Iodine

• Preventing and correcting iodine-deficiency goiter
• Pregnancy and lactation adequacy for fetal and infant brain development
• Vegan, low-dairy, and no-added-salt diets at risk of shortfall
• Populations without universal salt iodization
• Documented deficiency confirmed by a clinician

Iodine is an essential trace mineral with a singular and unambiguous biological role, incorporation into thyroid hormones thyroxine (T4, containing four iodine atoms) and triiodothyronine (T3, containing three iodine atoms). The thyroid gland actively concentrates iodide from blood through the sodium-iodide symporter (NIS), oxidizes it to elemental iodine via thyroid peroxidase (TPO), and incorporates it into tyrosine residues on thyroglobulin to form mono- and di-iodotyrosines that combine to produce T4 and T3. Adult body iodine content is small (~15-20mg in a 70kg adult), with approximately 70-80% concentrated in the thyroid gland. Iodine is the only nutrient required for human survival whose entire functional purpose is hormone biosynthesis, making iodine deficiency one of the cleanest mechanism-to-clinical-outcome relationships in essential nutrition. The thyroid hormone system regulates metabolism, growth, development, reproduction, and essentially every aspect of human physiology; sustained iodine deficiency produces predictable clinical consequences ranging from compensatory goiter (thyroid gland enlargement attempting to capture more iodine), to hypothyroidism, to (in severe pediatric iodine deficiency) cretinism with profound intellectual disability and physical stunting. The clarity of this deficiency biology has made iodine perhaps the most successful public health nutrition intervention in human history, global iodized salt programs have eliminated iodine deficiency disorders (IDD) as a major public health concern across most of the world, though approximately 30% of the global population still experiences inadequate iodine intake per WHO/UNICEF Iodine Global Network monitoring. The selenium-iodine interaction is functionally critical and emerged as substantial integrated science through the late 20th century. The selenoprotein iodothyronine deiodinases, DIO1 (peripheral T4 to T3 activation), DIO2 (intracellular T4 to T3 activation, particularly in CNS), and DIO3 (inactivation of excess T3), perform the peripheral activation and inactivation of thyroid hormones. Selenium deficiency therefore impairs proper utilization of iodine even when iodine intake is adequate; conversely, iodine supplementation in selenium-deficient individuals can paradoxically worsen hypothyroidism through inadequate peripheral activation. The Kashin-Beck disease (chondropathy primarily affecting children in selenium-iodine co-deficient regions of China, Tibet, Siberia) illustrates this co-deficiency clinical syndrome. Modern public health programs typically address both nutrients integratively. The thyroid pharmacology has additional complexity: the Wolff-Chaikoff effect describes acute thyroid hormone synthesis suppression following high-dose iodine exposure (relevant to radiocontrast administration and high-dose iodine supplementation); the Jod-Basedow effect describes iodine-induced hyperthyroidism in users with pre-existing thyroid nodules or autonomous thyroid tissue. The therapeutic window is genuinely narrow, RDA of 150mcg/day adult is supported by substantial WHO/UNICEF evidence; UL of 1100mcg/day reflects Jod-Basedow and Hashimoto-trigger concerns at chronic high intake. The "iodine megadosing" alternative medicine movement (Brownstein and others advocating 12.5-50mg/day, far above UL) represents one of the more substantial functional medicine vs mainstream nutritional science evidence disagreements.

Standard iodine supplementation aims at the WHO/IOM RDA of 150mcg/day adult (220mcg/day pregnancy, 290mcg/day lactation, age-specific in pediatrics). The Upper Limit (UL) is 1100mcg/day adults, substantially narrower than many essential mineral therapeutic windows. Iodized salt provides the foundational dietary contribution for most Western populations (~45-60mcg per 1/4 teaspoon), with seafood, dairy products (from iodine-containing teat dips in dairy industry), eggs, and seaweed providing additional dietary iodine. Targeted supplementation at AI doses (150-225mcg/day as potassium iodide or iodate) is appropriate for users with low iodized salt intake, restrictive diets, pregnancy/lactation, or documented iodine deficiency. The pregnancy critical window warrants explicit consideration, even mild maternal iodine inadequacy during pregnancy produces measurable cognitive consequences in offspring per Berbel 2009 and substantial subsequent evidence. Standard prenatal vitamins should include 150-220mcg iodine; many earlier prenatal vitamins lacked iodine entirely. The AAP/ATA recommendations and modern OB-GYN practice support pregnancy iodine adequacy as standard prenatal care. Selenium-iodine integration is functionally critical given selenoprotein deiodinase requirement for peripheral T4 to T3 activation; selenium-deficient users may not utilize iodine optimally regardless of intake. High-dose iodine protocols (Lugol's solution, Iodoral 12.5-50mg/day) substantially exceed UL and warrant specialist coordination, mainstream endocrinology consensus opposes routine high-dose supplementation outside specific clinical contexts (Graves' disease pre-operative preparation, radiation emergency, specialist clinical protocols). The Wolff-Chaikoff effect (acute thyroid suppression) and Jod-Basedow effect (iodine-induced hyperthyroidism in nodular thyroid) are real clinical concerns at high-dose chronic intake. The Hashimoto's thyroiditis precipitation risk in susceptible users is well-documented; AI-level intake is generally well-tolerated even in autoimmune thyroid disease. Take with or without food, absorption is acceptable either way. The geographic variation in dietary iodine intake produces substantial population-level status variation that may make supplementation more or less important based on residence and dietary patterns.

Adult RDA

150mcg/day

Pregnancy RDA

220mcg/day

Lactation RDA

290mcg/day

Pediatric AI ages 1-8

90mcg/day

Pediatric AI ages 9-13

120mcg/day

Adolescent AI

150mcg/day

Upper Limit (UL) adults

1100mcg/day

Iodized salt content

~45-60mcg per 1/4 tsp

• Potassium Iodide (KI)

  Rating: gold

  Simple inorganic iodine salt; the most pharmacologically characterized supplemental form. Used in dietary supplements (typically 150-225mcg potassium iodide providing 113-170mcg iodine), pharmaceutical preparations, and radiation emergency thyroid blockade (130mg KI per dose for adults). Excellent bioavailability and well-established safety at AI doses. Major supplement manufacturers (NOW Foods, Pure Encapsulations, Standard Process, Designs for Health) provide reliable KI products.

• Potassium Iodate (KIO3)

  Rating: gold

  Inorganic iodate form used predominantly in iodized salt fortification programs globally, chemically more stable than potassium iodide in tropical climates and prevented from losses during cooking. The dominant form in WHO iodized salt programs reaching billions of people. Less common as standalone supplement; reasonable alternative to potassium iodide.

• Iodized Salt (Public Health Fortification)

  Rating: gold

  The most consequential public health iodine intervention globally. Typical iodization: 15-77 ppm iodine (as KI or KIO3) in table salt, providing approximately 45-60mcg iodine per 1/4 teaspoon salt. Universal salt iodization (USI) is established WHO public health recommendation. The single most important practical iodine intervention for most populations.

• Kelp / Seaweed (Whole Food Sources)

  Rating: caution

  Kelp, kombu, wakame, nori, and other seaweeds provide natural iodine, but content varies enormously by species, growing location, and processing. Kombu (Laminaria) can contain extraordinarily high iodine (>1000mcg/g) producing risk of inadvertent UL exceedance. Japanese populations consuming kelp-based dashi broth as dietary staple have historically high iodine intake (1-10mg/day) without adverse health consequences in most users, but Western users adding kelp supplements can produce variable and potentially excessive iodine exposure. Reasonable for dietary inclusion; less reliable for targeted supplementation.

• Lugol's Solution (Iodine + Potassium Iodide)

  Rating: good

  Traditional Lugol's solution (5% iodine + 10% potassium iodide in water) developed by Jean Lugol in 1829. Each drop provides approximately 6.25mg iodine (5mg iodine + 7.5mg potassium iodide). Used in some clinical applications (Graves' disease pre-operative preparation, radiation prophylaxis) at specific protocols, and in functional medicine "iodine loading" practices. The doses substantially exceed WHO UL of 1100mcg/day; reasonable specialist use only.

• Nascent Iodine (Alternative Medicine)

  Rating: caution

  Alternative medicine product claimed to be "atomic" or "single-atom" iodine. The marketing chemistry claims are not validated by pharmacological evidence. Effectively similar to ordinary iodine preparations; substantially higher pricing than potassium iodide without demonstrated clinical superiority. Reasonable caution about marketing claims.

• Iodine Megadose Supplements (Iodoral, Optimox)

  Rating: caution

  High-dose iodine products (typically 12.5mg or 50mg per tablet, Iodoral being the most-prominent example from Optimox Corporation) marketed for "iodine sufficiency" protocols advocated by Brownstein and others. These doses substantially exceed WHO UL of 1100mcg/day and mainstream endocrinology consensus opposes routine use. The Wolff-Chaikoff effect, Jod-Basedow phenomenon, and Hashimoto's thyroiditis precipitation are real concerns at this dose range. Specialist clinician coordination essential; not appropriate for unsupervised consumer use.

• Iodine in Prenatal Vitamins

  Rating: gold

  Most quality prenatal vitamins now include 150-220mcg iodine reflecting elevated pregnancy AI (220mcg/day pregnancy, 290mcg/day lactation). The AAP/ATA recommendation that prenatal vitamins include 150mcg iodine has substantial public health relevance, many earlier prenatal vitamins lacked iodine entirely.

• Potassium Iodide for Radiation Emergency

  Rating: gold

  High-dose KI (130mg for adults, weight-adjusted for children) for thyroid blockade in radioactive iodine emergency exposure (nuclear reactor accidents, dirty bombs). Effective when administered before or within 4 hours of exposure. Pharmaceutical preparation (IOSAT, ThyroSafe); strategic national stockpile and household preparedness in some regions. Specialist emergency use.

• Pregnancy and lactation (foundational)

  Strength of evidence for this group: strong

  Pregnancy iodine RDA is 220mcg/day, lactation 290mcg/day, substantially elevated from 150mcg/day non-pregnant adult requirement. The pregnancy critical window for offspring neurodevelopment is among the most clearly-established essential nutrition contexts. Even mild maternal iodine inadequacy during pregnancy produces measurable cognitive consequences in offspring (Berbel 2009). The American Academy of Pediatrics and American Thyroid Association both recommend prenatal vitamin iodine content. Foundational pregnancy supplementation case.

• Documented iodine deficiency / endemic deficiency regions

  Strength of evidence for this group: strong

  WHO/UNICEF/Iodine Global Network monitoring identifies regions with population-level iodine deficiency. Targeted supplementation through iodized salt programs (universal salt iodization) is established public health intervention; individual supplementation at AI doses (150mcg/day) is appropriate for users in deficient regions or with documented inadequate intake.

• Healthy adults (general supplementation)

  Strength of evidence for this group: modest

  AI is 150mcg/day. Iodized salt provides foundational dietary intake for most Western populations; supplementation at AI doses (150-225mcg) reasonable for users with low salt intake, restrictive diets, or geographic context with limited iodized salt access. Higher doses not warranted in healthy non-deficient users without specific clinical indication.

• Strict vegan / restrictive diets

  Strength of evidence for this group: modest

  Plant-based diets typically provide minimal iodine without iodized salt or sea vegetable consumption. Vegan populations particularly likely to fall below AI; targeted supplementation reasonable. Coordinate sea vegetable consumption to avoid inadvertent UL exceedance.

• Hashimoto's thyroiditis

  Strength of evidence for this group: cautious

  Excessive iodine intake may precipitate or worsen autoimmune thyroiditis in genetically susceptible individuals, a substantial concern with "iodine megadosing" protocols. AI-level intake (150mcg/day) is generally well-tolerated; chronic high-dose supplementation is generally avoided in established autoimmune thyroid disease. Endocrinology coordination essential; selenium adequacy critical given selenoprotein deiodinase requirement.

• Graves' disease / hyperthyroidism

  Strength of evidence for this group: cautious

  Specific clinical use of high-dose iodine (Lugol's solution, super-saturated potassium iodide) for pre-operative thyroidectomy preparation and thyroid storm management, specialist endocrinology and surgical coordination required. Otherwise generally avoid supplementation in active hyperthyroidism; iodine can produce either Wolff-Chaikoff suppression or Jod-Basedow worsening depending on context.

• Multinodular goiter / autonomous thyroid nodules

  Strength of evidence for this group: cautious

  Jod-Basedow effect, iodine-induced hyperthyroidism in users with pre-existing thyroid nodules or autonomous thyroid tissue. Iodine status should be assessed before initiating supplementation; endocrinology coordination for users with known nodular thyroid disease.

• Radiation exposure prophylaxis

  Strength of evidence for this group: strong

  High-dose potassium iodide (130mg adults, weight-adjusted children) for thyroid blockade in radioactive iodine exposure (nuclear reactor accidents). Pharmaceutical KI preparations strategic stockpile. Effective when administered before or within hours of exposure; specialist emergency use.

• Breast health (preliminary functional medicine claim)

  Strength of evidence for this group: cautious

  Preliminary evidence and substantial functional medicine claims for iodine in breast health (fibrocystic breast disease, breast cancer prevention). Mechanistic plausibility through extrathyroidal iodine concentration in breast tissue; clinical evidence remains preliminary and contested. Mainstream oncology and breast health do not include iodine megadosing in standard guidance. Specialist coordination for users pursuing high-dose iodine for breast applications.

• Iodine megadosing (Brownstein / Optimox protocols)

  Strength of evidence for this group: cautious

  High-dose iodine protocols (12.5-50mg/day Iodoral or equivalent) advocated by Brownstein and others substantially exceed WHO UL of 1100mcg/day. Real risks: Wolff-Chaikoff effect, Jod-Basedow hyperthyroidism in nodular thyroid, Hashimoto's precipitation in susceptible individuals, "iodism" symptoms (acne, headache, metallic taste). Mainstream endocrinology consensus opposes routine use outside specific clinical contexts. Specialist clinician coordination essential.

• Pediatric use (deficiency contexts)

  Strength of evidence for this group: strong

  Age-specific AIs: 90mcg/day ages 1-8, 120mcg/day ages 9-13, 150mcg/day adolescents. Pediatric deficiency contexts (developing brain, growth) warrant targeted supplementation in deficient regions. WHO programs prioritize pediatric iodine adequacy. AI-level supplementation appropriate; high-dose pediatric supplementation requires specialist coordination.

• Selenium

  Interaction: synergy

  Mechanistically integrated through selenoprotein deiodinases (DIO1, DIO2, DIO3) that perform peripheral T4 to T3 conversion. Selenium-deficient users may not utilize iodine optimally. Iodine supplementation in selenium-deficient individuals can paradoxically worsen hypothyroidism. Comprehensive thyroid nutrition addresses both nutrients integratively. Kashin-Beck disease in selenium-iodine co-deficient regions illustrates the integrated clinical syndrome.

• Tyrosine

  Interaction: synergy

  L-tyrosine is the amino acid substrate for thyroid hormone synthesis (iodine added to tyrosine residues on thyroglobulin). Adequate dietary protein and tyrosine status support thyroid hormone synthesis given iodine adequacy. Mechanistically integrated but typically not co-supplemented unless tyrosine specifically indicated.

• Iron

  Interaction: synergy

  Iron is cofactor for thyroid peroxidase (TPO), the enzyme that oxidizes iodide for incorporation into thyroglobulin. Iron deficiency anemia impairs thyroid hormone synthesis even with adequate iodine intake. Common comprehensive thyroid nutrition consideration.

• Zinc

  Interaction: synergy

  Zinc supports thyroid hormone receptor function and may be cofactor for thyroid hormone metabolism. Common in comprehensive thyroid nutrition protocols.

• Vitamin A

  Interaction: synergy

  Vitamin A supports thyroid hormone metabolism through retinoid receptor mechanisms. Common consideration in comprehensive thyroid nutrition.

• Hashimoto's Thyroiditis

  Interaction: caution

  Excessive iodine can precipitate or worsen autoimmune thyroiditis in susceptible individuals. AI-level intake is generally well-tolerated; high-dose supplementation warrants endocrinology coordination in established autoimmune thyroid disease.

• Graves' Disease / Hyperthyroidism

  Interaction: caution

  Specific high-dose iodine clinical use (Lugol's solution, SSKI super-saturated KI) for Graves' pre-operative preparation; otherwise generally avoid supplementation in active hyperthyroidism. Specialist endocrine coordination essential.

• Multinodular Goiter / Autonomous Nodules

  Interaction: caution

  Jod-Basedow phenomenon, iodine-induced hyperthyroidism in nodular thyroid. Specialist coordination before initiating supplementation in users with known thyroid nodules.

• Amiodarone

  Interaction: caution

  Amiodarone contains substantial iodine (37% by weight), chronic use produces enormous iodine loading. Coordinate with cardiology; supplemental iodine generally avoided in amiodarone users.

• Radiocontrast Agents

  Interaction: caution

  Iodine-containing radiocontrast agents produce acute iodine loading. Wolff-Chaikoff effect may occur. Coordinate with imaging specialists for users on chronic iodine supplementation undergoing contrast imaging.

• Lithium

  Interaction: caution

  Lithium can affect thyroid function; iodine supplementation may interact with lithium effects on thyroid. Coordinate with psychiatry for users on lithium.

• Pregnancy / Lactation

  Interaction: synergy

  The most critical iodine integration context. Pregnancy elevated requirement; offspring neurodevelopmental consequences of maternal iodine inadequacy. Prenatal vitamin iodine adequacy as standard prenatal care.

Look for: specific iodine compound form disclosed (potassium iodide, potassium iodate, kelp); explicit mcg iodine content per serving; appropriate dose for intended use (150-225mcg general supplementation, 220mcg pregnancy in prenatal vitamins); USP or NSF third-party verification; reputable manufacturer with quality control disclosure. Avoid: products without specific iodine form disclosure; very high-dose products (>1100mcg/day) without specific clinical indication and specialist coordination; kelp supplements without iodine content disclosure (potential UL exceedance); "nascent iodine" products marketed with chemistry claims that exceed evidence base; pharmaceutical Lugol's solution sold outside specialist contexts at megadosing positioning; products from manufacturers without third-party testing disclosure.

Iodine's discovery came in 1811 (published 1813) through Bernard Courtois in Paris, a saltpeter manufacturer who accidentally produced violet vapor while extracting potassium nitrate from seaweed ash. Joseph Louis Gay-Lussac subsequently characterized the new element, naming it iodine from Greek iodes (violet) for the characteristic vapor color. The substantial seaweed-iodine connection in this discovery is fitting given iodine's biological role and the subsequent use of seaweed as natural iodine source. The goiter-iodine connection developed substantially through the 19th century. Jean Lugol developed Lugol's solution (5% iodine + 10% potassium iodide) in 1829 for goiter treatment in France. Eugen Baumann's 1895 discovery of iodine in thyroid tissue established the biological connection that would underpin all subsequent thyroid biology. Through the late 19th and early 20th centuries, goiter remained a major public health concern in iodine-deficient regions globally. The modern public health era began with David Marine and Oliver Kimball's 1920 JAMA Akron Ohio schoolchildren trial demonstrating sodium iodide supplementation prevented goiter in the iodine-deficient Great Lakes region. Morton Salt Company introduced the first US iodized salt in 1924, reaching mass consumer markets through marketing emphasizing goiter prevention. Switzerland had introduced iodized salt nationally in 1922; subsequent decades saw global expansion of universal salt iodization programs through WHO/UNICEF partnerships. The IDD (Iodine Deficiency Disorders) framework era developed substantially through the 1970s-1990s with Basil Hetzel's comprehensive framework characterization (Lancet 1983). Hetzel established that iodine deficiency produces a spectrum of disorders beyond goiter, including hypothyroidism, cretinism, pregnancy complications, and reduced cognitive function. The IDD framework drove substantial global public health intervention expansion through WHO/UNICEF/ICCIDD (now Iodine Global Network) coordination. The Pharaoh 1971 Lancet PNG cretinism prevention trial established the pregnancy critical window evidence framework. Glinoer 1997 Endocrine Reviews characterized maternal thyroid function changes during pregnancy and elevated iodine requirements. Berbel 2009 and substantial subsequent work characterized offspring cognitive consequences of even mild maternal iodine inadequacy. The modern epidemiology era through the 2000s-2020s has documented continued global iodine inadequacy. The Iodine Global Network monitoring demonstrates approximately 30% of global population remains iodine-deficient despite extensive iodized salt programs. The Vanderpump 2011 Lancet UK iodine survey demonstrated unexpected adolescent inadequacy in a developed country, prompting UK public health discussions. Many European countries maintain voluntary rather than mandatory salt iodization with substantial population variability in status. The selenium-iodine integration era developed through the 1990s-2010s with selenoprotein characterization. The DIO1, DIO2, DIO3 deiodinases' selenoprotein status established the functional integration that explains Kashin-Beck disease and broader selenium-iodine co-deficiency patterns. The iodine megadosing alternative medicine era emerged through the 2000s-2010s with David Brownstein's "Iodine: Why You Need It" (2009) and the Optimox Corporation Iodoral product line. The advocacy for 12.5-50mg/day iodine supplementation substantially exceeds WHO UL of 1100mcg/day and conflicts with mainstream endocrinology consensus. The Brownstein iodine sufficiency framework has substantial functional medicine influence; mainstream endocrinology rejects routine use outside specific clinical applications. The radiation emergency era developed substantially through Cold War nuclear preparedness and continued through Chernobyl 1986 and Fukushima 2011 emergencies. Potassium iodide thyroid blockade became established emergency response; strategic national stockpiles in nuclear-power-dependent countries support emergency distribution. The Chernobyl thyroid cancer epidemic in affected populations (particularly children at exposure) provides foundational evidence for iodine prophylaxis in radiation emergencies.

1. 1811-1813Courtois discovery and Gay-Lussac characterization of iodine
2. 1829Lugol develops Lugol's solution for goiter treatment
3. 1895Baumann discovers iodine in thyroid tissue
4. 1920Marine and Kimball Akron Ohio foundational goiter prevention trial
5. 1922Switzerland introduces national iodized salt
6. 1924Morton Salt Company introduces US iodized salt
7. 1948WHO begins global iodine deficiency disorders monitoring
8. 1971Pharaoh PNG cretinism prevention trial
9. 1983Hetzel establishes IDD framework (Lancet)
10. 1986Chernobyl nuclear disaster; KI thyroid blockade prophylaxis
11. 1990sICCIDD (later IGN) global IDD elimination program acceleration
12. 1997Glinoer pregnancy iodine endocrine review
13. 2009Berbel maternal iodine cognitive offspring evidence; Brownstein "Iodine" megadosing advocacy
14. 2011Vanderpump UK iodine status Lancet survey; Fukushima nuclear disaster
15. 2010s-2020sIGN ongoing global monitoring; pregnancy iodine prioritization guidance

• Whether the "iodine megadosing" alternative medicine practice (Brownstein, Optimox) will mature into specific evidence-based clinical applications or remain alternative medicine claim outside mainstream endocrinology consensus.
• Whether the breast tissue iodine concentration biology will translate to specific breast health applications, preliminary evidence is suggestive but mainstream oncology consensus does not support routine iodine megadosing for breast cancer prevention.
• Whether universal salt iodization programs should evolve given changing dietary patterns (reduced salt consumption, processed food alternatives, geographic supply variation).
• Whether mild iodine inadequacy in some developed countries (UK, parts of Europe, possibly subgroups of US population) warrants specific public health intervention beyond current iodized salt programs.
• Whether genetic variants affecting thyroid hormone synthesis or iodine handling produce individual variability in optimal iodine intake.
• Whether the pregnancy iodine supplementation guidance (150-220mcg in prenatal vitamins) is adequate given the substantial offspring neurodevelopmental consequences of even mild maternal inadequacy.
• How best to integrate iodine and selenium supplementation given the integrated thyroid biology, current programs typically address these nutrients separately.
• Whether seaweed-rich Japanese dietary iodine intake (1-10mg/day) reflects safe traditional pattern or represents acceptable population adaptation that does not generalize to Western users.

Universally available globally as dietary supplement, food fortification (iodized salt), and pharmaceutical preparations. Legal under DSHEA in the United States and equivalent supplement regulations in most jurisdictions. Not on WADA prohibited list. Pharmaceutical preparations: pharmaceutical-grade potassium iodide (IOSAT, ThyroSafe for radiation emergency), Lugol's solution (specialist use), SSKI (super-saturated potassium iodide solution for specific clinical applications), thyroid-specific products by prescription in select markets. Major retail supplement brands include NOW Foods, Pure Encapsulations, Designs for Health, Standard Process, Optimox (Iodoral high-dose, controversial), Magnascent (alternative nascent iodine), Lugol's solution from various sources. Iodized salt is universally available through table salt category from Morton (US originator since 1924), Cargill, and most major salt manufacturers globally. Sea vegetable sources (kelp, kombu, wakame, nori) available through Asian food markets and health food stores. Major prenatal vitamin brands (Theralogix Theranatal, Needed, FullWell, mainstream brands like Nature Made) include iodine content reflecting AAP/ATA pregnancy supplementation guidance. Production of pharmaceutical-grade potassium iodide is widely distributed; sea vegetable sourcing concentrates in Japan, Korea, China, and select North American sources. Quality variation across brands is modest given the well-established chemistry of potassium iodide; sea vegetable iodine content varies substantially. Third-party testing (USP, NSF) provides standard quality assurance.

Status current as of July 2026. Regulatory positions change, sometimes quickly.

Class

Essential trace mineral

Discovery

1811-1813 (Courtois/Gay-Lussac, France)

Discovery context

Seaweed ash byproduct

Biological role

Sole essential function: thyroid hormone synthesis

Adult RDA

150mcg/day

Pregnancy RDA

220mcg/day

What follows is unfinished work on our side, not a finding about Iodine. A short entry is not a safe entry.

• Cost and market. We have not documented what it sells for or who sells it.
• Supply chain. We have not mapped where it is made.
• Who uses it. We have not documented the user groups.
• What could change. No forward-looking summary yet.
• How it compares. We have not set it against the alternatives.
• Children and teenagers. We have not checked what is known about younger people.
• Where we land. We have not taken a position on this yet.