title: Consumption of folate-related nutrients and metabolism of arsenic in Bangladesh.
abstract: BACKGROUND
  Inorganic arsenic (InAs) is metabolized to monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), and this methylation facilitates urinary arsenic excretion. Previous studies suggest that persons with more complete methylation, characterized as greater proportions of DMA and lesser proportions of MMA and InAs in urine, have a lower risk of adverse arsenic-related health outcomes.
  
  
  OBJECTIVE
  The purpose of this study was to examine whether the capacity to methylate arsenic differs by nutrient intake.
  
  
  METHODS
  Participants were 1016 Bangladeshi adults exposed to arsenic in drinking water. Nutrient intake was assessed with a validated food-frequency questionnaire. Multivariate regression analyses were used to examine associations of nutrients with urinary arsenic metabolite profiles.
  
  
  RESULTS
  In multivariate analyses, higher intakes of cysteine, methionine, calcium, protein, and vitamin B-12 were associated with lower percentages of InAs and higher ratios of MMA to InAs in urine. Higher intakes of niacin (beta=0.22, P=0.02) and choline (beta=0.10, P=0.02) were associated with higher DMA-to-MMA ratios, after adjustment for age, sex, smoking, total urinary arsenic, and total energy intake.
  
  
  CONCLUSIONS
  Findings from the current study show the influence of multiple nutrients on arsenic methylation. In particular, this study highlights the potential importance of dietary intakes of cysteine, methionine, niacin, vitamin B-12, and choline on health effects of arsenic by modulating its metabolism.
authors.affiliation: Department of Epidemiology, Mailman School of Public Health and Institute for Social and Economic Research and Policy, Columbia University, New York, NY, USA.
authors.forename: Julia E
authors.initials: JE
authors.lastname: Heck
authors.forename: Mary V
authors.initials: MV
authors.lastname: Gamble
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Graziano
authors.forename: Vesna
authors.initials: V
authors.lastname: Slavkovich
authors.forename: Faruque
authors.initials: F
authors.lastname: Parvez
authors.forename: John A
authors.initials: JA
authors.lastname: Baron
authors.forename: Geoffrey R
authors.initials: GR
authors.lastname: Howe
authors.forename: Habibul
authors.initials: H
authors.lastname: Ahsan
mesh_terms: D000328:Adult; D001151:Arsenic / Q000378:metabolism* / Q000652:urine; D001152:Arsenicals / Q000378:metabolism / Q000652:urine; D001459:Bangladesh; D002101:Cacodylic Acid / Q000378:metabolism / Q000652:urine; D002794:Choline / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism; D004044:Dietary Proteins / Q000378:metabolism* / Q000652:urine; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure; D005260:Female; D005492:Folic Acid / Q000378:metabolism*; D006801:Humans; D008297:Male; D008715:Methionine / Q000378:metabolism; D008745:Methylation / Q000187:drug effects*; D008875:Middle Aged; D015999:Multivariate Analysis; D009525:Niacin / Q000378:metabolism; D011795:Surveys and Questionnaires; D014805:Vitamin B 12 / Q000378:metabolism; D014803:Vitamin B Complex / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000652:urine
chemical_list: D001152:Arsenicals; D004044:Dietary Proteins; D014874:Water Pollutants, Chemical; D014803:Vitamin B Complex; D009525:Niacin; D005492:Folic Acid; D008715:Methionine; D002101:Cacodylic Acid; C020300:monomethylarsonic acid; D003545:Cysteine; D001151:Arsenic; D002794:Choline; D014805:Vitamin B 12