Folic acid supplementation enhances arsenic methylation: results from a folic acid and creatine supplementation randomized controlled trial in Bangladesh.
Am J Clin Nutr
; 109(2): 380-391, 2019 02 01.
Article
em En
| MEDLINE
| ID: mdl-30590411
ABSTRACT
Background:
Arsenic exposure through drinking water persists in many regions. Inorganic As (InAs) is methylated to monomethyl-arsenical species (MMAs) and dimethyl-arsenical species (DMAs), facilitating urinary excretion. Arsenic methylation is dependent on one-carbon metabolism, which is influenced by nutritional factors such as folate and creatine.Objective:
This study investigated the effects of folic acid (FA) and/or creatine supplementation on the proportion of As metabolites in urine.Design:
In a 24-wk randomized, double-blinded, placebo-controlled trial, 622 participants were assigned to receive FA (400 or 800 µg per day), 3 g creatine per day, 400 µg FA + 3 g creatine per day, or placebo. The majority of participants were folate sufficient; all received As-removal water filters. From wk 12-24, half of the participants receiving FA received placebo.Results:
Among groups receiving FA, the mean decrease in ln(%InAs) and %MMAs and increase in %DMAs exceeded those of the placebo group at wk 6 and 12 (P < 0.05). In the creatine group, the mean decrease in %MMAs exceeded that of the placebo group at wk 6 and 12 (P < 0.05); creatine supplementation did not affect change in %InAs or %DMAs. The decrease in %MMAs at wk 6 and 12 was larger in the 800 µg FA than in the 400 µg FA group (P = 0.034). There were no differences in treatment effects between the 400 µg FA and creatine + FA groups. Data suggest a rebound in As metabolite proportions after FA cessation; at wk 24, log(%InAs) and %DMAs were not significantly different than baseline levels among participants who discontinued FA supplementation.Conclusions:
The results of this study confirm that FA supplementation rapidly and significantly increases methylation of InAs to DMAs. Further research is needed to understand the strong cross-sectional associations between urinary creatinine and As methylation in previous studies. This trial was registered at https//clinicaltrials.gov as NCT01050556.
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
2_ODS3
Base de dados:
MEDLINE
Assunto principal:
Arsênio
/
Arsenicais
/
Complexo Vitamínico B
/
Suplementos Nutricionais
/
Creatina
/
Ácido Fólico
Tipo de estudo:
Clinical_trials
/
Observational_studies
/
Prevalence_studies
/
Risk_factors_studies
Limite:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
País/Região como assunto:
Asia
Idioma:
En
Revista:
Am J Clin Nutr
Ano de publicação:
2019
Tipo de documento:
Article