Huang H, Guo J, Chen Q, et al. - In this cross-sectional study of 616 postmenopausal women (aged 49-86 y) from southern China, the association between estradiol (E₂) and 25-hydroxyvitamin-D [25(OH)D] with metabolic syndrome (MetS) and its components was examined. The women were assessed for serum E₂ and 25(OH)D measures. The analysis revealed a positive correlation between 25(OH)D and E₂. A favorable lipid profile, blood pressure, and glucose level were observed in association with higher 25(OH)D. A negative correlation of E₂ with cholesterol, triglycerides, and blood pressure was evident. Deficient vs sufficient women had the odds ratio for MetS of 2.19 after multivariable adjustment. After stratified analysis by VitD status, women with VitD deficiency had increased MetS risk in correlation with low E₂. Findings thereby indicate a synergistic role of VitD and E₂ deficiency in MetS in Chinese postmenopausal women.