%0 Journal Article %T The efficacy of vitamin D therapy for patients with COPD: a meta-analysis of randomized controlled trials %A Li, Xiaoyan %A He, Jie %A Yu, Mi %A Sun, Jian %J Annals of Palliative Medicine %D 2020 %B 2020 %9 %! The efficacy of vitamin D therapy for patients with COPD: a meta-analysis of randomized controlled trials %K %X %U https://apm.amegroups.org/article/view/37487 %V 9 %N 2 %P 286-297 %@ 2224-5839