title: Comparisons of serum vitamin D levels, status, and determinants in populations with and without chronic kidney disease not requiring renal dialysis: a 24-hour urine collection population-based study.
abstract: OBJECTIVE
  Vitamin D deficiency is frequent in the general population and might be even more prevalent among populations with kidney failure. We compared serum vitamin D levels, vitamin D insufficiency/deficiency status, and vitamin D level determinants in populations without chronic kidney disease (CKD) and with CKD not requiring renal dialysis.
  
  
  METHODS
  This was a cross-sectional, multicenter, population-based study conducted from 2010 to 2011. Participants were from 10 centers that represent the geographical and cultural diversity of the Swiss adult population (≥15 years old).
  
  
  METHODS
  CKD was defined using estimated glomerular filtration rate and 24-hour albuminuria. Serum vitamin D was measured by liquid chromatography-tandem mass spectrometry. Statistical procedures adapted for survey data were used.
  
  
  METHODS
  We compared 25-hydroxy-vitamin D (25(OH)D) levels and the prevalence of vitamin D insufficiency/deficiency (serum 25(OH)D < 30 ng/mL) in participants with and without CKD. We tested the interaction of CKD status with 6 a priori defined attributes (age, sex, body mass index, walking activity, serum albumin-corrected calcium, and altitude) on serum vitamin D level or insufficiency/deficiency status taking into account potential confounders.
  
  
  RESULTS
  Overall, 11.8% (135 of 1,145) participants had CKD. The 25(OH)D adjusted means (95% confidence interval [CI]) were 23.1 (22.6-23.7) and 23.5 (21.7-25.3) ng/mL in participants without and with CKD, respectively (P = .70). Vitamin D insufficiency or deficiency was frequent among participants without and with CKD (75.3% [95% CI 69.3-81.5] and 69.1 [95% CI 53.9-86.1], P = .054). CKD status did not interact with major determinants of vitamin D, including age, sex, BMI, walking minutes, serum albumin-corrected calcium, or altitude for its effect on vitamin D status or levels.
  
  
  CONCLUSIONS
  Vitamin D concentration and insufficiency/deficiency status are similar in people with or without CKD not requiring renal dialysis.
authors.affiliation: Unit of Population Epidemiology, Division of Primary Care, Department of Community Medicine, Primary Care and Emergency Medicine, Geneva University Hospitals, Geneva, Switzerland; Community Prevention Unit, University Institute of Social and Preventive Medicine, Lausanne, Switzerland; Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia. Electronic address: idris.guessous@hcuge.ch.
authors.forename: Idris
authors.initials: I
authors.lastname: Guessous
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia.
authors.forename: William
authors.initials: W
authors.lastname: McClellan
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia.
authors.forename: David
authors.initials: D
authors.lastname: Kleinbaum
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia.
authors.forename: Viola
authors.initials: V
authors.lastname: Vaccarino
authors.affiliation: Food Safety and Veterinary Office, Bern, Switzerland.
authors.forename: Otmar
authors.initials: O
authors.lastname: Zoller
authors.affiliation: Unit of Population Epidemiology, Division of Primary Care, Department of Community Medicine, Primary Care and Emergency Medicine, Geneva University Hospitals, Geneva, Switzerland.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Theler
authors.affiliation: Community Prevention Unit, University Institute of Social and Preventive Medicine, Lausanne, Switzerland.
authors.forename: Fred
authors.initials: F
authors.lastname: Paccaud
authors.affiliation: Service of Nephrology and Hypertension, Lausanne University Hospitals, Lausanne, Switzerland.
authors.forename: Michel
authors.initials: M
authors.lastname: Burnier
authors.affiliation: Community Prevention Unit, University Institute of Social and Preventive Medicine, Lausanne, Switzerland.
authors.forename: Murielle
authors.initials: M
authors.lastname: Bochud
mesh_terms: D000293:Adolescent; D000328:Adult; D000419:Albuminuria / Q000652:urine; D015992:Body Mass Index; D002118:Calcium / Q000097:blood; D002853:Chromatography, Liquid; D003404:Creatinine / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009752:Nutritional Status; D015995:Prevalence; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000150:complications; D012709:Serum Albumin / Q000378:metabolism; D013472:Sunlight; D013557:Switzerland; D053719:Tandem Mass Spectrometry; D059349:Urine Specimen Collection / Q000379:methods*; D014807:Vitamin D / Q000008:administration & dosage / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D012709:Serum Albumin; D014807:Vitamin D; D003404:Creatinine; D002118:Calcium