Vitamin D supplementation during pregnancy and the role of maternal prenatal depression

Background The current study sought to investigate the correlation between vitamin D supplementation in pregnant women with vitamin D deficiency in early pregnancy and the incidence of prenatal depression prior to delivery. Methods This is a retrospective, single-center study that was conducted at a tertiary hospital in Chengdu, China. We conducted an analysis on pregnant women who were initially diagnosed with vitamin D deficiency at 12-14 weeks of gestation. After starting vitamin D supplementation at a dose of 800 IU daily from 14 weeks onwards, we measured both their vitamin D concentration and depression scores again during median gestational week 39 prior to delivery. Results The study cohort comprised 1365 women who had been diagnosed with vitamin D deficiency at 12-14 weeks of gestation between November 1st, 2021 to November 1st, 2022. 537 pairs were matched based on a propensity score to control for other confounding factors. After propensity score matching, the baseline vitamin D levels were made consistent between the groups (P = 0.512). The incidence of depression in patients in vitamin D deficiency group following vitamin D supplementation was significantly higher than insufficiency group and reached statistical significance (P < 0.001). Additionally, we observed that serum 25-(OH) D concentration achieving insufficiency status after supplementation was 59.12%. Conclusion Our study indicates that daily supplementation of 800IU of vitamin D can improve the depressive symptoms of individuals who are vitamin D deficiency during early pregnancy but achieve vitamin D insufficiency after supplementation during prenatal period.