A new article published in Cleveland Clinic Journal of Medicine stated that owing to their potential to influence immune response, ascorbic acid (vitamin C), zinc and vitamin D are said to be useful in the prevention or treatment of coronavirus disease 2019 (COVID-19).

Vitamin Cacts as an antioxidant by reducing the reactive oxygen species(ROS), and evidence suggests thatits supplementation can impact the immune system. Human trials have found that vitamin C may decrease susceptibility to viral respiratory infections and pneumonia.

Zinc is important for immune function and playsimportant roles in antibody and WBC production. Deficiency of this micronutrientdecreases the production of antibodies, while its supplementation increases the ability of polymorphonuclear cells to fight infection. Increase in intracellular concentrations of zinc inhibitscoronavirus RNA polymerase activity and viral replication—as demonstrated in in vitro and cell culture model. Furthermore, high-dose zinc reduces the duration of symptoms of the common cold and is said to havethe potential to decrease coronavirus replication. Thus, zinc is currently being investigated for prophylaxis and treatment of patients with COVID-19.

Vitamin D has immunomodulatory effects – including inhibition of antigen-presenting cells; antiproliferative effects on T cells; modulating expression and secretion of type 1 interferon; and inhibition of proinflammatory cytokine expression – IL-6 and TNF alpha.Vitamin D supplementation decreases the incidence of acute respiratory infection. The protective effect of itssupplementation is found to be greater in patients with baseline serum 25-hydroxyvitamin D concentrations < 25 nmol/L (versus ≥ 25 nmol/L) and isolated to those receiving daily dosing (versus bolus dosing). A recent article recommended that patients at risk for COVID-19 should be started on daily vitamin D supplementation to reduce the risk for the infection. However, it has not been specifically evaluated for prevention of COVID-19 infection.

In summary, it was stated that vitamin C, D and zinc are candidates for clinical trials. Moreover, these supplements impose minimal risks to patients taking labeled over-the-counter doses.

Source: Cleveland Clinic Journal of Medicine. 2020 Jun 8. doi: 10.3949/ccjm.87a.ccc046.