Homocysteine-lowering effect of 500 mu g folic acid every other day versus250 mu g/day

Background/Aims: Elevated plasma total homocysteine (tHcy) concentrations a re a risk factor for neural tube defects and vascular diseases. Supplementa tion with folic acid decreases tHcy. We investigated whether supplementatio n with 500 mug folic acid every other day is as effective in lowering tHcy as 250 mug folic acid each day. Methods: In a 4-week intervention study, 22 healthy young women (18-40 years old) took either 500 mug folic acid every other day (500-mug/2d group) or 250 mug folic acid each day (250-mug/d gro up). Pasting blood was collected on days 0 and 28. Results: Plasma folate c oncentrations increased by 11.4 nmol/l (6.8-15.9) in the 250-mug/d group an d by 9.1 nmol/l (95% CI 1.9-16.3) in the 500-mug/2d group. These increases were not significantly different from each other. THcy concentrations decre ased by 1.52 mu mol/l (95% CI -2.09 to -0.95; p < 0.001) in the 250-<mu>g/d group and by 0.88 mu mol/l (-1.53 to -0.23; p < 0.05) in the 500-<mu>g/2d group. The difference in decrease between the 250-mug/d group and the 500-m ug/2d group was 0.64 mu mol/l (p = 0.11). Conclusion: Although not conclusi ve, this study suggests that supplying subjects with folic acid each day de creases tHcy more effectively than a double dose every other day. Copyright (C) 2000 S. Karger AG, Basel.