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Iodine

Supplement mineral general nutritionenergy
Aka: potassium iodide, kelp, Lugol's
Brands seen in Singapore: Life Extension, Life-flo, NOW Foods, Optimox, NaturesPlus
Not medical advice. Check with your doctor or pharmacist before you start, stop or change the timing of anything you take.
How to use
What it’s for
Making thyroid hormones t4 and t3 · metabolic activity
When to take
Timing not addressed by NIH ODS · no food rule given
Take with
Water · kelp pills vary: seaweed holds 16–2,984 mcg/g
Pros & cons
Pros
  • Small daily need: RDA 150 mcg (220 mcg in pregnancy)
  • HSA allows thyroid and energy-metabolism claims
  • Potassium iodide or kelp are the usual supplement forms
Cons
  • UL 1,100 mcg; excess: goiter, hypo- or hyperthyroidism
  • Autoimmune thyroid disease: harm at 'safe' intakes
  • HSA cap 0.15 mg a day; SG listings reach 12.5 mg a pill
Sources
  1. NIH ODS — Iodine Fact Sheet for Health Professionals (Updated: November 5, 2024) — Introduction + Table 1 RDAs · read 2026-08-27
    what it says
    “essential component of the thyroid hormones thyroxine (T4) and triiodothyronine (T3) … critical determinants of metabolic activity … [RDA, 19+ years] 150 mcg (male), 150 mcg (female), 220 mcg (pregnancy), 290 mcg (lactation)”
  2. NIH ODS — Iodine Fact Sheet for Health Professionals (Updated: November 5, 2024) — Dietary Supplements + Sources of Iodine (seaweed) · read 2026-08-27
    what it says
    “potassium iodide or sodium iodide … Supplements containing kelp, a seaweed that contains iodine, are also available … commercially available seaweeds in whole or sheet form have iodine concentrations ranging from 16 mcg/g to 2,984 mcg/g”
  3. NIH ODS — Iodine Fact Sheet for Health Professionals (Updated: November 5, 2024) — Health Risks from Excessive Iodine + Table 3 ULs · read 2026-08-27
    what it says
    “goiter, elevated TSH levels, and hypothyroidism … Iodine-induced hyperthyroidism can also result from high iodine intakes … burning of the mouth, throat, and stomach; fever; abdominal pain; nausea; vomiting; diarrhea; weak pulse; and coma … [UL, 19+ years] 1,100 mcg”
  4. NIH ODS — Iodine Fact Sheet for Health Professionals (Updated: November 5, 2024) — Health Risks from Excessive Iodine (sensitive groups) + Groups at Risk (pregnancy) · read 2026-08-27
    what it says
    “Some people, such as those with autoimmune thyroid disease and iodine deficiency, may experience adverse effects with iodine intakes considered safe for the general population … During pregnancy, the RDA for iodine increases from 150 to 220 mcg/day”
  5. NIH ODS — Iodine Fact Sheet for Health Professionals (Updated: November 5, 2024) — Interactions with Medications · read 2026-08-27
    what it says
    “Taking high doses of iodine with antithyroid medications can have an additive effect … [methimazole (Tapazole)] … Taking potassium iodide with ACE inhibitors can increase the risk of hyperkalemia … Taking potassium iodide with potassium-sparing diuretics … can increase the risk of hyperkalemia”
  6. FDA — Daily Value on the Nutrition and Supplement Facts Labels, Reference Guide: Daily Values for Nutrients (content current as of 03/05/2024) · read 2026-08-27
    what it says
    “DVs are the recommended amounts of nutrients to consume or not to exceed each day … Iodine 150mcg”
  7. HSA Singapore — Health Supplements Guidelines GL-CHPB-3-001 Rev. No. 020 (January 2026), clause 4.8 + Table 5 Minerals Limits · read 2026-08-27
    what it says
    “4.8 HS for use by the general adult population should not contain vitamins and minerals exceeding the stipulated limits stated in Tables 4 and 5 … Table 5: Minerals Limits … Iodine 0.15 mg”
  8. HSA Singapore — Health Supplements Guidelines GL-CHPB-3-001 Rev. No. 020 (January 2026), List of Health Claims (vitamins and minerals) · read 2026-08-27
    what it says
    “7. Maintain/support healthy thyroid gland function • Iodine, selenium … 23. Contribute to normal energy-yielding metabolism • Calcium, copper, iodine, iron, magnesium, manganese, phosphorus … 79. Maintain/support cognitive function/mental function • Iodine, iron, zinc”
  9. HSA Singapore — Guidelines on Prohibited and Restricted Ingredients in Health Supplements and Traditional Medicines, GL-CHPB-1-012 Rev. No. 001 (October 2025), Annex A · read 2026-08-27
    what it says
    “55. Iodine — Restricted use in HS and TM — When for oral use by general adult population, the maximum recommended daily dose should not provide more than 0.15mg”
  10. iHerb Singapore — Iodine category page (Supplements > Minerals > Iodine), default order, 50 results — positions 1–5 and 8 · read 2026-08-27
    what it says
    “Life Extension, Vitamins D and K with Sea-Iodine™ … Life-flo, Liquid Iodine Plus with Potassium Iodide … Life Extension, Sea-Iodine™, 1,000 mcg … NOW Foods, Kelp, 150 mcg, 200 Tablets … Optimox, Iodoral® IOD 12.5, 12.5 mg, 180 Scored Tablets … NaturesPlus, Iodine, 150 mcg”
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Updated 2026-08-29. Every line above traces to a numbered source. Kozen-X is not a medical device and does not give medical advice. It lists what published sources have written down — nothing more. A pair not listed is unrecorded, not cleared. Before you start, stop or re-time anything, talk to your doctor or pharmacist.