(P24-058-24) Vitamin D Status, Anthropometry, and Body Composition in Women of Reproductive Age

Objectives: To examine vitamin D status and its associations with anthropometry and body composition in women as part of a population-based biomarker survey in Southern India.

Methods: We examined associations of vitamin D status with anthropometry and body composition in women 15-40 y who were not pregnant or lactating (n=980). Plasma 25-hydroxyvitamin D₃ (25[OH]D₃; vitamin D; n=704) concentrations were evaluated in archived samples using liquid chromatography-mass spectrometry (LC-MS). Anthropometric measurements (including weight, height, waist, and hip circumferences) were collected using standardized protocols in triplicate. Bioelectrical impedance analysis was used to evaluate whole body (WF) and trunk (TF) percent fat mass in adults (≥18 y; n=665). Vitamin D deficiency and insufficiency were defined as 25[OH]D₃ < 30 and < 50 nmol/L, respectively. Vitamin D concentrations were natural logarithmically transformed prior to analyses. Linear and binomial regression models were used to examine associations of vitamin D status with anthropometric and body composition outcomes.

Results: A total of 18.2% of women had vitamin D concentrations < 30 nmol/L, and 65.8% had vitamin D concentrations < 50 nmol/L (Geometric mean [95% Confidence Interval (CI)]) 41.5 [40.2-42.8] nmol/L). Higher continuous naturally logarithmically transformed vitamin D was associated with lower WF (β [standard error (SE)]: -3.42 [0.90]) and TF (-4.20 [1.10]) in multivariable analyses, adjusted for age, employment, gravidity, and marital status. Women with vitamin D concentrations < 50 nmol/L had higher WF (2.20 [0.70]) and higher TF (2.76 [0.86]), compared to women with vitamin D concentrations < 50 nmol/L, in multivariable analyses adjusted for age, gravidity and marital status. Vitamin D status was not significantly associated with anthropometric measurements, including waist circumference, hip circumference, or waist-to-hip ratio.

Conclusions: The prevalence of vitamin D deficiency and insufficiency was substantial in this population. Lower vitamin D status was associated with some indicators of increased central adiposity.

Funding Sources: Centers for Disease Control and Prevention, University of South Carolina Disability Research and Dissemination Center; Fulbright-ANID (XEPM); NIH 5T32HD087137 (AF); NIH T32DK007158 (HMG)