A large-scale study finds vitamin D supplementation seems to alleviate depressive symptoms in adults. 

Conducted by an international team of researchers, a new meta-analysis includes dozens of studies from around the world on the effects of vitamin D supplements. 

Vitamin D is believed to regulate central nervous system functions, the disturbances of which have been associated with depression.

The new meta-analysis on the association of vitamin D supplementation with depression is the largest one published so far, including results from 41 studies from around the world. 

These studies investigated the efficacy of vitamin D in alleviating depressive symptoms in adults by randomised placebo-controlled trials in different populations. The studies included those carried out in patients with depression, in the general population, and in people with various physical conditions. 

The results of the meta-analysis show that vitamin D supplementation is more effective than a placebo in alleviating depressive symptoms in people with depression. 

There were major differences in the vitamin D doses used, but typically the vitamin D supplement was 50–100 micrograms per day.

“Our results suggest that vitamin D supplementation has beneficial effects in both individuals with major depressive disorder as well as in those with milder, clinically significant depressive symptoms,” the researchers said.

Depressive symptoms cause a significant disease burden worldwide. The therapeutic efficacy of current antidepressants is often insufficient, which is why further ways to alleviate the symptoms of depression have been sought, for example, from nutritional research.

The findings should “encourage new, high-level clinical trials in patients with depression in order to shed more light on the possible role of vitamin D supplementation in the treatment of depression,” according to researcher Tuomas Mikola of the Institute of Clinical Medicine at the University of Eastern Finland. The meta-analysis is part of Mr Mikola’s PhD thesis.

The full study is accessible here.