Selenium is an important trace element necessary for maintaining human health.
It plays a key role in the functioning of the immune system, maintaining heart health, and controlling oxidative processes in the body.
Selenium is essential for antioxidant protection, immune system function, and metabolism.
Selenium can improve thyroid function. It is involved in the metabolism of thyroid hormones and supports their normal functioning.
It is part of more than 25 selenium-containing proteins called selenoproteins, which are important for various biological functions, including reproductive health and detoxification.
Health Benefits
Mood. Some studies indicate a connection between selenium levels in the body and mental health conditions, including depression.
Improved vitamin absorption. It aids in the absorption of vitamins such as vitamin E, making it important for overall health.
Cancer. Research shows that selenium may help reduce the risk of certain types of cancer, including prostate cancer.
Fighting infections. Selenium may also help combat infections. Its role in maintaining the immune system makes selenium an important element in the prevention of infectious diseases.
Hair loss. Selenium deficiency may be linked to hair loss, as this nutrient is important for maintaining hair and skin health.
Daily Requirement and Sources
The daily requirement for selenium depends on age, sex, and health status.
On average, adults are recommended to obtain about 55 mcg of selenium per day. However, pregnant and breastfeeding women may need a little more of this trace element.
The requirement for selenium is relatively small, and it can be easily obtained from food.
Sources of selenium are diverse and include both animal and plant products. High-selenium foods include:
- Seafood (tuna, shrimp, salmon)
- Meat (beef, pork, chicken)
- Nuts, especially Brazil nuts: one Brazil nut contains the daily dose of selenium.
- Seeds
Health Consequences of Deficiency
A selenium deficiency in the body can cause cardiomyopathy, known as Keshan disease. It can also lead to thyroid dysfunction and impaired immune function, increasing susceptibility to infections.
Additionally, there is evidence of a link between low selenium levels and certain types of cancer.
Potential Risks of Excess and Toxicity
Excess selenium can lead to a condition known as selenosis. Symptoms include gastrointestinal disturbances, fatigue, irritability, and small nail defects. In more severe cases, hair loss, nerve damage, nausea, and diarrhea may occur.
Toxic effects can occur with an intake of more than 400 micrograms of selenium per day over an extended period.
Interesting Facts About Selenium
Discovered in 1817. Swedish chemist Jöns Jakob Berzelius isolated selenium from the mineral pyrolusite, marking an important step in the study of this element.
The name comes from the Greek word “selene.” This word translates to “moon,” reflecting the element’s connection to astronomy and mythology.
Recognized as an antioxidant in the 1970s. Its ability to neutralize free radicals made selenium important for combating aging and diseases.
Occurs in various forms. There are different chemical forms of selenium, including selenide, selenate, and selenite, each with its properties and applications.
Soil influence. Many believe that a varied diet fully covers selenium needs, but in reality, the content of this nutrient in food depends on the soil in which it is grown. In some regions, the level of selenium in the soil can be very low.
Bioavailability. Selenium can come from various sources, but its bioavailability and absorption can differ.
For example, organic forms of selenium, such as selenomethionine, are better absorbed than inorganic forms.
Used in electronics manufacturing. It is an important component in the production of semiconductors and solar panels.