Tehran University of Medical Sciences Archives of Anesthesiology and Critical Care 2423-5849 12 1 2026 01 01 71 83 Kavous Shahsavarinia Emergency and Trauma Care Research Center, Imam Reza General Hospital, Tabriz University of Medical Sciences, Tabriz, Iran. Shaghayegh Musazadeh Student Research Committee, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran. Morteza Ghojazadeh Research Center for Evidence-Based Medicine, Iranian EBM Centre: A JBI Centre of Excellence, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran. Nooshin Milanchian Department of Internal Medicine, Faculty of Medicine, Tabriz Medical Sciences, Islamic Azad University, Tabriz, Iran. Maryam Soleimanpour Clinical Research Development Unit of Tabriz Valiasr Hospital, Tabriz University of Medical Sciences, Tabriz, Iran. Hassan Soleimanpour Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran. 2025 05 11 2025 05 26 Background: Coronavirus disease 2019 (COVID-19) is an infectious illness resulting from the SARS-CoV-2 virus. The immune system overactivation triggered by this virus results in multiple organ damage. This infection has the potential to cause acute respiratory distress syndrome and may progress to respiratory failure, both of which can be life-threatening. Vitamin C is proposed as a possible treatment for immune system overactivation due to its antioxidant properties. Methods: This umbrella review seeks to evaluate the effectiveness of vitamin C in the management of COVID-19 infection. To identify pertinent literature, we conducted searches across Embase, PubMed, Scopus, and Web of Science databases. Our analysis incorporated eight systematic reviews and meta-analyses that examined the impact of vitamin C on COVID-19 treatment outcomes. Results: Our findings revealed that the odds ratio (OR) of mortality in the vitamin C group is 0.55 (0.48-0.63). The duration of hospitalization did not differ between the groups and the need for mechanical ventilation in both groups. This umbrella review discusses the use of vitamin C in COVID-19 patients, highlighting its potential to reduce mortality rates. While the duration and dose of treatment vary There was no notable distinction observed between the vitamin C group and the control groups in hospital length, ICU stay, or mechanical ventilation days. Conclusion: The study suggests further research to determine its effectiveness in reducing mortality rates and suggests larger studies with a more specific protocol. https://aacc.tums.ac.ir/index.php/aacc/article/view/1283