Controlled study on folate status following folic acid supplementation and discontinuation in women of child-bearing age

Background: To decrease the incidence of neural tube defects, active efforts are currently undertaken to promote folic acid (FA) intake among women. In 2003, the Food and Drug Administration approved the proposal of introducing an oral contraceptive (OC) and FA combination pill. It is unknown whether these pills will reduce neural tube defect incidence for couples who do not become pregnant soon after discontinuation. We studied FA kinetics up to 12 weeks discontinuation of eight weeks 500 mu g/d FA in 27 healthy Dutch women of child-bearing age. Methods: In this controlled study, women were assigned to an intervention group (n = 13) or a control group (n = 14). The total study duration was 20 weeks, during which the subjects had to give blood on nine occasions (week -8 [baseline], -4, 0, 1, 2, 3, 4, 8 and 12) for analyses of serum and erythrocyte folate, and plasma total homocysteine. The intervention group received 500 mu g/d FA during the first eight weeks, and discontinued the intake from weeks 0 to 12. No supplements were supplied to the control group. Results: Serum folate and plasma total homocysteine returned to baseline after 12 weeks of FA discontinuation, erythrocyte folate did not. Conclusion: An FA/OC combination pill seems to be of value for only a minor portion of women. Active efforts to stimulate women of child-bearing age to take FA remain essential.