Vitamin D supplementation during the Winter may be beneficial

Miclea A, Miclea M, Pistor M, Hoepner A, Chan A, Hoepner R. Vitamin D supplementation differentially affects seasonal multiple sclerosis disease activity. Brain Behav. 2017 Jul 11;7(8):e00761.

OBJECTIVES:Low ultraviolet-B (UVB) radiation causes hypovitaminosis D, which is a known risk factor for multiple sclerosis (MS) and associated with MS disease activity. Our objective is to test whether vitamin D supplementation is most effective in lowering disease activity during the period of the year with low UVB radiation and consequently low serum 25-hydroxyvitamin D3 (25(OH)D3) concentration.
METHODS:Retrospective analysis of medical records from our outpatient department identified 40 MS patients with available data of at least 6 months before and during oral vitamin D supplementation. Serum 25(OH)D3 concentration was analyzed using immunoassay. UVB radiation data were provided by the local government. Annualized and quarterly relapse rates before and during vitamin D supplementation served as outcome parameters.
RESULTS:During vitamin D supplementation (18,950 international units/week (mean, SD 3,397)), serum 25(OH)D3 concentration increased by 51 nmol/L and the UVB-related seasonal variability in 25(OH)D3 levels ceased (rho = -0.13, p > .05). Furthermore, the annualized relapse rate decreased by approximately 50%. This was almost solely driven by the prominent reduction in the quarterly relapse rate in late winter/early spring, when 25(OH)D3 levels of non-supplemented patients were the lowest.
CONCLUSIONS: Our study demonstrated the modulation of seasonal MS disease activity through vitamin D supplementation. Given the prominent reduction in the quarterly relapse rate in late winter/early spring, our data indicate a beneficial effect of supplementing MS patients with vitamin D, especially during this period of the year.

ProfG is an advocate of Vitamin Supplementation is areas where there is insufficient sunlight to make you vitamin d replete. In the UK this means you need to take your pills throughout the winter.  Does this do any good?

The advice we give is this will help maintain bone health and help protect you if you fall, etc.

The next question is whether it affects your immune system, to be beneficial.  I am quite sceptical on this and think the influence of vitamin D is long before diagnosis. But am willing to keep an open mind. In this study they retrospectively looked at the influence of supplementation and they found that supplementation during the winter months was associated with lower relapse rates. Great ProfG wins the argument, but if it were so easy to show this why wouldwe need trials involving hundreds of people. 

Is forty people in a trial  really enough. We will have to wait until it is repeated and repeated.