Selenium: Why We Need It

In an online article in the Cleveland Clinic’s Health Essentials series, the registered dietician Kayla Kopp explains that selenium is an essential trace element that helps thyroid gland function and reproductive function, among other health benefits [Cleveland Clinic 2023].

Hospital care
The Cleveland Clinic article about the essential trace element selenium highlights the effect of selenium on thyroid health, reproductive health, asthma management, and cancer.

What does it mean that selenium is an essential trace element? Answer: our bodies need adequate selenium to function well. However, our bodies cannot synthesize selenium. We have to get our selenium from our food.

What are the health benefits of adequate selenium intake and adequate selenium status? Answer: Kopp says that selenium is important for the following reasons [Cleveland Clinic 2023]:

  • helps to protect our cells from damage
  • promotes good thyroid function
  • promotes good reproductive function
  • plays a role in DNA synthesis

Selenium Supports Thyroid Health

The thyroid gland is responsible for producing and releasing the hormones that control our metabolism. The metabolism rate is what determines how rapidly or slowly our bodies convert food into energy. The selenium we absorb from our food or from supplements gets converted into selenoproteins. These selenoproteins then help to regulate our thyroid hormones [Cleveland Clinic 2023]. read more

Correcting Selenium Deficiency in Thyroid Disorders

Selenium supplementation. There seem to be two different approaches. One approach regards selenium supplementation as a direct pharmaceutical treatment. For example, it is considered a form of medication administered to thyroid disorder patients. Alone or together with thyroid disorder medication, the selenium supplementation is intended to 1) alleviate symptoms, 2) slow the progression of the disorder, and 3) perhaps provide a cure [Schomburg 2019].

Selenium researcher Urban Alehagen
Data from the Swedish KiSel-10 study show that combined daily selenium and Coenzyme Q10 supplementation has a beneficial effect on thyroid hormones and quality of life. outcomes.

A second approach to selenium supplementation does not regard the administration of selenium as a pharmaceutical intervention. Rather, the second approach considers selenium supplementation to be a nutritional intervention designed to address and correct a deficiency condition. This approach recognizes that both sub-optimal selenium status and selenium deficiency limit the body’s expression of vital selenoproteins. These selenoproteins are needed to minimize health risks and to alleviate disease symptoms. Supplemental selenium can be necessary to enable the full endogenous expression of selenoproteins [Schomburg 2019]. read more

Selenium and Thyroid Health

Good thyroid health depends, in part, upon the bio-synthesis of selenium-dependent seleno-enzymes called deiodinases. These seleno-enzymes are key factors in thyroid hormone metabolism and regulation. Thyroid hormones regulate the body’s metabolism (think: energy expenditure, body weight, body temperature, digestion, heart rate, etc.).

Dr. Jan Alexander - selenium researcher
Guest author Dr. Jan Alexander. MD, PhD, Eurotox Registered Toxicologist, and Professor at the Norwegian Institute of Public Health in Oslo. Co-author, together with Professor Urban Alehagen and Professor Jan Aaseth, of many articles about selenium and Coenzyme Q10.

There are three types of deiodinase enzymes. In normal thyroid function, these deiodinases regulate the activation and inactivation of the T4 and T3 thyroid hormones, as needed. Abnormal thyroid hormone function is closely associated with diminished health-related quality of life and with increased risk of cardiovascular morbidity and mortality.

In many selenium-poor regions of the world, including much of Europe and the Middle East, low selenium intake and status may cause sub-optimal synthesis of deiodinase enzymes and, consequently, sub-optimal thyroid gland function. Selenium is an essential trace element found in soil, and humans must get it from their food. read more

Selenium and Graves’ Hyperthyroidism

Thyroid disease. What is the role of the micronutrient trace element selenium in thyroid disease? The thyroid gland is the organ in the body that contains the greatest amount of selenium per gram of tissue [Wang 2023]. Even in times of low dietary selenium intakes, the thyroid gland has high priority for the supply of selenium in the body [Schomburg 2020].

Endocrine system depicted
The thyroid gland is part of the endocrine system. It plays an important role in the body’s metabolism. It has high priority for the supply of selenium in the body.

Dietary selenium intakes vary considerably from region to region in the world. There are large differences in the soil content of selenium and in the factors that influence the bioavailability of selenium to plants. As a consequence, individuals’ plasma/serum selenium status varies accordingly [Winther 2020]. Thus, widespread sub-optimal selenium status has been reported throughout Europe, the United Kingdom, and the Middle East [Stoffaneller & Morse 2015]. read more

Chronic Fatigue Syndrome and Impaired Selenium Transport

In a considerable number of chronic fatigue syndrome patients, researchers have observed the presence of autoantibodies to the selenium transporter Selenoprotein P. These autoantibodies disturb the normal transport of selenium to the tissues  in the body. They cause lower than normal levels of the antioxidant selenoenzyme glutathione peroxidase and lower than normal levels of deiodinase enzyme activity [Sun 2023].

Tired young woman at computer
Chronic fatigue syndrome is a complicated disorder that causes abnormal fatigue lasting six months or longer. Impaired selenium transport may be a factor underlying chronic fatigue syndrome.

Note: Autoantibodies are antibodies produced by the immune system and directed against the individual’s own proteins, in this case against selenoprotein P proteins. In an earlier study, researchers have identified autoantibodies to selenoprotein P in patients with Hashimoto’s thyroiditis, in which case the autoantibodies also impair selenium transport and selenoprotein expression [Sun 2021]. read more

Selenium Deficiency and Thyroid Disorders

Selenium plays an important role in optimal immune and endocrine system function. The role that selenium plays with respect to thyroid function is complex [Chmura 2022]:

Thyroid system
Good thyroid system function promotes improved metabolism, better growth and development, and increased effect of catecholamines. Note: Catecholamines are hormones released in response to emotional or physical stress. (Attribution: Mikael Häggström, Public domain, via Wikimedia Commons.)

The thyroid gland is the organ with the greatest amount of selenium per gram of tissue.

  • An adequate supply of selenium is necessary for synthesizing the enzymes – the iodothyronine deiodinases – that are involved in the metabolism of thyroid hormones.
  • Selenium supplementation may give beneficial effects to patients with autoimmune diseases of the thyroid gland.
  • There is a significant correlation between selenium deficiency and thyroid gland dysfunction. Selenium deficiency is defined as serum or plasma selenium levels below 70 mcg/L. Optimal serum/plasma selenium levels are approximately 125 mcg/L [Winter 2020].
  • Selenium Deficiency and Thyroid Dysfunction

    A 2022 review highlights the following relationships between selenium deficiency and thyroid gland dysfunction [Chmura 2022]: read more

    Adjuvant Treatment of Graves’ Hyperthyroidism with Selenium Yeast

    Thyroid disease. Hyperthyroidism. Adjuvant treatment of thyroid disease with selenium yeast supplementation. All topics of interest. At this writing (August 2022), we await the publication of the outcomes of the GRASS clinical trial. GRASS is the acronym for the selenium supplementation for patients with Graves’ hyperthyroidism study [study protocol described by Watt 2013].

    What is Graves’ Hyperthyroidism?

    Thyroid gland
    The thyroid gland is a butterfly-shaped endocrine gland in the neck below the Adam’s apple that makes and stores hormones that help regulate blood pressure, body temperature, heart rate, and the rate at which food is converted into energy. [This image is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.]
    Hyperthyroidism is an autoimmune disease. It causes overactivity of the thyroid gland, resulting in too much production of the hormone thyroxine. Hyperthyroidism can cause an acceleration of the body’s metabolism; it can cause weight loss and rapid or irregular heartbeat.

    Hyperthyroidism is caused by a number of conditions, including Graves’ disease, which is a common cause. Graves’ disease is the result of immune system disorder. It can affect anyone, but it is more common in women and in individuals under the age of 40. read more

    Selenium and Immune Function and DNA Repair

    Selenium is a trace element essential for for DNA repair, for  good immune function, and for reduced mortality risk.

    DNA double helix
    Cell studies, animal models, and human clinical trials suggest that an optimal supply of selenium is required to enhance the process of DNA damage repair.

    The Micronutrient Information Center maintained by staff members at the Linus Pauling Institute of the Oregon State University provides reliable information about the vitamins and minerals and trace elements used in nutritional supplements.

    Today, I want to summarize the information that the Center provides about selenium and supplement that information with the latest scientific research.

    An Introduction to Selenium and Selenoproteins

    Selenium is a trace element that is essential that humans need for the proper functioning of selenium-dependent selenoproteins. Free selenium is rare in the body. Instead, the selenium in the body is typically a component of selenomethionine, selenocysteine, and methyl-selenocysteine. read more

    Selenium Supplementation and Autoimmune Thyroiditis

    Autoimmune thyroiditis is the umbrella term for various types of thyroiditis in which the immune system mistakenly attacks the thyroid gland.

    Endocrine glands placement
    The thyroid gland is the butterfly-shaped endocrine gland in the lower part of the neck. It plays an essential role in the regulation of our basic metabolism.

    The result is often hypothyroidism, the insufficient functioning of the thyroid gland.

    The two major types of hypothyroidism are Hashimoto’s disease and atrophic thyroiditis.

    Thyroiditis is the medical term for inflammation of the thyroid gland.

    Immune system disorder can also cause an overactive thyroid, called hyperthyroidism; Graves’ disease is the most common form.

    Selenium Supplementation to Prevent Hypothyroidism

    In a 2021 review article, Filipowicz et al assert that many European endocrinologists prescribe selenium supplements to autoimmune thyroiditis patients.

    For example, a 2016 survey of 815 doctors (91% endocrinologists) has shown that almost 80% of the surveyed doctors prescribe selenium supplementation to autoimmune thyroiditis patients. The rationale for the selenium supplementation is the delay of the hypothyroidism or a decrease in thyroid antibodies [Filipowicz 2021]. read more