25-hydroxyvitamin D deficiency in kidney transplant recipients

INTRODUCTION. After kidney transplantation, patients appear to have vitamin D deficiency due to the use of immunosuppressive treatment and prevention of sunlight. This study was designed to determine vitamin D serum levels in kidney transplant patients in comparison with healthy individuals. MATERIALS AND METHODS. Forty-six kidney transplant patients with a creatinine clearance greater than 60 mL/min and 46 healthy individuals with normal kidney function were tested for serum levels of calcium, phosphorus, 25-hydroxyvitamin D, and parathyroid hormone at the end of the summer. RESULTS. Thirty-one participants were men and 15 were women in each group. The mean age was 41.0 ± 14.2 years in kidney transplant recipients and 41.4 ± 13.7 years in the control group. Inadequate serum 25-hydroxyvitamin D was seen in 93.5% of the transplant patients and in 89.1% of the controls. There was a 26.1% [corrected] vitamin D insufficiency (20 ng/mL to 30 ng/mL) and a 67.4% [corrected] deficiency (lower than 20 ng/mL) in the patients, and these rates were 21.7% [corrected] and 67.4% [corrected] in the control group, respectively. There was no significant difference between the two groups. CONCLUSIONS. Vitamin D deficiency is prevalent in kidney transplant patients. Lack of a significant difference between our two groups may be attributable to the high prevalence of vitamin D deficiency in general population and the use of vitamin D supplementation in transplant patients. Indeed, adequate doses of vitamin D in these patients are undetermined. They may need higher doses for normalization of serum vitamin D and metabolic requirements.