Full-text evidence summary

Multiple sclerosisIntroduction

  • Lower rates of MS are seen in areas that have more sunlight
  • Lower levels of vitamin D are associated with higher risk of MS
Multiple sclerosis (MS) is an autoimmune disease in which our nerves and brain tissues are damaged by our own immune system.

MS is likely caused by an immune response to Epstein Barr virus (EBV). 

The geographical distribution (higher prevalence at higher latitudes) and seasonal incidence variation (higher in spring) are consistent with lower Vitamin D levels.

Seasonal exacerbation in disease severity have been reported, with lower disease activity levels in summer.  This finding is consistent with vitamin D shifting production of immune fighting compounds to less inflammatory ones, but could also be due to higher frequency of viral infections in winter. 

Observational studies have found that lower levels of Vitamin D are linked to increased risk of developing MS. 

Trials with vitamin D supplementation have found limited evidence of reduced disease severity with higher vitamin D intake.

Multiple sclerosis (MS) is an autoimmune disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms1

Evidence points to Epstein Barr virus (EBV) infection and lack of vitamin D (serum 25-hydroxyvitamin D [25(OH)D] level) as important risk factors for developing MS in addition to genetic risk factors.

Page last edited: 09 January 2012


  1. Compston, A. Coles, A. Multiple sclerosis. Lancet. 2008 Oct 25; 372 (9648): 1502-17.