Selenium Deficiency

Researchers have found that low levels of the mineral selenium may contribute to someone developing thyroid eye disease (TED). According to a 2011 study, people with mild TED who took selenium supplements had reduced symptoms compared with those who took a placebo (inactive pill).^1-3

While it is a promising treatment option, more research is needed to understand how a deficiency in selenium can affect the signs and symptoms of thyroid eye disease.

What is selenium, and what functions does it serve in the body?

Selenium is a mineral that is essential to the health of our bodies. It plays an important role in controlling our metabolism, specifically the thyroid hormone metabolism.⁴

Selenium also plays a key role in reproduction, protecting us from infection, creating DNA, and guarding against cellular and tissue damage.⁴

Where is selenium found?

Selenium is most commonly found in the soil. Plants absorb the mineral from the soil, which then passes onto animals when the plants are eaten. Hence, humans get selenium by eating plants and animals.⁴

Selenium is also found in some foods, including:⁴

• Brazil nuts
• Seafood
• Organ meats, like liver
• Beef
• Poultry and eggs
• Dairy products
• Breads, cereals, and grain products

Some areas of the world have naturally higher concentrations of selenium in the soil than others. This can be caused by several different factors, including the pH of the soil and the amount of organic matter found in the soil. For example, certain parts of China and some European countries are known to have less selenium-rich soil than other regions of the world.^1,4

While selenium can be eaten by way of plants and animals, it can also be taken as a supplement. Selenium is available in many multivitamins and other dietary supplements. They are available to purchase over-the-counter in most drugstores and pharmacies.⁴

How does selenium impact TED?

The thyroid – the butterfly-shaped gland that is responsible for making hormones – contains more concentrated amounts of selenium than any other organ in the human body. It needs selenium to produce essential hormones to keep the thyroid healthy and functioning.⁵

If a person is deficient in this essential mineral, it can lead to thyroid problems like TED. Because of this, researchers believe that selenium deficiency may be a risk factor for thyroid eye disease.⁶

How is selenium used in treating TED?

Research shows that when taken regularly for at least 1 year, selenium supplements can improve symptoms and quality of life for people with TED who live in a region where the soil is selenium-deficient.¹

However, it is not yet known if selenium supplements would have the same effect for people with TED who live in selenium-rich regions of the world. More research is needed.¹

If you have mild thyroid eye disease and treatments are not working for you, talk with your doctor. Selenium supplements might be an option to help ease your TED symptoms. Selenium can interact with some drugs, so be sure to tell your doctor about any medicines you are currently taking before adding a selenium supplement to your diet.