Serum folate and whole blood global DNA methylation response to chronic folic acid supplementation in normal weight and obese women of child‐bearing age (817.2)

Abstract

Folate is a water‐soluble vitamin important for normal fetal development. Maternal obesity is associated with increased risk for birth defects; however the relationship between obesity and folate metabolism is not well understood. Recently, our lab reported a lower short‐term pharmacokinetic response to an acute oral dose of folic acid in obese vs normal weight women of child‐bearing age. This study determined the serum folate (microbiological assay) and whole blood DNA methylation (LC/MS) response to 8 wks of supplementation with 800 µg/d folic acid (FA) in healthy normal weight (n=13, BMI=21.5±0.4) and obese (n=7, BMI=37.6±0.8) women of child‐bearing age. Samples were collected at baseline and after 4 and 8 wks of supplementation. At baseline, serum folate was lower in obese vs normal weight women, whereas global DNA methylation was similar in both groups. Repeated measures ANOVA indicated an effect of FA on increasing serum folate over time (p < 0.0001) for all subjects combined, and a time x group interaction for global methylation (p < 0.05) characterized by a reduction in methylation from baseline to 8 wks in normal weight but not obese women. These data provide additional evidence suggesting differences in metabolic response to folic acid as a function of BMI in women of child‐bearing age and provide support for consideration of a BMI‐adjusted folic acid intake recommendation.Grant Funding Source: Funded in part by HATCH #GEO00706, #GEO00707, #FLA‐FOS‐004797 and the Obesity Initiative at the Univ