Vitamin D and its immunoregulatory role in multiple sclerosis.

Mapping the distribution of multiple sclerosis (MS) reveals a high prevalence of the disease in high-latitude areas, suggesting a positive relationship between vitamin D and MS. Vitamin D is known to play an important role in bone and mineral homeostasis. It has recently been reported that several types of immune cells express vitamin D receptors and that vitamin D has strong immune-modulating effects. Vitamin D and its analogues inhibited experimental autoimmune encephalomyelitis (EAE, an animal model of MS) and there have been reports of small clinical trials on the treatment of MS with vitamin D. Furthermore, there have been discussions on the association between vitamin D levels and MS and about the genetic risk of vitamin D receptor (VDR) gene polymorphisms in MS. The current review discusses the immunological functions of vitamin D, the association between vitamin D and MS and expectations regarding the role of vitamin D in future treatments of MS.