Pediatric Rheumatology Online Journal → June 2003 → Medical Treatment → Miscellaneous Medical Treatment→ Abstract #66
                                                                August 2003 → Bone → Abstract #66

CALCIUM AND VITAMIN D SUPPLEMENTATION IN CHILDREN WITH JUVENILE RHEUMATOID ARTHRITIS (JRA)

L. S. Hillman,¹ J. T. Cassidy.¹

¹Department of Child Health, University of Missouri, Columbia, MO, United State

Osteopenia is a consistent abnormality in children with JRA. In the current study, we evaluated the potentially beneficial effect of dietary calcium and vitamin D supplementation on bone mineralization, mineral homeostasis, and calcium absorption.
Methods: 16 patients with JRA, 8 - 15 years of age, received in random order daily supplements of 1000 mg calcium (Ca), 1600 IU vitamin D (D), 1000 mg calcium + 1600 IU vitamin D (Ca + D), or placebo (P) in a double-blind trial with each child receiving all four treatments sequentially. Each supplementation period lasted 6 months, followed by a 3-month washout. Biochemical assays and DEXA measurements (Hologic QDR-1000) were analyzed for significant changes (p0.05) from baseline. Calcium absorption was measured by a dual stable isotope method on a subset of subjects.
Results: The serum level of Ca decreased on P (-0.27 mg/dl) and increased on D (+0.47) and Ca +D (+0.94). Urinary Ca increased on Ca (+4.8 mg/dl) and Ca + D (+2.9). Serum 25-0HD increased only on D (+13.2 ng/ml) and Ca + D (+15.4). Serum 1,25(OH)²D increased on P (7.9 pg/ml) but decreased on D (-1.4) and Ca + D (-3.1). No changes were observed in PTH, bone alkaline phosphatase, osteocalcin or TRAP. Increases in whole body bone density (WBMD) were evident over 9 months on all treatments except P; however differences between supplementations could not be demonstrated. Calcium absorption appeared normal on all four supplements but differences may not have been evident due to the small sample size.
Conclusions: These data suggest that children with JRA absorb vitamin D and demonstrate increases in serum Ca and Mg with suppression of 1,25(OH)²D. Ca also appears to be normally absorbed by children with JRA. These data warrant longer treatment trials to establish efficacy.