Abstract
The association of total blood homocysteine concentration with the risk of atherosclerosis, osteoporosis, and cognitive dysfunction has been speculated because patients with homocysteinuria, a hereditary metabolic disease with very high levels of blood homocysteine, develop vascular complications, skeletal abnormality, and mental retardation. Abundant epidemiologic evidence has confirmed that moderate elevation in blood homocysteine, commonly seen in the general elderly population, is an independent risk factor for atherosclerotic vascular diseases including coronary, cerebrovascular, peripheral arterial disease, and deep vein thrombosis. Furthermore, in recent years, evidence is increasing that levels of homocysteine are associated with the occurrence of osteoporosis and cognitive impairment. Because administration of B vitamin supplements is a simple and safe means to lower blood homocysteine concentration, the supplementation should be considered if the causal relation between elevated plasma homocysteine concentration and these disorders is once established. Evidence indicates that elevated levels of homocysteine might be a modifiable risk factor among Japanese as well, especially elderly population. In this paper, current knowledge on the relation between levels of homocysteine, related vitamin B deficiencies, and neurocognitive dysfunction is reviewed.
