“Chicken or egg? Vitamin D and MS is another conundrum in need of a solution. We know that low vD levels are a susceptibility factor for MS and that MS incidence (number of new cases per year) and prevalence (total number of cases in the population) are strongly associated with latitude (distance from the equator) and in particular annual ultraviolet B light exposure (UVB). UVB is the spectrum of light required by your skin to synthesize vD. For these reasons we believe that low vD levels are part of the causal pathway that leads to the development of MS. However, what happens once you have MS? Will low vD levels increase your chances of having a poor prognosis? Will vD supplements improve your disease course? The study below addresses the former; CISers with low vD levels were more likely to do poorly over the next 5-years than CISers/MSers with high vD levels. This study, however, does not show causation. It is possible that low vD levels are simply a marker of a more active disease. In other words inflammation consumes vD and hence the more inflammation you have the lower your vD levels are. This could be untangled by an adequate double-blind placebo controlled trial of vD supplementation trial in CIS. If vD supplements reduces MS disease activity then vD is a DMT. If on the contrary vD supplements don’t reduce MS disease activity then low vD levels are likely to be a consequence of MS disease activity.” ]
Epub: Ascherio et al. Vitamin D as an Early Predictor of Multiple Sclerosis Activity and Progression. JAMA Neurol. 2014 Jan.
IMPORTANCE: It remains unclear whether vitamin D insufficiency, which is common in individuals with multiple sclerosis (MS), has an adverse effect on MS outcomes.