Grant: Travel Awards - Institute Community Support

Introduction: Canadian pregnant women are exposed to very high levels of folic acid (FA; synthetic form of a B vitamin, folate) due to periconceptional FA supplementation and mandatory FA fortification, both aimed at reducing the risk of neural tube defects (NTDs). Although FA fortification and supplementation have significantly reduced the rate of NTDs, heightened exposure to FA may modulate disease risks in the offspring later in life by altering epigenetic programming in utero as folate is an important co-factor in biological methylation reactions. Objective: To determine (i) intake levels and sources and (ii) predictors of blood levels of folate from diet and supplements during pregnancy. Methodology: Pregnant women (n=368) were recruited between 12-16 weeks gestation at St. Michael's Hospital. Dietary and supplemental intakes of folate were assessed using a food frequency questionnaire (FFQ) and blood folate concentrations were determined. Results: A mean intake of 595.0 ± 253.8 µg/day of dietary folate equivalents (DFE) from both natural and fortified foods was reported, and 44% of the women met the recommended dietary allowance (RDA) (600 µg/day DFE during pregnancy) through diet alone. Additionally, 90% reported taking an FA-containing supplement providing at least 400 µg during their first trimester. The mean concentrations of erythrocyte and serum folate were 2472.3 ± 526.0 nmol/L and 60.3 ± 46.2 nmol/L respectively, both indicative of supraphysiological levels. Conclusions: Canadian pregnant women are exposed to extremely high levels of folate for which the impact and functional ramifications on maternal and fetal health are currently unknown. Future studies are warranted to elucidate associated health outcomes and to determine safe intake levels of folate during pregnancy.