Whether vitamin D insufficiency is a contributing cause of depression remains unclear. We assessed whether serum 25-hydroxyvitamin D (S-25OHD) concentrations, the clinical marker of vitamin D status, were associated with major depression using Mendelian randomization. We used summary statistics data for six single-nucleotide polymorphisms significantly associated with S-25OHD concentrations in the Study of Underlying Genetic Determinants of Vitamin D and Highly Related Traits (SUNLIGHT) consortium and the corresponding data for major depression (n = 59,851 cases and 113,154 controls) from the Psychiatric Genomics Consortium. Genetically predicted S-25OHD concentrations were not associated with major depression. The odds ratio per genetically predicted one standard deviation decrease in S-25OHD concentrations was 1.02 (95% confidence interval 0.97⁻1.08; p = 0.44). The results of this study indicate that genetically lowered S-25OHD concentrations are not associated with increased risk of developing major depression.
Keywords: Mendelian randomization; depression; single nucleotide polymorphisms; vitamin D.