Multiple sclerosis is a chronic inflammatory disease of the central nervous system associated with demyelination and neurodegeneration. In recent years, vitamin D has gained attention in the medical community following suggestions that there is a correlation between the level of serum vitamin D and the risk of multiple sclerosis, disease progression and activity. The aim of this article was to review recent literature describing the effects of vitamin D supplementation on the immune, inflammatory and oxidative stress parameters in patients with multiple sclerosis. In clinical trials, vitamin D doses ranging from 800 IU/day to 14,000 IU/day were tested. Researchers noticed significant differences in the range of action of vitamin D. However, the overview of studies failed to yield a definite answer concerning an effective dose of vitamin D. We concluded that there was no clear evidence for the impact of vitamin D supplementation on inflammatory parameters in multiple sclerosis patients, even though studies show consistently that the vitamin has an influence on the immune system and contributes to a reduction of pro-inflammatory cytokines. What is more, little is still known about the effects of vitamin D supplementation on oxidative stress, especially with regard to the potential effective dose. Consequently, more research is needed to gain a better understanding of this issue. There is increasing evidence on the significant role of vitamin D in patients with multiple sclerosis but there are as yet no global recommendations regarding the benefits of vitamin D supplementation and the supplementation dose. It is necessary to conduct further studies on the influence of vitamin D on disease activity due to its potential role as an add-on therapy in this group of patients or even as a preventative measure.

multiple sclerosis, vitamin D, supplementation, oxidative stress, immune system, cytokines