- Selenium is an essential trace element.
- The selenium content of food depends on the selenium content of the soil.
- In Central Europe, soils are mostly poor in selenium. In some EU countries, selenium is added to the feed used in factory farming. Finland has taken a different route: they have been systematically adding selenium to agricultural fertilizers for decades.
- Overall, Europeans do not have an adequate intake of selenium, which makes selenium a critical nutrient. Even with an omnivorous diet, one-third of the adult population in Europe (and in Great Britain) consumes less than 35 µg selenium per day – well below the recommended intake of 60-70 µg per day.
- Only Finland has a sufficient selenium status.
- In the US, selenium intake is mostly sufficient due to the fact that soils are mostly rich in selenium.
Why Do We Need Selenium?
- It is a component of selenium-containing proteins and acts as a cofactor for multiple enzymes; as such, selenium has a wide variety of very important functions for the body
- Important for a strong immune system
- Antioxidant/protective function
- Important for thyroid hormone metabolism
- Important for cell division and DNA biosynthesis
- Modulates inflammatory processes and is especially anti-inflammatory
- Supports the detoxification system
Possible Causes of Deficiency
- Diet containing few selenium-rich foods (see below)
- High intake of chromium, zinc, or vitamin C.
- Excessive alcohol consumption
- Leaky gut
- Oral intake of arsenic, lead, cadmium, or mercury
- Additional arsenic contamination (biliary excretion of arsenic-selenium compounds)
Interaction with medication:
- e.g., antacids, clozapine, corticoids, diuretics, laxatives, valproic acid
Symptoms of Deficiency
- General: susceptibility to infection, fatigue, depression
- Immune system: increased tendency to allergies, depressed immune system
- Thyroid: impaired conversion of T4 to T3, hypothyroidism
- Skin/nails: streaked fingernails, erythema (reddening of the skin)
- Muscle weakness, myopathy
- Reduced fertility
- Serious deficiency can cause cardiomyopathy (Keshan disease) or degenerative osteoarthritis (Keshan-Beck disease)
Recommended intake for adults:
- German Nutrition Society (DGE): women 60 µg/day, men 70 µg/day
- USA Food and Nutrition Board (FNB): 55 µg/day for men and women
- German Nutrition Society (DGE): 75 µg/day
- USA Food and Nutrition Board (FNB): 70 µg/day
in children, depending on age, see:
Excessive intake (> 400 µg/day) should be avoided, as it can lead to an overdose:
- chronic overdose symptoms: hair loss, brittle fingernails, neuropathies
- acute overdose symptoms: diarrhea, nausea, abdominal pain
The Best Plant Sources (per 100 g)
Good sources include nuts, legumes, grains, sesame, mushrooms and soy.
- Brazil nuts – 1,900 µg (note: large fluctuations)
- Boletus mushrooms, fresh – 187 µg
- Sunflower seeds – 79 µg
- Sesame – 34.4 µg
- Lentils – 46 µg
- Mushroom – 26 µg
- Oatmeal – 10 µg
- Peanuts – 7.5 µg
- Soybeans – 7.3 µg
- Walnuts – 6 µg
- Chickpeas, cooked – 4 µg
- Lentils, cooked – 4 µg
Biesalski, H.K., Bischoff, S.C., Pirlich, M., Weidmann, A., (2018). Ernährungsmedizin – Nach dem Curriculum Ernährungsmedizin der Bundesärztekammer (5.Auflage). Stuttgart: Georg Thieme Verlag
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