Efficacy of folate and vitamin B12 in lowering homocysteine concentrations in hemodialysis patients

To evaluate the efficacy of supplementation with high dose folic acid with and with-out vitamin B 12 in lowering plasma total homocysteine (tHcy) concentrations in hemodialysis (HD) patients, we studied 36 HD patients randomized into four groups according to the received thera-peutic regimen: group I (only folic acid (FA), 5 mg/day), group II (FA, 5 mg/day + vitamin B 12 , 1 mg/day) group III (only FA, 15 mg/day), group IV (FA, 15 mg/day, vitamin B 12 , 1 mg/day) for a period of 8 weeks. Plasma tHcy and serum FA and vitamin B 12 levels were measured at baseline and after the supplementation period. Dietary intakes were assessed during the study period. At baseline, 27.8% of the patients had normal levels of tHcy and 72.2% had hyperhomocysteinemia. After supplementation, plasma tHcy increased by 1.35% in group I and decreased by 6.99%, 14.54% and 30.09% in groups II, III and IV respectively, which was only significant in group IV (P= 0.014). The patients did not show any significant changes in serum folic acid, but a significant change in serum vitamin B 12 in group IV (P= 0.006). Percentage of patients reaching normal levels of plasma tHcy was 5.6 fold higher in group IV than in the reference group (group I). No corre-lations were found between changes of plasma tHcy levels and dietary intakes. We conclude that oral supplementation with 15 mg/day folic acid together with 1 mg/day of vitamin B 12 is effective in reducing tHcy levels in HD patients. These supplements also have a desirable effect on serum folic acid and vitamin B12.