Calcium Supplements for Bone Health in Juvenile Rheumatoid Arthritis

This study looks at the effects of taking calcium pills on bone health in young people with juvenile rheumatoid arthritis (JRA). In this 2-year study, children aged 6-18 who have JRA will take either a calcium supplement or a matching placebo (inactive or "dummy" pill) containing no calcium. During the study, researchers and patients will not know if a patient is taking calcium or placebo. We believe that patients who take calcium supplements will have at least a 10 percent greater increase in total body bone mineral density compared to patients who take the placebo. We will evaluate patients at Children's Hospital Medical Center every 6 months for 2 years. During this 2-year period, participants in the study will take one multivitamin containing 400 IU (international units) of vitamin D and either 1,000 mg of calcium carbonate (Tums tablets) by mouth or a matching placebo once a day. We will check patients 6 and 18 months after the 2-year treatment period to find out if people in the Tums-treated group maintain any increases in bone formation that occurred during the 2-year treatment period.