Research records
Historical source snapshot. Not freshly verified, not a recommendation. Study findings, community accounts and app defaults are not interchangeable.
Publication suitability · 2026-10-15: Historical reference only; not a clinical verification. Clinical, regulatory, efficacy, safety and dose claims are not independently established by this review.
Selenium
An essential trace mineral studied for thyroid antibody levels.
Evidence category: Systematic review. This describes the source category, not approval or certainty.
Regulatory statement in source: Not separately recorded; do not infer approval from the evidence category.
Selenium is an essential trace mineral obtained from diet, such as Brazil nuts, seafood, and organ meats, and required for antioxidant enzymes and thyroid hormone metabolism. It has an established recommended dietary allowance and has been studied both for general adequacy and in randomized trials of people with autoimmune thyroid conditions such as Hashimoto thyroiditis. Meta-analyses of these trials report reductions in thyroid-stimulating hormone and thyroid antibody levels among people without thyroid hormone replacement, alongside long-established data defining safe upper intake levels.
Benefits reported in the imported source
- An essential nutrient with a well-established dietary allowance target set by national nutrition authorities
- Trials in people with Hashimoto thyroiditis found reductions in thyroid-stimulating hormone and thyroid antibody levels
Risks and limits
- Chronic excess intake can cause selenosis, with hair and nail brittleness as characteristic signs
- Benefit for thyroid antibodies has mainly been shown in people with diagnosed autoimmune thyroid disease, not the general population
Source bottom line: Selenium is a well-characterized essential nutrient with a defined safe intake range, and randomized trial evidence supports a role in lowering thyroid antibody levels for people with Hashimoto thyroiditis specifically.
Uncertainty: Reference information only. Not medical advice.
Study protocols — reports, not instructions
Thirty-five randomized controlled trials pooled across cohorts of people with Hashimoto thyroiditis, with and without thyroid hormone replacement therapy
- Reported regimen
- Oral selenium supplementation trials, commonly in the range of 80 to 200 micrograms per day for periods of three months to two years, compared against placebo
- Duration
- Three months to two years
- Reported outcome
- Selenium supplementation reduced thyroid-stimulating hormone and thyroid peroxidase antibody levels in patients not on hormone replacement, with comparable adverse-event rates between selenium and placebo groups and moderate overall certainty of evidence
- Source
- Selenium Supplementation in Patients with Hashimoto Thyroiditis: A Systematic Review and Meta-Analysis of Randomized Clinical Trials - PubMed
Claim provenance
evidence.json#/catalog:supplement:selenium/protocols/0
Community and practice descriptions
Accounts of a practice are not evidence of safety or effectiveness. Words such as “standard”, “safe” or “recommended” describe the source account, not verified consensus or this wiki’s advice. Commercial and self-published citations are retained for traceability, not vendor endorsement or independent clinical corroboration.
Historical research outcome: no-verified-description · 2026-10-06
No suitable community description was independently verified in these checks. The entry remains empty; this does not establish that no practice exists elsewhere. The excerpt describes product formulations and promotional claims rather than a community routine.
- https://nutritionsource.hsph.harvard.edu/selenium/: no-practice-description — The excerpt describes product formulations and promotional claims rather than a community routine.
Pharmacokinetic context
No half-life recorded in this source snapshot. No value has been inferred.
Source references
- Selenium - Health Professional Fact Sheet - NIH Office of Dietary Supplements (availability check 2026-10-15: source not retrieved; HTTP 403)
- Selenium Supplementation in Patients with Hashimoto Thyroiditis: A Systematic Review and Meta-Analysis of Randomized Clinical Trials - PubMed
Snapshot provenance
Source ID: catalog:supplement:selenium. Commit: adc7684614f9439b41d91a3312b62e7982c7e20e. Review state: historical-not-reverified. Authored links are retained separately from the canonical evidence links in the public data. App templates/defaults and rejected drafts are archived, not deployed.
Related entries and components
None listed.