Evidence check: Selen in the context of Fruchtbarkeit

Selenium is an essential trace element important for thyroid function and antioxidant defense, both of which can influence fertility. Observational studies suggest links between low selenium levels and male infertility (e.g., reduced sperm quality) as well as female reproductive issues. However, the evidence is moderate: no large randomized controlled trials clearly demonstrate benefit from selenium supplementation in individuals with adequate status. Most data come from case-control or cohort studies with mixed results. Moreover, selenium is toxic at high doses (selenosis), so supplementation without prior lab testing is not advisable. In practice, selenium is often marketed as a 'fertility booster,' which overstates the evidence. A blood test for selenium may be useful if deficiency is suspected, but it does not replace a comprehensive fertility workup. In summary: selenium deficiency can impair fertility, but supplementation without deficiency is not evidence-based and carries risks.