Selenium and the Thyroid

Dr. Hedberg provides world-wide, health consultations via phone or Skype. Become a patient today. >

Did you know that the thyroid gland has the highest concentration of selenium compared to any organ in the body? Selenium is a powerful and essential trace mineral actually first discovered by the Swedish chemist Berzelius in 1817. Selenium mainly acts as an antioxidant, anti-inflammatory and it is involved in the production and activation of thyroid hormone. Selenium is found mainly in high-protein foods such as:





-Brazil nuts

The content of selenium in foods is dependent on the soil concentration of selenium which is very low in some areas.

Selenium acts as a “thyroid antioxidant” and is vital for the production of thyroid hormone and it is involved in the conversion of T4 (inactive thyroid hormone) to T3 (active form). Selenium also can protect the thyroid by binding to mercury and making it completely inert. Mercury is a major thyroid disrupting chemical but not when selenium is present.

Selenium and iodine are intricately intertwined in the thyroid gland. They are both necessary for thyroid hormone production, but when iodine-deficient subjects were given selenium alone, it made their hypothyroidism much worse. Since iodine deficiency is very rare in industrialized nations, this is usually not something to be concerned about.

Selenium has been found to be highly effective in patients with Hashimoto’s thyroid disease. Multiple studies have shown that selenium supplementation significantly reduced thyroid antibodies which are an indicator of thyroid autoimmunity. In fact, the higher the antibody levels were at the beginning of the studies, the greater the positive effects from selenium. It was also found that selenium improved the overall sense of well-being in these individuals. Once the subjects stopped their selenium supplementation, their antibody levels rose back to where they were at the beginning!

Many women develop Hashimoto’s thyroid disease after they give birth. The effects of selenium supplementation were studied in pregnant women and after they gave birth. The results showed that the women who supplemented with selenium had much lower antibody levels and their thyroid glands were also protected as they did not change in size compared to the women who didn’t supplement.

Selenium has been studied in it’s use with Graves’ disease which is an autoimmune disease resulting in hyperthyroidism (too much thyroid hormone). The results showed that selenium reduced antibody levels, decreased free radicals and those patients who were in remission had the highest levels of selenium. Graves’ disease patients sometimes get what is called orbitopathy which occurs when the muscles of the eyes expand and their eyes begin to protrude out of their eye sockets. One study found that after 6 months of selenium supplementation in patients with orbitopathy, they reported improved quality of life, decreased eye damage and the progression of the eyes protruding significantly slowed.

Which form of selenium is best and how much is a safe dose? Sodium selenate and selenite are the most popular forms of selenium but only about 50% is absorbed. In addition, these forms of selenium increase the risk of selenium toxicity. Selenomethionine is the preferred form of selenium supplementation as it is the form found naturally in food and about 90% of it is absorbed. 200 micrograms each day is a safe dose as long as it is in the form of selenomethionine.

If you have a thyroid problem such as Hashimoto’s or Graves’ disease, selenium supplementation has been shown to be safe and highly beneficial!

"Dr. Hedberg is amazing to work with!  I feel so much better just four months in and keep noticing improvements as we go. Highly recommended!”

by - E.J.