title: Lung function, 25-hydroxyvitamin D concentrations and mortality in US adults.
abstract: OBJECTIVE
  To explore the associations between serum concentrations of vitamin D (25(OH)D) and all-cause mortality among US adults defined by lung function (LF) status, particularly among adults with obstructive LF (OLF).
  
  
  METHODS
  Data from 10,795 adults aged 20-79 years (685 with restrictive LF (RLF) and 1309 with OLF) who participated in the Third National Health and Nutrition Examination Survey (1988-1994), had a spirometric examination, and were followed through 2006 were included.
  
  
  RESULTS
  During 14.2 years of follow-up, 1792 participants died. Mean adjusted concentrations of 25(OH)D were 75.0 nmol/l (s.e. 0.7) for adults with normal LF (NLF), 70.4 nmol/l (s.e. 1.8) for adults with RLF, 75.5 nmol/l (s.e. 1.5) for adults with mild obstruction and 71.0 nmol/l (s.e. 1.9) among adults with moderate or worse obstruction (P=0.030). After adjustment for sociodemographic factors, lifestyle factors, clinical variables and prevalent chronic conditions, a concentration of <25 nmol/l compared with ⩾ 75 nmol//l was associated with mortality only among adults with NLF (hazard ratio (HR) 1.76; 95% confidence interval (CI) 1.03, 3.00). Among participants with OLF, adjusted HRs were 0.65 (95% CI 0.29, 1.48), 1.21 (95% CI 0.89, 1.66) and 0.97 (95% CI 0.78, 1.19) among those with concentrations <25, 25-<50 and 50-<75 nmol/l, respectively.
  
  
  CONCLUSIONS
  Baseline concentrations of 25(OH)D did not significantly predict mortality among US adults with impaired LF.
authors.affiliation: Division of Population Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: E S
authors.initials: ES
authors.lastname: Ford
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000097:blood / Q000473:pathology*; D002423:Cause of Death; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008173:Lung Diseases, Obstructive / Q000097:blood / Q000401:mortality* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys / Q000706:statistics & numerical data; D011237:Predictive Value of Tests; D012129:Respiratory Function Tests / Q000706:statistics & numerical data*; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D