The influence of homocysteine on osteoporosis

Osteoporosis is a major health problem, and the economic costs are expected to rise due to an increase in life expectancy throughout the world. Its major consequence is fractures, and especially hip fractures are associated with institutionalization and increased mortality. Homocysteine is an amino acid intermediate formed during the metabolism of methionine. Homocysteinuria is a rare autosomal recessive biochemical abnormality which causes elevated plasma concentrations of homocysteine and severe occlusive vascular disease. In patients with homocysteinuria, there is an increased prevalence of skeletal deformities, including osteoporosis, which is a primary risk factor for hip fracture. The high prevalence of osteoporosis among patients with homocysteinuria suggests that high levels of plasmatic homocysteine may also increase the risk of fractures. Nutritional factors such as vitamins B12, B6, and folate are cofactors in homocysteine metabolism, and vitamin intakes may inversely affect plasma homocysteine levels.