Selenium is an essential trace element that is often overlooked, but plays an important role in your overall health. In this blog, you will discover what selenium is, why it is so important for your body and why it works even more powerfully in combination with zinc.
In this article, you will read:
- What selenium is
- Why selenium is important for your health
- How much you need per day
- Which foods contain a lot of selenium
- The power of selenium and zinc together
What is selenium?
Selenium is a mineral that is also known as a trace element. This means that your body only needs very small amounts of it. It occurs in two forms: inorganic (such as selenite and selenate) and organic (such as selenomethionine and selenocysteine). The inorganic form occurs naturally in the soil. Plants absorb it and convert it into the organic form, which is more easily absorbed by humans and animals.
Because the body cannot produce selenium itself, it is important to obtain this mineral through food or supplements.
What is selenium good for?
Selenium contributes to your health in several ways. It is part of so-called selenoproteins, enzymes that are involved in important processes:
- Immune system
Selenium contributes to a properly functioning immune system. It supports the production of antibodies, helps white blood cells function properly and protects cells from damage caused by free radicals. - Thyroid function
The thyroid is a small organ in the neck that is essential for good health. It produces thyroid hormones, which are crucial for your metabolism, growth, energy management and hormonal balance. Your thyroid needs the enzyme deiodinase, which contains selenium, to convert the inactive thyroid hormone T4 into the active form T3. - Antioxidant effect
Selenium protects your cells against oxidative stress through its antioxidant effect. This is damage caused by free radicals that are released, for example, during stress, air pollution or illness. - Fertility
Because selenium is necessary for the production of thyroid hormones, it also plays an important role in the fertility of both men and women. In men, selenium helps in the production and maturation of healthy sperm cells, protects them from damage and supports testosterone balance.
In women, selenium plays a role in egg development, ovarian function and embryo implantation. Here too, it protects against oxidative stress, which is important for healthy fertility. - Skin, hair and nails
Selenium supports cell division in hair follicles and nail beds and is involved in the production of keratin, a protein that ensures strong, shiny hair and sturdy nails. Both a deficiency and an excess of selenium can lead to brittle nails or hair loss.
How much selenium per day?
The recommended daily amount of selenium varies according to age, gender and situation. For adults, the requirement is around 50 to 55 micrograms per day. During pregnancy, this increases to around 60 micrograms, and for women who are breastfeeding, 70 micrograms per day is recommended. The maximum safe upper limit for adults is around 300 micrograms per day.
For children, the amount of selenium they need each day varies. Children aged one to three years need around 20 micrograms per day, while children aged four to eight years benefit from around 30 micrograms per day.
Where is selenium found?
Selenium occurs naturally in both animal and plant foods. The amount of selenium in plant products depends heavily on the amount of selenium in the soil in which they are grown. The body absorbs about 70 per cent of the mineral from food. The richest sources are:
- Brazil nuts: Brazil nuts are by far the richest natural source of selenium. Just one nut contains an average of between 60 and 95 micrograms, so eating one or two nuts a day will quickly exceed the recommended daily allowance. They are also a good source of other nutrients, such as protein, fibre, magnesium and vitamin E.
- Fish: Fish is also an excellent source of selenium. Tuna in particular contains a lot, with about 90 to 100 micrograms per 100 grams. Salmon and sardines provide slightly less, but are still rich in selenium, with values between 35 and 60 micrograms per 100 grams.
- Meat and poultry: Meat and poultry also contribute well. Chicken breast and beef contain an average of 20 to 35 micrograms per 100 grams, while liver is particularly rich in selenium, with approximately 55 to 65 micrograms per serving.
- Eggs: Eggs provide a modest but valuable amount: one average egg contains about 13 to 20 micrograms of selenium.
- Whole grains and seeds: Finally, whole grains and seeds are also a good plant-based source, although the selenium content varies depending on the soil in which they are grown. Two slices of whole grain bread provide about 10 to 15 micrograms, while sunflower seeds and sesame seeds contain around 20 to 25 and 15 micrograms per 30 grams, respectively.
Selenium and child development
The first 1,000 days of life, from conception to around the age of two, are crucial for a child's physical and cognitive development. Selenium, a trace element that is essential for the functioning of various enzymes, plays an important role in this. Among other things, it is involved in brain development, the functioning of synapses (the connections between nerve cells) and cognitive processes such as learning and memory.
Various studies have shown that a selenium deficiency in early childhood can be associated with reduced cognitive performance, learning difficulties and possibly an increased risk of neurodevelopmental disorders such as autism. At the same time, it is known that excessive selenium intake can be toxic, which emphasises the importance of careful dosing.
How can you recognise a selenium deficiency or excess?
A selenium deficiency often develops gradually and the first signs are usually subtle. For example, you may notice that your hair is falling out more quickly, your nails are becoming brittle or showing white spots. Other common complaints include fatigue, concentration problems or a feeling of mental sluggishness, also known as “brain fog”. In addition, muscle weakness or muscle pain may occur, and you may feel that daily tasks are more difficult than normal.
If a selenium deficiency goes unnoticed for a long time, it can have more serious consequences. The functioning of the immune system and the thyroid gland can be disrupted, and fertility, the nervous system and even heart function can also be affected. In severe cases, musculoskeletal complaints such as coordination problems or muscle weakness can also occur.
However, too much selenium is not without risks either. A chronic excess can lead to symptoms such as nausea, hair loss, skin rashes or a metallic taste in the mouth. In extreme cases, it can even become toxic. That is why it is important not to take high doses without good reason or professional advice. The right balance is essential for good health.
The synergy of zinc, selenium and magnesium: a powerful combination
Zinc and selenium are often recommended together in supplement form, and with good reason. These two essential trace elements enhance each other's effects and contribute to your health on multiple levels. Not only do they support a strong immune system, they also function as antioxidants that help neutralise free radicals. Their combined action is particularly important in maintaining healthy cells and tissues, such as skin, hair and nails. They also play an important role in hormonal balance and fertility. Zinc, for example, is involved in sperm production, while selenium is essential for a properly functioning thyroid gland.
Magnesium also fits seamlessly into this powerful duo. While selenium and zinc focus on antioxidant protection, hormonal functions and tissue repair, magnesium acts as a cofactor in more than 300 enzymatic processes in the body. Among other things, it is crucial for energy metabolism, muscle function and nerve conduction. Together, these three minerals form a strong team: they complement each other in their role in the immune system, support recovery after illness or physical exertion, and contribute to mental clarity and energy.
Many foods contain one or more of these nutrients. These include seafood, eggs, nuts, seeds, meat and whole grains. However, in cases of stress, illness, fatigue or an unbalanced diet, it may be beneficial to supplement these minerals.
Conclusion
Selenium is an essential mineral that plays an important role in your vitality, immune system and the protection of your cells against harmful influences. In combination with zinc and magnesium, a powerful synergy is created: zinc supports the immune system and contributes to healthy skin, hair and nails, while magnesium is involved in numerous enzyme processes that ensure energy production and muscle function. Together, these minerals form an indispensable basis for optimal health. That is why it is important to ensure a balanced diet that contains these nutrients, or to choose a high-quality supplement as an addition, especially during periods of stress, recovery or increased need.
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