title: Severe and uncontrolled adult asthma is associated with vitamin D insufficiency and deficiency.
abstract: BACKGROUND
  Vitamin D has effects on the innate and adaptive immune system. In asthmatic children low vitamin D levels are associated with poor asthma control, reduced lung function, increased medication intake, and exacerbations. Little is known about vitamin D in adult asthma patients or its association with asthma severity and control.
  
  
  METHODS
  Clinical parameters of asthma control and 25-hydroxyvitamin D (25(OH)D) serum concentrations were evaluated in 280 adult asthma patients (mean ± SD: 45.0 ± 13.8 yrs., 40% male, FEV1 74.9 ± 23.4%, 55% severe, 51% uncontrolled).
  
  
  RESULTS
  25(OH)D concentrations in adult asthmatics were low (25.6 ±11.8 ng/ml) and vitamin D insufficiency or deficiency (vitamin D <30 ng/ml) was common (67%). 25(OH)D levels were related to asthma severity (intermittent: 31.1 ± 13.0 ng/ml, mild: 27.3 ± 11.9 ng/ml, moderate: 26.5 ± 12.0 ng/ml, severe: 24.0 ± 11.8 ng/ml, p = 0.046) and control (controlled: 29.5 ± 12.5 ng/ml, partly controlled 25.9 ± 10.8 ng/ml, uncontrolled: 24.2 ± 11.8 ng/ml, p = 0.030). The frequency of vitamin D insufficiency or deficiency was significantly higher in patients with severe or uncontrolled asthma and was associated with a lower FEV1 (vitamin D <30 vs. ≥30 ng/ml 2.3 ± 0.9 L vs. 2.7 ± 1.0 L, p = 0.006), higher levels of exhaled NO (45 ± 46 ppb vs. 31 ± 37 ppb, p = 0.023), a higher BMI (28.3 ± 6.2 vs. 25.1 ± 3.9, p < 0.001), and sputum eosinophilia (5.1 ± 11.8% vs. 0.5 ± 1.0%, p = 0.005). The use of oral corticosteroids or sputum eosinophilia was associated with a 20% or 40% higher risk of vitamin D insufficiency or deficiency.
  
  
  CONCLUSIONS
  25(OH)D levels below 30 ng/ml are common in adult asthma and most pronounced in patients with severe and/or uncontrolled asthma, supporting the hypothesis that improving suboptimal vitamin D status might be effective in prevention and treatment of asthma.
authors: Stephanie
authors: S
authors: Korn
authors: Marisa
authors: M
authors: Hübner
authors: Matthias
authors: M
authors: Jung
authors: Maria
authors: M
authors: Blettner
authors: Roland
authors: R
authors: Buhl
mesh_terms: D000368:Aged; D001249:Asthma / Q000150:complications / Q000453:epidemiology* / Q000503:physiopathology; D001835:Body Weight; D002112:Calcifediol / Q000097:blood; D003430:Cross-Sectional Studies; D004804:Eosinophils; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D016753:Interleukin-10 / Q000097:blood; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D013183:Sputum / Q000166:cytology; D014808:Vitamin D Deficiency / Q000150:complications / Q000453:epidemiology* / Q000503:physiopathology
chemical_list: D016753:Interleukin-10; D002112:Calcifediol