25-hydroxyvitamin D deficiency in renal transplant recipients

J Clin Endocrinol Metab. 2006 Feb;91(2):526-9. doi: 10.1210/jc.2005-0547. Epub 2005 Nov 22.


Context: Bone disease after kidney transplantation is a common problem. The serum levels of the active vitamin D metabolite 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D] have been studied extensively. In contrast, there has not been much concern about the serum levels of 25-hydroxyvitamin D(3) [25(OH)D]. However, it is well recognized that serum levels of 1,25(OH)(2)D are often normal in vitamin D-deficient patients. Moreover, inadequate serum 25(OH)D may limit the extrarenal production of 1,25(OH)(2)D that could lead to increased risk of many chronic diseases.

Objective: We analyzed whether renal transplant patients were at a higher risk of 25(OH)D deficiency because of the consequence of their need to protect themselves from sun exposure.

Design, setting, and patients: We hypothesized that renal transplant recipients are at high risk to develop 25(OH)D deficiency. Serum 25(OH)D levels were analyzed in renal transplant patients with adequate renal function and in an age- and gender-matched control group (n = 31) at the end of winter. All renal transplant patients practiced solar UV-protection after transplantation. 25(OH)D levels were compared using a nonparametrical test (Wilcoxon rank sum test).

Results: Serum 25(OH)D levels were significantly lower in renal transplant patients compared with controls (P = 0.007). Geometric mean (with 95% confidence interval) in renal transplant patients was 10.9 ng/ml (8.2-14.3) compared with 20.0 ng/ml (15.7-25.5) in the control group.

Conclusions: Renal transplant recipients are at high risk to develop 25(OH)D deficiency. Treatment with vitamin D is recommended to correct their vitamin D deficiency, which may help protect them from serious vitamin D deficiency-related health problems that include an increased risk for internal malignancies.

MeSH terms

  • Adult
  • Aged
  • Creatinine / blood
  • Female
  • Humans
  • Kidney Transplantation / adverse effects*
  • Male
  • Middle Aged
  • Parathyroid Hormone / blood
  • Seasons
  • Statistics, Nonparametric
  • Sunlight
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood
  • Vitamin D Deficiency / blood
  • Vitamin D Deficiency / etiology*


  • Parathyroid Hormone
  • Vitamin D
  • 25-hydroxyvitamin D
  • Creatinine