Vitamin D treatment in multiple sclerosis.

Multiple sclerosis is an immune-mediated disease of the central nervous system caused by a complex interplay between several different genetic as well as environmental factors. Vitamin D is one of the most attractive candidates among various environmental factors suggested to be involved in the development of the disease. Epidemiological evidence combined with clinical and laboratory analyses, and experimental animal models, suggest a possible influence of vitamin D on MS susceptibility as well as clinical disease activity. Supplement with vitamin D may reduce the risk of developing MS. An intervention may also reduce the risk of conversion from a first clinical event suggestive of MS to clinical definite MS, as well as reduce the relapse rate among patients with relapsing remitting MS. More studies are, however, needed to determine optimal dose and serum level for vitamin D, as well as target populations and optimal timing for intervention.