Iodine
Compiled from published pharmacological and botanical literature. Not independently verified by Herbuno. Spotted an error or have a correction? Flag it below →
| Compound Class | Essential trace element (halogen); substrate for thyroid hormone synthesis |
| Source | Spirulina and Chlorella — microalgal biomass, not macroalgal kelp |
| Standardisation | 0.5% (5000 ppm) iodine by ICP-MS; lot-specific assay essential |
| Comparator Forms | Potassium iodide and iodate (fortification standards); kelp and macroalgal iodine |
| Solubility / Format | Fine powder; ppm-scale dosing requires dilution and validated blend uniformity |
| Regulatory Note | Established NRV and authorised EU health claims; upper intake level 600 µg/day (EFSA), 1,100 µg/day (US) |
| Buy from Herbuno | Spirulina & Chlorella 0.5% |
| Origin | Processed / Sourced from India |
| MOQ | R&D 100 g / 250 g (subject to stock) · Pilot batch 1–5 kg · Bulk 10 kg, 25 kg and above |
| Lead Time | Dispatch within 72 hrs from stock · fresh-batch production (typically 50 kg+): 10 working days |
| Documentation | CoA & MSDS standard with every lot |
Name origin: Bernard Courtois discovered iodine in 1811 while processing seaweed ash for saltpetre during the Napoleonic wars, and Gay-Lussac named it from the Greek iodes, violet, for the vapour it gives off on heating. The discovery route is fitting: marine algae remain the most concentrated natural source of the element, and the connection between seaweed and goitre treatment predates the chemistry considerably.
Traditional use: Seaweed for goitre is one of the better-documented pre-scientific therapeutic traditions, recorded in Chinese medical texts more than two millennia before iodine was isolated — burnt sponge and seaweed preparations were used across several traditions for what we would now recognise as iodine-deficiency goitre. Spirulina and Chlorella, the sources here, have a much shorter history, entering food use principally through twentieth-century microalgal cultivation rather than through traditional practice.
Research trajectory: Iodine research is dominated by the twentieth century's most successful public health interventions — salt iodisation, which eliminated endemic goitre and cretinism across much of the world. Modern research has shifted to the other end of the curve. The relationship between iodine intake and thyroid dysfunction is U-shaped, with both deficiency and excess capable of causing disease, and it is the excess arm that now generates most of the clinically relevant literature on supplements.
Commercial source: Fortification and most supplementation use potassium iodide or iodate, which are chemically defined and dose-precise. Algal iodine is a distinct category valued for its natural-source positioning. The critical commercial distinction, and one frequently blurred in the trade, is between microalgal sources such as spirulina and Chlorella and macroalgal kelp: brown seaweeds accumulate iodine at concentrations orders of magnitude higher, and most of the documented safety literature concerns kelp rather than microalgae.
Evidence for Iodine Applications
Iodine's function is singular and unambiguous: it is the substrate for thyroxine and triiodothyronine synthesis, and there is no other physiological role of comparable significance. Deficiency causes goitre, hypothyroidism and, in pregnancy, irreversible impairment of fetal neurodevelopment — iodine deficiency remains the leading preventable cause of intellectual disability worldwide. Claim strength: High.
What distinguishes iodine from every other mineral in this catalogue is the narrowness of the usable range and the fact that excess is a documented, measurable harm rather than a theoretical one. In a controlled study of kelp supplementation in euthyroid subjects, short-term dietary supplementation significantly increased both basal and post-stimulation TSH, with dose-dependent increases in 24-hour urinary iodine excretion; total triiodothyronine fell significantly after high-dose kelp. [Clark 2003] These are healthy people with normal thyroid function experiencing measurable thyroid perturbation from a supplement. Claim strength: High.
The population data reinforce this. In a study of habitual seaweed consumers, median urinary iodine concentration was 1200 µg/L against an estimated non-seaweed dietary intake of 110 µg/day, indicating seaweed as the dominant contributor and an excessive iodine status; TSH levels, while within reference range, were higher than in comparable population groups, and labelling of iodine content was absent for a large share of products consumed. [Aakre 2020] A separate pre-post study found that median estimated intake exceeded the tolerable upper level before intervention and that cessation of seaweed consumption significantly decreased TSH, with the largest decreases in those with the highest prior intakes. [Seaweed cessation study] Claim strength: High.
Two conclusions follow that a responsible supplier should state rather than bury. First, the inadequate labelling repeatedly documented in these studies is a supply-chain failure, not a consumer failure — it is the direct consequence of selling variable natural material against nominal rather than assayed values. Second, the effects described are largely attributable to macroalgae, particularly brown seaweeds such as Laminaria, which can carry iodine at several hundred to several thousand micrograms per gram dry weight. Microalgal material such as spirulina and Chlorella does not concentrate iodine to the same degree, which is a genuine point of differentiation. Claim strength: Moderate.
The operative principle for any natural-source iodine is therefore lot-specific assay rather than nominal declaration. A standardised 0.5% specification determined by ICP-MS per lot addresses precisely the failure mode the published literature identifies, and it is the reason a defined algal concentrate is a materially different proposition from a whole kelp powder sold on a typical value. This is a documentation and analytical argument rather than a biological one, and it is the honest basis on which to specify the material. Claim strength: High.
Sourcing algal iodine: A 0.5% iodine concentrate from spirulina and Chlorella is available from Herbuno, assayed by ICP-MS per lot, with CoA and MSDS. View Iodine 0.5% →
Dosage & Formulator Specification
Production route. Spirulina and Chlorella biomass is cultivated in controlled systems, harvested, dried and concentrated to a defined 0.5% iodine specification. Because algal iodine content reflects the cultivation medium and conditions, input variability is intrinsic and is managed by assay and blending to specification rather than assumed away. This is the essential operational difference between a standardised concentrate and a whole algal powder sold against a typical value, and it is the difference that the published safety literature on natural iodine sources actually turns on.
Analytical standardisation. Total iodine is determined by ICP-MS following appropriate alkaline digestion; note that acid digestion is unsuitable for iodine because of volatilisation losses, so the digestion protocol matters and should be stated. Specify lot-specific assay explicitly rather than accepting a nominal figure. Heavy metals warrant particular attention for algal materials given their capacity to accumulate arsenic, cadmium and lead from the growth medium, and inorganic arsenic specifically is worth specifying separately from total arsenic.
Regulatory and handling context. Iodine has an established Nutrient Reference Value in the EU and authorised health claims covering normal cognitive function, normal energy-yielding metabolism, normal functioning of the nervous system, maintenance of normal skin, and normal production of thyroid hormones and thyroid function. Tolerable upper intake levels are 600 µg/day under EFSA and 1,100 µg/day in the United States. Individuals with pre-existing thyroid conditions, and those taking thyroid medication, are the populations where iodine loads can destabilise treatment, which is a finished-product labelling responsibility. Store cool, dry and sealed; iodine is volatile and can be lost from open containers.
Formulation behaviour. At 0.5%, delivering a 150 µg dose requires 30 mg of material, so blend uniformity is the critical control point and the consequences of failure are clinical rather than cosmetic. Use a validated geometric dilution sequence into a carrier and verify content uniformity analytically rather than inferring it from mixing time. Because iodine can be lost by volatilisation, avoid unnecessary heat during processing and specify packaging with an adequate barrier. In multi-mineral formulas, confirm that total iodine from all sources including any kelp or algal ingredients is accounted for against the upper level.
Frequently Asked Questions — Iodine
The distinction is real and worth understanding. Most documented cases of thyroid disturbance from natural iodine sources involve macroalgal kelp, particularly brown seaweeds such as Laminaria, which can carry several hundred to several thousand micrograms of iodine per gram dry weight. Microalgae such as spirulina and Chlorella do not concentrate iodine to that degree. That said, the deciding factor is not the organism but whether the material is assayed per lot against a defined specification or sold on a nominal value.
That measurable thyroid perturbation occurs in healthy people, not just susceptible ones. Controlled kelp supplementation in euthyroid subjects significantly raised both basal and post-stimulation TSH with dose-dependent urinary iodine increases. In habitual seaweed consumers, median urinary iodine reached 1200 micrograms per litre with TSH higher than comparable groups, and a separate study found TSH fell significantly after seaweed cessation, most in those with the highest prior intakes.
Because the failure mode documented repeatedly in the literature is inadequate or inaccurate labelling of iodine content in natural-source products, which is a supply-chain problem rather than a consumer one. Natural iodine content varies with species, origin and processing. A 0.5% specification determined by ICP-MS on each lot addresses that failure directly, whereas a typical or nominal value does not. We supply lot-specific assay as standard.
Delivering a 150 microgram dose requires 30 mg of material, so blend uniformity is critical and the consequences of a failure are clinical rather than only regulatory. Use a validated geometric dilution into a carrier and verify content uniformity analytically rather than by mixing time. Also avoid unnecessary heat, since iodine can be lost by volatilisation, and check total iodine from all ingredients against the upper level in multi-mineral formulas.
EFSA sets a tolerable upper intake level of 600 micrograms per day and the United States sets 1,100 micrograms per day, and these apply to total intake from all sources. Individuals with pre-existing thyroid conditions, and those on thyroid medication where iodine loads can alter dose requirements unpredictably, should be directed to medical advice. This warrants explicit finished-product labelling rather than being left for the consumer to work out.
Beyond lot-specific iodine by ICP-MS with a stated digestion protocol, request a full heavy metals panel with particular attention to arsenic, cadmium and lead, since algae accumulate these from the growth medium. Inorganic arsenic is worth specifying separately from total arsenic. Confirm the digestion method used for iodine, since acid digestion causes volatilisation losses and is unsuitable.
Related compounds: Selenium · Phycocyanin · Zinc
Claim strength scale: High — consistent human data or established biochemistry. Moderate — supportive human data with limitations. Emerging — mechanistic or preliminary evidence only.