IodineWhat is iodine?
Updated 10 Nov 2026
Short answer
Iodine is a trace element that the body needs to make thyroid hormones.[1] It is found in seaweed, fish, seafood, dairy, eggs and iodized salt.[1] Supplements usually contain potassium iodide or sodium iodide, and some contain kelp.[1]
The soil in some regions has little iodine, so crops grown there have little too. Iodized salt has greatly reduced iodine deficiency worldwide.[1]
Sources (1)
- Iodine: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov
More about iodine
Which foods contain iodine?What is iodine used for?What happens if you do not get enough iodine?Is iodine safe?Do you need an iodine supplement in pregnancy?Does iodine help brain development in children?For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.