Effects of high dose vitamin C administration in Covid-19 patients

The outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which emerged in Wuhan, China, was named as Coronavirus disease 2019 and declared as a pandemic (1). COVID-19 has a wide clinical spectrum, including asymptomatic infection, upper respiratory tract infection (URTI), pneumonia, acute respiratory distress syndrome (ARDS), and death (2). About 26% of patients with pneumonia findings due to COVID-19 require intensive care due to the development of ARDS and septic shock (3). There is currently no specific treatment or vaccine with proven safety and efficacy for COVID-19. Studies are ongoing to find an effective treatment and to develop a vaccine that provides complete protection against the disease. Although the treatment protocols of COVID-19 disease differ from country to country, combinations of drugs such as azithromycin, favipiravir, remdesivir, tocilizumab are generally used (2,4). Moreover, some supportive drugs and agents are added to the treatment of patients. One of them is vitamin C (VC), which has been shown to be effective in the treatment of patients developing ARDS (5). Proinflammatory cytokines that increase due to SARS-CoV-2 virus infection cause cytokine storm in the body. This cytokine storm causes the formation of free oxygen radicals and impairs alveolo-capillary membrane permeability, resulting in cellular damage in lungs ( 6 ). Antioxidants such as VC, N-acetyl-cysteine, and selenium are effective in preventing this damage. One of the most important parts of the non-enzymatic antioxidant system is VC (7). Vitamin C decreases organ injury caused by cytokines by activating the immune system, and increases survival (8). It is also involved in the synthesis of steroids and catecholamines, wound healing, carnitine synthesis and endothelial cell function (9). The efficacy of high-dose intravenous VC therapy in COVID-19 has not been clearly demonstrated yet. However, VC, which is used by millions of people, is one