Toxicity of food supplements as an adjuvant for COVID-19 treatment or prevention

ABSTRACT

Commercially available food supplements, especially vitamins and minerals, are be-coming increasingly popular in the era of COVID-19 pandemic. Sales of food supplements increased dynamically because of the belief that they could be more effective than conventional antiviral or corticosteroid drugs as well as missing the specific medical therapy for preventing or treating this disease. The greatest interest is associated with immune-related nutrients and antioxidant agents, including vitamin C, vitamin D, vitamin E, selenium (Se), and zinc (Zn). These are currently under clinical investigation for possible application in the prevention and management of COVID-19. This review summarizes postulated mechanisms of commonly used supplements suggested reducing the duration and severity of viral infections by improving immune response. Their toxicity in the context of potential adverse effects is also discussed. Whether these molecules and the amount could hurt patients with COVID-19 are research questions worth evaluating. Considering both efficacy and safety, evidence supporting larger intakes of specific nutrients with immune-boosting and/or antioxidant properties needs further research. Until relevant responses are provided, age and gender related tolerable upper intake levels for vitamins and minerals should be considered to avoid weight gaining as an additional risk factor of developing complications during the disease course, besides the risk of inappropriate doses associated with toxicity. Herein, high-quality information respecting specific nutrients proposed to have positive effect against COVID-19 is disseminated and certain research gaps are addressed, requiring the research on the health effects of supplements to be tightly correlated to age, nutritional status, wellbeing and particular to existing co-morbidities.