SynthesisPloS one2017
Effect of excess iodine intake on thyroid diseases in different populations: A systematic review and meta-analyses including observational studies.
Synthesis in PloS one, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 63 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
63 citing papers in PubMed, 1 synthesis or guideline pooled it, 136 citations in OpenAlex.
- Interference on Iodine Uptake and Human Thyroid Function by Perchlorate-Contaminated Water and Food.Nutrients · 2020Pooled it
- Letter regarding 'the association between serum iodine concentration in the first trimester and foetal ultrasound biometric parameters and birth size among Chinese pregnant women'.Annals of medicine · 2026Article
- The Role of Immunological Challenges, Oxidative Stress, and Dietary Interventions in Managing Hashimoto's Thyroiditis: A Narrative Review.Nutrition reviews · 2026Review
- Iodine in Health and Disease: A Comprehensive Review.Nutrients · 2026Review
- Adult thyroid volume determinants and reference values: a Chinese cross-sectional study.Endocrine · 2026Article
- Impact of habitual seaweed consumption on iodine nutrition and thyroid function: a non-randomized pre-post clinical study.European journal of nutrition · 2026Article
- Serum thyroglobulin levels are predictive of urinary iodine concentration thresholds for defining population iodine status.The British journal of nutrition · 2025Article
- Thyrotoxicosis and Excess Iodine Due to Habitual Use of Polyvinylpyrrolidone Iodine While Gargling in an Iodine-sufficient Area.Internal medicine (Tokyo, Japan) · 2025Article
- A Scoping Review on the Prevalence of Hashimoto's Thyroiditis and the Possible Associated Factors.Medical sciences (Basel, Switzerland) · 2025Article
- Seaweed in the Diet as a Source of Bioactive Metabolites and a Potential Natural Immunity Booster: A Comprehensive Review.Pharmaceuticals (Basel, Switzerland) · 2025Review
- Reference intervals for thyroid-stimulating hormone in the adult Lebanese population: Results from the last decade.Heliyon · 2025Article
- Relationship between thyroid nodules and iodine nutritional status, thyroglobulin (Tg), and other influencing factors: a 1:1 matched case-control study.Frontiers in endocrinology · 2025Article
- Beyond thyroid dysfunction: the systemic impact of iodine excess.Frontiers in endocrinology · 2025Review
- Machine learning-based exploration of the associations between multiple minerals' intake and thyroid dysfunction: data from the National Health and Nutrition Examination Survey.Frontiers in nutrition · 2025Article
- Low-Glycemic Load Diets and Thyroid Function: A Narrative Review and Future Perspectives.Nutrients · 2024Review
- Prevalence and Associated Factors of Thyroid Nodules Among 52,003 Chinese 'Healthy' Individuals in Beijing: A Retrospective Cross-Sectional Study.Risk management and healthcare policy · 2024Article
- Association study of urinary iodine concentrations and coronary artery disease among adults in the USA: National Health and Nutrition Examination Survey 2003-2018.The British journal of nutrition · 2023Article
- Bioavailability of iodine from a meal consisting of sushi and a wakame seaweed salad-A randomized crossover trial.Food science & nutrition · 2023Article
- Iodine Nutrition in Children ≤2 years of Age in Norway.The Journal of nutrition · 2023Article
- Survey of iodized salt coverage in areas with different water iodine concentrations and the iodine status of local women.European journal of nutrition · 2023Article
3 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundAlthough several reports concerning the association of iodine excess and thyroid disease have appeared, no systematic review of the association between iodine excess intake and thyroid diseases, especially hyperthyroidism and hypothyroidism, has yet been reported.
methodWe conducted a systematic search of Ovid MEDLINE, PubMed, Cochrane Central Register of Controlled Trials databases, Ichushi-Web and CiNii database for intervention trials and observational studies. Search terms were constructed from related words for excess AND iodine intake or excretion AND thyroid hormones or diseases AND study designs. After considering the qualitative heterogeneity among studies, a meta-analysis was conducted and odds ratios and 95% confidence intervals (CI) were estimated in random-effects models. A protocol was registered with PROSPERO (No. CRD42015028081).
results50 articles were included, including three intervention trials, six case-control studies, six follow-up studies and 35 cross-sectional studies. Three cross-sectional studies in adults included in meta-analysis. Odds ratio of overt and subclinical hypothyroidism between excess and adequate populations were 2.78 (CI:1.47 to 5.27) and 2.03 (CI:1.58 to 2.62) in adults, respectively. Source of excess iodine status was mainly iodized salt or water in included studies.
conclusionAlthough universal salt iodization has improved goiter rates, chronic exposure to excess iodine from water or poorly monitored salt are risk factors for hypothyroidism in free-living populations. Monitoring of both iodine concentration in salt as well as the iodine concentration in local drinking water are essential to preventing thyroid diseases. Hypothyroidism should be also carefully monitored in areas with excess iodine. Because of the low quality and limited number of included studies, further evidence and review are required.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.