Abstract: www.aging-us.com AGING 2021, Vol. 13, No. 5 Research Paper The efficiency and safety of high-dose vitamin C in patients with COVID-19: a retrospective cohort study Dengfeng Gao1,*, Min Xu1,*, Gang Wang2, Jianrui Lv3, Xiaorong Ma4, Yonghong Guo5, Dexin Zhang6, Huiyun Yang7, Wei Jiang1, Fuxue Deng1, Guozhi Xia1, Ziwei Lu1, Lv Lv1, Shouping Gong8 1 Department of Cardiology, The Second Affiliated Hospital, Xi’an Jiaotong University, Xi’an, Shaanxi, P.R. China Department of Critical Care, The Second Affiliated Hospital, Xi’an Jiaotong University, Xi’an, Shaanxi, P.R. China 3 Department of Anesthesiology, The Second Affiliated Hospital, Xi’an Jiaotong University, Xi’an, Shaanxi, P.R. China 4 Department of Hematology, The Second Affiliated Hospital, Xi’an Jiaotong University, Xi’an, Shaanxi, P.R. China 5 Department of Infectious Diseases, The Second Affiliated Hospital, Xi’an Jiaotong University, Xi’an, Shaanxi, P.R. China 6 Department of Respiratory and Critical Care, The Second Affiliated Hospital, Xi’an Jiaotong University, Xi’an, Shaanxi, P.R. China 7 Department of Nursing, The Second Affiliated Hospital, Xi’an Jiaotong University, Xi’an, Shaanxi, P.R. China 8 Department of Neurosurgery, The Second Affiliated Hospital, Xi’an Jiaotong University, Xi’an, Shaanxi, P.R. China *Equal contribution 2 Correspondence to: Shouping Gong, Dengfeng Gao; email: shpingg@mail.xjtu.edu.cn, gaomedic@mail.xjtu.edu.cn Keywords: coronavirus disease 2019, COVID-19, ascorbic acid, mortality, safety Received: October 28, 2020 Accepted: January 4, 2021 Published: February 26, 2021 Copyright: © 2021 Gao et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. ABSTRACT Background: The inflammatory reaction is the main cause of acute respiratory distress syndrome and multiple organ failure in patients with Coronavirus disease 2019, especially those with severe and critical illness. Several studies suggested that high-dose vitamin C reduced inflammatory reaction associated with sepsis and acute respiratory distress syndrome. This study aimed to determine the efficacy and safety of high-dose vitamin C in Coronavirus disease 2019. Methods: We included 76 patients with Coronavirus disease 2019, classified into the high-dose vitamin C group (loading dose of 6g intravenous infusion per 12 hr on the first day, and 6g once for the following 4 days, n=46) and the standard therapy group (standard therapy alone, n=30). Results: The risk of 28-day mortality was reduced for the high-dose vitamin C versus the standard therapy group (HR=0.14, 95% CI, 0.03-0.72). Oxygen support status was improved more with high-dose vitamin C than standard therapy (63.9% vs 36.1%). No safety events were associated with high-dose vitamin C therapy. Conclusion: High-dose vitamin C may reduce the mortality and improve oxygen support status in patients with Coronavirus disease 2019 without adverse events.