Background/Aim. Posttransplant steroid doses have been reduced with the use of new and potent immunosuppressive agents. However, posttransplant osteoporosis is still a serious problem. Our aim in this study was to investigate the effect of low-dose cholecalciferol and calcium supplementation on bone loss after transplantation in renal transplant patients. Methods. Fifty-eight renal transplantation patients were included in the study. Fourteen newly transplanted patients (group 1) and 44 renal transplantation patients with a graft age of at least six months (group 2) were involved. All patients received 400 IU/day orally cholecalciferol (vitamin D3) and 600 mg/day orally calcium replacement starting from the second day posttransplantion. All patients baseline serum and urine biochemistry, serum 25-hydroxy vitamin D3 (25 (OH)D3), and bone mineral density (BMD) tests were performed. Also, the same measurements were performed at the 12th month in group 1. Results. After one year of treatment, BMDs were improved in group 1. Patients in group 1 had a nonsignificant increase of lumbar spine (8.12 18.64% of baseline BMD) and femoral total (7.10 13.48% of baseline BMD) BMD at the end of the first year. On the other hand, there was a significant increase in femoral neck (10.06 15.70% of baseline BMD, p 0.05) measurements. The baseline results of group 2 were similar to group 1. In group 1, 25 (OH)D3 levels were increased while PTH levels were decreased at the end of the year. Conclusion. In renal transplant patients who use low-dose metilprednisolon and new immunosuppressive agents together, low doses of vitamin D3 and calcium replacement for one year provides a reduction in lumbar spine, femoral neck, and femoral total bone loss and prevents bone loss in group 2. In addition, it contributed to the normalization of PTH levels.