Vitamin D deficiency is associated with chronic obstructive pulmonary disease and exacerbation of COPD

Introduction: Low Vitamin D levels have been associated with Chronic Obstructive Pulmonary Disease (COPD) and acute exacerbations. Objectives: There is a paucity of data on Vitamin D and COPD, its severity and exacerbations in populations that are exposed to sunlight regularly with high levels of physical activity most of their lives. Methods: Serum levels of 25-OH-Vitamin-D were assessed in 100 COPD subjects and 100 age- and gender-matched controls from the rural community-based MUDHRA cohort in South India. Levels of <20 ng/mL were defined as Vitamin D deficiency. Smoking habits, occupation, Charlson co-morbidity index, Standard of living index(SLI), body mass index(BMI), 6-minute walking distance were examined for associations with logistic regression between controls and COPD subjects. Unconditional logistic regression was used to examine the association with exacerbation of COPD. Results: Vitamin D deficiency was observed in 64.5% (95%CI 57.7–70.8) of the subjects in spite of regular exposure to sunlight. Subjects with COPD had higher risk of Vitamin D deficiency (Adjusted OR: 5.05; 95%CI 1.4–17.8) as compared to controls. Amongst subjects with COPD, Vitamin D deficient subjects were three times more likely to have exacerbations in the previous year (Adjusted OR:3.51; 95%CI 1.27–9.67) as compared to COPD subjects without Vitamin D deficiency. Levels of Vitamin D <20.81 ng/mL and <18.45 ng/mL had the highest levels of combined sensitivity and specificity for COPD and acute exacerbation of COPD (AECOPD) respectively. Conclusion: In a rural population exposed to sunlight many hours a day throughout their lives, low Vitamin D levels were associated with COPD and exacerbations of COPD.