Selenium

Selenium is an essential trace element that is required for numerous vital functions in the human body.

Occurrence and intake

The selenium content in food depends heavily on the selenium content of the soil in which plants are grown or animals are reared. In Europe, soils and therefore many plant-based foods tend to be low in selenium. Important sources of selenium are

• Fish and seafood
• Meat and offal
• Eggs
• Brazil nuts (particularly rich in selenium)
• Cereal products
• Pulses
• Broccoli and white cabbage

Recommended intake

The German Nutrition Society (DGE) recommends a daily selenium intake of

• 60 μg for adult women
• 70 μg for adult men
• 75 μg for breastfeeding women

This recommendation corresponds to about 1 μg per kilogram of body weight per day.

Functions in the body

Selenium is a component of various enzymes (selenoproteins) and fulfils important tasks

• Protects cells from oxidative stress as an antioxidant
• Support of the immune system
• Involvement in thyroid hormone metabolism
• Promotion of male fertility (sperm production)
• Binding of heavy metals in the body

Deficiency and overdose

A selenium deficiency is rather rare in healthy people in Germany, but can occur with an unbalanced diet. Vegetarians and vegans have an increased risk of a deficiency, especially in regions with selenium-poor soils.

Symptoms of selenium deficiency can include

• Weakened immune system
• Restrictions in muscle function
• Disturbances in sperm production

An overdose through dietary supplements can lead to selenosis. Symptoms are

• Tiredness
• Nausea
• Diarrhoea
• Joint pain
• Hair loss
• Disturbed nail formation

Supplementation

According to the Federal Institute for Risk Assessment (BfR), the daily amount of 40 μg selenium in food supplements should not be exceeded. Long-term supplementation is not necessary for most people, as a balanced diet usually covers the selenium requirement.

Conclusion

Selenium is an important trace element for many bodily functions. A balanced diet generally covers the selenium requirement. Supplementation can be useful for risk groups, but should only be taken after consulting a doctor. Overdosing should be avoided due to possible negative effects.