The role of vitamin D in multiple sclerosis

OBJECTIVE: To evaluate the literature about the role of vitamin D in the prevention and treatment of multiple sclerosis (MS). DATA SOURCES: MEDLINE (1966-April 2006) and International Pharmaceutical Abstracts (1970-April 2006) searches were performed. In addition, pertinent references from identified articles were obtained. Key search terms included vitamin D, 25-hydroxyvitamin D, vitamin D deficiency, and multiple sclerosis. DATA SYNTHESIS: Vitamin D supplementation prevented the development and progression of experimental autoimmune encephalitis, an animal model of MS, in mice. A large, prospective, cohort study found that vitamin D supplementation was associated with a 40% reduction in the risk of developing MS. Four small, noncontrolled studies suggested that vitamin D supplementation may decrease exacerbation of MS symptoms. CONCLUSIONS: Vitamin D supplementation may help prevent the development of MS and may be a useful addition to therapy. However, current studies are in small populations and are confounded by other variables, such as additional vitamin and mineral supplementation.