Selenium Supplementation and COVID-19

There is, at present, an ongoing scientific debate about selenium supplementation and the possible prevention of COVID-19 disease. What is the evidence that selenium supplementation of individuals with sub-optimal selenium status might help to prevent the infection?

Margaret P. Rayman, selenium researcher
Margaret P. Rayman, Professor of Nutritional Medicine at the University of Surrey in the United Kingdom, is a long-time researcher into the effects of selenium and iodine on human health.

The answer from a group of longstanding selenium researchers is that selenium supplementation does not have “a sufficient direct antiviral effect to prevent infection.” Instead, selenium supplementation acts “by decreasing the harmful effects of the virus on the host” [Rayman 2024].

Selenium supplementation “does not necessarily prevent infection but rather decreases the severity and mortality resulting from the infection” [Rayman 2024]. The important thing to focus on is the interaction between the human host selenium status and infectious virus strain and virulence [Beck 2003]. read more

Selenium and Selenoproteins and Viral Infections

Selenium is an essential micronutrient. Humans cannot synthesize it. Therefore, we must get it from our diets. The selenium content of our diets depends on the richness or poorness of the selenium in the soil and the food. In fact, there are surprisingly large differences in selenium content in various regions of the world [Zhang 2020a].

Woman sneezing
Selenium deficiency and reduced selenoprotein expression have been associated with the pathogenicity of several viruses.

Selenium through its incorporation into 25 known selenoproteins is necessary for a range of biological functions. Zhang et al [2020a] list the following biological functions of selenium and selenium-derived selenoproteins:

  • Antioxidant function
  • Anti-inflammatory function
  • Anti-viral function
  • Cellular redox function
  • Immune cell function
  • Protection of the cardiovascular system
Selenoprotein Functions Relevant to Viral Infections

Selenium and selenium-derived selenoproteins such as the glutathione peroxidases (GPXs), the thioredoxin reductases (TXNRDs), and the endoplasmic-reticulum-associated selenoproteins influence viral pathogenicity. Among other things, these antioxidant selenoenzymes reduce the extent of oxidative stress generated by viral pathogens. Failure to counteract oxidative stress can result in mutations in the viral genome from benign to highly virulent strains [Zhang 2020a]. read more

Selenium Status and Covid-19 Patients

In cases of severe Covid-19 disease, patients have significantly lower concentrations of selenium and selenoprotein P and significantly higher levels of oxidative stress. That is to say, there is a more intense formation of harmful free radicals in patients with severe Covid-19 disease [Skesters 2022].

Corona virus
An adequate supply of selenium and zinc and vitamin D is essential for resistance to the corona viruses and to other viral infections. Here, Skesters er al show that Covid-19 patients have significantly lower levels of plasma selenium and selenoprotein P and significantly higher levels of oxidative stress.

Note: Oxidative stress is the bio-medical term for an imbalance between harmful free radical activity and protective antioxidant activity. Selenium is a key component of antioxidant selenoproteins such as the glutathione peroxidases and the thioredoxin reductases.

Role of Selenium and Selenoprotein P in Covid-19 Disease

Researchers have been investigating the role that selenium may play in reducing the severity and mortality of Covid-19 infections. Studies have shown a close relationship between low selenium status, Selenoprotein P deficiency, oxidative stress level, and Covid-19 disease incidence, severity, and prognosis [Skesters 2022]. read more

Selenium Supplementation Strengthens Immune Response to Covid-19

The available vaccines do not seem up to the task of preventing infection by the fourth wave of the Covid-19 virus. Accordingly, people in high-risk groups may want to start on a course of supplementation to address possible deficiencies of selenium, zinc, and vitamin D to strengthen their immune response [Alexander 2020].

Covid-19 vaccine
Resistance to Covid-19 and other viral infections, strengthening of immune system function, and reducing chronic inflammation all depend on adequate intakes of zinc, selenium, and vitamin D [Alexander 2020].
In this article, we will address the importance of adequate selenium intakes. Readers are encouraged to google zinc and Covid-19 and vitamin D and Covid-19 on their own.

Early initiation of adequate selenium, zinc, and vitamin D supplementation in high-risk individuals and in high-risk areas and, certainly, as soon as possible after the time of suspected infection with the Covid-19 virus can help the immune system [Alexander 2020]. read more