Vitamin D Deficiency in Kidney Transplant Recipients: Risk Factors and Effects of Vitamin D3 Supplements

Introduction. The Kidney Disease Outcome Quality Initiative (K/DOQI) clinical practice guidelines in chronic kidney disease (CKD) give some recommendations about diagnosis and treatment of vitamin D deficiency. These guidelines may also be applied to renal transplant recipients. The aim of the present study was to assess the vitamin D status and the effects of vitamin D3 supplements among a cohort of kidney graft recipients. Patients and Methods. Five hundred nine renal transplant recipients with a follow-up of more than 12 months were included in this retrospective cross-sectional study. A total of 189 patients were treated with vitamin D3 supplements, 171 with calcitriol (0.25 or 0.5 mu g X 3 weekly) and 18 with cholecalciferol (400 IU/d). Results. 25OHD deficiency was present in 38.3% of patients, insufficiency in 46.9%, and normal levels in 1.4.7%. There were no differences in the prevalence of deficiency or insufficiency between patients who were not treated or those who were treated with vitamin D3 supplements. Upon multivariate analysis, 25OHD concentrations correlated with gender, length of follow-up, season of 25OHD determination, iPTH and 1.25OHD concentrations, and treatment with ACEI/ARB (R-2 = 0.17; P = .000). Conclusions. 25OHD deficiency or insufficiency is frequent after renal transplantation even in sunny regions. The clinical significance of such a high prevalence of apparent 25OHD deficiency/insufficiency is unclear and requires further study.