Written by the Plenthera team (orthomolecular trained). Scientifically reviewed in April 2026. Last updated: April 30, 2026.
Iodine is perhaps the most underestimated mineral in the Dutch dietary situation. Since 1942, bakery salt in the Netherlands has been mandatorily iodized — for years, this has been the main source of iodine. With the growth of paleo, keto, gluten-free, and home-bbaking, more and more people unintentionally avoid this main source. RIVM data show a suboptimal status in 25-30% of women. At Plenthera, you will find iodine in all relevant forms: kelp for the natural route, potassium iodide for exact dosage, and drops for flexible supplementation. EFSA-approved for thyroid, energy, and cognition.
Which iodine is right for you?
| Form | Dosage | Best for |
|---|---|---|
| Kelp / seaweed extract | ~150-225 µg | Natural route, wholefood approach |
| Potassium iodide capsules | ~150 µg | Exact dosage, simplicity |
| KI drops | Flexible dosage | Customized per age, children |
| Nascent iodine | Variable | Premium niche |
| Lugol's solution | Variable | Traditional route |
| In multiminerals | 75-150 µg | Part of basic formula |
What is iodine?
Iodine (I) is an essential trace element. It is a main component of thyroid hormones T3 (triiodothyronine) and T4 (thyroxine), which regulate metabolism, energy production, brain development, and growth. The body cannot produce iodine itself and must obtain it from food or supplements.
Iodine deficiency was a serious problem in the Netherlands until the 20th century — especially in the inland provinces where little sea fish and seaweed were eaten. In 1942, iodized salt in bakery bread became mandatory — since then, iodine deficiency has dramatically decreased. But this protection relies on one source: bakery bread. For those who do not eat bakery bread (paleo, keto, gluten-free, home bakers using uniodized salt), iodine protection has disappeared. RIVM research shows that 25-30% of women of childbearing age have suboptimal iodine status.
Vegans and vegetarians are at additional risk. Plant-based foods provide little iodine (exception: seaweed — but not everyone eats it). Sea fish and dairy are the main non-bakery sources. For those who eat a fully plant-based diet without seaweed, targeted iodine supplementation is actually indispensable — especially during pregnancy when the need increases to 200 µg/day.
In supplements, common forms are potassium iodide (KI, exact dosage), kelp/seaweed extract (natural route, variable dosage — which is why standardization is important), and Lugol's solution (liquid, classic supplement). When choosing: multiminerals typically provide 75-150 µg of iodine, while单独iodine supplements offer 150-225 µg per serving. Also check our multimineral category and multivitamin category for the integrated route.
Iodine and EFSA — what is scientifically recognized?
Iodine has six recognized EFSA claims, included in EU Regulation 432/2012:
"Iodine contributes to the normal production of thyroid hormones and normal thyroid function."
"Iodine contributes to normal energy-yielding metabolism."
"Iodine contributes to normal cognitive function."
"Iodine contributes to the normal functioning of the nervous system."
"Iodine contributes to the maintenance of normal skin."
"Iodine is needed for normal growth of children."
Threshold: claims apply with a daily intake of at least 15% RI — which is 22.5 µg of iodine per serving. Our products typically provide 100-225 µg per serving, well above the threshold and below the EFSA upper limit of 600 µg/day.
Who is at risk of iodine deficiency in the Netherlands?
Since 1942, iodine has been added to bakery salt in the Netherlands. For a long time, this protected the entire population. But modern dietary trends make specific groups vulnerable:
Paleo and keto eaters: Usually avoid bakery bread. Main iodine source disappears — supplementation is logical.
Gluten-free eaters (celiac or preference): Gluten-free breads often do not contain iodized salt. Unintentional iodine loss.
Home bakers: Those who bake bread at home with regular salt (not iodized) miss the protection.
Vegans and vegetarians: No sea fish, no dairy — two secondary iodine sources are missing. Without seaweed in the diet: risk of deficiency.
Pregnant women: Need increases to 200 µg/day. Fetal development requires sufficient maternal iodine. Prenatal supplements typically contain 150 µg.
High-sodium salt avoiders: For those who actively limit salt: iodized salt intake also drops away.
For these groups, targeted iodine supplementation of 100-200 µg/day is a logical measure.
The iodine forms at Plenthera
Kelp / seaweed extract
Natural iodine source from kelp (Ascophyllum nodosum, Laminaria) or brown algae. Standardization of iodine content is crucial — raw kelp varies greatly. Dosages 150-225 µg per serving.
Potassium iodide (KI) drops or capsules
Classic standardized form. Exact dosage (typically 150 µg per serving). Drops for flexible dosing.
Nascent iodine
Protonated form — premium niche with claims of better bioavailability. Clinical research is limited.
Lugol's solution (liquid)
Classic liquid with potassium iodide and molecular iodine. Variable concentrations (2%, 5%, 7%). For those who prefer a traditional approach.
Iodine in multiminerals / multivitamins
Standard 75-150 µg per serving as part of a broader formula. Check our multimineral and multivitamin category.
How to use iodine?
Simple basic approach to iodine:
- Determine your risk profile: normal diet with bakery bread (often sufficient), paleo/keto/gluten-free (increased risk), vegan (high risk), pregnancy (increased need).
- Choose the right form: KI or kelp for general use, drops for customization, nascent or Lugol for specific preference.
- Standard supplementation: 100-150 µg per day for those at risk.
- Pregnancy and lactation: 200 µg/day (RI) — usually in a prenatal formula. See also the advice from the Health Council for pregnant women.
- Do not exceed 600 µg/day (UL) without medical supervision.
- For Hashimoto's, Graves' disease, or other thyroid conditions: consult a doctor beforehand and have TSH/FT4 + anti-TPO measured.
- Combine with selenium for T4→T3 conversion. Check our multimineral category.
- With thyroid medication (levothyroxine): at least 4 hours between doses.
Myths and misunderstandings about iodine
Myth 1: "In the Netherlands, no one has iodine deficiency thanks to iodized salt."
No longer true. With the growth of paleo, keto, gluten-free, and home baking, specific groups unintentionally avoid the bakery source. RIVM data show 25-30% of women with suboptimal status.
Myth 2: "The more iodine, the better the thyroid."
Incorrect and risky. Above the UL (600 µg/day), iodine excess itself can cause thyroid problems. In Hashimoto's, high doses can worsen the condition. Stick to RI or light supplementation.
Myth 3: "Kelp is always a safe natural source of iodine."
Partially true. Kelp varies greatly in iodine content (raw kelp 1,000-6,000 µg/g). Without standardization, a capsule can provide 50 µg or 1,500 µg. Choose standardized products with label indication.
Myth 4: "Pregnant women should not take iodine supplements."
Incorrect and quite the opposite — pregnant women need EXTRA iodine (200 µg/day). Iodine deficiency during pregnancy is associated with developmental effects. Prenatal formulas typically contain 150 µg.
Combining iodine with other supplements
Iodine works synergistically with other nutrients for thyroid and metabolism issues. Common combinations:
- Selenium: crucial cofactor in T4→T3 conversion (often found in multimineral formulas).
- Tyrosine: amino acid building block for thyroid hormones.
- Vitamin D: immune-modulating, relevant for autoimmune thyroid.
- Iron: cofactor in thyroid function.
- Multiminerals: complete formula with iodine + selenium.
- Seaweed category: for natural iodine plus mineral richness.
Frequently asked questions
What is iodine?
Essential trace element, main component of thyroid hormones T3 and T4.
What are iodine deficiency symptoms?
Fatigue, cold sensitivity, weight gain, dry skin, thinning hair, goiter (thyroid swelling), brain fog. If in doubt: measure TSH.
How much iodine per day?
RI 150 µg. Pregnancy/lactation 200 µg. UL 600 µg. For thyroid conditions, consult a doctor.
Which iodine is best?
For exact dosage: potassium iodide. For wholefood: standardized kelp. For customization: drops.
When to take iodine?
With or without food. Not together with levothyroxine (4 hours between doses).
Does iodine help for thyroid?
EFSA-recognized: iodine contributes to normal thyroid function. Deficiency demonstrably causes thyroid dysfunction.
Do I get enough iodine from food?
In NL, usually sufficient through iodized bakery salt. For paleo/keto/gluten-free/home baking/vegan: increased risk of deficiency.
Is iodine allowed during pregnancy?
Highly recommended — extra need (200 µg/day). Standard in prenatal formulas.
What is Lugol's solution?
Classic liquid with potassium iodide + molecular iodine. Variable concentrations.
Is iodine allowed with Hashimoto's?
Caution advised — high doses can worsen it. First measure TSH/FT4/anti-TPO, consult a doctor.
Sources
- EFSA Regulation (EU) 432/2012 — iodine claims.
- EFSA NDA Panel — Tolerable Upper Intake Level for iodine.
- RIVM — Iodine status of the Dutch population.
- Health Council NL — Nutritional standards for iodine and pregnancy.
- Pearce EN. et al., "Consequences of iodine deficiency and excess in pregnant women: an overview of current knowns and unknowns", Am J Clin Nutr (2016).
Disclaimer: This text is for informational purposes only and does not replace medical advice. Iodine is a dietary supplement, not a medicine. In case of doubt or if you are using medication, we recommend consulting a doctor or orthomolecular therapist first.