Vitamin D after Kidney Transplantation: Metabolism and Clinical Importance

Vitamin D (VD) is a key factor in calcium-phosphorus metabolism. In addition, it has increasing popularity due to its pleiotropic effects: renal protection, antineoplastic properties, and diabetes mellitus and hypertension control. The VD axis is severely impaired in chronic kidney disease. The changes are present even in the earliest stages and progress as kidney function worsens. Significant changes in VD occur after successful kidney transplantation, as different factors interplay, leading to widespread VD insufficiency in kidney transplant recipients. The aim of our review is to demonstrate the changes in VD metabolism after kidney transplantation and to reveal their full impact on graft and patient survival in the post-transplant setting. Furthermore, current strategies for VD supplementation and their efficacy will be discussed.