title: Predicting deficiency of vitamin D in renal transplant recipients in northern climates.
abstract: BACKGROUND
  Renal transplant patients have been shown to have a higher risk of bone disease than the general population. The aim of this study was to examine vitamin D status, a modifiable risk factor in bone disease, in the renal transplant population in a northern climate.
  
  
  METHODS
  This retrospective observational study included 331 subjects and analyzed demographic, biochemical, and medication information for associations with vitamin D.
  
  
  RESULTS
  Of the study population, 45.3% were vitamin D deficient. The percentage of deficient subjects increases to 76.5% if those receiving supplementation are excluded. The mean daily dose of vitamin D was 1275 IU for sufficient patients. For every 1000 IU of vitamin D daily, the risk of deficiency is decreased by 40.3%. Time from transplantation had a significant positive association (P<0.001) in which every year out of transplantation decreased the risk of deficiency by 9.1%. Body mass index had a significant negative association (P=0.012) with vitamin D in which the risk of deficiency increased by 6% for each kilogram per meter squared. Ethnicity was found to be statistically significant on univariate analysis (P=0.034), with white patients having 9.1% decreased risk of deficiency.
  
  
  CONCLUSIONS
  Despite a high rate of supplementation of vitamin D, close to half of the renal transplant population was still deficient. Those who were receiving over 1000 IU daily were more likely to be vitamin D sufficient. Early supplementation after transplantation along with higher doses for non-white patients or patients with a high body mass index may be warranted for normalization of vitamin D status.
authors.affiliation: Alberta Health Services-Calgary Zone, Pharmacy Services, Southern Alberta Transplant Program, Calgary, Alberta, Canada. Lesley.Beique@albertahealthservices.ca
authors.forename: Lesley C
authors.initials: LC
authors.lastname: Beique
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Kline
authors.forename: Bruce
authors.initials: B
authors.lastname: Dalton
authors.forename: Kimberly
authors.initials: K
authors.lastname: Duggan
authors.forename: Serdar
authors.initials: S
authors.lastname: Yilmaz
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001847:Bone Diseases / Q000453:epidemiology* / Q000209:etiology; D002980:Climate; D019587:Dietary Supplements; D005260:Female; D005843:Geography; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D051437:Renal Insufficiency / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D013472:Sunlight; D014807:Vitamin D / Q000627:therapeutic use; D014808:Vitamin D Deficiency / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology*
chemical_list: D014807:Vitamin D