Zangana SN, AL-Othman AA, Habeeb MA. The frequency of vitamin D deficiency in patients with left ventricular systolic dysfunction in Erbil-Iraq. Iraq Med J [Internet]. 2019 Mar. 30 [cited 2024 Nov. 23];3(1). Available from: https://iraqmedj.org/index.php/imj/article/view/557