Vitamin D supply may be linked with severity of multiple sclerosis

A new study from Iran reports that patients with severe multiple sclerosis have lower blood vitamin D concentrations than patients with a milder form of the disease.

In the observational study, blood vitamin D3 concentrations of 98 patients with relapsing-remitting multiple sclerosis (MS) of different severity were measured and compared with vitamin D values of healthy partici-pants (1). The study results showed that in general, MS patients had lower vitamin D levels (a mean of 31.7 nanograms/ml) than healthy participants (35.8 ng/ml). In patients with MS, disease severity correlated with vitamin D levels: those with severe relapsing-remitting MS had mean levels of 21.5 ng/ml, while those with a milder relapsing-remitting MS had mean levels of 33.6 ng/ml.

The researchers commented that vitamin D could be involved in the regulation of MS disease activity. Studies have indicated that getting enough vitamin D throughout life may reduce the risk of developing
MS (2). The incidence of MS is higher in countries further from the equator, leading many researchers to believe that adequate vitamin D supply – by sun exposure and/or supplementation – may be protective against MS (3). In Iran, despite the country being close to the equator, people dress in heavy clothing, restricting the skin’s ability to produce vitamin D. Thus, vitamin D deficiency is much more prevalent in Iran than expected (4). In recent years, researchers have noticed an increase in MS prevalence in the country.

1. Shahbeigi S. et al. Vitamin D3 concentration correlates with the severity of multiple sclerosis.
   Int J Prev Med. 2013; 4(5):585–591.
   
   2. Hayes C. E. Review Vitamin D: a natural inhibitor of multiple sclerosis.
   Proc Nutr Soc. 2000; 59(4):531–535.
   
   3. Munger K. L. et al. Vitamin D intake and incidence of multiple sclerosis. Neurology. 2004; 62(1):60–65.
   
   4. Bassir M. et al. Vitamin D deficiency in Iranian mothers and their neonates: a pilot study.
   Acta Paediatr. 2001; 90(5):577–579.