What is selenium good for? Properties, effects, and importance for health
Do you know that feeling when everything is under control? When your health is optimal, you're full of energy, and you stay focused no matter what? Many of these blessings come from chemical elements that we don’t usually think about. One of them is selenium. Even though it occurs in microscopic amounts in the human body, these small quantities are crucial for maintaining proper function. Selenium is an essential element that supports the immune system, protects against oxidative stress, and plays a significant role in preventing chronic diseases. Why is selenium so helpful, and what are its properties? In which products can you find it in the highest amounts? Does an excess of selenium cause toxic effects on the human body?
Table of contents
- What is selenium and why is it important for the human body?
- Selenium - properties
- What is selenium? Sources of selenium in daily diet
- Selenium deficiency - symptoms
- Selenium excess - symptoms
- How to avoid selenium deficiency?
- Selenium supplementation - what product to choose?
- Everything you need to know about selenium - summary
What is selenium and why is it important for the human body?
Selenium is a trace element that is key to maintaining the well-being of the human body. Although it occurs in tiny amounts, it is necessary for many significant processes to function effectively.
If you're wondering what selenium’s role is in the human body, you should know that:
- It supports the function of thyroid hormones and their activity (helping transform T4 into T3).
- It activates macrophages and lymphocytes and supports antibody production.
- It is a common component of enzymes like glutathione peroxidase, which neutralizes harmful free radicals and protects cells from oxidative stress.
- It protects neurons, reducing DNA damage and lipid peroxidation.
- It forms complexes with toxic heavy metals like mercury and cadmium, improving the body’s detoxification processes.
The human body typically contains between 10 to 15 mg of selenium. This chemical element is primarily found in the muscles, kidneys, liver, thyroid, and pituitary gland. Selenium metabolism is complex and largely depends on the form in which it is consumed through food. Selenium can be absorbed in both organic and inorganic forms.
Selenium - properties
Selenium is one of the strongest antioxidants known in nature. Its most important property is protecting cells from the harmful effects of free radicals. Because of this, it acts as a protective shield against numerous chronic illnesses, including cancer and Alzheimer's disease.
Proper selenium consumption is also important for the well-being of the immune system. Numerous studies have shown that selenium can support immunity and reduce inflammation, including conditions like rheumatoid arthritis and chronic colitis. Thanks to its immunomodulatory properties, selenium has a significant impact on the production of immune cells, including macrophages and B and T lymphocytes.
Selenium also regulates the hormonal system and is necessary for the production and metabolism of thyroid hormones. Glutathione peroxidase, found in the thyroid, protects it from oxidative stress, minimizing the amount of hydrogen peroxide produced during thyroid hormone synthesis. Furthermore, selenium has a major influence on the health of our skin, hair, and nails.
What is selenium? Sources of selenium in daily diet
The recommended daily intake of selenium for adults, according to the latest research, is approximately 45 - 55 μg per day. A properly balanced diet is the best way to maintain optimal levels of this element, ensuring the effective functioning of enzymes, the thyroid, and the immune system. So, where can you find selenium, and which foods contain the highest amounts?
Selenium is found in:
- brazilian nuts (1 - 2 nuts daily covers the body’s need for selenium)
- sea fish (tuna, cod, salmon)
- seafood
- meat and eggs
- whole-grain products
- dried legume seeds
Vegetables are a perfect source of selenium - especially those like broccoli, white cabbage, garlic, onion, asparagus. It’s worth remembering that selenium’s content in a meal is determined by its amount in the ground - and it varies a lot. What’s more, selenium from plant sources is assimilated in +/ - 90%, which is better than from animal products.
Selenium deficiency - symptoms
A deficiency in selenium can seriously affect one's health. A lack of this element can lead to reduced lymphocyte proliferation, impair natural killer (NK) cell activity, and disrupt iodine metabolism and thyroid hormone synthesis.
Symptoms of selenium deficiency:
- chronic fatigue and muscle weakness
- decreased immune function: returning infections
- excessive hair loss, nail breaking
- hypothyroidism, autoimmune disorders (like Hashimoto)
- inability to focus and deterioration of well-being
Selenium deficiency may also increase the risk of cardiovascular diseases and myocardial damage. Moreover, insufficient selenium levels can negatively impact fertility in men, reducing sperm motility and disrupting spermatogenesis. This is why maintaining optimal selenium levels through diet or supplementation is essential.
Selenium excess - symptoms
Long-term intake of selenium in the amount of 400 μg per day can cause developing selenosis. In the cause of intoxication with selenium there can be symptoms like metallic taste, nausea, diarrhea, stomachaches.
Other symptoms of selenium excess in the human body are:
- hair loss and nail breaking
- skin problems
- irritability
- painful joints
- fatigue and feeling of weakness
- in extreme cases: neurological disorders
Selenium overdosing can cause intoxication, evoke oxidation stress and lead to serious organ damage, also cirrhosis of the liver and pulmonary edema.
An adverse effect from long-term selenium supplementation can also be higher risk of developing diabetes, autoimmunological thyroid inflammation or Keshan disease - an endemic heart muscle disease. To avoid excessive intake it’s crucial to control the dose of selenium and to follow medical advice. Daily intake for adults should be 45 to 55 μg per day, and for pregnant and breastfeeding women it's 60 - 70 μg.
How to avoid selenium deficiency?
To avoid deficiency of selenium it’s worth taking care of a healthy, diverse and balanced diet, based on natural, unprocessed products. In case of problems with delivering the proper amount of this element with food, you can consider selenium supplementation.
Because selenium assimilability depends from various factors it’s worth remembering that:
- selenium supplementation shouldn’t be matched with major doses of zinc or vitamin C, as they can hinder its absorption
- during supplementation it’s recommended to restrict intake of chelating agents, because they can mix with and interfere selenium
- cautiousness while reading supplements composition list is key - not every kind of selenium works in the same way
- It's proven that absorption of selenium can be improved with vitamins A, C, E and also some amino acids (cysteine and methionine)
During long-term supplementation it’s key to regularly monitor the level of concentration of selenium in the body. The results can be analysed with laboratory tests of blood from the patient’s elbow vein.
Selenium supplementation - what product to choose?
When your daily diet is not meeting the body’s demands in selenium it’s worth considering supplementation, especially when you suffer from thyroid diseases, weak immune system or you are on elimination diet. The best absorpting form of this element is organic selenium - L-selenometionin, which has proven high bioaccessibility and good toleration.
The recommended daily intake of selenium for healthy adults is 45 to 55 μg. For pregnant and breastfeeding women, this amount rises to 60 - 70 μg. Because of the risk of toxicity from excessive doses, selenium supplementation should be done with caution. Always follow the recommended dosage to avoid side effects.
Everything you need to know about selenium - summary
Selenium is not only essential for health but also plays a key role in maintaining hormonal balance, supporting the immune system, and promoting overall well-being. To avoid deficiency, it’s important to maintain a diverse, balanced diet, especially since selenium can be absorbed from both animal and plant-based foods. Good sources of selenium include fish, seafood, eggs, nuts, vegetables, and whole grains.
If you want to ensure your body is receiving the right amount of selenium, choose reliable sources. Supplements containing selenium, such as those made by OstroVit, are known for their quality. High absorption, accurate doses, and convenient forms can support your body without the risk of overdosing. Sometimes, it's the small elements that have the biggest impact on your well-being.
Is proper thyroid function, a strong immune system, and free radical protection important to you? Let selenium become your ally in supporting your health and well-being!
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