Selenium

What it is

Selenium is an essential trace mineral incorporated into roughly 25 selenoproteins, including glutathione peroxidases and the iodothyronine deiodinases that activate thyroid hormone. Through these enzymes it supports antioxidant defense, thyroid hormone metabolism, and immune function.

Benefits

Correcting a selenium deficit supports normal selenoprotein and thyroid function; in autoimmune (Hashimoto) thyroiditis, 6 months of supplementation has reduced thyroid peroxidase antibody levels, though an effect on actual thyroid function is not established. Studied doses for antibody reduction were typically 80-200 mcg/day as selenomethionine.

When to take it

Take with food, once daily; timing is not critical. Benefits in thyroid trials emerged only after roughly 6 months of consistent use.

Side effects

Well tolerated near the RDA. Chronic intake above the 400 mcg/day upper limit can cause selenosis: hair and nail loss or brittleness, garlic breath, metallic taste, rash, nausea, and nerve abnormalities. Avoid stacking multiple selenium-containing supplements.

Sources

• Selenium — Health Professional Fact Sheet (NIH Office of Dietary Supplements)
• Clinical efficacy of selenium supplementation in patients with Hashimoto thyroiditis: a systematic review and meta-analysis

Products containing Selenium

No products in our database contain this ingredient yet.