Full-text evidence summary

Multiple sclerosisPrevention

  • Having the right amount of vitamin D may prevent multiple sclerosis.
  • Low levels of vitamin D are associated with higher risk of multiple sclerosis.

The epidemiology of MS with respect to latitude, season, and EBV infection strongly indicate that an important way to prevent MS is to maintain high serum 25(OH)D levels, especially in winter and spring and at higher latitudes.  The appropriate level is probably at least 30-40 ng/mL (75-100 nmol/L), with higher levels providing more protection.

There is evidence that prediagnostic serum 25(OH)D levels are protective against MS.  In a prospective, nested case-control study among more than 7 million US military personnel who have serum samples stored in the Department of Defense Serum Repository, among whites (148 cases, 296 controls), the risk of MS significantly decreased with increasing levels of 25(OH)D (odds ratio [OR] for a 50-nmol/L increase in 25(OH)D, 0.59; 95% confidence interval (CI), 0.36-0.97)1.

The evidence that vitamin D reduces the risk of MS is reviewed by Ascherio et al2.  They concluded that the evidence is only moderate, primarily because of the scarcity of large longitudinal (prospective observational) studies. 

Page last edited: 03 May 2011


  1. Munger, K. L. Levin, L. I. Hollis, B. W. Howard, N. S. Ascherio, A. Serum 25-hydroxyvitamin D levels and risk of multiple sclerosis. JAMA. 2006 Dec 20; 296 (23): 2832-8.
  2. Ascherio, A. Munger, K. L. Simon, K. C. Vitamin D and multiple sclerosis. Lancet Neurol. 2010 Jun; 9 (6): 599-612.