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3/5 Moderate evidence

Thyroid health evidence brief

Selenium

Selenium is an essential trace mineral, but supplement claims for thyroid antibodies, prostate cancer prevention, or general immunity need restraint.

Context-dependent thyroid evidence health 6 linked sources Content audit 2026-05-05

Headline Finding

Hashimoto meta-analyses show antibody and TSH signals, while Cochrane judged earlier evidence insufficient for confident routine use.

Dose Context

Dietary intake, regional soil status, thyroid diagnosis, and baseline selenium status matter; high-dose use narrows the safety margin.

Important Caveat

Excess selenium can be harmful. It should not be used for cancer prevention, and thyroid use should be discussed with a clinician.

Source Drawer

Linked Research

6 papers and evidence links - audit 2026-05-05
  1. Review NIH ODS selenium fact sheet
  2. Meta-analysis Hashimoto meta-analysis PubMed
  3. Meta-analysis Hashimoto meta-analysis full text
  4. Review Cochrane Hashimoto summary
  5. Trial SELECT cancer prevention trial
  6. Review SELECT prostate cancer insights

How To Read This Rating

The score reflects evidence that the supplement does its stated job. Some jobs are direct, such as strength, endurance, or recovery; others are indirect, such as sleep, mood, appetite, or health support. A real effect can still receive a cautious practical rating when dose, safety, product quality, or audience fit remain uncertain.

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