Prevalence of hypovitaminosis D and the different-dose cholecalciferol supplementation effects on renal transplant recipients.

High prevalence of hypovitaminosis D has been observed in patients with chronic kidney disease. However, there is not much data about its prevalence in kidney transplant recipients (KTRs). The study included 83 adult KTRs at a single center to calculate the prevalence of hypovitaminosis D. Among the 83 patients, those with incomplete data were excluded leaving 22 patients available for study. The demographic and biochemical data were analyzed retrospectively. Serum concentrations of 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), phosphorus, calcium, and creatinine were evaluated. The 22 selected patients were divided into two groups: (1) those who received 10,000 IU of cholecalciferol orally per week, and (2) those who received 10,000-20,000 IU/week. The Vitamin D level rate was calculated to evaluate the time necessary to reach serum values ≥30 ng/mL. Hypovitaminosis D was present in 80.7% (67/83) of the patients. Eleven patients received 10,000 IU/week of cholecalciferol, and the other 11 patients received 10,000-20,000 IU/week (approximately 64,000 IU/month). The calcium, phosphorus, and PTH values did not show any differences between the two groups. We estimate that a dose of approximately 64,000 IU/month of cholecalciferol was sufficient to reach values of ≥30 ng/mL of 25(OH)D in approximately 2.1 months in the insufficient and 4.3 months in Vitamin D-deficient patients. The prevalence of hypovitaminosis D was high among Brazilian KTR, and low-level doses of cholecalciferol (approximately 64,000 IU/month) were sufficient to control hypovitaminosis D.