title: Can a model predictive of vitamin D status be developed from common laboratory tests and demographic parameters?
abstract: OBJECTIVE
  Vitamin D deficiency is highly prevalent and has been linked to increased morbidity and mortality. There has been an increase in testing for vitamin D with a concomitant increase in costs. While individual factors are significantly linked to vitamin D status, prior studies have not yielded a model predictive of vitamin D status or 25(OH)D levels. The purpose of this investigation was to determine if a prediction model of vitamin D could be developed using extensive demographic data and laboratory parameters.
  
  
  METHODS
  Patient data from 6 Veterans Administration Medical Centers were extracted from medical charts.
  
  
  RESULTS
  For the 14,920 available patients, several factors including triglyceride level, race, total cholesterol, body mass index, calcium level, and number of missed appointments were significantly linked to vitamin D status. However, these variables accounted for less than 15% of the variance in vitamin D levels. While the variables correctly classified vitamin D deficiency status for 71% of patients, only 33% of those who were actually deficient were correctly identified as deficient.
  
  
  CONCLUSIONS
  Given the failure to find a sufficiently predictive model for vitamin D deficiency, we propose that there is no substitute for laboratory testing of 25(OH)D levels. A baseline vitamin D 3 daily replacement of 1000-2000 IU initially with further modification based on biannual testing appears to factor in the wide variation in dose response observed with vitamin D replacement and is especially important in high-risk groups such as ethnic minorities.
authors: Department of Internal Medicine, East Tennessee State University, Johnson City, TN 37614, USA. Peiris@etsu.edu
authors: Alan N
authors: AN
authors: Peiris
authors: Beth A
authors: BA
authors: Bailey
authors: Bhuvana N
authors: BN
authors: Guha
authors: Rebecca
authors: R
authors: Copeland
authors: Todd
authors: T
authors: Manning
mesh_terms: D002762:Cholecalciferol / Q000493:pharmacokinetics / Q000627:therapeutic use; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D015995:Prevalence; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D014481:United States / Q000453:epidemiology; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood* / Q000453:epidemiology / Q000517:prevention & control
chemical_list: D014807:Vitamin D; D002762:Cholecalciferol