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

Covid-19 and Selenium and Coenzyme Q10

The individual’s status of selenium and Coenzyme Q10 may be a decisive factor in his or her immune system’s response to the SARS-CoV-2 virus that causes the acute respiratory distress of a Covid-19 infection.

Corona virus
A research review shows that selenium and CoQ10 supplementation has positive effects on the free radical-induced oxidative stress and the inflammation associated with patients with COVID-19 disease.

In particular, immune system cells require adequate selenium and Coenzyme Q10 to protect against oxidative stress and to modulate the inflammatory effect.

This is the conclusion of the authors of a 2021 review of the relevant research literature [Hargreaves & Mantle].

Iain R. Hargreaves, a biochemistry faculty member in the Pharmacy and Biomolecular Sciences Department of the Liverpool John Moores University, together with the medical doctor David Mantle, has written that adequate selenium status and adequate Coenzyme Q10 status may be important factors: read more

Selenium Deficiency and Covid-19 Infection

Selenium is a natural trace element that has an important role in the functioning of the immune system (summarized in an earlier article).

Corona virus
Individuals with low serum selenium concentrations, e.g. below 70 mcg/L, are at greater risk of contracting Covid-19 and at greater risk of a more severe outcome. Selenium supplementation may give therapeutic benefits.

SARS-CoV-2 is a single-stranded RNA virus responsible for COVID-19 infections. Covid-19 infections have a complex metabolism that is comparable to RNA virus infections such as coxsackievirus, influenza virus, Hanta virus, and HIV virus infections.

  • Selenium deficiency is associated with a higher susceptibility to RNA viral infections and with more severe disease outcomes [Hiffler 2020].
  • Selenium deficiency is associated with increases in the mutation, replication, and virulence of RNA viruses [Hiffler 2020].
  • There may be a protective effect of selenium supplementation against the susceptibility to and the severity of Covid-19 infections in selenium deficient individuals [Hiffler 2020].
  • Selenium Deficiency Promotes Mutations, Replication, and Increased Virulence of RNA Viruses

    Selenium deficiency – frequently defined as serum selenium status below 70 mcg/L – increases the risk of infection with RNA viruses: read more

    Selenium Status and Viral Infections

    Selenium and viral infections, what do we know?

    • Selenium is a micronutrient that is essential for good health.
    • Low serum selenium status (below 85 microg/mL) and marginal serum selenium status (between 85 and 100 microg/mL) are common in many regions of the world, especially in many parts of Europe, the Middle East, China, and East Asia.
    • Selenium status is a key factor regulating the immune response to viral infections [Hiffler 2020].
    • Selenium status influences the immune system response to the severe acute respiratory syndrome corona virus infections [Bermano 2020].
    •  Selenium status is a risk factor that could well influence the outcome of a Covid-19 infection, particularly if the infected individuals have a sub-optimal or low selenium intake [Bermano 2020].
    • Selenium supplementation may limit the severity of Covid-19 infections, particularly in regions in which the selenium intake is low [Bermano 2020, Hiffler 2020].

    Evidence for a Link Between Selenium Status and Viral Infection Severity

    The early evidence came from study of the Keshan Disease in China – caused by the combination of the coxsackie B3 virus and low selenium status. By adding selenium to the soil fertilizer and by encouraging the use of selenium supplements, Chinese authorities have been able to reduce significantly the incidence of the disease [Bermano 2020].

    Then came evidence from mouse studies that showed that there is increased virulence to coxsackie and influenza viruses in hosts with low selenium status [Bermano 2020].

    Next came evidence that low selenium status, commonly seen in HIV-infected patients, is associated with reduced numbers of CD4 T cells and with increased disease progression and death rates [Bermano 2020]. read more

    Selenium to Raise Anti-Viral Resistance Against COVID-19

    COVID-19 Virus Infection
    COVID-19 virus infections are accompanied by excessive activation of the innate immune system, by progressive inflammation, and by cytokine storms. A review of the medical journal literature shows that an adequate supply of the micronutrients selenium, zinc, and vitamin D is necessary to strengthen immune function and to reduce inflammation.

    Adequate intakes of selenium, zinc, and vitamin D are essential to ensure resistance to viral infections, to promote strong immune function, and to reduce levels of inflammation. A team of Norwegian, Swedish, and Russian researchers recommends the initiation of adequate supplementation with these micronutrients in high-risk areas and in cases of suspected exposure to SARS-CoV-2 [Alexander 2020].

    Selenium Supplementation to Protect Against the Hyper-Inflammation Associated with COVID-19

    The team of researchers concluded from its review of the available medical literature that an adequate selenium intake/status can protect against the hyper-inflammation associated with corona viral infections.

    Consequently, individuals at high risk who have a selenium status below 100 micrograms per liter should consider daily supplementation at a dose of 100–200 micrograms of selenium per day [Alexander 2020]. read more

    China and COVID-19 Virus: The Selenium Connection

    Map of China
    China has regions with selenium-rich soils and foodstuffs and regions with selenium-poor soils and foodstuffs. Researchers have compared the COVID-19 cure-rate and death-rate for infected individuals in selenium-rich and selenium-poor regions in China. They have found that regions with low selenium status have lower cure-rates and higher death-rates.

    China and Corona Virus will be forever linked in our minds.  However, there is another important connection that we should be making: selenium status and its effect on COVID-19 virus in China.

    Let me explain. Chinese and American and British researchers have published a letter in the American Journal of Clinical Nutrition in which they report evidence of a significant association between regional selenium status and the reported cure-rate of COVID-19 infected patients in China [Zhang 2020].

    The researchers’ data show a statistically significant association between the reported cure-rates for COVID-19 virus infections and selenium status in China [Zhang 2020].

    The Selenium Status and COVID-19 Cure-Rate

    Beginning in mid-February 2020, the researchers collected data from the Baidu website, which they describe as a non-governmental website that provides daily updates of reports from the health commission of each province in China. read more

    Selenium and Viral Infections

    Selenium deficiency is associated with increased virulence of viruses in human hosts.

    Selenium and selenoproteins have a role to play in the protection of humans against viral infections [Méplan & Hughes 2020].

    Viruses and viral infections are scary enough in and of themselves. Witness the effects of the current corona virus pandemic COVID-19.

    Even more scary are the effects of nutritional deficiencies such as selenium deficiency on the body’s ability to fight off a viral infection.

    Selenium Deficiency Associated with Increased Virulence of Viruses

    Low selenium status, defined variously as serum selenium status below 70 micrograms per liter or below 85 micrograms per liter, is associated with the following deleterious effects of viral contagion [Méplan & Hughes 2020]:

    • The viral pathogens induce oxidative stress by generating more harmful free radicals. The result is oxidative damage to cells, proteins, and DNA.
    • The viral pathogens diminish the cells’ antioxidant defenses including diminishing the activity of the antioxidant seleno-enzymes, e.g. the glutathione peroxidases and the thioredoxin reductases.
    • The viral pathogens increase oxidative stress to the extent that it can induce mutations of the genomes of the attacking virus. The result is that the mutated viruses are more virulent than the initial viruses were. This increased virulence of mutated viruses has been seen in both coxsackie viruses and influenza viruses. The consequence of the increased virulence is to make the viruses more dangerous even to people with adequate selenium status.
    • The viral pathogens reduce the ability of the immune system to respond to the virus. This reduced immune response to viruses has also been seen in the response of selenium deficient humans to the HIV virus and the hepatitis B and C viruses.

    Re selenium deficiency: Bomer et al reported more severe signs and symptoms of heart failure and poorer exercise capacity and poorer quality of life in heart failure patients with serum selenium concentrations below 70 mcg/L.  Rayman reported that serum and plasma levels below 85 mcg/L are associated with decreased survival in HIV-infected patients [Bomer 2019; Rayman 2012]. read more