Selenium – Benefits and Information | MyMineralMix
Selenium – Benefits and Information
The trace element selenium (chemical symbol Se), named after the Greek moon goddess Selene, belongs to the group of chalcogens ("ore formers") and was discovered in 1817 by the Swedish chemist Jöns Jakob Berzelius. In nature, selenium is mostly found as an admixture in sulfur-containing ores, so-called metal selenides. The following forms of selenium are of biomedical importance:
- Inorganic selenate (SeO42−) and selenite (SeO32−): These forms are found in water, seafood, and selenium-containing supplements.
- Organically bound selenocysteine (SeCys) and selenomethionine (SeMet): Selenomethionine predominates in plant foods; in animal foods, selenocysteine is mainly present.
Functions of Selenium
The total body selenium content of an adult varies between 10 and 15 mg and is distributed ubiquitously throughout the human body. Particularly high concentrations are found in the tissues of the thyroid, renal cortex, pancreas, and liver. Selenium is part of about 25 selenoproteins and performs the following essential functions in the body:
- Antioxidant protection: As part of glutathione peroxidase, selenium is an important component of the cell's antioxidant defense system. It helps to eliminate hydrogen peroxide (H2O2) and lipid peroxides, which are produced in greater quantities during oxidative stress. In this way, selenium protects cells from oxidative stress.
- Thyroid function: Selenium-dependent thyroxine deiodinases are essential for the thyroid gland as they catalyze the removal of iodine from the hormone thyroxine. Selenium thus contributes to normal thyroid function.
- Thioredoxin reductases: These enzymes are involved in RNA synthesis and play a role in the formation of disulfide bridges during protein folding. In this way, selenium influences cell growth and division and contributes to normal sperm formation.
- Function of hair and nails: Selenium helps maintain normal hair and nails.
- Immune defense: The activity of immune system cells depends on selenium. The trace element thus contributes to normal immune function.
Recommended Dosage and Sources
A selenium source should contain at least 15% of the recommended daily dose of 55 μg selenium. Good natural sources of selenium are:
- Brazil nuts
- Seafood (e.g., fish, shrimp)
- Meat (e.g., beef, chicken)
- Whole grains
- Egg yolk
Scientific Support
The role of selenium in supporting hair, nail, thyroid, and immune system health is well researched. For more scientific information, see the National Institutes of Health (NIH) and the European Food Safety Authority (EFSA).
Conclusion
Selenium is an important trace element that supports the health of hair, nails, and immune function. It also plays an essential role in protecting against oxidative stress and in thyroid function. By regularly consuming foods containing selenium, you can support these important functions and promote your overall health.
Good to know: Selenium intake varies greatly around the world. In European countries such as Germany, the average intake is about 40 μg per day, while in the USA it is about 134 μg per day. Germany is therefore considered a typical selenium-deficient region, as the intake among large parts of the population is inadequate. The metabolism of selenomethionine and selenite shows clear differences: selenomethionine is largely non-specifically incorporated into body proteins and is therefore not available for specific selenium functions, whereas selenite does not have these unwanted effects. The bioavailability of the selenium forms is as follows: selenite > selenocysteine > selenomethionine.
Sources: REGULATION (EU) No 432/2012 OF THE COMMISSION of 16 May 2012