Selenium and Vitamin D for Thyroid Health

Supplementation with selenium and vitamin D can improve the prognosis of type 2 diabetes mellitus and Hashimoto’s thyroiditis. Adding a daily dose of selenium and vitamin D to conventional diabetes medication can give significant health benefits [Yu 2024].

Selenium and Vitamin D for Type 2 Diabetes and Thyroid Disorder
A Chinese study suggests that combining conventional diabetes medicine with selenium and vitamin D supplements  reduces the levels of TSH and TPOAb and blood glucose and blood lipids in patients with concomitant type 2 diabetes and Hashimoto’s thyroiditis.

Researchers at Hunan University of Chinese Medicine, Hunan Province, China, recommend 100-200 mcg/day of selenium and 100 mcg/day of vitamin D for three to six months for patients with Hashimoto’s thyroiditis and especially for Hashimoto’s thyroiditis patients with concomitant type 2 diabetes [Yu 2024].

A 2024 study by Feng et al has shown that adding 200 mcg of selenium daily and 100 mcg of vitamin D to standard anti-diabetic drugs significantly improved thyroid function, thyroid antibodies, blood glucose, and blood lipids in type 2 diabetes patients who were also diagnosed with Hashimoto’s thyroiditis. read more

Selenium Supplementation and COVID-19

There is, at present, an ongoing scientific debate about selenium supplementation and the possible prevention of COVID-19 disease. What is the evidence that selenium supplementation of individuals with sub-optimal selenium status might help to prevent the infection?

Margaret P. Rayman, selenium researcher
Margaret P. Rayman, Professor of Nutritional Medicine at the University of Surrey in the United Kingdom, is a long-time researcher into the effects of selenium and iodine on human health.

The answer from a group of longstanding selenium researchers is that selenium supplementation does not have “a sufficient direct antiviral effect to prevent infection.” Instead, selenium supplementation acts “by decreasing the harmful effects of the virus on the host” [Rayman 2024].

Selenium supplementation “does not necessarily prevent infection but rather decreases the severity and mortality resulting from the infection” [Rayman 2024]. The important thing to focus on is the interaction between the human host selenium status and infectious virus strain and virulence [Beck 2003]. read more

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

Selenoprotein P for Better Quality of Life and Longevity

In a KiSel-10 trial sub-study, Prof. Urban Alehagen and a team of researchers have observed a positive association between the levels of serum selenoprotein P (SELENOP) and the serum levels of both total selenium and the seleno-enzyme glutathione peroxidase GPx3. Accordingly, the researchers noted that the serum SELENOP concentration level can serve as a useful biomarker for the selenium status of individual study participants and of individual patients [Alehagen 2024].

Prof Urban Alehagen - selenium researcher
Prof Urban Alehagen is the lead researcher on the KiSel-10 trial of the effect of combined selenium and Coenzyme Q10 supplementation on the quality of life and longevity of elderly Swedish citizens with low dietary selenium intakes.

Important to note here is that daily supplementation with 200 mcg of selenium from a selenium-enriched yeast preparation induced significantly higher serum concentrations of SELENOP in elderly community dwelling Swedish citizens, average age: 77 years. In the active treatment group, the selenium supplementation resulted in the saturation of SELENOP in the blood at a serum selenium level of 146 mcg/L. The selenium supplementation also resulted in a saturation of GPx3 at a serum selenium level of 99 mcg/L. This positive association between the level of SELENOP, on the one hand, and serum selenium and GPx3, on the other hand, is in agreement with the existing research literature [Alehagen 2024]. read more

Selenium and Hashimoto’s Thyroiditis

Hashimoto’s disease is an autoimmune disease. It is a disease that causes underactive thyroid (hypothyroidism). The body’s own immune-system cells attack the cells of the thyroid gland and gradually break them down and destroy them. This, of course, has a detrimental effect on thyroid gland function and on important metabolic processes in the body.

Selenium and thyroid gland function
The thyroid gland regulates energy metabolism, heart rate, breathing, digestion, body temperature, mental activity, and other body processes. Adequate selenium intake is necessary for thyroid hormone production.

Hashimoto’s is a bit tricky. In its early development and progression, there may not be any obvious symptoms. Eventually, such symptoms as fatigue and lethargy and weight gain will make themselves manifest. Hashimoto’s thyroiditis is a debilitating disease. It lessens a person’s quality of life. It tends to affect women more than men.

Of all the organs in the body, the thyroid gland has the highest concentration of selenium. It is a greedy organ with respect to selenium. An adequate intake of selenium can lessen the severity of hypothyroidism symptoms and is associated with lowered levels of autoimmune thyroid peroxidase antibodies. read more

Maternal Selenium Status and Offspring Risk of Autism and ADHD

A healthy pregnancy. Selenium is an essential trace element needed to support a healthy pregnancy. However, to date, studies of the mother’s selenium status and the child’s growth and development are scarce. Data from the Odense Child Cohort study in Denmark give researchers an opportunity to investigate the possible effects of the mother’s low selenium intake and low selenium status on the child’s neuro-development [Demircan 2023; Demircan 2024].

Dannebrog - Denmark's flag
Denmark is a country with selenium-poor soil and selenium-poor crops and fruits. The estimated mean daily intake of selenium in Denmark is 48 mcg/day with a 5th percentile intake of 27 mcg/day [Larsen 2004].
The pregnant women enrolled in the Odense Child Cohort study had borderline selenium deficiency status. Their serum selenium levels ranged from 57 to 75 mcg/L [Demircan 2024]. For the sake of comparison, note that Alexander & Olsen propose 110 mcg/L as an optimal selenium saturation level [Alexander & Olsen 2023]. read more

Selenium: An Essential Trace Element

We humans need an adequate dietary supply of selenium. Like iron and iodine, our bodies need this essential trace element in sufficient amounts from food for normal physiological functioning.

Prof Jan Alexander, selenium expert
Guest author Prof. Jan Alexander, MD PhD, specialist in occupational medicine, professor and former specialist director at the Norwegian Institute of Public Health, Oslo, Norway.

The content of selenium in food varies according to the selenium content of the soil in any particular region [Stoffaneller & Morse 2015]. Unfortunately, in most areas of the Nordic and Baltic countries, the soil is poor in selenium. Accordingly, the local crops and fruits tend to have low selenium content. An exception is Finland, which enriches soil fertilizers with selenium. Import of wheat from regions with high contents of selenium in the soil has earlier been an important source of selenium in Norway [Alexander & Olsen 2023].
read more

Selenium and Heart Disease

Heart disease. The evidence from clinical studies is increasing. Selenium deficiency is associated with an increased risk of heart trouble [Bomer 2020]. Selenium supplementation of elderly individuals who have low selenium status is associated with improved survival, improved heart function, and improved quality of life [Alehagen 2013].

Map of Europe
Selenium intakes and selenium status in countries in northern Europe are generally quite low. Consequently, clinical trials conducted in northern Europe tend to be more valuable than clinical trials conducted in the USA where dietary selenium intakes are considerably higher for the most part.

Especially in northern Europe, clinical studies show the relationship between the need for selenium and the risk of heart disease. This makes sense because the dietary selenium intake in northern Europe is considerably lower than the dietary selenium intake in much of the United States. Consequently, the mean plasma selenium concentrations in Europe tend to be well below 80–90 mcg/L. In the USA, on the other hand, the mean plasma selenium concentrations are generally above 120 mcg/L [Alehagen 2022]. 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