Vitamin D Supplementation for Depressive Symptoms: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Psychosom Med. 2014 Apr;76(3):190-6. doi: 10.1097/PSY.0000000000000044.

Abstract

Objective: The aim of this study was to review the effects of vitamin D supplementation on depressive symptoms in randomized controlled trials. Although low vitamin D levels have been observationally associated with depressive symptoms, the effect of vitamin D supplementation as an antidepressant remains uncertain.

Methods: MEDLINE, CINAHL, AMED, PsycINFO, Scopus, The Cochrane Library, and references of included reports (through May 2013) were searched. Two independent reviewers identified and extracted data from randomized trials that compared the effect of vitamin D supplementation on depressive symptoms to a control condition. Two additional reviewers assessed study quality using The Cochrane Risk of Bias Tool. Seven trials (3191 participants) were included.

Results: Vitamin D supplementation had no overall effect on depressive symptoms (standardized mean difference [SMD], 0.14; 95% confidence interval [CI], -0.33 to 0.05, p = .16), although considerable heterogeneity was observed. Subgroup analysis showed that vitamin D supplementation for participants with clinically significant depressive symptoms or depressive disorder had a moderate, statistically significant effect (2 studies: SMD, -0.60; 95% CI, -1.19 to -0.01; p = .046), but a small, nonsignificant effect for those without clinically significant depression (5 studies: SMD, -0.04; 95% CI, -0.20 to 0.12; p = .61). Most trials had unclear or high risk of bias. Studies varied in the amount, frequency, duration, and mode of delivery of vitamin D supplementation.

Conclusions: Vitamin D supplementation may be effective for reducing depressive symptoms in patients with clinically significant depression; however, further high-quality research is needed.

Publication types

  • Meta-Analysis
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Antidepressive Agents / therapeutic use*
  • Data Interpretation, Statistical
  • Depression / drug therapy*
  • Depressive Disorder / drug therapy*
  • Dietary Supplements
  • Humans
  • Randomized Controlled Trials as Topic / statistics & numerical data*
  • Treatment Outcome
  • Vitamin D / therapeutic use*
  • Vitamins / therapeutic use*

Substances

  • Antidepressive Agents
  • Vitamins
  • Vitamin D