The Role of Vitamin C in Human Immunity and Its Treatment Potential Against COVID-19: A Review Article

Abstract

The outbreak of the COVID-19 pandemic has left clinicians around the world searching for viable prevention and treatment options to use against the virus. The important physiologic properties of vitamin C have been well documented regarding its use by immune cells and its role as an antioxidant. It has previously shown potential as a prophylactic and treatment option for other respiratory viruses, and because of this, there has been intrigue into whether these positive outcomes translate into a cost-effective prevention and treatment option for COVID-19. To this point, there have only been a few clinical trials performed to assess the validity of this notion, with very few showing definitive positive outcomes when vitamin C has been incorporated into prophylactic or treatment protocols to use against coronavirus. When being used to specifically treat the severe complications that arise from COVID-19, vitamin C is a reliable option to treat COVID-19induced sepsis but not pneumonia or acute respiratory distress syndrome (ARDS). As a treatment option, high-dose therapy has shown flashes of promise in a few studies although investigators in these studies often subject the testing group to multimodal therapies that include vitamin C as opposed to just vitamin C alone. Given the role that vitamin C has shown to uphold regarding the human immune response, it is currently advised for all individuals to maintain a normal physiologic range of plasma vitamin C through diet or supplements for adequate prophylactic protection against the virus. More research with definitive outcomes will be needed before it is recommended to provide high-dose vitamin C therapy to prevent or treat COVID-19.

Role of micronutrients in the modulation of immune system and platelet activating factor in patients with COVID-19; a narrative review

“…In humans, vitamin C supplementation improves the immune system and reduces the severity and duration of infectious diseases ( 71 , 72 ). Studies have shown that vitamin C supplementation may control respiratory tract infections and reduces the mortality of patients with infectious diseases ( 73 ). Vitamin C supplementation (from 50 to 1500 mg/kg/d) can be considered as a complementary treatment for SARS-CoV-2 ( 30 , 74 – 76 ).…”

Broad-Spectrum Antivirals Derived from Natural Products

“…Individuals with scurvy are highly susceptible to fatal infections, such as pneumonia [ 82 ]. Clinical trials have shown that high doses of Vitamin C have effects against virus infection [ 82 , 83 , 84 , 85 ], and research suggests that the antiviral effect might be attributable to the production of antiviral cytokines (IFNs), free radical formation, or direct binding to the virus [ 86 ]. In addition, vitamin D has shown regulatory effects on both innate immunity and acquired immunity [ 87 ].…”

The Lasting Effects of COVID-19 on the Progression of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

“…COVID-19 was declared a pandemic in March 2020 and has infected millions of people worldwide [1,2]. The disease manifested a wide range of clinical symptoms involving several organ systems [3][4][5][6]. The liver is the second most commonly affected organ in COVID-19, following the lungs [7][8][9].…”