ENDOCRINE, cilt.91, sa.1, 2026 (SCI-Expanded, Scopus)
Purpose: We aimed to investigate the associations of serum vitamin D and parathyroid hormone (PTH) with body composition parameters, including bone weight and mineral content, in obese premenopausal and postmenopausal women. Methods: In this retrospective study, 200 pre-menopausal and 200 post-menopausal obese women were evaluated. Body composition was assessed using a bioelectrical impedance analyzer (TANITA-48M), and biochemical parameters were measured by standard laboratory methods. Results: The mean serum vitamin D level was significantly lower in pre-menopausal women compared with post-menopausal women (16.91 ± 13.17 vs. 22.59 ± 16.49 ng/mL, p < 0.05). Overall, 83.75% (n = 335) of the study population had vitamin D deficiency or insufficiency, while only 16.25% (n = 65) demonstrated normal vitamin D levels. BMI did not differ significantly between the two groups (p > 0.05). In pre-menopausal women, serum vitamin D levels were negatively correlated with PTH and mineral content. In post-menopausal women, vitamin D levels showed a negative correlation with BMI, body weight, body fat percentage, and PTH (p < 0.05). Conclusions: The prevalence of hypovitaminosis D was remarkably high (83.75%) among obese women. Moreover, declining vitamin D levels were associated with increased body weight and adiposity, as well as elevated PTH.