title: Age, race and season predict vitamin D status in African American and white octogenarians and centenarians.
abstract: OBJECTIVE
  Poor vitamin D status has been associated with osteoporosis, falls, cardiovascular diseases, cancer, autoimmune diseases, pain, nursing home placement, and other age-related conditions, but little is known about the prevalence and predictors of vitamin D status in those aged 80 and older. Thus, this study tested the hypothesis that vitamin D status would be 1) poorer in a population-based multi-ethnic sample of centenarians as compared with octogenarians and 2) predicted by specific dietary, demographic or environmental factors.
  
  
  METHODS
  Cross-sectional population-based analyses.
  
  
  METHODS
  Northern Georgia in the United States.
  
  
  METHODS
  Men and women aged 80 to 89 (octogenarians, n=80) and 98 and older (centenarians, n=237).
  
  
  METHODS
  Regression analyses were used to examine the associations of serum 25-hydroxyvitamin D [25(OH)D] with age, gender, race, living arrangements, dairy food intake, supplement intake, and season.
  
  
  RESULTS
  The prevalence of vitamin D insufficiency [25(OH)D<50 nmol/L] was higher in centenarians than in octogenarians (p<0.02). In logistic regression analyses, the risk of being vitamin D insufficient was significantly increased by being a centenarian vs. octogenarian (p<0.005) and by being African American vs. white (p<0.001) and decreased by taking a supplement with vitamin D (p<0.001) or by having vitamin D status measured in the summer or fall (each p<0.05), compared with spring.
  
  
  CONCLUSIONS
  Centenarians and octogenarians are at high risk for vitamin D insufficiency for many of the same reasons identified in younger populations. Given the numerous potential adverse consequences of poor vitamin D status, efforts are needed to ensure vitamin D adequacy in these older adults.
authors.affiliation: The University of Georgia, Department of Foods and Nutrition, 280 Dawson Hall, Athens, GA 30602, USA. mjohnson@fcs.uga.edu
authors.forename: M A
authors.initials: MA
authors.lastname: Johnson
authors.forename: A
authors.initials: A
authors.lastname: Davey
authors.forename: S
authors.initials: S
authors.lastname: Park
authors.forename: D B
authors.initials: DB
authors.lastname: Hausman
authors.forename: L W
authors.initials: LW
authors.lastname: Poon
mesh_terms: D001741:Black or African American; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D019587:Dietary Supplements; D005260:Female; D005845:Georgia / Q000453:epidemiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D015995:Prevalence; D012621:Seasons; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000208:ethnology*; D044465:White People
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D