Introduction: Data on vitamin D status in COPD in Indian population are limited while those comparing with GOLD stages, frequency of AECOPD, hospitalization and smoking status are lacking. Aim: To evaluate vitamin­D levels in patients of COPD and its clinical correlation. Materials and Methods: A total of 100 patients of COPD (post­bronchodilator FEV1/ FVC <0.70) with age e”40 years (82 male and 18 female) were studied. Serum vitamin D levels were measured by ELISA and clinically analyzed for Age, sex, BMI, smoking status, FEV1 %predicted, FEV1 volume, FVC, FEV1 /FVC ratio, GOLD stages, frequency of AECOPD and hospitalization during the previous year. Results: Prevalence of vitamin­D deficiency and insufficiency were 42% and 31% respectively among COPD patients. We found positive correlation of Vitamin­D levels to FEV1% predicted (r =0.891; P<0.0001), FVC (r = 0.859; P<0.0001) and FEV1 /FVC (r =0.637; P <0.0001). The mean vitamin­D levels were not statistically significantly different in relation to age, gender, BMI and residence but were significantly lower in current smokers (P <0.0001) and significantly decreased with increasing frequency of AECOPD (P<0.0001). The mean vitamin­D levels of frequent exacerbators was lower than nonfrequent exacerbators (P= <0.0001) and it was also lower in hospitalized patients for AECOPD as compared to not hospitalized (P= <0.0001). Lower levels of vitamin­D was found with increased severity (GOLD stages) of COPD (P<0.0001). Conclusions: COPD is associated with a significantly low level of vitamin­D which was independent to patient’s age, gender, BMI and residence but dependent on current smoking. The lower level of vitamin­D is associated with severity of COPD, increased frequency of AECOPD and increased risk for hospitalization. The relationship between lung functions and levels of vitamin D is almost linear.

Keywords: Vitamin­D; COPD; AECOPD; Frequent Exacerbator; Current Smoking; GOLD Stage.