Immune imbalance mediates the relationship between plasma vitamin D concentration and preeclampsia in Chinese pregnant women: A case-control study

This study aims to investigate the role of immune dysregulation in linking maternal vitamin D deficiency to the development of preeclampsia among Chinese pregnant women. In a case-control design, pregnant women diagnosed with preeclampsia and healthy normotensive controls matched for age and gestational week were recruited. Plasma 25-hydroxyvitamin D [25(OH)D] levels were measured using enzyme-linked immunosorbent assay (ELISA). Peripheral immune cell subsets, including T helper (Th)1, Th2, Th17, and regulatory T (Treg) cells, as well as related cytokines, were quantified to assess immune balance. Statistical analyses were conducted to explore associations between vitamin D concentration, immune parameters, and preeclampsia risk. Mediation models were applied to evaluate whether immune imbalance mediates the effect of vitamin D on preeclampsia. The findings are expected to provide mechanistic insight into how vitamin D status influences immune function during pregnancy and contributes to the pathogenesis of preeclampsia, offering potential targets for early prevention and intervention strategies.