Selenium’s effects that really change everything
ca. 17 Minuten
The effects of selenium are impressively diverse—it acts as a bodyguard for your cells, fuel for your thyroid, and a boost for your immune system. This vital trace element is involved in countless processes that are essential to your well-being and help you better understand your body.
What is selenium and why is it so important to you?
Think of selenium as an invisible but extremely hardworking helper who tirelessly works for you. Your body cannot produce this essential trace element itself, which means you have to get all of it through your diet. Its role is anything but minor.
Basically, selenium is a fundamental building block for so-called selenoproteins. These are special proteins that function like highly specialized tools in your body. Without selenium, these important tools cannot be built—and many crucial processes grind to a halt.
The following infographic clearly shows how selenium acts as a protective shield at the cellular level and safeguards your cells from everyday attacks.
As you can see, these are the foundations of your health. A strong protective shield for your cells is the basis of your overall vitality.
The key functions of selenium
From fighting pathogens to hormone production—selenium has a wide range of effects. To give you a better overview, we’ve summarized its most important functions in a table.
The main functions of selenium at a glance
This table summarizes the key functions of selenium and shows which body systems benefit directly from it.
| Area of effect | Function of selenium | Health benefit |
|---|---|---|
| Cell protection | Is a powerful antioxidant that neutralizes free radicals. | Slows aging processes and protects cellular DNA. |
| Immune system | Essential for the production and activity of immune cells. | Strengthens the immune response and helps fight infections more effectively. |
| Thyroid | Activates thyroid hormones and protects thyroid tissue. | Regulates overall metabolism, energy levels, and body temperature. |
| Fertility | Contributes to the production of healthy sperm in men. | Supports male reproductive function. |
These key functions show how deeply selenium affects our basic bodily functions. A deficiency often goes unnoticed for a long time, but can have far-reaching consequences—from your energy and immune system to the appearance of your skin.
Why your genes matter too
Now things get really interesting: The effects of selenium depend not only on how much you consume, but also on your genetic makeup. Your DNA also determines how efficiently your body can use selenium to protect itself from oxidative stress.
A genetically determined weakness in this protective system can, for example, have a direct effect on skin aging.
This is exactly where the mybody-x Skincare DNA Metabolism Test comes in. It analyzes your genes and shows whether you have an individually increased need for antioxidants such as selenium. This gives you a personalized tool to support your skin and body from within and take charge of your health.
How selenium specifically supports your body
Now that we’ve covered what selenium generally does, it’s time to take a deeper look at its specific “superpowers.” Don’t think of selenium as an all-rounder, but rather as a highly specialized expert that keeps things in order in very specific areas of your body. From energy metabolism to your cells’ protective shield, selenium’s effects are at work at critical points.
Your thyroid as a command center
Your thyroid is basically the powerhouse of your metabolism, and selenium is one of the most important technicians keeping the machinery running. It’s no coincidence that this small organ stores more selenium than any other part of the body except the brain.
Selenium is absolutely essential for activating thyroid hormones in the first place. It helps convert the relatively inactive storage hormone T4 into the active and effective hormone T3. Without this important step, your metabolic engine would sputter, which can quickly lead to fatigue and low energy.
At the same time, selenium protects sensitive thyroid tissue from oxidative stress produced during hormone production. This protective function is particularly important in autoimmune diseases such as Hashimoto’s thyroiditis. Although research in this area is not yet complete, a good selenium intake is often considered an important part of supportive treatment. In fact, selenium is already used as part of treatment for autoimmune thyroid diseases in Germany, as an official assessment of selenium in Germany by the BfArM shows.
Your immune system as a shield
A strong immune system needs the right equipment to defend you—and selenium is a crucial part of it. It helps your defense cells respond to invaders such as viruses or bacteria quickly and effectively.
Without selenium, production of these important defense cells can quickly stall. The result? You become more susceptible to infections and may take longer to recover from illness.
You could say selenium is the training coach for your immune cells. It not only ensures there are enough players on the field, but also that they’re fit, fast, and ready for action at any time.
Cell protection against premature aging
Probably the best-known effect of selenium is its role as a powerful antioxidant. In everyday life, your body is constantly exposed to so-called free radicals—whether from environmental toxins, stress, or normal metabolic processes. These aggressive molecules attack your cells and can accelerate the aging process.
This is where selenium comes in. It is a key component of the enzyme glutathione peroxidase, one of the body’s most powerful antioxidants. It captures free radicals, neutralizes them, and protects the DNA in cells from damage. This protective mechanism is important not only for healthy skin, but for the health of every single cell in your body. The Skincare DNA Metabolism Test from mybody-x can give you a deeper understanding of how well equipped your body is in this regard.
Strengthen skin, hair, and nails from within
Strong hair, firm nails, and healthy skin are often a direct reflection of your nutrient intake. This makes sense, because when the body is lacking something, it prioritizes vital processes and supplies hair and nails last.
Selenium officially contributes to the maintenance of normal hair and nails. It supports structural proteins and protects the cells in hair roots and nail beds from oxidative stress. Brittle nails or diffuse hair loss can therefore be an early, visible sign that your body is lacking an important nutrient. You can also find out whether your genetic predisposition plays a role in your skin health and whether you have an increased need for protective nutrients such as selenium with our DNA test.
Recognizing selenium deficiency and interpreting it correctly
Do you feel tired all the time without knowing exactly why? Are your nails brittle, or have you noticed more hair falling out lately? Signs like these can be really frustrating, especially when you just can’t figure out the cause. Often, subtle but persistent symptoms like these simply stem from deficiencies in important nutrients—such as selenium.
A selenium deficiency is deceptive because it usually creeps up quietly. The first signs are often so nonspecific that they’re easy to mistake for everyday stress or other minor ailments. But that’s exactly why they’re important signals from your body that you should never ignore.
So, instead of staying in the dark and getting frustrated, it’s worth taking a closer look at these signs. Taking responsibility for your health starts right there: understanding and taking your body’s signals seriously.
Typical but nonspecific symptoms
A selenium deficiency can show up in so many different ways that self-diagnosis quickly becomes little more than guesswork. Still, there are some classic signs that may be linked to inadequate selenium intake:
- Weakened immune system: You catch every cold going around and it takes you ages to get back on your feet.
- Hair loss and brittle nails: When the body is lacking something, it often cuts back first on “unimportant” things like hair and nails. Changes in these areas are often an early, visible warning sign.
- Tiredness and exhaustion: A selenium deficiency can affect thyroid function, which can directly lead to persistent low energy.
- Muscle weakness: Selenium also plays a role in muscle function. A deficiency can therefore cause weakness or even pain.
- Mood swings: Your mental health can suffer too. Do you often feel irritable or have trouble concentrating? That could be a sign as well.
Of course, these symptoms aren’t definite proof of a selenium deficiency. But they’re a damn good reason to take a closer look. If you want to know more about how deficiencies can show up, check out our article on the most common nutrient deficiency symptoms—there’s even more useful information there.
Who’s at risk?
Certain lifestyles and dietary habits make it more likely that you’ll develop a selenium deficiency. One major factor is that soils in Europe are naturally relatively low in selenium. That alone makes it a little challenging for all of us to get enough from food alone.
Selenium deficiency is not uncommon. Especially here in Europe, where the soil contains little selenium, making sure you get enough is essential for staying healthy.
These groups of people in particular should be especially mindful:
- Vegans and vegetarians: Animal products are often a fairly reliable source of selenium (usually because of fortified animal feed). So anyone following a purely plant-based diet needs to consciously include selenium-rich foods in their diet.
- People with chronic intestinal conditions: Conditions such as Crohn’s disease or celiac disease can severely impair the absorption of nutrients like selenium in the gut.
- People in selenium-poor regions: Those who eat a lot of local food depend directly on the selenium content of the local soil. And here in Germany, that content is often not particularly high.
But before you start taking supplements on a whim and perhaps even risk an overdose, get a clear picture first. A mybody-x nutrient test shows you exactly what your selenium status is. This gives you a reliable basis for targeted measures and helps you give your body exactly what it really needs.
How to meet your daily selenium needs
A strong selenium effect naturally starts with getting the right amount. But how much selenium do you really need, and what are the best sources? Here, I’ll show you how to give your body what it needs—naturally, through your diet.
Official recommendations are a great starting point, but your personal needs can vary considerably depending on your lifestyle, age, and health. That’s why it’s so important to know the best sources of selenium and consciously include them in your diet.
Official recommendations and your individual needs
The German Nutrition Society (DGE) gives us a clear guideline: it recommends a daily intake of 60 micrograms (µg) for women and 70 µg for men. The requirement is slightly higher for breastfeeding women, at 75 µg. These figures are a good guideline for meeting basic needs.
But life isn’t always standard. Your personal needs may well be higher, for example if you:
- You follow a vegan or vegetarian diet.
- You struggle with chronic gastrointestinal conditions that make it harder to absorb nutrients.
- You smoke or drink alcohol regularly.
- You’re exposed to a lot of oxidative stress, whether from intense exercise or environmental pollutants.
Another important point is that soils in Germany tend to be low in selenium. This directly affects the selenium content of plant-based foods. Studies show that average intake among adults is often only between 31 µg and 66 µg per day. This makes it clear how important it is to choose foods mindfully.
The best natural sources of selenium for your diet
The good news is that you can easily meet your selenium needs with the right foods on your plate. The focus should always be on natural sources, as this is the best way for your body to absorb and use this trace element.
Nature has blessed us with an abundance of selenium-rich foods. A colorful and varied diet is and always will be the best way to give your body everything it needs.
Here are some of the very best sources of selenium:
- Brazil nuts: They’re the undisputed stars! Just one or two nuts a day can meet your daily requirement. But be careful: because they’re so extremely rich in selenium, you should really enjoy them only in moderation.
- Fish and seafood: Tuna, herring, sardines, and shrimp are particularly great sources of selenium.
- Meat and organ meats: Beef, pork, and poultry, as well as liver and kidneys, are also packed with this trace element.
- Eggs: The humble chicken egg makes a valuable contribution to your daily intake.
- Legumes: Lentils, chickpeas, and beans are fantastic plant-based sources - a must for vegans and vegetarians.
- Whole grains: Oatmeal, brown rice, and a good whole-grain bread also provide a solid foundation.
- Vegetables: Certain vegetables, such as broccoli, white cabbage, onions, and garlic, also do their part.
Ultimately, it’s the mix that makes the difference. A balanced diet featuring a colorful variety of these foods is the key to success. If you want to dive deeper into the topic, take a look at our guide to selenium-rich foods. You’ll find even more information and practical everyday tips there.
How your genes affect the effects of selenium
Have you ever wondered why the healthiest diet works wonders for some people, but somehow falls flat for others? Our genes often have a say in it. And the same goes for the effects of selenium. Your body gets selenium from food, but how well it can ultimately use it to protect your cells is partly encoded in your DNA.
This fascinating interplay between what we eat and our genetic predisposition is called nutrigenetics. It’s about understanding how our unique genes influence how we absorb, metabolize, and use nutrients. If you’re curious, take a look at our article What Is Nutrigenetics and How Does It Shape Our Lives.
The role of genes in antioxidant protection
Each of us is unique - and of course, that applies to our genes too. Certain genes determine how diligently our bodies produce antioxidant enzymes. Selenium is a key building block for one of the most important protective enzymes of all: glutathione peroxidase.
Here’s the crucial point: Some people have genetic variants that mean their built-in defense system is naturally somewhat weaker. This means their bodies can’t use selenium quite as effectively to capture and neutralize free radicals.
You can think of it this way: Your body has a built-in repair system for cell damage. Your genes determine how this system is equipped. Some people have a premium workshop, while others have a solid standard setup.
This genetic predisposition may mean that you personally need more antioxidants such as selenium to achieve the same level of protection as someone with a “stronger” gene variant. This difference becomes especially noticeable when your body is exposed to oxidative stress - for example, from too much sun, environmental toxins, or an unhealthy lifestyle.
How a DNA test brings clarity
And this is where it gets personal. Instead of groping in the dark, you can find out what your genetic predisposition is really like. That’s the great strength of the mybody-x Skincare DNA Metabolism Test. It’s much more than a simple skin test, because it also analyzes the genes that are key to your antioxidant protection.
The test gives you clear answers to the questions that really matter:
- How well does your natural defense system work? You’ll find out whether your genes provide optimal protection or whether you’re predisposed to weaker protection.
- Do you have an increased need for antioxidants? Based on your DNA, the test shows whether you would benefit especially from nutrients such as selenium, as well as vitamins C and E.
- How can you specifically support your skin? You’ll get clear, practical recommendations tailored to your genes to help protect your skin from premature aging from within.
This makes the test your personal tool. It lets you tailor your diet and skincare to your genetic needs. That way, you can make the most of the effects of selenium and support your body exactly where it needs it most – for healthy skin and a strong cellular defense system.
Find the right dosage and avoid risks
When it comes to selenium, there's one very important rule: more isn't always better. As with most trace elements, the right balance matters. An overdose can be just as problematic as a deficiency, so you should always manage your intake mindfully and carefully.
Too much of a good thing can lead to so-called selenosis, a serious case of selenium poisoning. Although this is rare, it's still important to know the risks, especially if you're using high-dose supplements.
What happens in an overdose?
If the body is exposed to too much selenium for an extended period, it eventually becomes overwhelmed. The symptoms of selenosis are quite varied and can affect both the body and the nervous system.
Watch out for these possible signs of an overdose:
- Gastrointestinal symptoms: If nausea, diarrhea, or abdominal cramps occur, this could be an early sign.
- Hair loss and brittle nails: Paradoxically, these symptoms resemble those of a deficiency, which makes things tricky.
- Skin changes: Rashes or redness can also occur.
- Garlic-like breath: This is a very specific and quite noticeable symptom.
- Neurological disorders: In severe cases, this can cause fatigue, irritability, or even nerve damage.
The European Food Safety Authority (EFSA) has set a safe daily upper limit, known as the Tolerable Upper Intake Level. For adults, this is 300 micrograms (µg) per day. You should not exceed this dose over the long term.
Test, don't guess – for maximum peace of mind
The data is fairly clear: Selenium levels in Germany tend to be on the low side. The German Environment Agency has found that average intake is often at the lower end of the recommended range, which can increase the risk of certain diseases. So getting enough is important, as you can read in the German Environment Agency's findings on selenium.
The surest path to optimal care is through knowledge, not guesswork. A test gives you the clarity you need to take targeted action without risk.
And this is exactly where mybody-x tests come in. Instead of supplementing blindly and possibly risking an overdose, a nutrient test gives you a precise picture of your current selenium status. And with the Skincare DNA Metabolism Test, you can understand your genetic makeup. This lets you address a confirmed deficiency or adjust your diet proactively. That way, you can make sure you get all the benefits of selenium without putting your health at risk. If you’d like to learn more about the role of nutrients like these, also read our article about what minerals actually are.
Your questions about how selenium works - answered briefly and clearly
There are always questions about selenium. To help you get a clear picture, we’ve gathered the most common questions here and answered them in an easy-to-understand way.
Why is selenium so important for the thyroid?
Think of selenium as the ignition key for your thyroid hormones. It’s essential for converting the relatively inactive storage hormone T4 into the highly active hormone T3 - and that’s what revs up your entire metabolism. At the same time, selenium acts like a shield, protecting your thyroid’s delicate tissue from oxidative stress.
Can I meet my selenium needs through diet alone?
Yes, you can, but it takes a little planning. The problem in Europe is that our soils are often very low in selenium, which means plant-based foods tend to contain less of it, too. The best way to get enough is to focus on animal products or selenium-rich plant sources such as Brazil nuts and lentils.
How do my genes affect the way selenium works?
Every body is different - and that applies to how we process nutrients, too. Your DNA determines how well your cells’ own defense systems work. Some people have a genetic predisposition that means they need more antioxidants like selenium. This is important for effectively protecting cells, especially skin cells, from free radicals. The Skincare DNA Metabolism Test from mybody-x gives you insights into exactly that.
Do you want to know exactly how your genes influence your individual nutrient needs? The mybody-x Skincare DNA Metabolism Test gives you personalized insights and helps you support your health in a targeted way.
