What should I know about vitamin selen wirkung bedarf und dosierung?

Selenium is not a vitamin but an essential trace mineral, incorporated into selenoproteins (e.g., glutathione peroxidases) that act as antioxidants, support thyroid function, and modulate immune responses. The recommended dietary allowance for adults is about 55 µg/day (DGE), with slightly higher needs during pregnancy and lactation. Supplementation is justified only when deficiency is confirmed; chronic excess (above 300–400 µg/day) can cause selenosis – garlic breath, hair loss, nail changes, and neuropathy. Evidence for preventive effects against cancer or cardiovascular disease is mixed; large trials (SELECT, NPC) found no benefit and even potential harm at high doses. The provided MyBody-X context does not contain specific selenium data. Therefore, this answer relies on established reference intakes and mechanistic understanding. Caveat: Total selenium intake from diet and supplements should generally not exceed 200 µg/day unless medically supervised. Evidence grade: mechanistic/practice, as no direct sources from the context are available.