Dietary Calcium but Not Elemental Calcium from Supplements Is Associated with Body Composition and Obesity in Chinese Women

Objective: We assessed whether dietary calcium intake or calcium supplements associated with body composition and obesity in a Chinese population. Methods: A cross-sectional survey was performed in a population of 8940, aged 20 to 74 y. 8127 participants responded (90.9%). Height, weight, fat mass (FM), waist circumference (WC) and hip circumference were measured. Obesity definition: body mass index (BMI) >= 28 kg/m(2) (overall obesity); WC >= 85 cm for men or >= 80 cm for women (abdominal obesity I) and waist hip ratio (WHR) >= 0.90 for men or >= 0.85 for women (abdominal obesity %). The data on dietary calcium and calcium supplements were collected using food-frequency questionnaire and self-report questionnaire. Multivariate linear and multivariable logistic regressions were used to examine the associations between dietary calcium intake or calcium supplements and body composition and obesity. Principal Findings: The average dietary calcium intake of all subjects was 430 mg/d. After adjusting for potential confounding factors, among women only, negative associations were observed between habitual dietary calcium intake and four measures of body composition (beta, -0.086, P < 0.001 for BMI; beta, -0.072, P < 0.001 for WC; beta, -0.044, P < 0.05 for WHR; and beta, -0.058, P < 0.01 for FM, respectively) and both measures of abdominal obesity (Odds Ratio [OR] = 0.86, 95% Confidence Interval [CI], 0.80-0.93; P < 0.001, for abdominal obesity I; OR = 0.92, 95% CI, 0.86-0.99; P = 0.026, for abdominal obesity II). These associations were not observed among men (P > 0.05). Similarly, among both men and women, we did not observe significant associations between calcium supplements and any measures of body composition or abdominal obesity (P > 0.05). Conclusions: Dietary calcium from food rather than elemental calcium from calcium supplements has beneficial effects on the maintenance of body composition and preventing abdominal obesity in Chinese women.