Ca is the major mineral in bone, and 99% of the Ca in the body resides in the skeleton. Skeletal mass is a determinant of risk of fracture in childhood as well as adulthood. Over 40% of adult peak bone mass is acquired during adolescence. This period is when lifestyle choices, including ensuring adequate dietary Ca, regular weight-bearing exercise and avoiding hormonal insufficiency, are especially important. Current Ca intakes for adolescent females are woefully inadequate.