The effect of vitamin B12 on total plasma homocysteine concentration in folate-replete hemodialysis patients.

Abstract

AIM: Results from several studies indicate that the total homocysteine (tHcy) concentration in plasma is an independent risk factor for cardiovascular disease in hemodialysis patients. Folic acid is the established mainstay of homocysteine-lowering treatment, but since such treatment does not normalize plasma tHcy concentration in hemodialysis patients, it is of importance to search for additional therapy. METHODS: Twenty-eight folate-replete hemodialysis patients were randomized to 2 equally sized groups, a treatment group and a control group. The treatment group received vitamin B12 tablets at a dose of 2 mg 3 times a week for 6 weeks (after each dialysis session) while the control group received no such treatment. Blood samples were collected before and at the end of the treatment period for analysis of tHcy in plasma and vitamin B12, methylmalonic acid as well as folate in serum. RESULTS: At the end of the study period, serum vitamin B12 concentrations were significantly higher in the treatment group than in the control group. Plasma tHcy concentrations decreased significantly in both groups during the study period. However, there was no difference between the responses of the 2 groups. CONCLUSION: The results of this open, randomized controlled study did not support the hypothesis that treatment with oral vitamin B12 has considerable homocysteine-lowering effect in folate-replete hemodialysis patients.