Background: Therapy with low-dose corticosteroids is commonly used to treat allergic and autoimmune diseases. Long-term use of corticosteroids can lead to loss of bone mineral density and higher risk for vertebral fractures. Calcium and vitamin D3 supplementation is rational therapy for minimizing bone loss, but little evidence for its effectiveness exists.
Objective: To assess 1) the effects of supplemental calcium and vitamin D3 on bone mineral density of patients with rheumatoid arthritis and 2) the relation between the effects of this supplementation and corticosteroid use.
Design: 2-year randomized, double-blind, placebo-controlled trial.
Setting: University outpatient-care facility.
Patients: 96 patients with rheumatoid arthritis, 65 of whom were receiving treatment with corticosteroids (mean dosage, 5.6 mg/d).
Intervention: Calcium carbonate (1000 mg/d) and vitamin D3 (500 IU/d) or placebo.
Measurements: Bone mineral densities of the lumbar spine and femur were determined annually.
Results: Patients receiving prednisone therapy who were given placebo lost bone mineral density in the lumbar spine and trochanter at a rate of 2.0% and 0.9% per year, respectively. Patients receiving prednisone therapy who were given calcium and vitamin D3 gained bone mineral density in the lumbar spine and trochanter at a rate of 0.72% (P = 0.005) and 0.85% (P = 0.024) per year, respectively. In patients receiving prednisone therapy, bone mineral densities of the femoral neck and the Ward triangle did not increase significantly with calcium and vitamin D3. Calcium and vitamin D3 did not improve bone mineral density, at any site in patients who were not receiving corticosteroids.
Conclusion: Calcium and vitamin D3 prevented loss of bone mineral density in the lumbar spine and trochanter in patients with rheumatoid arthritis who were treated with low-dose corticosteroids.