Monthly during the intervention trial, the study coordinator will contact all participants by phone in a blinded fashion to increase compliance and encourage continued participation in the trial. We will evaluate participants 6 and 18 moths after the end of the intervention trial. At each of these visits, we will obtain the following: general and medication history, general and joint physical exam, Tanner Stage, anthropometric measurements, blood for minerals and calcitropic hormones, 24-hour urine collection for measurements of bone turnover markers and mineral excretion, JAFAR, physical activity questionnaire, and total body and lumbar spine DXA scans. The YAQ and 3-day diet diary will be completed at the 42-month visit. Prior to every DXA scan, we will do a urine pregnancy test in all menstruating females to ensure that they are not pregnant. Any patient who withdraws from the blinded portion of the study early will complete an evaluation as outlined for the 24 months visit. Patients who withdraw early during the open phase of the study will complete the 42 months evaluation.