Obesity augments calcium-induced increases in skeletal calcium retention in adolescents

Abstract

Context: Overweight adolescents have low bone mineral content for weight and are at increased risk for fractures. Objective: The aim was to determine whether overweight and obesity influence the positive relationship between dietary calcium intake and skeletal calcium retention in adolescents. Design: Analysis of pooled data from calcium balance studies in adolescents. Setting: Participants each underwent a 3-wk calcium balance study in a controlled environment. Participants: Participants included 280 White, Black, and Asian boys (n=73) and girls (n=207) ages 10-16 yr. Main Outcome Measure: The relationship among body mass index (BMI), calcium intake, and calcium retention was modeled using linear regression. Results: Calcium intake, BMI, sex, race, and age explained 27.9% of the variation in calcium retention. At low calcium intakes, there was no effect of BMI on skeletal calcium retention, but at higher calcium intakes, BMI increased skeletal calcium retention. Conclusions: Greater gains in calcium retention occur with increases in calcium intake in adolescents with higher BMI compared with those with lower BMI. Additional studies are needed to investigate whether increasing calcium intake reduces the increased risk of fracture associated with overweight and obesity in adolescents. Copyright © 2011 by The Endocrine Society.