| ABSTRACT:Vitamin D deficiency and insufficiency are common worldwide and associated with pulmonarydiseases. Epidemiological studies indicated low levels of serum Vitamin D is associated with impaired pulmonaryfunction. The aim of present study was to evaluate the vitamin D levels and its correlation to adult asthmatic patients. 120 asthmatic patients older than 18 years of age submitted to Yaspulmonaryclinic (Tabriz, Iran) from June 2014 to June 2015were included in the study. The information of patients like sex, age (18-30 Years, 30-45 Years, 45-60 years and >60 years), duration of disease (>10 years, 5-10 years, 1-5 years and <1 year) and BMI (<20, 20-25, 25-30 and >30) were recorded. The severityof asthma and levels of asthma control were assessed according to the Global Initiative for Asthma guidelines at four levels (Intermittent, mild, moderate and severe) were recorded or investigated. Serum vitamin D levels were determined and defined at four levels (Sever, mild to moderate deficiency, insufficiency and normal). Duncan's new multiple range test was used to compare the means of vitamin D with other variables. Most of patients have been found to beseverely deficientinvitaminD (44.3%). The normal range of serum vitamin D was observed in just 13/131 patients (9.9%). The patients aged more than 60 years old (22 ng/m) had the highest mean value of vitamin D that was significantly higher than the younger patients aged 30-45 years (12.44 ng/m) and 18-30 years (8.17 ng/m). There was not any significant correlation among vitamin D levels, severity and duration of asthma. The prevalence of vitamin D deficiency in thin people (12.09 ng/m) was significantly more than fat people (19.44 ng/m). The results of present study demonstrated the insignificant correlation between serum vitamin D levels and asthma in adults. Definitely, this relationship being affected by multiple factors other than vitamin D. further investigations should be conducted to find theinterrelation between all effective factors |