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

Selenium, Fish, and Mercury: Important Facts

Fish should be an important part of our diets. Professor Nick Ralston at the University of North Dakota has drawn our attention to the webpages entitled Fish, Mercury, and Nutrition: The Net Effects. The URL is

The Cover of the Fish, Mercury, and Nutrition brochure
The Fish, Mercury, and Nutrition webpages contain fact sheets, a documentary video, video clips, and links to informative websites.

On these webpages, Professor Ralston and his colleagues explain why the benefits of regularly eating fish, especially ocean fish, are often overlooked. Too many of us have cut back on our fish consumption because we have been worried about exposure to toxic mercury.

However, we have been receiving insufficient information about the relative benefits and risks of eating ocean fish. In fact, our avoiding fish meals may be having negative health consequences in some cases. read more

Selenium in the Prevention and Treatment of Thyroid Disorders

Throid gland in the neck
The thyroid gland is an endocrine gland in the front of the neck just below the Adam’s apple. It consists of two lobes connected by the thyroid isthmus. Selenium deficiency and less than optimal activity of the selenoproteins may be a factor in autoimmune thyroid diseases.

A 2017 summary of the research literature supports the idea that optimal selenium levels are needed for antioxidant protection against harmful free radicals in the thyroid gland and for the normal metabolism of thyroid hormones [Ventura 2017].

A 2018 research literature review shows that selenium supplementation can reduce anti-thyroperoxidase antibody levels and can improve thyroid ultrasound features. In addition, selenium supplementation is associated with improved symptoms and improved quality of life in patients with Graves orbitopathy [Santos 2018].

Note: Anti-thyroperoxidase antibody levels that are too high (>500 IU/ml) are associated with an increased risk of hypothyroidism in autoimmune thyroiditis, which is the most common form of thyroid disorder [Ehlers 2016]. read more

Selenium and Coenzyme Q10 for Senior Citizens

Professor Urban Alehagen
Like a good detective inspector, Professor Urban Alehagen has investigated the biological mechanisms that could explain how combined selenium and Coenzyme Q10 supplementation reduces the risk of death from heart disease in senior citizens. Among the suspects that he has investigated are oxidative stress, systemic inflammation, fibrosis, and endothelial function.

Four years of daily supplementation with 200 micrograms of a patented high-selenium yeast and 200 milligrams of Coenzyme Q10 (in divided doses: 2 x 100 milligrams) has lowered the risk of dying from cardiovascular disease significantly by 54% (p=0.02) [Alehagen 2013].

The study participants were senior citizens aged 70-88 years (average age: 78 years) who were still able to live at home.

Professor Urban Alehagen and a team of researchers from Linköping University in Sweden randomly assigned the senior citizens to take the active treatment (selenium plus Coenzyme Q10) or matching placebos in a double-blind clinical study named the KiSel-10 Study [Alehagen 2013].

Improved Heart Function with Coenzyme Q10 and Selenium

Compared to the senior citizens in the placebo group, the senior citizens in the active treatment group had a significant improvement in heart function as measured on echocardiograms compared to placebo (p=0.03) and a significant improvement in a biochemical marker, NT-proBNP (p=0.014). NT-proBNP is a reliable indicator for heart disease; the heart muscle typically produces more of the NT-proBNP protein whenever the heart is exposed to stress or injury [Alehagen 2013]. read more

Selenium and Mercury Toxicity

A plate of salmon.
Eating fish will give pregnant women and children selenium and other nutrients that will promote the children’s growth and development. Eating fish may give adults heart health benefits. However, some ocean fish contain more mercury than selenium and should therefore be avoided. Consequently, the US Food and Drug Administration advises against eating meals from predatory whales, sharks, swordfish, king mackerel, marlin, orange roughy, tilefish, and big-eye tuna. Most other ocean fish will have more selenium than mercury in their tissues and should be safe, even advisable, to eat.

The selenium in our cells is the molecular “target” of toxic mercury. Inhibition of the normal biological activity of seleno-enzymes is the mechanism by which mercury damages our cells, most particularly our brain and nerve cells [Ralston & Raymond 2018].

Conceiving of selenium as the “target” of mercury leads to a better understanding of mercury toxicity than the old theory of selenium as the “tonic” that binds toxic mercury in a form that is no longer harmful [Ralston & Raymond 2018].

Professor Nicholas Ralston and consultant Lisa Raymond have done a review of the research literature about the characteristics of mercury toxicity to identify the selenium-dependent aspects of mercury’s biochemical mechanisms and effects. Their conclusions [Ralston & Raymond 2018]: read more

Selenium Status and Major Trauma Patients

Abnormally low selenium status is characteristic of critical illness and major trauma. The fall in selenium status occurs very rapidly after major trauma and is associated with poor survival odds. For it to be effective, adjuvant treatment with selenium must be initiated as soon as possible.

Serum selenium and selenoprotein P concentrations drop to very low levels very quickly following major traumatic injury. The very low selenium and selenoprotein P levels are associated with poor survival odds [Braunstein].

These findings in a study done at the University Hospital in Munich, Germany, suggest that selenium supplementation may be a meaningful adjuvant treatment strategy for patients who have suffered major trauma [Braunstein].

Selenium and Critical Illness

Lower than normal selenium status is characteristic of critical illness. Low selenium status can affect the course and the outcome of various diseases [Braunstein].

For example, Bomer et al [2019] found that heart failure patients with serum selenium levels below 70 micrograms per liter had poorer quality of life, poorer exercise capacity, and poorer prognosis than heart failure patients with higher serum selenium levels. read more

Selenium Supplementation and Graves’ Disease

Low selenium status is associated with increased risk of Graves’ Disease. Graves’ Disease is an autoimmune disease of the thyroid. It is the most common cause of hyperthyroidism. It often results in an enlarged thyroid.

A 2018 meta-analysis of randomized controlled trials shows that adjuvant selenium supplementation may enhance the restoration of normal thyroid function in patients with Graves’ Disease [Zheng].

Graves’ Disease is the most common cause of hyperthyroidism in adults. It is characterized by below-normal serum TSH levels and increased serum levels of free thyroxine (FT4) and/or triiodothyronine (T3). The basal metabolic status of Graves’ Disease patients is accelerated; the result is an increase in the production of harmful free radicals and reactive oxygen species [Zheng].

Intra-cellular antioxidant enzymes such as superoxide dismutase (SOD), glutathione reductase, and glutathione peroxidase (GPx) protect against the cellular damage caused by oxidative stress. read more

Selenium Supplementation and Glucose Metabolism

The evidence from a randomized controlled trial shows that 2.9 years of supplementation with 200 micrograms per day had no effect on insulin sensitivity and no effect on pancreatic beta-cell function compared with placebo [Jacobs 2019]. The evidence from randomized controlled trials does not support a role for selenium in the risk of developing type-2 diabetes [Kohler 2018].
The findings from a 2018 meta-analysis show no consistent evidence that selenium supplementation plays a role in the development of type 2 diabetes among adults.

Researchers at the University of Arizona in Tucson, home of the Arizona Cancer Center, identified a statistically significant direct relationship between selenium and Type-2 diabetes in observational studies but no statistically significant relationship in randomized controlled trials [Kohler 2018].

Note: Randomized controlled trials are the gold standard for scientific evidence in the bio-medical field. The randomization of the study participants should produce comparable groups and should eliminate accidental bias.  In observational studies, the researchers do not randomly assign the study participants to groups and do not decide which treatments each group receives or does not receive. read more

Selenium Status and Heart Failure

Heart failure patients with low serum selenium levels are much more likely to be re-hospitalized and/or to die than are heart failure patients with serum selenium levels above 100 micrograms per liter.

A multi-national cohort study has shown that selenium deficiency in heart failure patients is associated with impaired exercise tolerance and with a 50% higher mortality rate [Bomer].

In-vitro studies of cultured human heart muscle cells from the heart failure patients show that  low selenium levels in the heart muscle cells are associated with impaired mitochondrial function [Bomer].

Recent information shows that up to 50% of heart failure patients suffer from some form of micronutrient insufficiency, e.g. selenium, zinc, iron, or iodine [Bomer].

Selenium: An Essential Micronutrient

Selenium intakes and status vary considerably from geographical region to region according to the content of selenium in the soil and in the food.

Sufficient intakes of selenium are necessary for important biological functions: read more