Table 1: Summary of the evidence outlining the effects of Vitamin C use in COVID-19.

References	Name of the Study	Findings/ Conclusion
Fowler III et al. [21]	Effect of Vitamin C Infusion on Organ Failure and Biomarkers of Inflammation and Vascular Injury in Patients with Sepsis and Severe Acute Respiratory Failure: The CITRIS-ALI Randomized Clinical Trial	Administration of approximately 15g/day of IV VC for 4 days may reduce the mortality rates in sepsis-related ARDS patients.
Carr et al. [25]	A new clinical trial to test high-dose vitamin C in patients with COVID-19	A new randomized control trial (RCT) tests the effects of IV VC in viral infections in 140 patients. The study will investigate the effects of IV VC with a dose of 24g/day for 7 days vs. placebo. It will assess the requirements for mechanical ventilation and vasopressor drugs, organ failure scores, ICU length of stay, and 28-day mortality.
Hemilä et al. [23]	Vitamin C and SARS coronavirus	Three RCTs reported that VC supplementation lowered the incidence of Pneumonia in VC supplemented group, showing that VC may affect the susceptibility of lower respiratory tract infections under specific conditions.
Wang et al. [22]	Effects of different ascorbic acid doses on the mortality of critically ill patients: a meta-analysis	IV Ascorbic acid at doses 3-5 g/day decreases the duration of vasopressor support and mechanical ventilation, thus reducing the overall mortality rates in ARDS patients.
Messina et al. [24]	Functional Role of Dietary Intervention to Improve the Outcome of COVID-19: A Hypothesis of work	Dietary supplementation with VC, Flavonoids, and polyphenols reduces inflammation and immune response, blocking nuclear NF- B translocation, hence has a potential effect in improving the response in COVID patients.
Cheng et al. [26]	Can early and high intravenous doses of vitamin C prevent and treat coronavirus disease 2019 (COVID-19)	COVID-19 patients have high levels of inflammatory markers due to oxidative stress, leading to the activation of important pathways like Nrf 2 signaling. This could lead to modulation in the antioxidant response element (ARE) driven cytoprotective protein expression by various transcription factors. The use of high dose Intravenous VC can be a potential target to prevent and relieve oxidative stress in COVID-19 patients.
Shanghai Expert Panel et al. [27]	High Dose Vitamin C Infusions Being Used To Treat COVID-19	High-dose intravenous. 10g-20g intravenous dosage of VC was used for 8-10 hrs. for 50 moderate and 19 severe COVID-19 cases in China, which led to a successful treatment. Though critical cases needed higher doses, their oxygenation index improved, directing the situation towards cure and discharge.
Hemilä et al. [28]	Vitamin C Can Shorten the Length of Stay in the ICU: A Meta-Analysis	High-dose intravenous VC infusions (e.g., 200 mg/kg body weight/day, divided into 4 doses) shorten the intensive care unit (ICU) stay by 7.8%, accompanied by a significant reduction in the mortality rate.
Berger et al. [29]	Vitamin C supplementation in the critically ill patient.	Patients under critical care like sepsis, burns, trauma, etc. have an improved clinical outcome when high dose VC (3g/day) is administered for several days.
Marik et al. [30, 31] Christin et al. [32]	1. Hydrocortisone, vitamin C, and thiamine for the treatment of severe sepsis and septic shock: a retrospective before-after study 2. ARDS complicating pustular psoriasis: treatment with low-dose corticosteroids, vitamin C and thiamine 3. Vitamin C infusion for gastric acid aspiration-induced acute respiratory distress syndrome (ARDS)	Severe cases of ARDS show clinical benefit evidenced by improving symptoms and radiological signs with VC supplementation 24-48 hours post ECMO procedures.
Fowler III et al. [33] Spiegel et al. [34] Hager at al [35].	1. Effect of vitamin C infusion on organ failure and biomarkers of inflammation and vascular injury in patients with sepsis and severe acute respiratory failure: the CITRIS-ALI randomized clinical trial 2. Myths in Emergency Medicine: Vitamin C Trial Lacks Answers for Sepsis 3. Vitamin C for Sepsis and Acute Respiratory Failure	Critical cases after organ failure have decreased mortality by 16.5%, respiratory assistance requirements by 2.5 days, ICU stays by 3.2 days, and hospital admission by 6.7 days after VC administration. However, inflammatory markers failed to improve significantly during the CITRIS-ALI trial.