Calcium and calcitriol prophylaxis attenuates posttransplant bone loss

We performed a prospective, randomized, double-blind study to determine whether calcium and calcitriol prevents posttransplant bone loss. Thirty-eight nondiabetic and 26 diabetic patients without prior steroid exposure undergoing their first kidney or kidney-pancreas transplant were randomized to calcium, calcium plus calcitriol, or placebo. Lumbar spine (LS), femoral neck (FN), and distal radius (DR) bone mineral density scans (BMDs) were obtained at baseline, 6, and 12 months. At 1 year, patients treated with placebo experienced a 2% decline in BMD at the LS and DR and a 1.3% increase at the FN. In contrast, patients treated with calcium and vitamin D had a 0.1% decline at the LS and 2.9% and 4.8% increases at the DR and FN, respectively. Patients receiving cyclosporine had more bone loss than those receiving tacrolimus. Our results demonstrate a small therapeutic effect of calcium and calcitriol and suggest that tacrolimus is less osteotoxic than cyclosporine.