Vitamin D, asthma prevalence and asthma exacerbations: a large adult population-based study

Allergy. 2014 Dec;69(12):1673-80. doi: 10.1111/all.12508. Epub 2014 Oct 3.


Background: The impact of low vitamin D status on asthma, asthma morbidity and control is unclear. We aimed to investigate in adults the associations between serum 25-hydroxyvitamin D level and prevalent asthma as well as asthma exacerbations.

Methods: A cohort of Israeli adults aged 22-50 years with documented vitamin D status were extracted from Clalit Health Services (HMO) between July 1, 2008 and July 1, 2012. Among this population, those with physician-diagnosed asthma and asthma exacerbations were identified. Asthma exacerbations were defined as any of the following: prescription for oral corticosteroids, >5 prescriptions for short acting beta agonists and more than four visits to a physician for asthma. Logistic regression models assessed the associations between vitamin D and both asthma and asthma exacerbations.

Results: Approximately 308 000 members with at least one vitamin D measurement were included in the cohort. Among them, 6.9% (21 237) had physician-diagnosed asthma vs 5.7% in the general population. Serum 25-OHD levels across both groups were similar. However, among those with vitamin D deficiency, the odds of having an exacerbation were 25% greater compared to those with levels in the normal range. This association remained significant after controlling for known confounders.

Conclusion: While there was no significant association between vitamin D status and physician-diagnosed asthma, there was a strong association with asthma exacerbations. The presented evidence supports vitamin D screening in the subgroup of asthmatics that are uncontrolled and experience recurrent exacerbations.

Keywords: asthma; asthma control; asthma exacerbation; vitamin D; vitamin D deficiency.

MeSH terms

  • Adult
  • Asthma / blood*
  • Asthma / diagnosis
  • Asthma / epidemiology*
  • Asthma / etiology
  • Disease Progression
  • Female
  • Humans
  • Male
  • Middle Aged
  • Population Surveillance
  • Prevalence
  • Risk Factors
  • Vitamin D / analogs & derivatives
  • Vitamin D / blood*
  • Vitamin D Deficiency / complications
  • Young Adult


  • Vitamin D
  • 25-hydroxyvitamin D