Selenium requirements: beware of selenium deficiency and selenium overdose

Headlines such as "In Germany, many people are undersupplied with selenium",  "Vegetarians and vegans in particular tend to have a selenium deficiency" or advertisements on the packaging of selenium supplements - for example "Supports cell protection, normal thyroid function and a healthy immune system" - unsettle many people. However, no one should simply reach for dietary supplements without consulting their family doctor. After all, a selenium deficiency actually leads to serious physical impairments in the long term. But too much selenium is also harmful: an overdose can lead to so-called selenosis, a poisoning.

The most important facts about selenium at a glance:

- What does the body need selenium for?
- What is the selenium requirement?
- What are symptoms of a selenium deficiency?
- How is a selenium deficiency detected?
- How can selenium requirements be met?
- What is selenosis?

Selenium is a trace element that is vital for humans. It performs numerous functions in the organism: Selenium acts as a motor for organ systems. In particular, selenium has a cell-protecting and anti-inflammatory effect. In addition, selenium is considered to have an uplifting effect and thus also has an impact on the human psyche. Important: Both a selenium deficiency and a selenium overdose can have an influence on the development of certain types of cancer.

Selenium is needed, albeit in varying amounts, but basically in the entire body. Selenium is found in tissues, organs and also in the blood to ensure optimal body function. If a selenium deficiency occurs, the selenium content is not evenly reduced in the body, but a redistribution occurs: The most important organs of the body are primarily supplied with selenium, so that less selenium remains for other organs. The organs that receive a lower priority supply of selenium then include the kidneys, the thyroid, the pancreas and also the reproductive organs.

Selenium requirements vary from person to person and depend on several factors. The most important factors include gender and age. The requirement values listed below, which were published by the German Society for Nutrition, are therefore only estimated values. However, anyone who regularly consumes the specified amount of selenium is reliably supplied with selenium. If a selenium deficiency nevertheless occurs, not only must the selenium deficiency be corrected, but the causes of the increased selenium requirement must also be sought.

Selenium requirements babies, children and adolescents:
- 0 to 4 months: 10 micrograms
- 4 months to 4 years: 15 micrograms
- 4 to 7 years: 20 micrograms
- 7 to 10 years: 30 micrograms
- 10 to 13 years: 45 micrograms
- 13 to 15 years: 60 micrograms

Girls and women:
- from 15 years: 60 micrograms
- during pregnancy: 60 micrograms
- During breastfeeding: 75 micrograms

Boys and men:
- From 15 years: 70 micrograms

An increased need for selenium can have different causes. On the one hand, a low-protein diet can lead to an increased need for selenium. Diseases of the gastrointestinal tract can lead to a reduced absorption of selenium from food. Smokers and alcoholics also require more selenium than the estimated values. In addition, increased selenium requirements can occur due to kidney disease and in the context of cancer. Vegans and vegetarians do not have an increased selenium requirement. However, they may be nutritionally deficient in selenium. This is due to the fact that selenium is also found primarily in animal foods.

Because selenium is needed throughout the body, a deficiency of selenium manifests itself in very different ways. The most common symptoms that can occur due to a selenium deficiency include:
- Fatigue
- Breathing problems
- Water retention
- Susceptibility to infections (especially colds and gastrointestinal diseases)
- White patches on the skin
- Pale, scaly skin
- Thin hair, hair loss
- Joint problems
- Decreased fertility in men

A severe or long-standing selenium deficiency can lead to serious physical ailments:
- Liver dysfunction
- Hypothyroidism
- Heart muscle disease

Among the most serious consequences of selenium deficiency are Keshan disease and Kaschin-Beck disease. These affect the heart muscle and the joints, respectively. Both diseases do not actually occur in Europe.

In children, potential signs of selenium deficiency include the following symptoms:
- Reduced size growth
- Increased risk of developing tumor diseases

Most of the symptoms shown above that can occur with a selenium deficiency are very general physical complaints. All of the symptoms listed can also have a variety of other causes. If you observe one or more of these symptoms, it does not necessarily mean that you are suffering from a selenium deficiency. And because an overdose of selenium can also have serious consequences, you should never take selenium supplements without a doctor's order.

Selenium deficiency should only be diagnosed by a doctor. Your doctor will first ask you about your symptoms and take a look at your medical history. This is followed by a thorough physical examination and then a blood draw. The laboratory can determine whether a selenium deficiency is the cause of your symptoms.

If you eat a conscious and balanced diet and do not belong to any of the risk groups listed above (smokers, alcoholics), you can usually cover your selenium requirements simply through your diet. Here you can find out which foods are particularly rich in selenium:

(selenium content per 100 grams)

- Coconuts: 400 - 800 micrograms per 100 grams
- Porcini mushrooms: 190 micrograms per 100 grams
- Pistachios: 130 micrograms per 100 grams
- Wheat bran: 100 micrograms per 100 grams
- Soybeans: 45 micrograms per 100 grams

Selenium content per serving (gram count therefore varies):

- Wholemeal rye bread: 70 micrograms per 100 grams
- Emmental cheese: 70 micrograms per 60 grams (2 slices)
- Chicken egg: 70 micrograms per piece
- Mackerel: 70 micrograms per 150 grams
- Rice: 70 micrograms per 250 grams
- Mushrooms: 70 micrograms per 250 grams
- Lentils: 70 micrograms per 100 grams
- Poultry meat: 70 micrograms per 150 grams
- Brazil nuts: 60 micrograms per 25 grams
- Gouda: 60 micrograms per 60 grams (2 slices)
- Bismarck herring: 60 micrograms per 150 grams
- Potatoes: 60 micrograms per 250 grams
- Banana: 60 micrograms per 100 grams (1 banana)
- Yogurt: 60 micrograms per 150 grams
- White cabbage: 60 micrograms per 150 grams.

Note: The values given are average values. The actual selenium content of the food depends on the area of cultivation or the feed of the animals from which the meat, eggs or dairy products are derived.

Selenosis occurs when too much selenium is supplied to the body. In fact, too much selenium is just as harmful as a lack of selenium. Depending on the amount or duration of the overdose, selenium can cause severe damage to health. A distinction is made between acute and chronic selenosis. Acute selenosis occurs when four to eight (or more) milligrams of selenium are ingested within 24 hours. Chronic selenosis occurs when 0.6 milligrams or more is ingested per day over an extended period of time.

The main symptoms of selenosis include:

- Initially unspecific complaints of the gastrointestinal tract
- Nausea
- vomiting
- diarrhea
- As a consequence: dehydration (dehydration) of the body
- Muscle pain
- Feeling of weakness and severe fatigue
- Sensory disturbances
- Skin rashes, hair loss, loss of fingernails and toenails.

Selenium requirements depend on several factors. Among the most important are age and gender. As a rule, the selenium requirement of a healthy person can be well covered by the diet. A selenium deficiency is manifested by a variety of symptoms, which are, however, very unspecific. A clarification should always be made by the family doctor. Under no circumstances should you take dietary supplements if you merely suspect a selenium deficiency. Because an overdose has serious health consequences: an overdose leads to poisoning.