title: Vitamin D Insufficiency and Asthma in a US Nationwide Study.
abstract: BACKGROUND
  Vitamin D insufficiency (a serum 25-hydroxy vitamin D level of <30 ng/mL) has been associated with asthma morbidity.
  
  
  OBJECTIVE
  To examine vitamin D insufficiency, asthma, and lung function among US children and adults.
  
  
  METHODS
  Using data from the National Health and Nutrition Examination Survey from 2001 to 2010, we examined vitamin D insufficiency and (1) current asthma or wheeze in 10,860 children (6-17 years) and 24,115 adults (18-79 years) and (2) lung function in a subset of participants. Logistic or linear regression was used for the multivariable analysis, adjusting for age, sex, race/ethnicity, income, body mass index, smoking, and C-reactive protein level.
  
  
  RESULTS
  Vitamin D insufficiency was associated with current asthma (odds ratio, 1.35; 95% CI, 1.11-1.64) and current wheeze in children, as well as with current wheeze in adults (odds ratio, 1.17; 95% CI, 1.04-1.31). After stratifying the analysis by race/ethnicity and (in adults) current smoking, vitamin D insufficiency was associated with current asthma and wheeze in non-Hispanic white children only; in adults, vitamin D insufficiency was associated with current wheeze in non-Hispanic whites and blacks. Vitamin D insufficiency was also associated with lower FEV1and forced vital capacity in children and adults. When analyzing each National Health and Nutrition Examination Survey wave separately, vitamin D insufficiency prevalence was 72% to 76% from 2001 to 2006, and then decreased from 2007 to 2010 (64%-65%); interestingly, asthma prevalence decreased for the first time from the period 2007 to 2008 (8.2%) to the period 2009 to 2010 (7.4%).
  
  
  CONCLUSIONS
  We show racial/ethnic-specific associations between vitamin D insufficiency and current asthma or wheeze in children and adults. Moreover, we report parallel recent decrements in the prevalence of vitamin D insufficiency and asthma.
authors.affiliation: Division of Pediatric Pulmonary Medicine, Allergy, and Immunology, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh, Pittsburgh, Pa.
authors.forename: Yueh-Ying
authors.initials: YY
authors.lastname: Han
authors.affiliation: Division of Pediatric Pulmonary Medicine, Allergy, and Immunology, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh, Pittsburgh, Pa.
authors.forename: Erick
authors.initials: E
authors.lastname: Forno
authors.affiliation: Division of Pediatric Pulmonary Medicine, Allergy, and Immunology, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh, Pittsburgh, Pa. Electronic address: juan.celedon@chp.edu.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Celedón
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000453:epidemiology*; D044383:Black People; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012135:Respiratory Sounds; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D014797:Vital Capacity; D014808:Vitamin D Deficiency / Q000453:epidemiology*; D044465:White People; D001741:Black or African American
keywords: Asthma; Lung function; NHANES; Vitamin D insufficiency; Wheezing