Homocysteine as a risk factor for cardiovascular disease.

Homocysteine is an amino acid that appears to damage the vascular endothelium and promote thrombosis. The most frequent causes of hyperhomocyst(e)inemia are the inherited defect of the enzyme cystathinonine B-synthase and nutritional deficiency of vitamin B(12) or folate. Hyperhomocyst(e)inemia is associated, perhaps causally, with atherosclerotic vascular disease. Interactions with risk factors such as cigarette smoking, hyperlipidemia, and hypertension are possible, but not yet defined. Dietary supplementation with vitamin B(12), folate, and other substances can reduce homocysteine levels. Such simple measures may reduce the risk of vascular disease in hyperhomocyst(e)inemic subjects.