Classical risk factors of development of cardiovascular diseases does not allow to detect all persons needing active prevention. Because of this reason great attention is given to novel biomarkers one of which is homocysteine. Most widely-spread causes of elevation of homocysteine level are such factors as deficit of folic acid and B6 and B12 vitamins, as well as genetic peculiarities. Main damaging effect of homocysteine is activation of atherothrombosis. Therapy with folic acid causes significant lowering of homocysteine level. Effect of therapy with vitamins on the risk of development of cardiovascular diseases has been assessed both in observational epidemiological studies and large prospective randomized trials. Their results are controversial. The present review is devoted to the analysis of these trials.