Effects of B Vitamins on Homocysteine Lowering and Thrombotic Risk Reduction-A Review of Randomized Controlled Trials Published Since January 1996.

Homocysteine is an amino acid derived from methionine which is metabolized via vitamin B6 (pyridoxine)- and vitamin B12 (cobalamin)-dependent pathways. Supplementation of B vitamins has been shown to effectively reduce plasma homocysteine levels. Previous research has also demonstrated an association between lower plasma homocysteine levels and decreased risk of myocardial infarction, stroke, and venous thromboembolism. However, whether supplementation of B vitamins is associated with risk reduction in thromboembolic events and confers clinical benefits remains inconclusive. This review examines clinical trials published over the past 29 years to assess the effects of B vitamin supplementation on thrombotic risk reduction and homocysteine metabolism. The findings from these studies are inconsistent, and the impact of B vitamins on thrombosis prevention remains uncertain. Given the conflicting evidence, further clinical and translational research is necessary to clarify the role of B vitamin supplementation in thrombosis risk reduction.