RT Journal Article SR Electronic T1 Late-breaking abstract: Effect of vitamin D deficiency and vitamin supplementation on severity and exacerbation rate of asthma JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP P4002 VO 44 IS Suppl 58 A1 Antonio Ciuffreda A1 Michela Bellocchia A1 Emanuele Pivetta A1 Paolo Solidoro A1 Marco Bardessono A1 Giuseppe Tabbia A1 Alessio Mattei A1 Caterina Bucca YR 2014 UL http://erj.ersjournals.com/content/44/Suppl_58/P4002.abstract AB Background: We evaluated if vitamin D (25-OHD) deficiency may influence the severity of asthma.Methods: We assessed 25-OHD during the winter 2012-2013 in 121 asthmatic patients attending our clinic since one year at least, and related vitamin levels to airway obstruction, dose of inhaled corticosteroids (ICS) and asthma exacerbations (AE) in the last year (derived from medical records). The effect of one year vitamin D supplementation on lung function and AE was also assessed.Results: The 121 patients were 95 women and 26 men, mean age 52 +/- 16 yrs, 15 current smokers (12.4%).GINA class distribution: class 1=9% - 2=31% - 3=34% - 4=26%. 25-OHD was deficient in all the patients but 13, severely (<10 ng/ml) in 27 (22%), lowest in patients with >= 2 AE. 25-OHD levels were significantly related directly to FEV1% predicted (r=0.24, p=0.009), and inversely to GINA class (r=0.28, p=0.002) and ICS dose (r=0.20, p=0.023). The adjusted odds ratio of having frequent AE if having severe 25-OHD deficiency, was 4.38(CI 1.1-17.5).The effect of vitamin D supplementation was assessed in 56 patients showing satisfactory compliance with treatment. These patients had more severe asthma and higher number of AE.Vitamin D supplementation for one year was associated with decreased AE number (p=0.0001) and improved airway obstruction (p<0.0001).Conclusion: Severe 25-OHD deficiency was common in our asthmatic patients and was related to airway obstruction, higher ICS dose and higher AE rate. Vitamin D supplementation was associated with decreased rate of AE and improvement of airway obstruction.