Aim: The aim of this study was the identification and summary of studies examining the relationship between vitamin D levels and the risk of depression and depressive symptoms severity, published between January 2008 and January 2019.
Material and methods: A systematic review of literature published within the last 10 years and accessible in PubMed database was conducted by each author separately based on predetermined inclusion criteria.
Results: Out of the 823 studies qualified to the initial abstract analysis, 24 were included into the full-text review and 18 into the meta-analysis. Statistically significant odds ratio was obtained for risk of depression in the course of vitamin D deficiency (OR = 1.51; 95% CI: 1.4-1.62; p < 0.01).
Conclusions: The analysis of available literature seems to indicate that there is an association between risk of depression and vitamin D deficiency. However, current literature does not give the possibility to state explicitly what is the exact mechanism and direction of this dependency.
Keywords: calcitriol; depression; vitamin D.