Selenium and Good Immune System Response

In people with selenium deficiency (variously defined as serum selenium status below 60 mcg/L or 70 mcg/L), the responses of the innate and adaptive immune systems may be impaired.

Immunity spelled with Scrabble pieces
Selenium intake and status play a big role in the functioning of the immune system. Selenoproteins help to lower oxidative stress, reduce inflammation, and strengthen immune response to pathogens.

Selenium deficiency can lead to an immune-incompetence that is associated with increased susceptibility to infections [Avery & Hoffmann 2018; Hiffler et al. 2020].

In cell culture models, in rodent models, in livestock and poultry studies, and in human studies, researchers have found evidence that adequate levels of dietary selenium and the efficient incorporation of selenium into selenoproteins are important for immune system function [Avery & Hoffmann 2018].

Studies of selenium supplementation to boost immunity against pathogens have not provided entirely clear-cut results; however, selenium and selenoproteins do play a role in regulating immune cell functions. Dysregulation of these immune cell processes can lead to inflammation and immune-related diseases [Avery & Hoffmann 2018]. 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, Selenoproteins, and Antioxidant Systems

Disinfection materials
Low selenium status is associated with increased virulence of virus infections, with worse symptoms of heart failure, and with greater risk of some forms of cancer.

Oxidative stress is the bio-medical term for a lack of balance between 1) the production of harmful reactive oxygen and reactive nitrogen species and 2) the protective action of antioxidant systems. According to the news network of the Mayo Clinic, oxidative damage has been linked to several conditions such as Alzheimer’s, cancer, cataracts, diabetes, heart disease, macular degeneration, and Parkinson’s.

Free Radicals and Oxidative Damage

The reactive oxygen and reactive nitrogen species are popularly referred to as free radicals. They are molecules produced as natural by-products of metabolic processes and as a consequence of exposure to pollutants, to heavy metals, to industrial chemicals, to some drugs, to some forms of radiation including x-rays, and to cigarette smoking. read more

Selenium: Protection Against Viruses and Bacteria

Changing our behavior will help to protect us against viral infections, e.g. wearing a mask in public, washing our hands with soap and water or an alcohol-based hand rub, maintaining a distance of at least one meter from other people, avoiding crowded places, not touching our eyes, nose, and mouth, covering our mouth and nose with a bent elbow or tissue when we cough or sneeze, self-isolating if we have symptoms. But, equally important, we should make sure we have optimal selenium intakes and status. Selenium strengthens the immune system and protects against viral and bacterial infections.

In a 2015 review of the research literature, the selenium researchers Holger Steinbrenner and Helmut Sies from the Heinrich-Heine-University in Düsseldorf, Germany, give an overview of the effect of selenium status and supplementation in infectious diseases caused by viruses (e.g. HIV, influenza A virus, hepatitis C virus, polio virus, West Nile virus) and bacteria (e.g. M. tuberculosis, Helicobacter pylori) [Steinbrenner 2015].

  • Deficient intake and status of the essential trace element selenium are associated with viral and bacterial infections.
  • In the absence of adequate selenium status, otherwise benign strains of Coxsackie viruses and influenza viruses can mutate to highly virulent strains.
  • Nutritional supplementation with selenium supply to boost selenium status seems to confer health benefits for patients suffering from some viral diseases, in particular patients with HIV and influenza A virus infections.
  • Multi-micronutrient supplements containing selenium have been shown to improve several clinical and lifestyle variables in patients co-infected with HIV and Mycobacterium tuberculosis.
  • Selenium status may affect the function of cells of both adaptive and innate immunity.
  • Supplemental intakes of selenium are associated with the enhanced proliferation and differentiation of naive CD4-positive T lymphocytes toward T helper 1 cells, thereby supporting the acute cellular immune response.
  • Similarly, supplemental intakes of selenium are associated with the directing of macrophages toward the M2 type, thereby counteracting the excessive activation of the immune system with resulting host tissue damage.
  • Data from epidemiological studies and intervention trials, with selenium administered alone or in combination with other micronutrients have shown that selenium status and intake affect immune system functions.

Selenium Status and Intake

In her 2012 review article in The Lancet, the selenium researcher Margaret P. Rayman points out that selenium intakes average 40 micrograms/day in Europe compared with 93 micrograms/day for women and 134 micrograms/day for men in the United States.  Nutritional supplements can provide an additional 50–200 micrograms of selenium per day [Rayman 2012]. 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

We must not waste selenium

Selenium exists only in scarce quantities. Adequate dietary and supplemental intakes are vital for human health.  We need to use it carefully, and we need to begin to stockpile it for the use of future generations.

Selenium is a trace element.  It exists only in rare quantities in the world.  It is produced primarily as a by-product of the process of mining copper.  It is not recyclable.  It is very unevenly distributed in the soils of the earth.

Consequently, the availability of selenium in grasses and grains and, at the next stage of the food chain, in animals, varies considerably from region to region in the world. The human dietary intakes of selenium vary accordingly around the world.

Selenium a vital nutrient for humans
Selenium is a necessary micronutrient that our bodies do not produce.  We get our selenium primarily from our diets.  Selenium is important for good immune system function, good thyroid function, good reproductive function, and good protection of our cells’ DNA. read more

How we know that selenium supplementation is important

Selen supplementation, virus
Adequate intakes of selenium are needed to ensure the optimal functioning of the selenoproteins in the body. Selenoproteins provide protection against the development of cancer and heart disease; they are important for immune system defense; they protect against damage caused by heavy metals and chemical toxins and radiation. And, there is evidence that some of the selenoproteins have anti-viral properties.

Selenium?  A trace element?  You might well ask: How do we know that adequate amounts of dietary and supplemental selenium are important to us?
The first answer is: because we can see that selenium deficiency makes people sick.
A further answer is that we now know that selenium is an essential component of antioxidant enzymes.
And, on the basis of the results of randomized controlled trials, we know that selenium supplementation reduces the risk of cancer, reduces the risk of heart disease, and improves immune function.
Selenium is also very useful for reducing the toxic effects of heavy metals in the body.

Reason number one: Selenium-deficiency diseases
Keshan disease
In the 1960’s and 1970’s, thousands of people living in a region of China with selenium-poor soil, and, consequently, with selenium-poor food, died from the effects of a form of heart disease.  The disease, which took its name from Keshan county in the afflicted region of China, is characterized by inflammation and enlargement of the heart muscle and excess fluid in the lungs. The primary cause of the disease was selenium deficiency. read more

Dr. Gerhard N. Schrauzer – renowned selenium researcher

Dr. Gerhard N. Schrauzer was the first scientist to study the biological functions of selenium systematically. He was known internationally for his pioneering work in the cancer-protective properties of selenium. (Picture: Cancer Research, vol. 49 no. 23, Dec. 1, 1989)

Dr. Gerhard N. Schrauzer was the grand old man of selenium science.  Actually, he was the grand old man of trace element research in the United States for 30 years or more.  He was one of the pioneers and one of the major figures in selenium research.   Let’s take a look at the useful contributions of information to the selenium supplementation knowledge base that Dr. Schrauzer made.

First, who was Dr. Schrauzer in the context of selenium research?
Dr. Schrauzer did his graduate study in chemistry at the University in Munich, Germany. He was awarded his Ph.D. summa cum laude.  From 1966 to 1994, he was a chemistry and biochemistry professor at the University of California in San Diego (UCSD). After his retirement, he was a professor emeritus at UCSD. read more

The functions of selenium supplements

skin-cells antioxidant
Selenium is an important component of the antioxidant defense in the cells. It helps to protect against oxidative damage to both cells and DNA. It has been shown to have a protective effect against the damage to skin cells caused by ultraviolet radiation.

Why the interest in selenium facts?  Here, at the beginning of the website, we want to review in broad terms what we know about the functions of selenium supplementation. We are especially interested in selenium’s antioxidant and anti-inflammatory effects in the human body.

Selenium is an essential trace element in the human diet, and, in many regions of the world, it is an absolutely necessary nutritional supplement.  It has many and diverse functions in the human body.

One of the interesting things about selenium is that it does not perform its functions as an element or an ion.  Instead, it functions as a component of more complex compounds.  In particular, it is an essential component of the 21st amino acid, selenocysteine. read more

Professor Jørgen Clausen: early selenium researcher

professor J. Clausen
Professor Jørgen Clausen was one of the first researchers to realize the importance of supplementation with selenium in regions of the world with selenium-poor soil.

Professor Jørgen Clausen, long-time professor in the Institute for Life Sciences and Chemistry, Roskilde University Center, in Roskilde, Denmark, was one of the early researchers to do clinical studies of the effects of supplementation with selenium. As such, it seems instructive to go back and look at the research done by Dr. Clausen and his colleagues at the end of the 20th century.

Professor Clausen’s selenium studies
Basically, Professor Clausen’s research can be described in five different categories:

  • Effect of selenium supplementation on the health of the elderly nursing home residents
  • Effect of selenium supplementation on the health of cigarette smokers
  • Effect of selenium supplementation on the health of patients with chronic neurologic disorders
  • Effect of selenium supplementation on the toxic effects of lead poisoning
  • Effect of selenium supplementation on the activity levels of the selenium-dependent antioxidant enzyme glutathione peroxidase

In addition, Professor Clausen was an early leader in the investigation of the absorption and health effects of various forms of inorganic and organic selenium supplements.

Selenium supplementation and smokers and oxidative stress
To understand Dr. Clausen’s interest in the effect of selenium supplementation on smokers, we must first understand the concept of oxidative stress and the related concept of oxidative damage.  Oxidative stress occurs when, in the process of metabolism of oxygen, the body produces, as a by-product, various reactive oxygen species (for example: peroxide, superoxide, hydroxyl, and singlet oxygen radicals) to excess. read more