[\'Department of Endocrinology and Metabolism, Şırnak State Hospital, Şırnak, Turkey. dr.mguven@gmail.com.\', \'Department of İntensive Care Unit, Şırnak State Hospital, Şırnak, Turkey.\']
The effect of high-dose parenteral vitamin D3 on COVID-19-related inhospital mortality in critical COVID-19 patients during intensive care unit admission: an observational cohort study.