Calcium and vitamin D3 supplementation prevents bone loss in the spine secondary to low-dose corticosteroids in patients with rheumatoid arthritis: a randomized, double-blind, placebo-controlled trial

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 [D.sub.3] 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 [D.sub.3] 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 [D.sub.3] (500 lU/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 [D.sub.3] 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 [D.sub.3] Calcium and vitamin [D.sub.3] did not improve bone mineral density at any site in patients who were not receiving corticosteroids. Conclusion: Calcium and vitamin [D.sub.3] prevented loss of bone mineral density in the lumbar spine and trochanter in patients with rheumatoid arthritis who were treated with low-dose corticosteroids.
Vitamin D3 and calcium treatments appear to increase bone formation at some sites in patients with rheumatoid arthritis treated with steroids. Bone formation is measured by bone mineral density. For two years 96 patients with rheumatoid arthritis took one of four treatments including prednisone, vitamin D3, and calcium; prednisone and placebo; vitamin D3, calcium, and placebo; or placebo alone. Bone mineral densities in the upper leg and lower spine increased by 0.85% and 0.72% in patients taking prednisone, calcium, and vitamin D3. These measurements decreased or did not change in the other treatment groups.