Long-term vitamin D supplementation demonstrates protective effect against relapse of Multiple Sclerosis: a systematic review

Abstract

Introduction. Multiple Sclerosis (MS) is a demyelinating, inflammatory, chronic and degenerative disease of the central nervous system. The main hypotheses for the disease is the genetic predisposition associated with environmental factors, which originates the immune system dysfunction. Studies suggest a relationship between vitamin D deficiency and MS, and according to researchers, vitamin D has a role in preventing and decreasing the rates of disease recurrence. Treatment for MS is established by the use of immunosuppressants and immunomodulators and some studies demonstrate evidence of the immunomodulary effects of vitamin D, which stimulates T cell activation in patients with MS. Objective. In the present study, we address the possibility to discuss and investigate, through a systematic review, the effectiveness of vitamin D supplementation treatment in MS patients. Method. This study is a systematic review of the literature, carried out in the electronic databases PubMed, MedLine, Scielo and Lilacs, using the combination of specific terms. Results. The scientific search resulted in 219 studies, however, applying the inclusion and exclusion criteria, five articles were selected. Conclusion. This review demonstrated that vitamin D supplementation, used for long periods, increases the amount of the metabolically active form of vitamin D in plasma, and consequently acts as a protective factor against MS. However, further studies are needed to elucidate the protective mechanism of vitamin D.