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ingestible · for thyroid support

Iodine (Dietary Adequacy)

Reviewed by the Nimbera editorial team · Last updated May 2026

Iodine deficiency is the leading preventable cause of thyroid disorder worldwide. A global review in Nature Reviews Endocrinology 2012 (PMID 22473332) documented iodine deficiency still insufficient in 47 countries. WHO recommends 150 mcg/day for adults, 250 mcg/day during pregnancy. Evidence for supplementation is strongest in documented deficiency.Under $5/month via iodized salt. Multivitamins with iodine: $10-$20/month.

How to use

Meet the RDA of 150 mcg/day through iodized salt (use 1/4 teaspoon daily), dairy products, seafood, and eggs. If you avoid these food groups, a multivitamin containing 150 mcg of iodine covers the gap. Do not take high-dose iodine supplements without confirmed deficiency testing.

How it works

Iodine is an essential mineral required to synthesize thyroid hormones T3 (triiodothyronine) and T4 (thyroxine). Without adequate iodine, the thyroid cannot produce sufficient hormones, causing hypothyroidism and goiter.

Where to buy

Iodized table salt is the primary source. A standard multivitamin with iodine (look for 150 mcg) is appropriate for those who do not use iodized salt. Kelp supplements are not recommended due to unpredictable iodine content.

Typical cost: Under $5/month via iodized salt. Multivitamins with iodine: $10-$20/month.

Safety notes

CAUTION: Excess iodine is harmful and can trigger or worsen both hypothyroidism and hyperthyroidism, particularly in people with Hashimoto's thyroiditis or Graves' disease. Do not take high-dose iodine supplements (above 500 mcg/day) without medical supervision. Kelp and "thyroid support" blends often contain uncontrolled amounts of iodine - avoid these. Get a 24-hour urine iodine test if deficiency is suspected.

Drug & supplement interactions

  • Always tell your doctor or pharmacist about any supplements you take.
  • Interactions can occur with prescription medications, blood thinners, and immunosuppressants.
  • Herbal remedies can affect how the body absorbs or metabolises drugs.
  • Check drugs.com interactions checker before starting.

This information is compiled from primary clinical literature and is for informational purposes only. It is not a substitute for professional medical advice. Read our full disclaimer.