http://onlinelibrary.wiley.com/doi/10.1111/ajt.12738/abstract

Vitamin D in Renal Transplantation – from Biological Mechanisms to Clinical Benefits
R. McGregor1,2,†, G Li1,†, H Penny1, G Lombardi1,2, B. Afzali1,2,3,† andD.J. Goldsmith1,2,3,†,*
DOI: 10.1111/ajt.12738
American Journal of Transplantation
Volume 14, Issue 6, pages 1259–1270, June 2014

Abstract
Recent developments in our understanding of vitamin D show that it plays a significant role in immunological health, uniquely occupying both an anti-microbial and immunoregulatory niche. Vitamin D deficiency is widespread amongst renal transplant recipients (RTRs), thus providing one patho-mechanism that may influence the achievement of a successful degree of immunosuppression. It may also influence the development of the infectious, cardiovascular and neoplastic complications seen in RTRs. This review examines the biological roles of vitamin D in the immune system of relevance to renal transplantation (RTx) and evaluates whether vitamin D repletion may be relevant in determining immunologically-related clinical outcomes in RTRs, (including graft survival, cardiovascular disease and cancer). While there are plausible biological and epidemiological reasons to undertake vitamin D repletion in RTRs, there are few randomized-controlled trials in this area. Based on the available literature, we cannot at present categorically make the case for routine measurement and repletion of vitamin D in clinical practice but we do suggest that this is an area in urgent need of further randomized controlled level evidence.