Expert explores link between Covid severity and selenium deficiency


Selenium is an essential mineral, and scientists say it must be obtained through our diet, that it’s only needed in small amounts but plays a major role in important processes in our body, including our metabolism and thyroid function. Top of Form

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Selenium deficiency, scientists further say, has a striking yet overlooked link with Covid-19 brutality, and they argue there is a need for a Selenium supplementation action plan, looking at the severity with which the pandemic continues to ravage communities of the world.

Public Eye Editor TEBOHO KHATEBE MOLEFI (PE) engaged AIDS, Ebola and Covid-19 researcher and Director of the Selenium Education and Research Centre (SERC), HOWARD ARMISTEAD (HA), to establish the basis for this scientific theory and what link Selenium has to Covid-19 severity in hard hit societies.

PE: What is selenium? Are there risks involved in selenium deficiency in the body?

HA: Selenium is an essential trace element required for good health. Every cell of the body contains selenium. It maintains the structural integrity of cellular membranes and forms the functional element of GPx, the universal antioxidant that helps keep every cell clean and detoxified. Selenium is also the key element required for all aspects of the immune system to function properly.

Although most people worldwide do not get enough selenium in their diet, extremely few are so deficient they suffer serious negative health consequences. That rarely occurs and only in places where levels of selenium in the soil are extremely low, such as one district in China, another in the Congo, and a few other far-flung places.

Serious selenium deficiency is usually the result of disease. Viruses, bacteria, and cancer cells all require selenium to construct their bacterial and cancer cells and viral particles. These disease agents obtain the selenium they need by acquiring it from the body’s cells and organs. When bacteria, cancer or viruses multiply faster, they deplete cell selenium faster, causing a dangerously low level.

As selenium resources are used up by disease causing organisms, the immune system gradually collapses into immune deficiency, inflammatory excess, loss of CD4 cells and immune control, a cytokine storm rages, followed by organ failure, sepsis, and death. AIDS, Ebola, and critical stage Covid-19 all follow this same pattern.

PE: Why would a person have to take selenium supplements for a selenium deficiency?

HA: Selenium is as essential to health as oxygen or water. Most people know about oxygen and water. Most do not know much about selenium.

If a person loses 20 percent of the water in their body, they die. If the average person loses 20 percent of the total selenium supply in their body they suffer “immune deficiency”, as in AIDS. Their CD4 count would be low, and their immune system would not function well. Opportunistic infections would begin to occur. If a person loses 30 percent of their selenium, they will be on the way to see their ancestors.

Most fatal viruses cause death because they deplete the immune system of selenium. Some like HIV, a lentivirus, do so slowly. Others like Ebola do this in just a few short weeks. The faster a virus drains selenium, the faster the limit of mortality is reached.

To prevent death from dehydration all one does is to replace the missing hydrant – water, or H2O. Likewise, to re-boost the immune system, restore immunocompetence and the antioxidant balance one needs to supplement selenium back into the body at the required amount. The more severely immune compromised or the more advanced the disease is, the more and more quickly selenium needs to be supplemented.

PE: Is the effect of selenium deficiency checked by other dietary nutrients? Which are they?

HA: Selenium can be affected both positively and negatively by some other nutrients. Vitamin E may give selenium a slight boost and in some limited circumstances even substitute for the benefit of selenium. Zinc is a cellular receptor antagonist to selenium. They compete for the same receptor to enter cells. Very high levels of zinc may reduce somewhat the cellular absorption and efficiency of selenium.

Likewise, extremely high levels of vitamin C will reduce the benefits of selenium. How high? Probably anything over 1 000mg of vitamin C daily will retard the beneficial effect of selenium.

PE: Although only a small amount of selenium is needed, what key role does it play in metabolism?

HA: Selenium supplementation increases the body’s rate of metabolism; it slightly increases the body’s energy level. The thyroid gland primarily controls metabolism. The thyroid is the part of the human body with the highest concentration of selenium. 

PE: What are the upper limits for consumption of selenium for adults and children?  

HA: Selenium toxicology is a fascinating subject. Even the word “toxic” means different things to different people. As with alcohol, there are many degrees or shades of toxicity. In fact, selenium is a well-known antidote for heavy metal poisoning. It is also used to treat radiation sickness. Doctors in Ukraine used it to treat victims of the 1986 Chernobyl nuclear disaster. So, selenium can be used as an anti-toxin. It can probably also help against alcohol poisoning.

The minimum recommended daily requirement (RDA) of selenium for adults and children 14 years old and over is 55mcg per day. Many scientists suggest 100mcg provides a more optimal level for full immunity.

However, people over the age of sixty or who suffer from chronic conditions often benefit from supplementation. These people often need a full strength 200mcg selenium supplement to maintain optimal health.

Selenium toxicity is graduated from marginally toxic, to heavily toxic. Again, one person’s supposedly “toxic” level is another person’s “medicine” – depending on their health condition. Using selenium as a supplement over 400mcg daily, it is considered a drug and should be used with a doctor’s recommendation. As with many medicines, dosage depends on the intended application.

Highly successful clinical trials of selenium against deadly viral illnesses like the haemorrhagic fever Hantavirus have used 2.0gr of selenium to reduce mortality rates by 80 percent. When the Liberian Ministry of Health asked me in 2014 to bring to selenium to test against Ebola, I told the doctors to use 2.0mg per day. That was the dose reported in the scientific literature that had been used successfully in reducing deaths from fatal viral diseases. Instead, the Liberian doctor only used 1.2mg per day.

However, when added to the WHO standard of care for Ebola alone, within just over a week selenium reduced the mortality rate fell by 46.8 percent. If the higher recommended dose had been used it should have reduced the dying by about 65 percent.

China has one district where soil selenium is extremely high and people on average take in approximately 4 500mcg per day, year after year. That is enough to make people’s hair fall out, just as if they were taking an anticancer drug. That extremely high dose, although physiologically damaging, still does not kill people outright. A higher dose, perhaps over 5 000mcg might eventually prove fatal. As the nutrition textbook Perspectives in Nutrition explains, “Daily intakes as low as 2 000-3 000mcg can cause toxicity symptoms if taken for many months.”

As a supplement, a 200mcg tablet provides all the benefits of boosted immunity. However, some people with highly adverse chronic conditions may require 400mcg. The only time a doctor would want to recommend a dosage higher than 400mcg is with something like pneumonia, encephalitis, meningitis, or advanced viral disease such as with AIDS below 100CD4 count, Ebola, Hantavirus, or hospitalized Covid patients. With those potentially fatal conditions, using the correct higher dose of selenium may save a life.

The proper dose of selenium for children depends on age. The recommended minimum daily requirement of selenium for children ages four to eight is 30mcg, and for ages nine to 12 is 40mcg.

PE: What are the risks of taking selenium?

 HA: Because selenium is the key element required for the immune system and it is needed by every cell in the body to keep them healthy and detoxified, the main risk of taking selenium supplements is being healthier. In fact, the “risk” is in not taking selenium. For instance, selenium has been shown to be the strongest thing to help prevent cancer.

Many scientists suggest selenium slows the aging process because it keeps cells healthier for longer, slowing down the need to replace old cells with new. Selenium supplements increase the appetite slightly so some people may gain a kilo or two in weight.

The mineral selenium is also used in some industrial processes. Industrial strength selenium is a thousand time as concentrated as nutritional supplement selenium. Industrial selenium is deadly poisonous. However, science has never recorded a single death from taking selenium nutritional supplements.

They are 100 percent safe if taken sensibly. Selenium is also beneficial for the mood. According to the Lancet medical journal, selenium helps against anxiety, depression, confusion, and hostility. In short, selenium works not only as an immune booster increasing CD4 count but a mood enhancer as well. It also reduces the frequency of colds and flu.

PE: Is there a correlation between viral disease severity and selenium levels in humans?

HA: Yes. Most harmful viruses attack the selenium supply of the cells they infect because they need that selenium to construct more viruses and subvert immune defences. As viruses replicate and viral load increases, multiplying viruses increasingly use up selenium, so the body and the immune system’s selenium supply is progressively depleted. As selenium levels fall, CD4 count falls as well. That contributes to the immune dysfunction that results in an immunological cascade toward death.

As aggressive viruses progressively deplete both selenium and CD4 count, the informed physician should accelerate selenium supplementation to compensate for the higher loss of selenium during critical, late-stage illness. With highly lethal viruses like Marburg and Hantavirus, 2.0mg selenium daily has been used to achieve massive reductions in mortality rates.

It would be logical to apply this dosage for critical Covid-19 patients with at least 1.0mg daily for hospitalised patients and those taking supplemental oxygen. The extremely high replication rate of the SARS-CoV-2 Delta variant calls for rapid replacement of the body’s selenium supply.

PE: Can selenium deficiency be related to increased case fatality rates for Covid-19?

HA: Yes. Chinese researchers reported in the International Journal of Infectious Disease that 100 percent of Covid patients that are on ventilators, are in critical condition, or that die are all deficient in selenium. The only other nutrient that is significantly deficient and needs to be supplemented in these advanced Covid patients is vitamin D3.

Selenium levels fall as viral replication and viral load increase. The more virus there is, the lower the selenium level and CD4 count, the sicker the patient, and the higher the fatality rate. Recently, the SARS-2 Delta variant has been reported to produce viral loads 1 000 times as high as the original, wild-type corona virus.

PE: Has selenium had an impact on the varying fatality rates around the world?

HA: If selenium were used widely to treat Covid-19 it would have a major impact in reducing deaths everywhere. It has not been used widely because WHO bureaucrats are not generally scientists. They focus on protecting their institutional interests and those of their funders. They rarely if ever rise above the lowest common denominator of conservative medical consensus, which often runs years behind cutting-edge science.

Developed nations with more developed or comprehensive healthcare systems have a Covid fatality rate about half that of developing countries. However, nutritional selenium levels in populations do not exert a noticeable effect because the small difference in dietary selenium is not enough to affect disease outcomes. One exception is in China.

Levels of soil selenium vary greatly around the world. There are some places where people average only about 30mcg selenium per day including one district in China. A few districts away lies another with a much higher level of selenium intake – over 1 000mcg. Scientists conducted a statistical comparison of the Covid-19 mortality rate between the two districts and the one with the much lower selenium intake had five times the case fatality rate as the district with higher levels of selenium.

PE: What affects the selenium content of food? Does it depend on the level of selenium in the soil?

HA: Selenium is contained in practically every food we eat because it is found in almost every animal cell, and most plant cells. It in everything we eat except table salt – NaCl. Ironically, selenium is quite scarce, but found almost everywhere. It is an essential trace element measured in minute amounts. Dietary selenium concentrates up the food-chain, with higher levels in meat, chicken, and seafood, and much lower in fruits and vegetables. Many commercial animal feeds are supplemented with selenium so commercially produced meat and eggs tend to be slightly higher in selenium.

Soil and dietary selenium levels range widely around the world with some of the lowest levels in New Zealand and Liberia with higher levels in the United States, Japan and Venezuela. Like most of Europe, most Southern African soils and diets are slightly selenium deficient, so most people in Southern Africa could benefit by taking a selenium supplement each day.

PE: What foods contain a lot of selenium?

HA: Every food contains at least a tiny amount of selenium because all animals and edible plants contain this essential protective mineral element. However, the amount of selenium contained in different foods varies widely.

Most people get the largest portion of dietary selenium from staple grains. Wheat, bread, and pasta contain a good supply of selenium. Rice provides only half as much as wheat, and corn only a quarter as much. That is why a corn-based diet tends to be lower in selenium.

In general, fruits and vegetables are poor sources of selenium, but there are exceptions. Vegetables like broccoli and cauliflower are relatively good sources, as are mushrooms. Oranges have more than most fruits and some seeds and nuts are a source.

The most concentrated source of dietary selenium is Brazil nuts. One Brazil nut contains 160-180mcg of selenium. However, Brazil nuts also contain minute doses of mercury. Selenium from nutritional supplements is safer, measure-controlled, widely available, and no more expensive than Brazil nuts.

Selenium is concentrated up the food chain. Animal products such as meat and eggs contain much higher levels of selenium than fruits and vegetables. Because selenium is concentrated in the cells and organs of the immune system, kidney and liver meat are especially excellent sources.

Seafood, including shellfish, is also quite high in selenium. Many commercial livestock feeds are supplemented with selenium because livestock farmers want to keep their pigs, chickens, and cattle healthy and productive. They know about selenium. Thus, commercially raised meat and eggs may have a slightly higher selenium content. While livestock farmers realise the health benefits of selenium and provide that to their animals; remarkably, no one seems to do that for humans.

Thus, most people do not enjoy the benefits of selenium supplementation. Naturally, many people jump to the conclusion that if they get sick and selenium is known to be beneficial for their condition, they can just eat more selenium rich foods.

Unfortunately, that is not sufficient because viral diseases drain selenium perhaps ten times faster than one can replenish it through dietary means alone. Taking measured amounts of selenium via nutritional supplements is much more cost efficient and effective than trying to eat liver meat three times a day.

PE: How does selenium differ between countries and continents? What about China, the US, Europe or Lesotho?

HA: Selenium in the food chain originates from selenium in the soil. Soil selenium content varies widely between and within countries. For instance, both China and the DRC Congo have some areas that are very high in selenium and other places that have extremely low levels.

Most people in most nations are marginally selenium deficient because the soil of most countries is moderately low in selenium. Some countries are especially low such as New Zealand and Liberia. However, New Zealanders have a diet rich in meat and many Liberians have access to seafood. Like Southern Africa, most European countries have relatively low selenium soil content.

Due to intensive farming methods using fertilizers, the level of selenium in the soil has dropped by as much as 50 percent in the last 80 years. Finland decided to supplement selenium into their agricultural soil because selenium also works as a natural agent to help prevent cancer.

A few nations enjoy a relatively high soil selenium content including the United States and especially Venezuela. Japan enjoys perhaps the highest dietary content of selenium due to the high portion of diet composed of seafood and seaweed. This fact combined with the cradle-to-grave, free healthcare system results in the longest average lifespan of any nation on earth.

PE: If someone thinks they might not be getting enough selenium and wanted to take supplements, how much should they take?

HA: Most selenium supplements provide 200mcg of selenium, although some come in 100mcg or 60mcg strengths. One 200mcg tablet provides all the immune boosting power most adults require. For people with no health problems 100mcg per day is sufficient. However, people who suffer serious chronic ailments like rheumatoid arthritis, may need up to 400mcg per day. That is still an extremely safe dose.

PE: Is it necessary to avoid selenium toxicity?

HA: One good thing about selenium is how safe it is. Except at extremely high doses that one should never need for health maintenance, selenium supplements have virtually no negative side effects. But it does have some positive side effects as listed below.

Real selenium toxicity starts at 800 to 1 200mcg per day although some literature sets it at a lower level. That distorts the meaning of the word toxic. The first signs of low-level selenium toxicity are fingernails beginning to darken slightly and garlic breath.

It is virtually impossible to “overdose” on selenium. But there is no reason to take more than necessary. 200mcg is enough for 95% of people unless they are battling a viral infection, active tuberculosis, cancer, or other potentially fatal condition.

Working through the immune system, selenium provides so many health benefits including improving the skin, hair, and nails; reducing minor aches and pains, boosting immunity and CD4 count; helping prevent colds and flu, helping against cardiovascular disease including reducing heart attack and stroke; reducing depression and improving mood; and retarding cancer.

It can improve male fertility and reduce many problems related to pregnancy and childbirth. Generally, selenium helps to improve health, boost energy, mood, and immunity, and perhaps marginally extend life.

PE: In Covid-19, does selenium deficiency affect the fatality rate of the elderly?

HA: Elderly patients are usually the most susceptible group when it comes to pandemic disease like Covid-19, influenza, or tuberculosis. There are two reasons for that. First, as we age, we develop what doctors refer to as co-morbidities. That means additional illnesses or disease such as diabetes, kidney or heart disease, or cancer, TB, or HIV.

Each of these co-morbidities cause stress on the body and stress the body’s selenium supply. Second, as people age their immune system begins to decline, especially over the age of 65. Giving immunity a boost with selenium supplements is sensible for any health-conscious senior.

Scientists have determined that the SARS-CoV-2 virus causes Covid-19 by attacking the selenium supply found in antioxidants. The virus destroys those antioxidants causing harm to cells and blood vessels, as well as the lungs, heart, liver, and kidneys. As Covid disease progresses, the selenium supply is progressively depleted as viral load increases along with the severity of the disease.

Replacing the body’s lost selenium, boosting immunity, and rebalancing the prooxidant-antioxidant balance in the body is an important way that both young and old people can take advantage of scientific knowledge to help survive Covid-19 as well as most other viral infections.

You and your personal physician should utilise this knowledge to improve health and reduce the chance of disease fatality. The science suggests that safe, affordable, available selenium supplements can probably reduce the mortality rate of Covid-19 significantly. The question is – who will act based on the facts of science to save more lives from this pandemic disease?

  • Howard Armistead is an AIDS, Ebola and Covid-19 researcher and Director of the Selenium Education and Research Centre (SERC) in Johannesburg. He has studied selenium’s effects on viruses and disease for over twenty years. More information can be found at


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