Afzaal Ali Khan, Rukhsana Anwar, Muhammad Jalal, Said Ul Siyab, Muhammad Sajjad. Association Between Vitamin D Levels and Infective Exacerbation of Chronic Obstructive Pulmonary Disease (COPD). JHWCR [Internet]. 2025 Jun. 15 [cited 2025 Jun. 16];:e359. Available from: https://jhwcr.com/index.php/jhwcr/article/view/359