mineral · for lack of focus
Iodine
Essential for thyroid hormone synthesis.
How strong is the research?
Not verified evidence
205 young adults, mildly short of iodine, took it for 32 weeks. Their iodine levels rose. Memory and thinking test scores did not.
Different group studied
1 paper read, 1 against.
Tested as: Potassium iodate, 150 mcg iodine daily
Who was studied: Adults aged 18 to 30 in Dunedin, New Zealand. All were mildly short of iodine.
We found 1 study on this. We have not finished reading them yet, so we are not ready to say either way.
How much to take
150 mcg
Before you take it
- Benefit from supplementation in iodine-sufficient individuals is not established; iodine status testing before supplementation is advisable given the documented risk of harm in sufficient individuals.
- Drug interaction: combined use with antithyroid medications (methimazole, propylthiouracil) produces an additive hypothyroid effect at high iodine doses (NIH ODS).
- Drug interaction: potassium iodide salt forms increase hyperkalemia risk when combined with ACE inhibitors (benazepril, lisinopril, fosinopril) — NIH ODS.
- Drug interaction: potassium iodide salt forms increase hyperkalemia risk when combined with potassium-sparing diuretics (spironolactone, amiloride) — NIH ODS.
- NIH ODS Tolerable Upper Intake Level (UL) for adults 19+ is 1,100 mcg/day from all sources (food, beverages, and supplements combined).
- Pregnancy RDA increases to 220 mcg/day (WHO recommends 250 mcg/day); UL remains 1,100 mcg/day; supplementation during pregnancy and lactation should be medically supervised.
- Risk of triggering or accelerating autoimmune thyroiditis (Hashimoto's disease) in individuals with pre-existing thyroid autoimmunity, a common and often undiagnosed condition.
- Wolff-Chaikoff effect: excess iodine intake in iodine-sufficient individuals can paradoxically suppress thyroid hormone synthesis, potentially inducing the very hypothyroidism it purports to treat.