Efficacy of vitamin D in the treatment of depression: a systematic review and meta-analysis

Abstract

Introduction. Vitamin D is a fat-soluble vitamin that performs multiple functions in the body. In addition to regulating calcium and phosphate levels in the body and contributing to bone mineralization, it participates in various brain and neurocognitive processes. In fact, the deficiency of this vitamin has also been linked to various psychiatric disorders, including depression.

Objective. To review if the administration of vitamin D is effective in the treatment of depression in adults compared to placebo.

Methodology. An electronic search was carried out in 4 databases (PubMed, Embase, Web of Science-Science Citation Index and Scopus) of randomized clinical trials (RCT) to assess the efficacy of vitamin D, in adults with depression compared to placebo, from 2013 to date of search (2019). The outcome measure used for the effect size calculation was the depressive symptom score. The effect sizes for the trials were calculated using the standardized mean difference and the I2 test was used to assess sample heterogeneity. The critical evaluation of the articles was carried out using the funnel plot tool.

Results. A total of 10 RCTs involving 1.393 participants were included in the study. Given the heterogeneity of the studies, the random effects model was used. The result of the meta-analysis indicates that oral administration of vitamin D did not have a significant effect on the reduction of post-intervention depression scores. The standardized mean difference for the pooled data was -0,91 (95% confidence interval -2,02 – 0,19).

Conclusions. This study has not detected a significant therapeutic effect in the administration of vitamin D in depression.