Food and Behaviour Research

Donate Log In

Food Affects Behaviour: 20+ Years of FAB Research – What next? - BOOK HERE

Efficacy of vitamin D supplementation in depression in adults: a systematic review.

Li G, Mbuagbaw L, Samaan Z, Falavigna M, Zhang S, Adachi JD, Cheng J, Papaioannou A, Thabane L. (2014) J Clin Endocrinol Metab.  99(3) 757-67. Epub 2013 Dec 11. 

Web URL: View this and related abstracts via PubMed here. Free full text of this article is available online.


CONTEXT: Randomized controlled trials (RCTs) investigating the efficacy of vitamin D (Vit D) in depression provided inconsistent results.

OBJECTIVE: We aim to summarize the evidence of RCTs to assess the efficacy of oral Vit D supplementation in depression compared to placebo.

DATA SOURCES: We searched electronic databases, two conference proceedings, and gray literature by contacting authors of included studies.

STUDY SELECTION: We selected parallel RCTs investigating the effect of oral Vit D supplementation compared with placebo on depression in adults at risk of depression, with depression symptoms or a primary diagnosis of depression.

DATA EXTRACTION: Two reviewers independently extracted data from relevant literature.

DATA SYNTHESIS: Classical and Bayesian random-effects meta-analyses were used to pool relative risk, odds ratio, and standardized mean difference. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation tool.

RESULTS: Six RCTs were identified with 1203 participants (72% females) including 71 depressed patients; five of the studies involved adults at risk of depression, and one trial used depressed patients. Results of the classical meta-analysis showed no significant effect of Vit D supplementation on postintervention depression scores (standardized mean difference = -0.14, 95% confidence interval = -0.41 to 0.13, P = .32; odds ratio = 0.93, 95% confidence interval = 0.54 to 1.59, P = .79). The quality of evidence was low. No significant differences were demonstrated in subgroup or sensitivity analyses. Similar results were found when Bayesian meta-analyses were applied.

CONCLUSIONS: There is insufficient evidence to support the efficacy of Vit D supplementation in depression symptoms, and more RCTs using depressed patients are warranted.


While Vitamin D is best known for its importance for bone health and immune function, it also has important effects on brain development and function, and therefore mental health. Vitamin D receptors are found throughout the brain and nervous system, and Vitamin D is also needed to make some key neurotransmitters, including serotonin and dopamine.

Associations between low Vitamin D levels and depressive symptoms have often been reported - but observational studies cannot address cause-and-effect.

Clinical trials of supplementation have provided some positive findings - e.g. Jorde et al 2008 (who tested high doses of Vitamin D over 1 year in overweight and obese adults). However, other findings have been mixed.

This systematic review found no overall benefit of Vitamin D for depressive symptoms when pooling results from six different trials - involving different populations and dosages.

As the authors noted, however, only 71 of the 1203 participants had an actual diagnosis of clinical depression - highlighting the need for more trials involving this kind of population.

For more information on this subject, please see the following lists of articles, which are regularly updated.