Dose-response association between perinatal 25(OH)D status and postpartum depression

Postpartum depression (PPD) is a common perinatal disorder that affects maternal and child health. Although vitamin D deficiency has been linked to depressive symptoms, the dose‑response relationship between perinatal serum 25(OH)D and PPD and predictive value remains unclear.

To investigate the dose‑response relationship between perinatal 25(OH)D and PPD and evaluate its predictive value.

A total of 326 perinatal women were enrolled, PPD was assessed within 6 weeks postpartum, and serum 25(OH)D was measured at 24-48 hours after delivery. Analyses included baseline characteristics, EPDS scores, risk factors, dose‑response, predictive performance, and interactions with supplementation.

PPD incidence was 23.31%. The PPD group had lower 25(OH)D, negatively correlated with EPDS scores. Each 1 ng/mL increase in 25(OH)D reduced PPD risk by 25% (OR = 0.75, 95% CI: 0.68-0.82, P < 0.001). Primiparity and fair spousal relationship were risk factors; planned pregnancy, sunlight, and oral supplementation were protective. Positive interactions with sunlight and supplementation were observed, with linear dose‑response. The AUC was 0.822, with an optimal cutoff of 24.26 ng/mL (sensitivity 67.11%, specificity 85.20%).

Perinatal 25(OH)D levels are linearly and negatively correlated with PPD risk and show good screening utility; exogenous supplementation appears to modify this protective effect.