Component
Subclinical hypothyroidism incidence
Subclinical hypothyroidism incidence. Study-specific scope and measurement methods are recorded with each claim.
2 recorded relationships. Experimental role, claim status and evidence remain attached to each record.
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.
Other things that act on it
Enzymes, hormones, genes, and other components with a recorded effect. These are not nutrients, so they do not count toward the arrows above. Each finding names the chapter that recorded it.
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.
What acts on it
Subclinical hypothyroidism occurred in 5% of the 400-microgram/day supplement group and 15–47% of the 500–2000-microgram/day groups.
Experimental context and source evidence
- cross_nutrient
- false
- evidence_location
- Primary indexed abstract.
- experimental_model
- Four-week randomized double-blind placebo-controlled dose trial in 256 euthyroid Chinese adults
- exposure
- Twelve groups received 0–2000 micrograms/day supplemental iodine. Mean reported dietary and salt iodine contributions were 105 ± 25 and 258 ± 101 micrograms/day.
- limitations
- Short study with small dose groups. Total background iodine differs among participants; the approximately 800 micrograms/day total at the 400-microgram supplement is the authors’ estimate, not a universal safe/unsafe threshold. Exact chemical formulation not verified from abstract. These percentages are reported study-group findings, not an individual risk calculator. The authors estimated about 800 micrograms/day total intake in the 400-microgram supplement group; adding two overall mean background values is not a group-specific intake measurement.
- nutrient_topic
- Iodine research collection; topical membership is not evidence of a direct dietary effect. · Iodine
- organism
- Homo sapiens
- plain_language
- Higher iodine exposure produced abnormal thyroid-function classifications in some participants.
- primary_references
- [iod-clin-sang2012] Exploration of the safe upper level of iodine intake in euthyroid Chinese adults: a randomized double-blind trial. (2012). https://pubmed.ncbi.nlm.nih.gov/22205314/ DOI: 10.3945/ajcn.111.028001
- tissue_or_cell_type
- Serum thyroid indices, ultrasound and urinary iodine
Iodine: thyroid hormone production, deficiency, excess and nutrient interactions (2026-09-17) · lines 1468–1480
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Four-week randomized double-blind placebo-controlled dose trial in 256 euthyroid Chinese adults · source_derived_draft · unverified_draft
### iod-clin-excess-subclinical Subclinical hypothyroidism occurred in 5% of the 400-microgram/day supplement group and 15–47% of the 500–2000-microgram/day groups. Condition category: normal nutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect. plain_language: Higher iodine exposure produced abnormal thyroid-function classifications in some participants. organism: Homo sapiens tissue_or_cell_type: Serum thyroid indices, ultrasound and urinary iodine experimental_model: Four-week randomized double-blind placebo-controlled dose trial in 256 euthyroid Chinese adults limitations: Short study with small dose groups. Total background iodine differs among participants; the approximately 800 micrograms/day total at the 400-microgram supplement is the authors’ estimate, not a universal safe/unsafe threshold. Exact chemical formulation not verified from abstract. These percentages are reported study-group findings, not an individual risk calculator. The authors estimated about 800 micrograms/day total intake in the 400-microgram supplement group; adding two overall mean background values is not a group-specific intake measurement. exposure: Twelve groups received 0–2000 micrograms/day supplemental iodine. Mean reported dietary and salt iodine contributions were 105 ± 25 and 258 ± 101 micrograms/day. cross_nutrient: false evidence_location: Primary indexed abstract. [iod-clin-sang2012] Exploration of the safe upper level of iodine intake in euthyroid Chinese adults: a randomized double-blind trial. (2012). https://pubmed.ncbi.nlm.nih.gov/22205314/ DOI: 10.3945/ajcn.111.028001
Complete structured claim and evidenceFive-year subclinical hypothyroidism incidence was 0.2%, 2.6% and 2.9% in the regions with mildly deficient, more-than-adequate and excessive iodine exposure, respectively.
Experimental context and source evidence
- cross_nutrient
- false
- evidence_location
- Primary indexed abstract.
- experimental_model
- Prospective five-year observational follow-up in three Chinese regions;3761 enrolled and 3018 followed
- exposure
- Regional baseline median urinary iodine 84, 243 and 651 micrograms/L; followed 1999–2004.
- limitations
- Regional exposure is not randomized individual dosing; confounding and baseline susceptibility may contribute. Median urinary iodine defines cohort exposure, not an individual disease threshold. The corresponding overt hypothyroidism incidences were 0.2%, 0.5% and 0.3%, so the study does not show a monotonic rise for every thyroid outcome.
- nutrient_topic
- Iodine research collection; topical membership is not evidence of a direct dietary effect. · Iodine
- organism
- Homo sapiens
- plain_language
- Higher regional iodine exposure was associated with more subclinical hypothyroidism.
- primary_references
- [iod-clin-teng2006] Effect of iodine intake on thyroid diseases in China. (2006). https://pubmed.ncbi.nlm.nih.gov/16807415/ DOI: 10.1056/nejmoa054022
- tissue_or_cell_type
- Serum thyroid function/antibodies and thyroid ultrasound
Iodine: thyroid hormone production, deficiency, excess and nutrient interactions (2026-09-17) · lines 1482–1494
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Prospective five-year observational follow-up in three Chinese regions;3761 enrolled and 3018 followed · source_derived_draft · unverified_draft
### iod-clin-regional-subclinical Five-year subclinical hypothyroidism incidence was 0.2%, 2.6% and 2.9% in the regions with mildly deficient, more-than-adequate and excessive iodine exposure, respectively. Condition category: normal nutrient_topic: Iodine research collection; topical membership is not evidence of a direct dietary effect. plain_language: Higher regional iodine exposure was associated with more subclinical hypothyroidism. organism: Homo sapiens tissue_or_cell_type: Serum thyroid function/antibodies and thyroid ultrasound experimental_model: Prospective five-year observational follow-up in three Chinese regions;3761 enrolled and 3018 followed limitations: Regional exposure is not randomized individual dosing; confounding and baseline susceptibility may contribute. Median urinary iodine defines cohort exposure, not an individual disease threshold. The corresponding overt hypothyroidism incidences were 0.2%, 0.5% and 0.3%, so the study does not show a monotonic rise for every thyroid outcome. exposure: Regional baseline median urinary iodine 84, 243 and 651 micrograms/L; followed 1999–2004. cross_nutrient: false evidence_location: Primary indexed abstract. [iod-clin-teng2006] Effect of iodine intake on thyroid diseases in China. (2006). https://pubmed.ncbi.nlm.nih.gov/16807415/ DOI: 10.1056/nejmoa054022
Complete structured claim and evidence
The events it takes part in
A mechanism often involves more than two components. These are the full events, with every participant and its role.
Situations it appears in
Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.
In the sources
Preserved passages that mention this component, quoted exactly. Open one to read it in context.
Open hypotheses
Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.
This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.