[Vitamin D tweets light to genes in multiple sclerosis].

The relationship between sunlight exposure and the incidence of multiple sclerosis and the understanding of immunomodulatory effects of vitamin D triggered, in recent years, a broad range of investigations. Immunological studies performed in vitro and in vivo have demonstrated how tolerogenic vitamin D can be. Epidemiological studies confirmed an increased incidence of multiple sclerosis in vitamin D deficient subjects and signs of increased disease activity in such MS patients. Although small-scale observational studies have suggested a beneficial impact of vitamin D supplementation on the incidence and severity of multiple sclerosis, large scale clinical trials remain warranted to confirm these preliminary results.