ABSTRACT Objective To investigate the link between serum 25‐hydroxyvitamin D 25(OH)D and obesity in postmenopausal women, and to evaluate the potential mediating effect of the atherogenic index of plasma (AIP). Methods In this cross‐sectional analysis, data from 3386 postmenopausal women were extracted from the National Health and Nutrition Examination Survey (2011–2018). Participants were stratified by vitamin D status: deficient (< 50 nmol/L), insufficient (50–75 nmol/L), and sufficient (≥ 75 nmol/L). Adjusted weighted regression models assessed associations with body mass index (BMI) and obesity (BMI ≥ 30 kg/m 2 ), while mediation analysis quantified the role of AIP. Results After comprehensive covariate adjustment, a significant inverse relationship was observed between serum 25(OH)D and BMI ( β = −2.36, 95% CI: −3.16, −1.55). Vitamin D deficient women exhibited a mean BMI increase of 1.98 units (95% CI: 0.96, 3.00) and an elevated odds of obesity (OR = 1.81, 95% CI: 1.30, 2.50) relative to the sufficient group. These findings were robust across demographic and clinical subgroups. Mediation analysis indicated AIP accounted for 9.53% of the association with BMI and 9.40% with obesity (both p < 0.001). Conclusion This study demonstrates a significant inverse association between vitamin D status and obesity in postmenopausal women, with lipid metabolism, as reflected by AIP, partially mediating this relationship. Further longitudinal research is required to establish causality.
Lu et al. (Fri,) studied this question.