How are Selen and Müdigkeit related?

Selenium is an essential trace mineral critical for thyroid hormone metabolism and antioxidant defense. The thyroid requires selenium to convert T4 into the active T3; inadequate selenium can impair thyroid function and indirectly contribute to fatigue. Additionally, selenium is a component of glutathione peroxidases, which reduce oxidative stress—a factor linked to exhaustion. However, direct evidence that selenium supplementation reduces fatigue in healthy, non-deficient individuals is limited. Some studies in patients with Hashimoto's thyroiditis or chronic fatigue syndrome show modest benefits, but results are inconsistent. Importantly, selenium supplementation should only be taken if deficiency is confirmed or under medical supervision, as excess selenium is toxic (selenosis). For persistent fatigue, more common causes like iron deficiency, sleep disorders, or psychological factors should be investigated first. Overall, the evidence for a causal relationship between selenium and fatigue is moderate and context-dependent.