Objective: Women of reproductive age are advised to consume supplements or fortified foods containing at least 400 microg/d folic acid for the prevention of neural tubes defects. Concerns exist about the adverse effects of folic acid on zinc status.
Methods: Seventy-eight women (18 to 49 y) were assigned for 12-wk to receive either a placebo or a 400 microg/d folic acid supplement.
Results: At 12-wk mean (95% CI) red cell folate increased by 431 (350-511) nmol/L in the supplemented group relative to placebo (P < 0.001) but there was no change in plasma zinc in either group (P = 0.213).
Conclusions: Folic acid supplementation does not reduce plasma zinc concentrations in women of childbearing age.