Vitamin D as a risk factor for patient survival after kidney transplantation: A prospective observational cohort study

Background Short-term survival after kidney transplantation is excellent, but long-term survival remains low and is equivalent to non-end-stage renal disease patients with many invasive malignancies. The aim of the study was to explore vitamin D status in the early phase after transplantation as a prognostic marker for long-term graft and patient survival. Methods All first-time kidney transplant recipients between October 2007 and October 2012 in Norway were included. Vitamin D was measured 10 weeks post-transplant. Information on graft failure and death was obtained from the Norwegian Renal Registry. Results Seven hundred and sixty-two first-time kidney transplant recipients were included, with a median age of 57 years and a median follow-up of 82 months. In the follow-up period, there were 172 graft failures (23%) and 118 deaths (15%). Eighty-six percent of the transplant recipients with sufficient vitamin D levels were alive with a well-functioning graft after 5 years using Kaplan-Meier survival estimates, compared with 79% and 76% of the patients with vitamin D deficiency and insufficiency, respectively (P = 0.006). Conclusion In a nation-wide cohort of 762 first-time kidney transplant recipients, long-term graft and patient survival were better in recipients with vitamin D sufficiency 10 weeks post-transplant compared with those with vitamin D deficiency and insufficiency.