Are 25(OH) D concentrations associated with asthma control and pulmonary function test?

Background The relationship between vitamin D and asthma is still under investigation. We aimed to evaluate the association between serum vitamin D levels and clinical characteristics of asthma, and the impact of vitamin D deficiency on the clinical manifestations, as them being the issues of debate. Methods Patients who were admitted to the outpatient clinics of Chest Diseases Department of Akdeniz University Hospital between January 2014 and December 2014, have been diagnosed as asthma according to the GINA 2014 guidelines were included in this study. Subjects with COPD, bronchiectasis, pneumonia or tuberculosis were excluded. Asthma exacerbation was defined, according to the GINA guidelines, as episodes of progressive shortness of breath, cough, wheezing or chest tightness accompanied by PFT abnormalities such as decreased PEF or FEV1. Results A total of 158 patients with mean age of 48.8 years were included in the study. Twenty-seven (17.08%) of the patients demonstrated sufficient vitamin D serum levels (i.e. ≥30 ng/mL), while the remaining 131 (82.92%) patients had vitamin D insufficiency (i.e. Conclusion Vitamin D deficiency was significantly associated with poorer pulmonary functions and higher hospitalization numbers.