Consumption of a folic acid‐containing prenatal vitamin yields supra‐physiologic folate status in pregnant and non‐pregnant women

Abstract

With the goal of reducing neural tube defect incidence, the CDC recommends that women of childbearing age consume 400mcg/d folic acid (FA) from fortified foods and/or dietary supplements. About 40% of women use supplements containing FA; prenatal vitamins often contain ≥600mcg FA. Consumption of a prenatal vitamin plus fortified foods, which supply 200–250mcg/d FA, may result in FA intakes that exceed metabolic requirement and near or exceed the 1000mcg/d UL. Study objective measurement of folate status markers in response to a mixed diet combined with daily FA containing prenatal vitamin in nonpregnant and third trimester pregnant women. Results Total serum and RBC folates were >20 and >400ng/mL, respectively, in both the nonpregnant and pregnant groups. Mean urinary folate excretion was 460 and 250mcg/d in nonpregnant and pregnant women, respectively. Preliminary measurements characterizing folate species found un-metabolized FA in urine. Conclusion The consumption of a prenatal vitamin containing 600mcg FA in addition to food folate from a mixed diet (400mcg/d DFE) results in supra-physiologic folate status in nonpregnant and third trimester pregnant women as evidenced by reported folate biomarker concentrations. These findings warrant revisiting prenatal vitamin FA formulation. Funded in part by USDA, ENC and the Beef Checkoff; AAW is supported by an ENC Dissertation Fellowship.