The Emerging Role of Vitamin C in the Prevention and Treatment of COVID-19

Abstract

Investigation into the role of vitamin C in the prevention and treatment of pneumonia and sepsis has been underway for many decades. This research has laid a strong foundation for translation of these findings into patients with severe coronavirus disease (COVID-19). Research has indicated that patients with pneumonia and sepsis have low vitamin C status and elevated oxidative stress. Administration of vitamin C to patients with pneumonia can decrease the severity and duration of the disease. Critically ill patients with sepsis require intravenous administration of gram amounts of the vitamin to normalize plasma levels, an intervention that some studies suggest reduces mortality. The vitamin has pleiotropic physiological functions, many of which are relevant to COVID-19. These include its antioxidant, anti-inflammatory, antithrombotic and immuno-modulatory functions. Preliminary observational studies indicate low vitamin C status in critically ill patients with COVID-19. There are currently a number of randomized controlled trials (RCTs) registered globally that are assessing intravenous vitamin C monotherapy in patients with COVID-19. Since hypovitaminosis C and deficiency are common in low–middle-income settings, and many of the risk factors for vitamin C deficiency overlap with COVID-19 risk factors, it is possible that trials carried out in populations with chronic hypovitaminosis C may show greater efficacy. This is particularly relevant for the global research effort since COVID-19 is disproportionately affecting low–middle-income countries and low-income groups globally. One small trial from China has finished early and the findings are currently under peer review. There was significantly decreased mortality in the more severely ill patients who received vitamin C intervention. The upcoming findings from the larger RCTs currently underway will provide more definitive evidence. Optimization of the intervention protocols in future trials, e.g., earlier and sustained administration, is warranted to potentially improve its efficacy. Due to the excellent safety profile, low cost, and potential for rapid upscaling of production, administration of vitamin C to patients with hypovitaminosis C and severe respiratory infections, e.g., COVID-19, appears warranted.

Susceptibility of the patients infected with Sars-Cov2 to oxidative stress and possible interplay with severity of the disease

“…The inflammatory response has led researchers to believe that there might be possible differences in the redox profile of patients with COVID-19 [ 8 , 15 , 16 ], and thus, the use of antioxidants as a complementary therapeutic strategy in COVID-19 has been proposed [ [37] , [38] , [39] , [40] ]. Oxidative stress affects the immune system through altering the immune cell function and inflammatory response [ 21 ].…”

Vitamin C and COVID-19

“…However, the excellent safety profile of vitamin C and the necessity of ICU treatment for a high proportion of COVID-19 patients may justify consideration of clinical application of vitamin C, even before the results of large clinical trials are available ( 24 ). Vitamin C has been proposed for COVID patients also by other authors ( 25 – 27 ).…”

Current Updates on Naturally Occurring Compounds Recognizing SARS-CoV-2 Druggable Targets

“…According to the authors, a significant decrease in intensive care unit stay and hospital mortality was observed in the vitamin C treated patients [ 44 ]. Overall, vitamin C seemed to possess relevant pharmacological properties against severe respiratory infections, including COVID-19 [ 45 , 46 ]. Several clinical trials, assessing the efficacy of high dose vitamin C infusion, are still ongoing and will provide more definitive evidence.…”

“…Overall, vitamin C seemed to possess relevant pharmacological properties against severe respiratory infections, including COVID-19 [45,46]. Several clinical trials, assessing the efficacy of high dose vitamin C infusion, are still ongoing and will provide more definitive evidence.…”