Comparison between the Effects of Calcitriol and Cholecalciferol on Bone Mineral Density of Renal Transplant Patients

Abstract

Background: Vitamin D and its analogues are a part of preventing rapid bone loss after kidney transplantation. According to difference in cost of active and inactive forms of vitamin D, we decided to compare the effects of these drugs on bone mineral density (BMD) of kidney transplant patients. Methods: In a randomized, controlled, clinical trial, 37 kidney transplant patients were treated with vitamin D plus calcium or calcitriol plus calcium carbonate for one year. Drug dose in both groups was changing according to serum calcium and 24-hour urine calcium. BMD was measured before and one year after transplantation. Serum calcium and phosphorus were checked monthly. Serum parathyroid hormone (PTH) and alkaline phosphatase (ALKP) levels were checked before transplantation and every six months. Glomerular filtration rate (GFR) and 24-hour urine calcium were measured every three months. Findings: In the vitamin D group, T and Z scores in lumbar spine and hip were increased. However, in the calcitriol group, the scores decreased in lumbar spine and increased hip. The increment in Z scores of lumbar spine in vitamin D group and the difference between Z scores of the two groups were significant (P = 0.03). In both groups, PTH and ALKP decreased significantly. In the calcitriol group, 24 h urine calcium increased significantly (P = 0.01). Conclusion: Compared to calcitriol, vitamin D-calcium is cheaper and more effective on BMD. Therefore, we recommend the use of vitamin D-calcium in kidney transplant patients. Keywords: Kidney transplantation, Vitamin D3, Calcitriol, Bone mineral density