Serum 25-hydroxyvitamin D as a dynamic biomarker for preeclampsia risk across pregnancy trimesters: A retrospective case–control study

This study aims to evaluate the association between serum 25-hydroxyvitamin D (25(OH)D) levels and preeclampsia risk across different pregnancy trimesters, exploring its potential as an early predictive biomarker for this condition. A retrospective case–control study of 301 pregnant women was assessed, with serum 25(OH)D levels and clinical parameters recorded in early, mid, and late pregnancy. Spearman correlation and logistic regression analyses revealed a significant inverse relationship between 25(OH)D levels and both blood pressure and proteinuria, particularly in the late trimester. Logistic regression further indicated that decreased serum 25(OH)D levels are significantly associated with an elevated risk of preeclampsia development even after adjusting for confounders such as age, body mass index, smoking, and alcohol consumption (adjusted odds ratio = 0.790, 95% confidence interval = 0.736–0.847). Receiver operating characteristic analysis demonstrated high predictive accuracy of 25(OH)D levels for preeclampsia in early pregnancy (area under the curve AUC = 0.969), with lower but moderate predictive accuracy in mid (AUC = 0.810) and late pregnancy (AUC = 0.770). Notably, early pregnancy 25(OH)D levels below 20 ng/mL were associated with a significantly higher preeclampsia risk. These findings support serum 25(OH)D as a feasible early biomarker for preeclampsia, suggesting that early pregnancy screening may facilitate timely intervention, potentially improving maternal and fetal outcomes. Further studies are warranted to validate these findings and explore the benefits of vitamin D supplementation in at-risk populations.