Weekly high-dose folic acid supplementation is effective in lowering serum homocysteine concentrations in women

Aims: To compare the efficacy of a weekly high-dose (2,800 μg) folic acid supplement with a daily (400 μg) folic acid supplement in lowering homocysteine concentrations in healthy women of childbearing age. Methods: Free-living healthy women of childbearing age (n = 138) were randomized to receive a weekly (2,800 μg), a daily (400 μg) folic acid supplement, or placebo. Blood samples were collected at baseline and at 12 weeks and analyzed for serum homocysteine and erythrocyte folate. Results: At 12 weeks the mean (95% CI) serum homocysteine concentrations declined significantly (p < 0.05) in women receiving the daily [week 12 - baseline: -1.4 (-2.0, -0.70) μmol/l] and the weekly supplement [-1.3 (-2.1, -0.5) μmol/l] versus placebo [0.0 (-0.5, 0.5) μmol/l]. There was no significant difference between the two folate-treated groups (p > 0.05). At 12 weeks the mean erythrocyte folate concentration increased significantly in both supplemented groups versus placebo (p < 0.001). The increase in erythrocyte folate was significantly greater (p < 0.001) in the daily group than in the weekly group [451 (380, 521) vs. 288 (240, 335) nmol/l]. Conclusion: A weekly high-dose folic acid supplement was as effective as a daily supplement in lowering homocysteine concentrations in healthy women of childbearing age. Further study is needed to determine if weekly folic acid supplementation is effective in lowering homocysteine concentrations in populations with high homocysteine.