Ikhsan Tri Kurnia and Dewi Wijaya (2026) “Vitamin D Supplementation Efficacy in Severe Vitamin D-Deficient versus Insufficient COPD Patients: A Stratified Meta-Analysis of Exacerbation Risk”, Bioscientia Medicina : Journal of Biomedicine and Translational Research, 10(3), pp. 988-1001. doi: 10.37275/bsm.v10i3.1545.