Selenium is an essential trace element. It is particularly important for the thyroid gland and a deficiency can worsen an underactive thyroid. But selenium is also very important for hyperthyroidism. Unfortunately, selenium is often lacking in Germany because Germany is a selenium-deficient area.
In this article you will learn what you need to know about selenium for the thyroid.
Importance of selenium for the thyroid
Selenium has important functions in the formation of thyroid hormones: it is needed for the conversion of thyroxine (T4) into active triiodothyronine (T3).
Selenium is also a component of antioxidant enzymes. It captures free radicals in the thyroid. The formation of thyroid hormones produces hydrogen peroxide, a very reactive molecule that causes oxidative stress. 1
Selenium for Hashimoto and hypothyroidism
Selenium is particularly important for Hashimoto's disease, as it improves the tolerance of iodine. Iodine is often avoided by people with Hashimoto's disease, as it is usually very poorly tolerated. However, iodine is an essential nutrient that should not be neglected. It is not only important for the thyroid, but also for all other organs.
However, iodine can cause oxidative stress in the thyroid, which is already very high in Hashimoto's disease. Selenium intercepts free radicals in the thyroid and thus counteracts this.
Some studies also suggest that taking selenium could help reduce TPO antibodies and TG antibodies in Hashimoto's disease. 2 However, the research is not clear on this. Selenium supplementation is probably most effective when there is a selenium deficiency.
But selenium is also a very critical nutrient in other forms of hypothyroidism, because a selenium deficiency can worsen hypothyroidism.
Selenium for hyperthyroidism
A good supply of selenium is also important in cases of hyperthyroidism. This sounds a bit counterintuitive at first: Since selenium promotes thyroid function and the thyroid is too active in cases of hyperthyroidism, one might think that selenium increases the hyperthyroidism.
However, it is important to remember that hyperthyroidism is not caused by an oversupply of selenium. Conversely, it therefore makes no sense to deprive the thyroid of essential nutrients. Especially when you consider that selenium is not only important for the thyroid, but also for the rest of the body.
Selenium is indeed very important in cases of hyperthyroidism: hyperactivity of the thyroid is associated with increased oxidative stress, which causes inflammation. This can be counteracted by a good supply of selenium. 3
It is therefore not surprising that taking selenium in Graves' disease can reduce inflammation and improve quality of life and well-being. 4 Again, selenium probably has the greatest effect when there is a deficiency.
Selenium supply in Germany
Germany is a selenium-deficient area. This means that our soils are low in selenium. As a result, our food also contains little selenium and we usually do not consume enough selenium through our diet.
According to the German Society for Nutrition (DGE), the daily selenium requirement is 60 ug for women and 70 ug for men. 5 It is estimated that around 70% of Germans do not consume enough selenium. 6 On average, women consume only 38 ug of selenium, men 47 ug. 7
There are also indications that the DGE estimates the requirement too low. 80 – 100 ug daily seem to be necessary for optimal function of selenium-dependent enzymes. 8
Dosage of selenium for the thyroid
For thyroid diseases, approximately 100 - 200 ug of selenium daily is generally recommended. For long-term supplementation, it should be noted that selenium is toxic in high doses. An overdose should therefore be avoided at all costs.
If the selenium status is unknown, selenium in the form of sodium selenite is recommended. Sodium selenite is absorbed via the selenium transporter. This depends on requirements, which is why it is difficult to overdose on this form.
Selenomethionine, on the other hand, is incorporated into proteins as methionine. As a result, the selenium is not recognized as selenium and there is a risk of overdose. For this reason, selenomethionine should only be taken in higher doses (over 100 µg daily) if the selenium level is regularly checked.
Normal values in whole blood are 121 – 200 ug/l.
