title: Probability of Vitamin D Deficiency by Body Weight and Race/Ethnicity.
abstract: BACKGROUND
  While most physicians recognize that vitamin D status varies by skin color because darker skin requires more light to synthesize vitamin D than lighter skin, the importance of body weight to vitamin D status is a newer, less recognized, finding. The purpose of this study was to use nationally representative US data to determine the probability of vitamin D deficiency by body weight and skin color.
  
  
  METHODS
  Using data for individuals age ≥6 years from the 2001 to 2010 cycles of the US National Health and Nutrition Examination Survey, we calculated the effect of skin color, body weight, and age on vitamin D status. We determined the probability of deficiency within the normal range of body weight for 3 race/ethnicity groups at 3 target levels of 25-hydroxyvitamin D.
  
  
  RESULTS
  Darker skin colors and heavier body weights are independently and significantly associated with poorer vitamin D status. We report graphically the probability of vitamin D deficiency by body weight and skin color at vitamin D targets of 20 and 30 ng/mL.
  
  
  CONCLUSIONS
  The effects of skin color and body weight on vitamin D status are large both statistically and clinically. Knowledge of these effects may facilitate diagnosis of vitamin D deficiency.
authors.affiliation: From the Department of Health and Behavior Studies (TW, SR) and the Department of Human Development (BK), Teachers College, Columbia University, New York, NY. jtw2117@columbia.edu.
authors.forename: Tom
authors.initials: T
authors.lastname: Weishaar
authors.affiliation: From the Department of Health and Behavior Studies (TW, SR) and the Department of Human Development (BK), Teachers College, Columbia University, New York, NY.
authors.forename: Sonali
authors.initials: S
authors.lastname: Rajan
authors.affiliation: From the Department of Health and Behavior Studies (TW, SR) and the Department of Human Development (BK), Teachers College, Columbia University, New York, NY.
authors.forename: Bryan
authors.initials: B
authors.lastname: Keller
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001835:Body Weight; D002648:Child; D005006:Ethnicity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys / Q000706:statistics & numerical data; D011336:Probability; D044469:Racial Groups; D012737:Sex Factors; D012880:Skin Pigmentation; D014481:United States / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000208:ethnology*; D055815:Young Adult
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: Minority Health; Nutritional Sciences; Preventive Medicine; Vitamin D