Risk factors for multiple sclerosis: decreased vitamin D level and remote Epstein-Barr virus infection in the pre-clinical phase of multiple sclerosis
- Department of Clinical Research, Hokkaido Medical Center, Sapporo, Japan
- Correspondence to Dr Masaaki Niino, Department of Clinical Research, Hokkaido Medical Center, Yamanote 5-jo 7-chome, Nishi-ku, Sapporo 063-0005 Japan;
Contributors Dr MN is the sole author of this manuscript.
- Received 11 June 2012
- Accepted 26 June 2012
- Published Online First 20 August 2012
A number of environmental and genetic factors are implicated in the complex aetiology of multiple sclerosis (MS). Among several types of environmental risk factors that have been considered, the major factors are thought to be low vitamin D concentration and Epstein-Barr virus (EBV) infection. Among vitamin D metabolites, 25-hydroxyvitamin D (25(OH)D) has been widely used to determine vitamin D status, and a large prospective study demonstrated an inverse correlation of 25(OH)D levels with the risk of MS among whites, which was particularly strong for 25(OH)D levels measured before 20 years of age.1 EBV is a B-lymphotropic herpesvirus that establishes persistent latent …