Abstract
Objective
To examine the effects of daily supplementation with calcium (Ca) in combination with vitamin D on total body and lumbar spine bone mineral density (BMD) in patients with juvenile rheumatoid arthritis (JRA) who had not taken corticosteroids for at least 3 months prior to the beginning of the study.
Methods
One hundred ninetyโeight children and adolescents (141 girls and 57 boys) with JRA, ages 6 to 18 years, with a mean ยฑ SD age of 11.7 ยฑ 3.3 years and a mean ยฑ SD disease duration of 5.6 ยฑ 3.8 years at the beginning of the study, were enrolled in this randomized doubleโblind, placeboโcontrolled trial to receive either daily oral supplements of 1,000 mg of Ca and 400 IU of vitamin D (n = 103) or matched placebo tablets and 400 IU of vitamin D (n = 95) for 24 months. Total body BMD (TBBMD) was measured by dual xโray absorptiometry at baseline and every 6 months for 24 months.
Results
At baseline, the mean ยฑ SD TBBMD was 0.89 ยฑ 0.14 gm/cm^2^ among patients randomized to the Ca group and 0.87 ยฑ 0.14 gm/cm^2^ among those randomized to placebo (P = 0.445). At 24 months, the mean ยฑ SD TBBMD among those receiving Ca was 0.95 ยฑ 0.13 gm/cm^2^, compared with 0.92 ยฑ 0.14 gm/cm^2^ among those receiving placebo. A longitudinal randomโeffects mixed model analysis that controlled for differences in the subject's initial BMD, sex, Tanner stage, adherence to the study medication regimen, and body composition revealed significantly higher TBBMD among patients who received Ca compared with patients who received placebo during the study period (P = 0.03).
Conclusion
Ca supplementation resulted in a small, but statistically significant, increase in TBBMD compared with placebo in children with JRA.