Kidney transplant recipients usually have low vitamin D levels, especially in the early
posttransplantation period, but the association between vitamin D status with renal
outcomes is not well described in this population. Here, we studied a prospective
cohort of 634 kidney recipients who underwent transplantation at a single institution
between January 2005 and June 2010. In this cohort, low 25-hydroxyvitamin D
concentrations 3 months after transplantation did not predict early death or graft loss
but were independently associated with lower measured GFR at 12 months
(P=0.001) and higher risk for interstitial fibrosis and tubular atrophy (P=0.01). In
contrast, levels of calcium, phosphorus, calcitriol, parathyroid hormone, or fibroblast
growth factor-23 were not consistently associated with any of the studied outcomes.
In conclusion, low 25-hydroxyvitamin D concentration measured 3 months after
transplantation is an independent risk factor for interstitial fibrosis progression and is
associated with a lower GFR 1 year after transplantation
COMMENTS
In this large prospective observational study of patients who had recently received a
kidney transplant, low 25(OH)D levels 3 months after transplantation were
independently associated with reduced mGFR 9 months later.
In this large prospective observational study of patients who had recently received a
kidney transplant, low 25(OH)D levels 3 months after transplantation were
independently associated with reduced mGFR 9 months later. In contrast, other
hormones implicated in mineral metabolism, including 1,25(OH)D, PTH, and FGF-23,
were not independent predictors of 12-month mGFR or interstitial/fibrous atrophy
(IF/TA) progression.
Cholecalciferol supplementation is a safe way to increase 25(OH)D concentrations in
kidney transplant recipients. The results of this study should encourage randomized
controlled trials evaluating the effect of early cholecalciferol supplementation on renal
allograft function.
Pr. Jacques CHANARD
Professor of Nephrology