The Folic Acid and Creatine Trial: Treatment effects on arsenic metabolite concentrations in blood

Background and Aim. Arsenic exposure is a global issue. Inorganic As (InAs) undergoes methylation to monomethyl (MMAs) and dimethyl-arsenical species (DMAs); full methylation to DMAs facilitates urinary excretion and can reduce risk of adverse health outcomes. Folate and creatine influence one-carbon metabolism which provides methyl groups for As methylation. We investigated the effects of folic acid (FA) and/or creatine supplementation on As metabolites and primary (PMI: MMAs/InAs) and secondary (SMI: DMAs/MMAs) methylation indices in blood in Bangladeshi adults. Methods. In this double-blind, placebo-controlled trial, 622 participants (20% folate deficient) were randomized to receive FA (400 or 800 μg/day), 3 g creatine/day, 3 g creatine+400 μg FA/day, or placebo for 12 weeks. For the following 12 weeks, half of the FA…