Iodine
Mineral ·Exploratory record · not publication-reviewed ·Updated July 13, 2026
Essential for thyroid hormone production. Deficiency is the leading cause of preventable intellectual disability worldwide. Many people are mildly deficient.
Exploratory record, not a reviewed medical publication.
See the editorial and medical-review policies for the publication gate.
This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.
What the research says.
A quick, data-only summary. The full evidence, dosing, and sources are below.
Iodine is a mineral most often used for thyroid function, metabolism, cognitive development. NutriStack rates the overall evidence as strong. A typical adult dose is 150–300 mcg daily, commonly taken as potassium iodide or kelp-derived iodine. This profile indexes 20 sources.
The bottom line
Evidence rating strong. Most-documented uses: thyroid function, metabolism, cognitive development. 20 sources indexed (2009–2023), with 0 interaction records on file.
How it works, mechanistically.
Core mechanism
Incorporated into thyroid hormones T3 (triiodothyronine) and T4 (thyroxine) by thyroid peroxidase. T3 is the active hormone that regulates metabolic rate, body temperature, growth, and development in virtually every cell.19,9
Dosing & protocol.
Selenium is required for proper thyroid hormone conversion; take together5,7
What it actually costs.
Real-world pricing across three quality tiers. Assumes Potassium Iodide / Kelp Iodine.
Assumes 150 mcg/day from goal dosage. Vendor basis: NOW/iHerb, Vitacost, Life Extension, and Amazon marketplace; iodine is inexpensive but dosing should be thyroid-aware. Updated 2026-05-28.
The same dose, as food.
How much you'd eat to match a supplemental dose.
Seaweed iodine content varies a lot by type.
Kelp can overshoot quickly, so supplement labels matter.
Full safety detail.
Side effects
- Thyroid dysfunction (excess)
- Acne
- Metallic taste
Contraindications
- Hashimoto's thyroiditis (consult doctor)
- Hyperthyroidism16
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Meta-analyses & systematic reviews
15- 1Correlation Between Drinking Water and Iodine Status: a Systematic Review and Meta-analysisPMIDAzevedo FM, Machamba AAL, Candido AC et al. · Biological trace element research · 2023
Azevedo FM, Machamba AAL, Candido AC et al.. Correlation Between Drinking Water and Iodine Status: a Systematic Review and Meta-analysis. Biological trace element research. 2023
- 2Iodine status during child development and hearing ability: a systematic reviewPMIDDineva M, Hall A, Tan M et al. · The British journal of nutrition · 2023
Dineva M, Hall A, Tan M et al.. Iodine status during child development and hearing ability: a systematic review. The British journal of nutrition. 2023
- 3Maternal Iodine Status and Birth Outcomes: A Systematic Literature Review and Meta-AnalysisPMIDGreenwood DC, Webster J, Keeble C et al. · Nutrients · 2023
Greenwood DC, Webster J, Keeble C et al.. Maternal Iodine Status and Birth Outcomes: A Systematic Literature Review and Meta-Analysis. Nutrients. 2023
- 4Systematic review and meta-analysis of iodine nutrition in modern vegan and vegetarian dietsPMIDEveleigh ER, Coneyworth L, Welham SJM · The British journal of nutrition · 2023
Eveleigh ER, Coneyworth L, Welham SJM. Systematic review and meta-analysis of iodine nutrition in modern vegan and vegetarian diets. The British journal of nutrition. 2023
- 5Effects of iodine supplementation on thyroid function parameter: Systematic review and meta-analysisPMIDCandido AC, Azevedo FM, Silva DLF et al. · Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS) · 2023
Candido AC, Azevedo FM, Silva DLF et al.. Effects of iodine supplementation on thyroid function parameter: Systematic review and meta-analysis. Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS). 2023
- 6The efficacy and safety of Iodine-131-metaiodobenzylguanidine therapy in patients with neuroblastoma: a meta-analysisPMIDHe H, Xu Q, Yu C · BMC cancer · 2022
He H, Xu Q, Yu C. The efficacy and safety of Iodine-131-metaiodobenzylguanidine therapy in patients with neuroblastoma: a meta-analysis. BMC cancer. 2022
- 7Systematic review and meta-analysis of the effects of iodine supplementation on thyroid function and child neurodevelopment in mildly-to-moderately iodine-deficient pregnant womenPMIDDineva M, Fishpool H, Rayman MP, Mendis J, Bath SC · American Journal of Clinical Nutrition · 2020
In 37 publications (10 RCTs), most showed no effect of iodine supplementation on maternal or infant thyroid function. Meta-analyses of 2 RCTs showed no effect on child cognitive, language, or motor scores. Evidence is insufficient to support routine supplementation in mild-to-moderate deficiency.
- 8Iodine deficiency status in the WHO Eastern Mediterranean Region: a systematic reviewPMIDMohammadi M, Azizi F, Hedayati M · Environmental geochemistry and health · 2018
Mohammadi M, Azizi F, Hedayati M. Iodine deficiency status in the WHO Eastern Mediterranean Region: a systematic review. Environmental geochemistry and health. 2018
- 9Micronutrients, iodine status and concentrations of thyroid hormones: a systematic reviewPMIDO'Kane SM, Mulhern MS, Pourshahidi LK et al. · Nutrition reviews · 2018
O'Kane SM, Mulhern MS, Pourshahidi LK et al.. Micronutrients, iodine status and concentrations of thyroid hormones: a systematic review. Nutrition reviews. 2018
- 10Effects of iodine supplementation during pregnancy on child growth: a meta-analysisSource linkedPMIDFarebrother J, Naude CE et al. · Thyroid · 2018
- 11Effect of excess iodine intake on thyroid diseases in different populations: A systematic review and meta-analyses including observational studiesSource linkedPMIDKatagiri R, Yuan X, Kobayashi S et al. · PLoS One · 2017
- 12Therapy of endocrine disease: Impact of iodine supplementation in mild-to-moderate iodine deficiency: systematic review and meta-analysisPMIDTaylor PN et al. · Eur J Endocrinol · 2014
Iodine supplementation improves some maternal thyroid indices and may benefit cognitive function in school-age children in marginally iodine-deficient areas
- 13Iodine supplementation improves cognition in iodine-deficient schoolchildren: a systematic review and meta-analysisSource linkedPMIDTaylor PN, Okosieme OE, Dayan CM, Lazarus JH · Eur J Endocrinol · 2014
- 14Effect of iodine supplementation in pregnancy on child development and other clinical outcomes: a systematic review of randomized controlled trialsPMIDZhou SJ et al. · Am J Clin Nutr · 2013
Iodine supplementation during pregnancy reduced cretinism risk in severe deficiency areas but insufficient evidence for benefits in mild-to-moderate deficiency
- 15Adverse effects of iodine thyroid blocking: a systematic reviewPMIDSpallek L, Krille L, Reiners C et al. · Radiation protection dosimetry · 2012
Spallek L, Krille L, Reiners C et al.. Adverse effects of iodine thyroid blocking: a systematic review. Radiation protection dosimetry. 2012
Reviews & position papers
4- 16Excess iodine intake: sources, assessment, and effects on thyroid functionPMIDFarebrother J et al. · Ann N Y Acad Sci · 2019
High iodine tolerated by most healthy individuals, but may precipitate hyperthyroidism, hypothyroidism, goiter, or thyroid autoimmunity in susceptible persons
- 17Iodine deficiency and thyroid disordersPMIDZimmermann MB, Boelaert K · Lancet Diabetes Endocrinol · 2015
Iodine is essential for thyroid hormone synthesis; deficiency causes goiter, hypothyroidism, and is the most common cause of preventable brain damage worldwide
- 18Iodine deficiencySource linkedPMIDZimmermann MB, Boelaert K · Endocr Rev · 2015
- 19Role of iodine, selenium and other micronutrients in thyroid function and disordersPMIDTriggiani V et al. · Endocr Metab Immune Disord Drug Targets · 2009
Iodine incorporated into T3 and T4 thyroid hormones via thyroid peroxidase; selenium, iron, and zinc also essential for proper thyroid function
Observational studies
1- 20Mild to moderate iodine deficiency in pregnancy: a risk factor for child neurodevelopmentSource linkedPMIDBath SC, Steer CD, Golding J et al. · Lancet · 2013
Common questions.
Quick answers about Iodine, drawn from the data on this page.
What is Iodine?
Essential for thyroid hormone production. Deficiency is the leading cause of preventable intellectual disability worldwide. Many people are mildly deficient.
What is Iodine used for?
Commonly cited benefits of Iodine include: Thyroid function; Metabolism; Cognitive development; Energy; Hormone balance. NutriStack rates the overall evidence as strong.
What is a typical dose of Iodine?
A typical adult dose of Iodine is 150–300 mcg daily. The commonly recommended form is Potassium iodide or kelp-derived iodine. These are general ranges, not personalized advice; confirm the right dose with a clinician.
What are the side effects of Iodine?
Reported side effects include thyroid dysfunction (excess), acne, metallic taste. This is educational information; check with a healthcare professional before use.
How strong is the evidence for Iodine?
NutriStack rates this as Strong, meaning multiple high-quality meta-analyses or systematic reviews converge on the same finding. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
Use this with your stack
Iodine in NutriStack.
Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.