High-dose Vitamin C supplementation in the treatment of patients with COVID-19: A systematic review

Introduction: Vitamin C supplementation has been seen as a supportive treatment to control and prevent complications of COVID-19 by enhancing the immune response against infection. However, the effects of high doses of this vitamin are not yet fully understood. Objective: To analyze the effects of high -dose vitamin C in patients with COVID-19. Methods: This was a systematic review, using original studies published from April 2020 to November 2022 in PubMed, ScienceDirect, Scopus and Web of Science databases. The combination of descriptors registered in Medical Subject Headings (MeSH) used to search for articles were: (("vitamin C" OR "ascorbic acid") AND ("COVID-19" OR "SARS-CoV-2" OR "coronavirus")). Original articles of clinical trials conducted with patients diagnosed with COVID-19 and submitted to high -dose vitamin C supplementation were included. Results: Eligible studies included patients in intensive care units, wards, or outpatient clinics, who were given doses of vitamin C, ranging from 6,000 to 8,000 mg/day, with an average duration of 6.25 days of supplementation and mostly intravenous administration. A reduction in fever and myalgia was observed, as well as an improvement in oxygen saturation and lung impairment rate. Conclusion: The role of high -dose vitamin C in patients affected by COVID-19 requires further study, however, to date, the results have been promising for symptom reduction and improvement in lung function and oxygenation.