wo ist selen enthalten — what does this mean exactly?

The question 'wo ist selen enthalten' translates to 'where is selenium contained?' – it asks for food sources of selenium, an essential trace mineral crucial for thyroid function, immunity, and antioxidant defense. Selenium is found in animal sources: organ meats (kidney, liver), fish (tuna, sardines, mackerel), eggs, and meat. Plant sources like Brazil nuts, coconut, legumes, and grains vary greatly depending on soil selenium content. In Germany, soil is often low in selenium, making animal products more reliable. MyBody-X offers blood nutrient tests that measure selenium levels, useful if deficiency is suspected. However, genetic tests for selenium metabolism (e.g., GPX1, SEPP1 variants) have weak evidence – effects are small and not clinically actionable. A balanced diet usually meets needs; supplementation should only be done under medical supervision due to selenium toxicity risk (upper limit 300 µg/day).