Today hyperhomocysteinemia is a well known and important risk factor for arteriosclerotic vascular and venous thromboembolic disease with a high prevalence in the general population. Elevation of plasma homocysteine levels are caused either by genetic defects in the enzymes involved in homocysteine metabolism or by nutritional deficiencies of vitamin cofactors (folate, vitamin B12, vitamin B6). A number of other factors may influence homocysteine metabolism, such as several disease states and medications. It has been demonstrated, that supplementation of folate, vitamin B12, or vitamin B6 can correct mild and moderate hyperhomocysteinemia.