Effect of different doses of folic acid on serum homocysteine level in patients on hemodialysis.

INTRODUCTION: Hyperhomocysteinemia is common in patients with end-stage renal disease. It is one of the risk factors for cardiovascular disease. We evaluated the effect of different doses of folic acid on serum homocysteine level in patients on hemodialysis. MATERIALS AND METHODS: Patients on maintenance hemodialysis were randomized into 4 groups to receive oral folic acid at doses of 2, 5, 10, and 15 mg/d, each for a period of 4 weeks. Serum homocysteine level was measured in all of the patients before and at the end of each week of therapy. Folic acid supplementation was discontinued during a washout period of 1 week between each of the four phases of the trial. RESULTS: Thirty-one hemodialysis patients completed the four phases of treatment with each dose of folic acid (17 women and 14 men). The mean age of patients was 57.6 ± 14.6 years. Serum homocysteine level was reduced significantly compared to its basal level after treatment with folic acid at different doses (P < .001). Different doses of folic acid were not significantly different in lowering serum homocysteine levels. CONCLUSIONS: Our study failed to show any difference between high-dose and low-dose folic acid therapy regarding their effect on serum homocysteine level. It seems folic acid, 2 mg/d, is an adequate dose, and there is no need to administer a higher dose of it.