Component

Selenomethionine (SeMet)

Selenium-containing methionine analogue that can enter both nonspecific protein incorporation and functional selenium metabolism.

9 recorded relationships. Experimental role, claim status and evidence remain attached to each record.

Read recorded mechanisms Open recursive mind map

How nutrients influence it

Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.

How nutrients reach it in more than one step

Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.

Tracing routes…

What it does

Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.

Recorded relationships

What it acts on

  1. Mean serum free T4 fell from 11.8 ± 6.7 to 8.4 ± 4.1 pmol/L after selenium treatment (P<0.01).

    Selenomethionine (SeMet) → Serum free thyroxine concentration source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    true
    evidence_location
    Primary indexed abstract.
    experimental_model
    Placebo-controlled selenium intervention in 52 schoolchildren from a region of severe iodine and selenium deficiency in northern Zaire
    exposure
    Selenium 50 micrograms/day as selenomethionine or placebo for two months; no concurrent iodine-repletion regimen reported in the abstract.
    limitations
    The abstract reports before/after changes in the selenium group; do not mistake these for adjusted between-group estimates. DIO1 restoration was a proposed explanation, not directly measured. Hormone changes do not themselves establish symptomatic deterioration or a universal order for supplement treatment.
    nutrient_topic
    Iodine research collection; topical membership is not evidence of a direct dietary effect. · Iodine
    organism
    Homo sapiens
    plain_language
    The free T4 measurement also fell after selenium was added.
    primary_references
    [iod-clin-contempre1992] Effect of selenium supplementation on thyroid hormone metabolism in an iodine and selenium deficient population. (1992). https://pubmed.ncbi.nlm.nih.gov/1424183/ DOI: 10.1111/j.1365-2265.1992.tb02268.x
    tissue_or_cell_type
    Serum thyroid-hormone concentrations
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Iodine: thyroid hormone production, deficiency, excess and nutrient interactions (2026-09-17) · lines 1272–1284

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Placebo-controlled selenium intervention in 52 schoolchildren from a region of severe iodine and selenium deficiency in northern Zaire · source_derived_draft · unverified_draft

    ### iod-clin-selenium-free-t4 Mean serum free T4 fell from 11.8 ± 6.7 to 8.4 ± 4.1 pmol/L after selenium treatment (P<0.01). Condition category: nutrient_deficiency nutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect. plain_language: The free T4 measurement also fell after selenium was added. organism: Homo sapiens tissue_or_cell_type: Serum thyroid-hormone concentrations experimental_model: Placebo-controlled selenium intervention in 52 schoolchildren from a region of severe iodine and selenium deficiency in northern Zaire limitations: The abstract reports before/after changes in the selenium group; do not mistake these for adjusted between-group estimates. DIO1 restoration was a proposed explanation, not directly measured. Hormone changes do not themselves establish symptomatic deterioration or a universal order for supplement treatment. exposure: Selenium 50 micrograms/day as selenomethionine or placebo for two months; no concurrent iodine-repletion regimen reported in the abstract. cross_nutrient: true evidence_location: Primary indexed abstract. [iod-clin-contempre1992] Effect of selenium supplementation on thyroid hormone metabolism in an iodine and selenium deficient population. (1992). https://pubmed.ncbi.nlm.nih.gov/1424183/ DOI: 10.1111/j.1365-2265.1992.tb02268.x
    Complete structured claim and evidence

  2. Mean reverse T3 fell from 124 ± 115 to 90 ± 72 pmol/L after selenium treatment (P<0.05), while serum T3 and TSH did not change significantly.

    Selenomethionine (SeMet) → Serum reverse T3 concentration source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    true
    evidence_location
    Primary indexed abstract.
    experimental_model
    Placebo-controlled selenium intervention in 52 schoolchildren from a region of severe iodine and selenium deficiency in northern Zaire
    exposure
    Selenium 50 micrograms/day as selenomethionine or placebo for two months; no concurrent iodine-repletion regimen reported in the abstract.
    limitations
    The abstract reports before/after changes in the selenium group; do not mistake these for adjusted between-group estimates. DIO1 restoration was a proposed explanation, not directly measured. Hormone changes do not themselves establish symptomatic deterioration or a universal order for supplement treatment.
    nutrient_topic
    Iodine research collection; topical membership is not evidence of a direct dietary effect. · Iodine
    organism
    Homo sapiens
    plain_language
    The hormone pattern changed unevenly; T3 and TSH did not simply rise with selenium.
    primary_references
    [iod-clin-contempre1992] Effect of selenium supplementation on thyroid hormone metabolism in an iodine and selenium deficient population. (1992). https://pubmed.ncbi.nlm.nih.gov/1424183/ DOI: 10.1111/j.1365-2265.1992.tb02268.x
    tissue_or_cell_type
    Serum thyroid-hormone concentrations
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Iodine: thyroid hormone production, deficiency, excess and nutrient interactions (2026-09-17) · lines 1286–1298

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Placebo-controlled selenium intervention in 52 schoolchildren from a region of severe iodine and selenium deficiency in northern Zaire · source_derived_draft · unverified_draft

    ### iod-clin-selenium-rt3 Mean reverse T3 fell from 124 ± 115 to 90 ± 72 pmol/L after selenium treatment (P<0.05), while serum T3 and TSH did not change significantly. Condition category: nutrient_deficiency nutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect. plain_language: The hormone pattern changed unevenly; T3 and TSH did not simply rise with selenium. organism: Homo sapiens tissue_or_cell_type: Serum thyroid-hormone concentrations experimental_model: Placebo-controlled selenium intervention in 52 schoolchildren from a region of severe iodine and selenium deficiency in northern Zaire limitations: The abstract reports before/after changes in the selenium group; do not mistake these for adjusted between-group estimates. DIO1 restoration was a proposed explanation, not directly measured. Hormone changes do not themselves establish symptomatic deterioration or a universal order for supplement treatment. exposure: Selenium 50 micrograms/day as selenomethionine or placebo for two months; no concurrent iodine-repletion regimen reported in the abstract. cross_nutrient: true evidence_location: Primary indexed abstract. [iod-clin-contempre1992] Effect of selenium supplementation on thyroid hormone metabolism in an iodine and selenium deficient population. (1992). https://pubmed.ncbi.nlm.nih.gov/1424183/ DOI: 10.1111/j.1365-2265.1992.tb02268.x
    Complete structured claim and evidence

  3. Mean serum total T4 fell from 73.1 ± 45.4 to 48.3 ± 23.7 nmol/L after two months of selenium treatment (P<0.001) in the iodine/selenium-deficient setting.

    Selenomethionine (SeMet) → Serum total thyroxine concentration source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    true
    evidence_location
    Primary indexed abstract.
    experimental_model
    Placebo-controlled selenium intervention in 52 schoolchildren from a region of severe iodine and selenium deficiency in northern Zaire
    exposure
    Selenium 50 micrograms/day as selenomethionine or placebo for two months; no concurrent iodine-repletion regimen reported in the abstract.
    limitations
    The abstract reports before/after changes in the selenium group; do not mistake these for adjusted between-group estimates. DIO1 restoration was a proposed explanation, not directly measured. Hormone changes do not themselves establish symptomatic deterioration or a universal order for supplement treatment.
    nutrient_topic
    Iodine research collection; topical membership is not evidence of a direct dietary effect. · Iodine
    organism
    Homo sapiens
    plain_language
    Selenium alone lowered circulating T4 in this co-deficient population.
    primary_references
    [iod-clin-contempre1992] Effect of selenium supplementation on thyroid hormone metabolism in an iodine and selenium deficient population. (1992). https://pubmed.ncbi.nlm.nih.gov/1424183/ DOI: 10.1111/j.1365-2265.1992.tb02268.x
    tissue_or_cell_type
    Serum thyroid-hormone concentrations
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Iodine: thyroid hormone production, deficiency, excess and nutrient interactions (2026-09-17) · lines 1258–1270

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Placebo-controlled selenium intervention in 52 schoolchildren from a region of severe iodine and selenium deficiency in northern Zaire · source_derived_draft · unverified_draft

    ### iod-clin-selenium-total-t4 Mean serum total T4 fell from 73.1 ± 45.4 to 48.3 ± 23.7 nmol/L after two months of selenium treatment (P<0.001) in the iodine/selenium-deficient setting. Condition category: nutrient_deficiency nutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect. plain_language: Selenium alone lowered circulating T4 in this co-deficient population. organism: Homo sapiens tissue_or_cell_type: Serum thyroid-hormone concentrations experimental_model: Placebo-controlled selenium intervention in 52 schoolchildren from a region of severe iodine and selenium deficiency in northern Zaire limitations: The abstract reports before/after changes in the selenium group; do not mistake these for adjusted between-group estimates. DIO1 restoration was a proposed explanation, not directly measured. Hormone changes do not themselves establish symptomatic deterioration or a universal order for supplement treatment. exposure: Selenium 50 micrograms/day as selenomethionine or placebo for two months; no concurrent iodine-repletion regimen reported in the abstract. cross_nutrient: true evidence_location: Primary indexed abstract. [iod-clin-contempre1992] Effect of selenium supplementation on thyroid hormone metabolism in an iodine and selenium deficient population. (1992). https://pubmed.ncbi.nlm.nih.gov/1424183/ DOI: 10.1111/j.1365-2265.1992.tb02268.x
    Complete structured claim and evidence

  4. SeMet can enter the methionine pool and be nonspecifically incorporated into proteins.

    Selenomethionine (SeMet) → SeMet incorporation into proteins source_derived_draftsource_reported: Biochemical metabolism and source synthesis; not a claim of superiority in intervention trials.
    Experimental context and source evidence
    availability_state
    Selenomethionine contributes to measured selenium during exposure or repletion.
    experimental_scope
    Selenium-form pharmacokinetics and interpretation of status markers.
    limitations
    Form alone does not determine clinical outcomes; baseline status, dose, duration, population, and endpoint matter. This comparison provides no product or dosing recommendation.
    trigger_kind
    biomarker_context

    Selenium deficiency: a mechanism-first reference · lines 661–663

    Supplied selenium deficiency reference · supports · Supplied reference; verify the primary study and experimental context. · source_derived_draft · unverified_draft

    Selenomethionine (SeMet) Well absorbed; can enter the methionine pool and be nonspecifically incorporated into proteins, and can also be metabolized into the functional selenium pool
    Complete structured claim and evidence

  5. SeMet can also be metabolized into the functional selenium pool.

    Selenomethionine (SeMet) → Functional selenium precursor pool source_derived_draftsource_reported: Biochemical metabolism and source synthesis; not a claim of superiority in intervention trials.
    Experimental context and source evidence
    availability_state
    Selenomethionine contributes to measured selenium during exposure or repletion.
    experimental_scope
    Selenium-form pharmacokinetics and interpretation of status markers.
    limitations
    Form alone does not determine clinical outcomes; baseline status, dose, duration, population, and endpoint matter. This comparison provides no product or dosing recommendation.
    trigger_kind
    biomarker_context

    Selenium deficiency: a mechanism-first reference · lines 661–663

    Supplied selenium deficiency reference · supports · Supplied reference; verify the primary study and experimental context. · source_derived_draft · unverified_draft

    Selenomethionine (SeMet) Well absorbed; can enter the methionine pool and be nonspecifically incorporated into proteins, and can also be metabolized into the functional selenium pool

    Selenium deficiency: a mechanism-first reference · lines 681–681

    Supplied selenium deficiency reference · supports · Supplied reference; verify the primary study and experimental context. · source_derived_draft · unverified_draft

    Calling SeMet only “storage” and selenite only “functional” is too simple. Form changes pharmacokinetics and metabolism, but baseline status, dose, population, duration, endpoint, and study design also determine outcomes.
    Complete structured claim and evidence

  6. SeMet supplementation increased functional selenium biomarkers including SELENOP and plasma GPX activity in selenium-deficient people.

    Selenomethionine (SeMet) → Functional selenium precursor pool source_derived_draftliterature_reviewed:supported_interpretation
    Experimental context and source evidence
    cell_type
    Circulating biomarkers
    experimental_model
    Randomized SeMet supplementation in selenium-deficient people
    limitations
    Baseline-deficient population; not disease-prevention evidence in selenium-replete people.
    organism
    Homo sapiens

    Selenium: literature corrections and mechanism additions · lines 1456–1466

    Metabolic Ledger literature curation, 17 September 2026; primary papers linked individually · supports · Randomized SeMet supplementation in selenium-deficient people · secondary_verified · secondary_verified

    ## semet-functional SeMet can supply functional selenium as well as enter protein storage. SeMet supplementation increased functional selenium biomarkers including SELENOP and plasma GPX activity in selenium-deficient people. Organism: Homo sapiens Cell type: Circulating biomarkers Experimental model: Randomized SeMet supplementation in selenium-deficient people Limitations: Baseline-deficient population; not disease-prevention evidence in selenium-replete people. Primary reference: [Optimization of selenoprotein P and other plasma selenium biomarkers for the assessment of the selenium nutritional requirement: a placebo-controlled, double-blind study of selenomethionine supplementation in selenium-deficient Chinese subjects](https://pubmed.ncbi.nlm.nih.gov/20573787/)
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. SELECT did not demonstrate prostate-cancer prevention with vitamin E plus selenium (HR 1.05, 99% CI 0.89–1.22 versus placebo).

    All-rac-alpha-tocopheryl acetate → Prostate cancer incidence source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    true
    experimental_model
    SELECT randomized factorial prevention trial; 34887 men in primary analysis, 35533 originally randomized
    exposure
    All-rac-alpha-tocopheryl acetate 400 IU/day; selenium arm 200 micrograms/day selenium as L-selenomethionine; supplements stopped in 2008, follow-up continued to July 2011.
    limitations
    Trial-specific formulation, dose and population; does not establish the effect of food intake or of every vitamin E form. Group results cannot identify an intracellular mechanism. The nonsignificant combination estimate is not proof that selenium mechanistically neutralizes vitamin E-associated harm.
    nutrient_topic
    Vitamin E research collection; topical membership is not evidence of a direct dietary effect. · Vitamin E
    organism
    Homo sapiens
    plain_language
    Adding selenium did not demonstrate a prostate-cancer prevention benefit.
    primary_references
    [e-clin-select2011] Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). (2011). https://pubmed.ncbi.nlm.nih.gov/21990298/ DOI: 10.1001/jama.2011.1437
    tissue_or_cell_type
    Prostate and whole-person outcomes

    Vitamin E: transport, membrane protection and nutrient interactions (2026-09-17) · lines 1297–1308

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · SELECT randomized factorial prevention trial; 34887 men in primary analysis, 35533 originally randomized · source_derived_draft · unverified_draft

    ### e-clin-select-combination-boundary SELECT did not demonstrate prostate-cancer prevention with vitamin E plus selenium (HR 1.05, 99% CI 0.89–1.22 versus placebo). Condition category: normal nutrient_topic: Vitamin E research collection; topical membership is not evidence of a direct dietary effect. plain_language: Adding selenium did not demonstrate a prostate-cancer prevention benefit. organism: Homo sapiens tissue_or_cell_type: Prostate and whole-person outcomes experimental_model: SELECT randomized factorial prevention trial; 34887 men in primary analysis, 35533 originally randomized limitations: Trial-specific formulation, dose and population; does not establish the effect of food intake or of every vitamin E form. Group results cannot identify an intracellular mechanism. The nonsignificant combination estimate is not proof that selenium mechanistically neutralizes vitamin E-associated harm. exposure: All-rac-alpha-tocopheryl acetate 400 IU/day; selenium arm 200 micrograms/day selenium as L-selenomethionine; supplements stopped in 2008, follow-up continued to July 2011. cross_nutrient: true [e-clin-select2011] Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). (2011). https://pubmed.ncbi.nlm.nih.gov/21990298/ DOI: 10.1001/jama.2011.1437
    Complete structured claim and evidence

  2. In SELECT, vitamin E alone increased prostate-cancer incidence relative to placebo (HR 1.17, 99% CI 1.004–1.36); the absolute increase was 1.6 cases per 1000 person-years.

    All-rac-alpha-tocopheryl acetate → Prostate cancer incidence source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    true
    experimental_model
    SELECT randomized factorial prevention trial; 34887 men in primary analysis, 35533 originally randomized
    exposure
    All-rac-alpha-tocopheryl acetate 400 IU/day; selenium arm 200 micrograms/day selenium as L-selenomethionine; supplements stopped in 2008, follow-up continued to July 2011.
    limitations
    Trial-specific formulation, dose and population; does not establish the effect of food intake or of every vitamin E form. Group results cannot identify an intracellular mechanism.
    nutrient_topic
    Vitamin E research collection; topical membership is not evidence of a direct dietary effect. · Vitamin E
    organism
    Homo sapiens
    plain_language
    The tested high-dose vitamin E preparation increased prostate-cancer diagnoses in this trial.
    primary_references
    [e-clin-select2011] Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). (2011). https://pubmed.ncbi.nlm.nih.gov/21990298/ DOI: 10.1001/jama.2011.1437
    tissue_or_cell_type
    Prostate and whole-person outcomes

    Vitamin E: transport, membrane protection and nutrient interactions (2026-09-17) · lines 1284–1295

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · SELECT randomized factorial prevention trial; 34887 men in primary analysis, 35533 originally randomized · source_derived_draft · unverified_draft

    ### e-clin-select-prostate-incidence In SELECT, vitamin E alone increased prostate-cancer incidence relative to placebo (HR 1.17, 99% CI 1.004–1.36); the absolute increase was 1.6 cases per 1000 person-years. Condition category: normal nutrient_topic: Vitamin E research collection; topical membership is not evidence of a direct dietary effect. plain_language: The tested high-dose vitamin E preparation increased prostate-cancer diagnoses in this trial. organism: Homo sapiens tissue_or_cell_type: Prostate and whole-person outcomes experimental_model: SELECT randomized factorial prevention trial; 34887 men in primary analysis, 35533 originally randomized limitations: Trial-specific formulation, dose and population; does not establish the effect of food intake or of every vitamin E form. Group results cannot identify an intracellular mechanism. exposure: All-rac-alpha-tocopheryl acetate 400 IU/day; selenium arm 200 micrograms/day selenium as L-selenomethionine; supplements stopped in 2008, follow-up continued to July 2011. cross_nutrient: true [e-clin-select2011] Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). (2011). https://pubmed.ncbi.nlm.nih.gov/21990298/ DOI: 10.1001/jama.2011.1437
    Complete structured claim and evidence

  3. TSH fell from baseline in the myo-inositol-plus-selenomethionine arm, while no TSH change was reported in the selenomethionine-only arm; the reported TSH P value was a within-group comparison.

    Myo-inositol → Serum TSH concentration source_derived_draftungraded
    Experimental context and source evidence
    evidence_span
    {"source_cache": "artifacts/inositol-research/24224112.fulltext.txt", "locator": "Exact primary full-text span; zero-based, end-exclusive Unicode character offsets", "file_sha256": "b9b55ed122a2f26149680eb0f4bfab9ea981927754bcbb40305d4697c5d32412", "start_char": 7984, "end_char": 8184, "text_sha256": "34e1c5b3fe451ea1278c2adfb27f4977a40d100b82946252ecad03a7879592dc"}
    experimental_model
    Double-blind randomized combination trial
    exposure
    Myo-inositol plus selenomethionine versus selenomethionine
    limitations
    Small combination trial without a myo-inositol-only arm. A significant within-group change versus a nonsignificant change in the other arm is not by itself a significant between-group difference or nutrient synergy.
    nutrient_topic
    Inositol research collection; topical membership is not evidence of a direct dietary effect. · Inositol (stereoisomer family)
    organism
    Homo sapiens
    plain_language
    A thyroid blood marker improved in the combined-treatment group, but these comparisons do not establish a statistical interaction between nutrients.
    primary_references
    [ino-p24224112] Combined treatment with Myo-inositol and selenium ensures euthyroidism in subclinical hypothyroidism patients with autoimmune thyroiditis. (2013). https://pubmed.ncbi.nlm.nih.gov/24224112/ DOI: 10.1155/2013/424163
    tissue_or_cell_type
    Women with autoimmune subclinical hypothyroidism

    Inositol: synthesis, signaling, mineral interactions and conditional deficiency (2026-09-17) · lines 1419–1430

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Double-blind randomized combination trial · source_derived_draft · unverified_draft

    ### ino-thyroid-combination TSH fell from baseline in the myo-inositol-plus-selenomethionine arm, while no TSH change was reported in the selenomethionine-only arm; the reported TSH P value was a within-group comparison. Condition category: normal nutrient_topic: Inositol research collection; topical membership is not evidence of a direct dietary effect. plain_language: A thyroid blood marker improved in the combined-treatment group, but these comparisons do not establish a statistical interaction between nutrients. organism: Homo sapiens tissue_or_cell_type: Women with autoimmune subclinical hypothyroidism experimental_model: Double-blind randomized combination trial limitations: Small combination trial without a myo-inositol-only arm. A significant within-group change versus a nonsignificant change in the other arm is not by itself a significant between-group difference or nutrient synergy. exposure: Myo-inositol plus selenomethionine versus selenomethionine evidence_span: {"source_cache": "artifacts/inositol-research/24224112.fulltext.txt", "locator": "Exact primary full-text span; zero-based, end-exclusive Unicode character offsets", "file_sha256": "b9b55ed122a2f26149680eb0f4bfab9ea981927754bcbb40305d4697c5d32412", "start_char": 7984, "end_char": 8184, "text_sha256": "34e1c5b3fe451ea1278c2adfb27f4977a40d100b82946252ecad03a7879592dc"} [ino-p24224112] Combined treatment with Myo-inositol and selenium ensures euthyroidism in subclinical hypothyroidism patients with autoimmune thyroiditis. (2013). https://pubmed.ncbi.nlm.nih.gov/24224112/ DOI: 10.1155/2013/424163
    Complete structured claim and evidence

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

    This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.

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