The role of vitamin D in the pathogenesis and course of multiple sclerosis

Abstract Multiple sclerosis (MS) is a progressive, inflammatory demyelinating disease of the central nervous system, with an unknown aetiology. The pathogenesis of MS is mainly related with the autoimmune process, environmental factors and genetic predispositions. In recentyears, hypovitaminosis D has been considered as an independent factor increasing the risk of multiple sclerosis. Hypovitaminosis D is defined as a condition in which the concentration of 25(OH)D in serum is lower than 75 nmol/l (30 ng/ml). Numerous studies have documented the relation between the occurrence of MS, its course and activity, and vitamin D concentration dependent on sunlight and dietary intake. Conclusions from research on the effectiveness of supplementation have also been presented. They indicate the necessity of using higher doses of calcitriol. Most authors consider a preventive dose of 4000 IU daily as safe and well-tolerated by people living in low-insolation latitudes. It has been pointed out that vitamin D supplementation is indicated and effective only in cases of actual deficiency. The low risk and low cost of vitamin D supplementation, as well as patients' positive attitude towards it, makes it a promising strategy for decreasing the incidence and alleviating the signs and symptoms of multiple sclerosis.