Deakin University

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The effect of vitamin D supplementation on depressive symptoms in adults: A systematic review and meta‐analysis of randomized controlled trials

journal contribution
posted on 2023-02-10, 01:50 authored by T Mikola, Wolf MarxWolf Marx, MM Lane, M Hockey, Amy Loughman, S Rajapolvi, Tetyana RocksTetyana Rocks, A O’Neil, D Mischoulon, M Valkonen-Korhonen, SM Lehto, Anu RuusunenAnu Ruusunen
Neurosteroid and immunological actions of vitamin D may regulate depression-linked physiology. Meta‐analyses investigating the effect of vitamin D on depression have been inconsistent. This meta-analysis investigated the efficacy of vitamin D in reducing depressive symptoms among adults in randomized placebo-controlled trials (RCT). General and clinical populations, and studies of ill individuals with systemic diseases were included. Light therapy, co-supplementation (except calcium) and bipolar disorder were exclusionary. Databases Medline, PsycINFO, CINAHL and The Cochrane Library were searched to identify relevant articles in English published before April 2022. Cochrane risk-of-bias tool (RoB 2) and GRADE were used to appraise studies. Forty-one RCTs (n = 53,235) were included. Analyses based on random-effects models were performed with the Comprehensive Meta-analysis Software. Results for main outcome (n = 53,235) revealed a positive effect of vitamin D on depressive symptoms (Hedges’ g = −0.317, 95% CI [−0.405, −0.230], p < 0.001, I2 = 88.16%; GRADE: very low certainty). RoB assessment was concerning in most studies. Notwithstanding high heterogeneity, vitamin D supplementation ≥ 2,000 IU/day appears to reduce depressive symptoms. Future research should investigate possible benefits of augmenting standard treatments with vitamin D in clinical depression. PROSPERO registration number: CRD42020149760. Funding: Finnish Medical Foundation, grant 4120 and Juho Vainio Foundation, grant 202100353.



Critical Reviews in Food Science and Nutrition


United States







Publication classification

C1 Refereed article in a scholarly journal