Vitamin D status in kidney transplant patients: need for intensified routine supplementation

Am J Clin Nutr. 2008 Feb;87(2):431-7. doi: 10.1093/ajcn/87.2.431.


Background: A high prevalence of vitamin D insufficiency has been found in the general population and in patients with chronic kidney disease.

Objective: The aim was to examine vitamin D status and determinants and metabolic correlates of serum 25-hydroxyvitamin D in a population of adult Danish kidney transplant patients.

Design: This was a cross-sectional study of 173 adult kidney transplant patients with a mean (+/-SD) age of 53.4 +/- 11.7 y and a median graft age of 7.4 y (interquartile range: 3.3-12.7 y). Serum concentrations of intact parathyroid hormone (S-PTH), 25-hydroxyvitamin D [S-25(OH)D], and 1,25-dihydroxyvitamin D [S-1,25(OH)(2)D] were measured. Dietary and supplementary intake of vitamin D, avoidance of solar ultraviolet B exposure, and selected lifestyle factors were assessed in a subgroup (n = 97).

Results: Fifty-one percent of the patients had vitamin D insufficiency [S-25(OH)D 40-75 nmol/L], and an additional 29% had moderate-to-severe vitamin D deficiency [S-25(OH)D < or = 39 nmol/L]. In multiple regression analysis, sun avoidance (negative association) and vitamin D supplementation (positive association) were independent determinants of S-25(OH)D concentrations. Low S-25(OH)D concentrations were associated with 1) increased S-PTH concentrations (P = 0.0002), independently of S-1,25(OH)(2)D concentrations, and 2) decreased S-1,25(OH)(2)D concentrations (P = 0.002), independently of graft function.

Conclusions: Hypovitaminosis D is common among Danish kidney transplant patients and is associated with reduced concentrations of S-1,25(OH)(2)D and increased S-PTH concentrations. Sun avoidance and vitamin D supplementation are important determinants of vitamin D status. The observed hypovitaminosis D might be corrected by intensified routine vitamin D supplementation as opposed to the current supplementation practice.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Calcium, Dietary / administration & dosage
  • Cross-Sectional Studies
  • Denmark / epidemiology
  • Dietary Supplements*
  • Female
  • Humans
  • Kidney Transplantation*
  • Life Style
  • Male
  • Middle Aged
  • Prevalence
  • Regression Analysis
  • Sunlight
  • Vitamin D / administration & dosage*
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood
  • Vitamin D Deficiency / blood
  • Vitamin D Deficiency / epidemiology*


  • Calcium, Dietary
  • Vitamin D
  • 25-hydroxyvitamin D