Bones Needs Energy, Too

Previous laboratory studies indicate that an adequate energy supply might be as important to optimal bone formation as dietary calcium and vitamin D intake. Investigators studied the effects of energy intake, menstrual history, and serum hormones on bone mass and bone turnover in 39 female adolescent cross-country runners (mean age, 15.7 years) who had competed in a mean of four endurance running seasons. Participants completed a detailed assessment of diet, sports participation, and menstrual patterns and underwent measurements of bone density, bone turnover, serum hormones, and body composition. Serum biomarkers of bone turnover that exceeded the 97th percentile for age were considered elevated.

The 13 runners with elevated bone turnover (…