Dietary Supplements and Nutraceuticals under Investigation for COVID-19 Prevention and Treatment

Abstract

Coronavirus disease 2019 (COVID-19) has caused global disruption and a significant loss of life. Existing treatments that can be repurposed as prophylactic and therapeutic agents may reduce the pandemic’s devastation. Emerging evidence of potential applications in other therapeutic contexts has led to the investigation of dietary supplements and nutraceuticals for COVID-19. Such products include vitamin C, vitamin D, omega 3 polyunsaturated fatty acids, probiotics, and zinc, all of which are currently under clinical investigation. In this review, we critically appraise the evidence surrounding dietary supplements and nutraceuticals for the prophylaxis and treatment of COVID-19. Overall, further study is required before evidence-based recommendations can be formulated, but nutritional status plays a significant role in patient outcomes, and these products may help alleviate deficiencies. For example, evidence indicates that vitamin D deficiency may be associated with a greater incidence of infection and severity of COVID-19, suggesting that vitamin D supplementation may hold prophylactic or therapeutic value. A growing number of scientific organizations are now considering recommending vitamin D supplementation to those at high risk of COVID-19. Because research in vitamin D and other nutraceuticals and supplements is preliminary, here we evaluate the extent to which these nutraceutical and dietary supplements hold potential in the COVID-19 crisis. IMPORTANCE Sales of dietary supplements and nutraceuticals have increased during the pandemic due to their perceived “immune-boosting” effects. However, little is known about the efficacy of these dietary supplements and nutraceuticals against the novel coronavirus (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) or the disease that it causes, CoV disease 2019 (COVID-19). This review provides a critical overview of the potential prophylactic and therapeutic value of various dietary supplements and nutraceuticals from the evidence available to date. These include vitamin C, vitamin D, and zinc, which are often perceived by the public as treating respiratory infections or supporting immune health. Consumers need to be aware of misinformation and false promises surrounding some supplements, which may be subject to limited regulation by authorities. However, considerably more research is required to determine whether dietary supplements and nutraceuticals exhibit prophylactic and therapeutic value against SARS-CoV-2 infection and COVID-19. This review provides perspective on which nutraceuticals and supplements are involved in biological processes that are relevant to recovery from or prevention of COVID-19.

Pathogenesis, Symptomatology, and Transmission of SARS-CoV-2 through Analysis of Viral Genomics and Structure

“…Epithelial cells have also emerged as the major cellular target of the virus, contextualizing the respiratory and gastrointestinal symptoms that are frequently observed in COVID-19. Many of the mechanisms that facilitate the pathogenesis of SARS-CoV-2 are currently under consideration as possible targets for the treatment or prevention of COVID-19 ( 10 , 11 ). Research in other viruses also provides a foundation for understanding the transmission of SARS-CoV-2 among people and can therefore inform efforts to control the virus’s spread.…”

“…These spikes, which are critical both to viral pathogenesis and to the response by the host immune system, have been visualized using cryo-electron microscopy ( 9 ). Because they induce the human immune response, they are also the target of many proposed therapeutic agents ( 10 , 11 ). Viral pathogenesis is typically broken down into three major components: entry, replication, and spread ( 12 ).…”

The Impact of Nutrition on the COVID-19 Pandemic and the Impact of the COVID-19 Pandemic on Nutrition

“…The capacity for a variety of nutraceuticals and nutritional supplements to confer protection from and survival after infection by H1N1 has been demonstrated in animal studies [ 10 , 11 , 12 ]. Because of this, sales of these products have increased but suspicions have arisen regarding their actual efficacy against H1N1 in humans [ 13 , 14 ]. In trials of patients with Ebola virus infection, multivitamin therapy was associated with lower mortality rates [ 15 ].…”

Consumption of Phenolic-Rich Food and Dietary Supplements as a Key Tool in SARS-CoV-19 Infection

“…Currently, there is a wide availability of dietary supplements based on foods and plants with nutraceutical value, in order to improve the supply of nutrients or molecules in which the diet could be deficient [ 112 , 113 ]. This fact shows an upward trend due to the ease of consuming concentrated formulations derived from foods or natural products [ 114 ].…”

“…This fact is due to the importance of having a competent immune system capable to modulate the COVID-19 infection and the response to it, which can be achieved through a complete and balanced diet, and the intake of dietary supplements [ 63 ]. For this reason, interest in the development of supplementation therapies based on the active properties of different foods to increase the contribution of active compounds able to act as a preventive approach against viral diseases [ 112 ].…”