The relationship between COVID-19 and blood vitamin C; a systematic review study

Introduction: The rapid worldwide spread of COVID-19 has caused a global health crisis. Unfortunately, no vaccine or special antiviral drug has been developed against COVID-19 to date, symptomatic supportive care has been the most common treatment. Objectives: the purpose of this systematic review aims to provide a timely, rigorous, and continuously updated summary of the available evidence on the role of vitamin C in treating patients with COVID-19. Methods: In this review, we identified studies published in 2020 that describe on the relationship between COVID-19 and vitamin C. We searched PubMed, Google Scholar, Scopus, Magiran, SID and Web of Science for research articles published up to 23 December 2020 using the keywords of vitamin C, COVID-19, SARS-COV-2 and coronavirus 2. Results: At the initial stage of screening, 181articles were excluded after reviewing the title and removing irrelevant and duplicate titles, 52 articles were selected to review the abstract. After reviewing the abstract (or in articles without abstracts after reviewing the original text), nine articles were finally considered suitable for this purpose and were reviewed and finalized. Vitamin C is a pivotal component of the immune system, with proven antioxidant, cytokine storm suppressor and anti-inflammatory properties and has been tested in numerous studies for its role in severe sepsis and ICU care, especially when used as a continuous high-dose intravenous infusion. In addition, some studies indicated high-dose intravenous vitamin C treatment was associated with fewer days on mechanical ventilation, shorter ICU stay, and earlier recovery compared to the average length of mechanical ventilation, disease duration, and ICU stay in critical COVID-19 patients. Conclusion: Vitamin C can significantly improve clinical symptoms, inflammatory response, immune and organ function in COVID-19 patients. In patients affected with COVID-19, high-dose intravenous vitamin C is expected to improve pulmonary function and reduce mortality for patients with COVID-19 and can be beneficial in aspects of inflammatory response, immune and organ function for aggravation of COVID-19 patients, however further clinical trials are necessary.