Vitamin D3 supplementation in multiple sclerosis: Symptoms and biomarkers of depression

Depressive symptoms are common in multiple sclerosis (MS), and both depression and MS have been associated with a poor vitamin D status. As cytokine-mediated inflammatory processes play a role in the pathogenesis of both disorders, we hypothesized that vitamin D3 supplementation reduces depressive symptoms in MS via its immunomodulatory properties. In this randomized pilot study relapsing remitting (RR) MS patients received either vitamin D3 supplementation (n = 20; 14.000 IU/day) or placebo (n = 20) during 48 weeks. Pre- and post-supplementation depression scores, measured using the Hospital Anxiety Depression Scale (HADS) depression subscale (HADS-D), showed a significant decrease within the vitamin D3 group (median HADS-D 4.0 to 3.0, p = 0.02), a trend towards a decrease within the placebo group (median HADS-D 3.0 to 2.0, p = 0.06), but no significantly different reductions between groups (p = 0.78). Furthermore, no reductions in pro- and anti-inflammatory cytokine balances, secreted by stimulated leukocytes and CD8+ T cells, were found in the vitamin D3 compared to the placebo arm. Therefore, we found no evidence for a reduction of depressive symptoms or related biomarkers upon vitamin D3 supplementation in RRMS patients in this exploratory study. Whether vitamin D3 supplementation is of benefit in manifest depression in MS needs to be assessed by additional studies.