Homocysteine and osteoporotic fracture risk: a potential role for B vitamins.

Hyperhomocysteinemia (elevated plasma homocysteine levels) has been linked to increased risk of neural tube defects, cardiovascular disease, Alzheimer's dementia, pregnancy complications, and inflammatory bowel disease. Evidence for a role of hyperhomocysteinemia in the etiology of osteoporosis has recently been strengthened by the findings of two separate studies, which both reported that high homocysteine levels significantly increased risk of osteoporotic fracture. While the etiology of hyperhomocysteinemia is considered to be multifactorial (including genetic, nutritional, and lifestyle factors), a deficiency of one or more B vitamins certainly has a role. These vitamins are involved in the metabolism and clearance of homocysteine, and thus may have a protective effect against osteoporotic fracture risk.