What is the recommended dose of Selenium?

- **Look for:** Selenium as selenomethionine (best absorbed) or sodium selenite; 55-200mcg per serving; third-party verified - **Avoid:** Doses >200mcg without medical indication; products combinin...

Is Selenium safe to take daily?

Selenium is rated "Generally Safe" based on clinical evidence. Always consult your healthcare provider before starting any supplement.

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Ingredient Research

Graded against 173,636 supplements + 177 published clinical interactions, sourced from PubMed, FDA CAERS, openFDA, NIH DSLD

Selenium

MODERATE EVIDENCEMineralLast updated

AVELOR SUMMARY

Selenium is an essential trace mineral that serves as a cofactor for 25 selenoproteins, including glutathione peroxidase (GPx) and thyroxine deiodinase (thyroid hormone activation). Our research highlights a critical lesson: the NPC trial (1996) suggested selenium reduced prostate cancer by 63%, but the massive follow-up SELECT trial (35,533 men) found NO cancer prevention benefit — and actually showed a non-significant INCREASE in type 2 diabetes. The therapeutic window is narrow: deficiency impairs immunity and thyroid function, but excess (>400mcg/day) causes selenosis. Form matters enormously — selenomethionine is well-absorbed but can accumulate; selenite/selenate are better regulated.

WHAT IT DOES

Selenium is incorporated as selenocysteine (the "21st amino acid") into 25 selenoproteins: (1) glutathione peroxidases (GPx1-6) — the primary cellular antioxidant defense system; (2) thioredoxin reductases — redox regulation; (3) iodothyronine deiodinases — convert T4 (inactive) to T3 (active thyroid hormone) and deactivate excess T3; (4) selenoprotein P — selenium transport protein and antioxidant. In Hashimoto's, selenium supplementation may reduce autoimmune thyroid inflammation by reducing oxidative damage to thyroid tissue.

OPTIMAL DOSAGE

Look for: Selenium as selenomethionine (best absorbed) or sodium selenite; 55-200mcg per serving; third-party verified
Avoid: Doses >200mcg without medical indication; products combining selenium with vitamin E at high doses (SELECT trial found no benefit); Brazil nut "supplements" (variable selenium content)
Minimum effective dose: 55mcg/day (RDA); 200mcg/day for thyroid autoimmunity studies
Third-party tested brands: Thorne (selenomethionine), Life Extension, NOW Foods

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SAFETY PROFILE

Critical Interactions (Do Not Combine Without Medical Supervision)

No critical interactions at standard doses.

Moderate Interactions (Monitor Closely)

Theoretical/Low-Risk Interactions

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Independently graded against 173,636 indexed supplements with 177 published clinical interactions, sourced from PubMed, FDA CAERS, openFDA, and NIH DSLD | Last updated:

Not medical advice. Based on published clinical research and systematic reviews.

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