associated bacteria as well as a decrease in biotin concentration in particle-free fluid. In conclusion, it appears that ruminal B-vitamin concentration is altered by changes in the forage to concentrate ratio, which suggests that the supply of vitamins to dairy cows is influenced by diet composition. Key words: B-vitamins, dairy cow, ruminal fractions, forage to concentrate ratio


2017 ◽  
Vol 117 (1) ◽  
pp. 124-133 ◽  
Author(s):  
I. Iglesia ◽  
I. Huybrechts ◽  
M. González-Gross ◽  
T. Mouratidou ◽  
J. Santabárbara ◽  
...  

AbstractThis study aimed to examine the association between vitamin B6, folate and vitamin B12biomarkers and plasma fatty acids in European adolescents. A subsample from the Healthy Lifestyle in Europe by Nutrition in Adolescence study with valid data on B-vitamins and fatty acid blood parameters, and all the other covariates used in the analyses such as BMI, Diet Quality Index, education of the mother and physical activity assessed by a questionnaire, was selected resulting in 674 cases (43 % males). B-vitamin biomarkers were measured by chromatography and immunoassay and fatty acids by enzymatic analyses. Linear mixed models elucidated the association between B-vitamins and fatty acid blood parameters (changes in fatty acid profiles according to change in 10 units of vitamin B biomarkers). DHA, EPA) andn-3 fatty acids showed positive associations with B-vitamin biomarkers, mainly with those corresponding to folate and vitamin B12. Contrarily, negative associations were found withn-6:n-3 ratio,trans-fatty acids and oleic:stearic ratio. With total homocysteine (tHcy), all the associations found with these parameters were opposite (for instance, an increase of 10 nmol/l in red blood cell folate or holotranscobalamin in females produces an increase of 15·85 µmol/l of EPA (Pvalue <0·01), whereas an increase of 10 nmol/l of tHcy in males produces a decrease of 2·06 µmol/l of DHA (Pvalue <0·05). Positive associations between B-vitamins and specific fatty acids might suggest underlying mechanisms between B-vitamins and CVD and it is worth the attention of public health policies.


2008 ◽  
Vol 67 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Robert Clarke

Elevated plasma homocysteine (Hcy) concentrations have been implicated with risk of cognitive impairment and dementia, but it is unclear whether low vitamin B12 or folate status is responsible for cognitive decline. Most studies reporting associations between cognitive function and Hcy or B-vitamins have used a cross-sectional or case–control design and have been unable to exclude the possibility that such associations are a result of the disease rather than being causal. The Hcy hypothesis of dementia has attracted considerable interest, as Hcy can be easily lowered by folic acid and vitamin B12, raising the prospect that B-vitamin supplementation could lower the risk of dementia. While some trials assessing effects on cognitive function have used folic acid alone, vitamin B12 alone or a combination, few trials have included a sufficient number of participants to provide reliable evidence. An individual-patient-data meta-analysis of all randomised trials of the effects on cognitive function and vascular risk of lowering Hcy with B-vitamins will maximise the power to assess the epidemiologically-predicted differences in risk. Among the twelve large randomised Hcy-lowering trials for prevention of vascular disease, data should be available on about 30 000 participants with cognitive function. The principal investigators of such trials have agreed to combine individual-participant data from their trials after their separate publication.


2018 ◽  
Author(s):  
Laura Gómez-Consarnau ◽  
Rohan Sachdeva ◽  
Scott M. Gifford ◽  
Lynda S. Cutter ◽  
Jed A. Fuhrman ◽  
...  

Aquatic environments contain diverse microbial communities whose complex interactions mediate the cycling of major and trace nutrients such as vitamins. B-vitamins are essential coenzymes that many organisms cannot synthesize. Thus their exchange among de-novo synthesizers and auxotrophs is expected to play an important role in the microbial consortia and explain some of the temporal and spatial changes observed in diversity. In this study, we analyzed metatranscriptomes of a natural coastal microbial community, diel sampled-quarterly over one year to try to identify the potential major B-vitamin synthesizers and consumers. Our transcriptomic data show that the best-represented taxa dominated the expression of synthesis genes for some B-vitamins but lacked transcripts for others. For instance, Rhodobacterales dominated the expression of vitamin-B12synthesis, but not of vitamin-B7, whose synthesis transcripts were mainly represented by Flavobacteria.In contrast, bacterial groups that constituted less than 4% of the community (e.g., Verrucomicrobia) accounted for most of the vitamin-B1synthesis transcripts. Furthermore, ambient vitamin-B1concentrations were higher in samples collected during the day, and were positively correlated with chlorophyll-aconcentration. Our analysis supports the hypothesis that the mosaic of metabolic interdependencies through B-vitamin synthesis and exchange are key processes that contribute to shaping microbial communities in nature.


2000 ◽  
Vol 59 (2) ◽  
pp. 221-237 ◽  
Author(s):  
Michelle C. McKinley

Numerous case–control and prospective studies have identified elevated plasma homocysteine as a strong independent risk factor for cerebovascular, cardiovascular and peripheral vascular disease. Homocysteine is formed as a result of the breakdown of the dietary amino acid methionine. Once formed, homocysteine is either remethylated to methionine, or undergoes a trans-sulfuration reaction to form cysteine. The re-methylation of homocysteine to methionine is dependent on three B-vitamins, i.e. riboflavin, vitamin B12and folate. The second pathway of homocysteine metabolism is the trans-sulfuration pathway which requires both vitamin B6and riboflavin for its activity. Thus, up to four B-vitamins are required for intracellular homocysteine metabolism. Many studies have noted strong inverse relationships between homocysteine levels and the status of both vitamin B12and folate. However, the relationship between vitamin B6status and homocysteine is still uncertain. Similarly, numerous intervention studies have demonstrated effective lowering of homocysteine levels as a result of folate and vitamin B12supplementation, while the homocysteine-lowering ability of vitamin B6is unclear. Even though riboflavin plays a crucial role in both the trans-sulfuration and remethylation pathways of homocysteine metabolism, the relationship between riboflavin status and homocysteine levels has not been investigated. The exact mechanism that explains the vascular toxicity of elevated homocysteine levels is unknown at present, studies indicate that it is both atherogenic and thrombogenic. To date, no randomized clinical trial has demonstrated that lowering of homocysteine levels is beneficial in terms of reducing the prevalence of vascular disease. It is probable, however, that optimal B-vitamin status is important in the prevention of vascular disease.


Sign in / Sign up

Export Citation Format

Share Document