Vitamin D deficiency is frequent in Northern Europe as 90% of Vitamin D is synthesized in the skin under the effect of the sun’s ultraviolet irradiation. Low Vitamin D blood levels in childhood and adolescence are a factor in the development of multiple sclerosis in adulthood. In a Finnish study published in March 2016, mothers with inadequate Vitamin D levels in early pregnancy almost doubled the risk of their children developing multiple sclerosis.

Not only this vitamin is important to calcium and bone metabolism, but also aids the maturation of the immune system and has immunomodulating properties. The prevalence of the disease is twice as high in the North and East of France as in Provence and the Côte d’Azur; this prevalence is in reverse proportion to the ultraviolet irradiation in these areas and to the average Vitamin D blood levels of the populations concerned. In MS patients, low Vitamin D levels are associated with increased disease activity detected by brain resonance imaging.

This inverted ratio was particularly observed in two studies of interferon beta 1b (Betaferon), the BENEFIT and BEYOND studies. The presence of a high Vitamin D blood level, between 40 and 60 ng/ml, decreased the number of active lesions detected by brain imaging by almost 50%. These studies also demonstrated a synergetic effect between Vitamin D and beta interferon, which has not yet been demonstrated in the case of glatiramer acetate or other immunomodulating treatments used in the disease.

Vitamin D is not toxic, even when taken at high doses, up to 20,000 units per day (one ampoule of D Cure contains 25,000 units). In the current state of knowledge, maintaining a Vitamin D blood level of 40 to 60 ng/ml in MS patients – and in their children – is a justified precaution. Two placebo-controlled scientific studies concerning the addition of Vitamin D to the treatment of multiple sclerosis patients are under way or nearing completion (EVIDIMS and SOLAR). Their results will be important in the generalisation of Vitamin D as an additional therapy for multiple sclerosis.

Prof. Christian Sindic