Vitamin D is an independent risk factor for multiple sclerosis

Yet more evidence for the importance of immune regulation by vitamin D is presented in a paper just published in the journal Neurology. This study investigates the association between vitamin D and central nervous system (CNS) demyelination, the pathological process by which the fatty conductive nerve 'insulation' is damaged in disorders like multiple sclerosis. The authors set out to...

"...examine whether past and recent sun exposure and vitamin D status (serum 25-hydroxyvitamin D [25(OH)D] levels) are associated with risk of first demyelinating events (FDEs) and to evaluate the contribution of these factors to the latitudinal gradient in FDE incidence in Australia."

Over a period of three years they compared 216 subjects aged 18–59 years with a FDE to 395 controls matched for age, sex, and study region who had no CNS demyelination. Besides self-reported sun exposure by life stage the gathered objective measures of skin type and sun related damage, along with vitamin D status. Not surprisingly...

"Higher levels of past, recent, and accumulated leisure-time sun exposure were each associated with reduced risk of FDE... Higher actinic skin damage and higher serum vitamin D status were independently associated with decreased FDE risk. Differences in leisure-time sun exposure, serum 25(OH)D level, and skin type additively accounted for a 32.4% increase in FDE incidence from the low to high latitude regions."

There was a 93% decrease in first demyelinating events for every 10 nmol/L increase in serum 25(OH)D). The authors conclude:

"Sun exposure and vitamin D status may have independent roles in the risk of CNS demyelination. Both will need to be evaluated in clinical trials for multiple sclerosis prevention."