SEATTLE—Vitamin D and calcium supplementation is commonly used to prevent bone loss after kidney transplantation, but new findings presented at the 2013 American Transplant Congress suggest that such supplementation may not work.
Knut T. Smerud, MSc, and colleagues at the University of Oslo in Norway studied 124 new kidney transplant recipients with early stable renal function, defined as a glomerular filtration rate of 30 mL/min/1.73 m2 or greater within the first 28 days post-transplantation. Of these, 63 received oral calcitriol 0.25 mcg/day (vitamin D3) and calcium 500 mg twice daily for 52 weeks and 61 did not. Patients in the control arm had a tendency toward lower baseline lumbar spine (L2-L4) bone mineral density (BMD) scores, with similar trends in other skeletal compartments.
The difference in change in L2-L4, femur, and ultradistal radius BMD score from baseline to 52 weeks between the intervention group and controls was not statistically significant. All patients preserved BMD throughout the year, however.
Based on the findings, Smerud said, the decision to prescribe calcitriol/calcium supplementation should be based on individual patient risk factors for bone loss.
The advent of better bone-sparing immunosuppressive protocols may in part explain why calcitriol/calcium supplementation had no added effect on BMD preservation, he said.
Smerud pointed out that that study was limited by its small sample size. He also noted that transplant recipients at his institution, which is the only transplantation center in Norway, stay in a hotel for three months following transplantation and undergo intensive exercise training, which could have attenuated bone loss.