Iodine

Medically Reviewed by Melinda Ratini, MS, DO on September 07, 2023
Written by R. Morgan Griffin
3 min read

Iodine is a mineral that's important for good health. It's available in the U.S. as an FDA-approved treatment and a supplement.

Iodine is essential for everyone. Supplements may be needed if you don't get enough in your diet. But most people in the U.S. get enough iodine through their normal diet. In other parts of the world, though, low iodine levels are a serious cause of health problems.

In the U.S., pregnant women have a higher risk of low iodine levels. Low iodine raises the risk of developmental problems in babies.

Iodine plays a key role in thyroid health. As a treatment, radioactive iodine helps with goiters (enlargements of the thyroid gland) and high thyroid levels such as in thyroid storm. After exposure to radiation, iodine can provide some protection against thyroid damage.

Iodine may have other uses. There's some evidence it can be applied to the skin to help treat foot ulcers related to diabetes. It may help protect against mouth irritation caused by chemotherapy.

It also seems to help with fibrocystic breast change. That's a noncancerous condition that happens to some women around the time of their period.

Most people get more than enough iodine in their diets. One teaspoon of iodized salt contains 400 micrograms of iodine. That's more than twice as much as most adults need each day.

For other uses of iodine for specific medical conditions, ask your doctor about the amount you need.

Iodine is in many foods, especially ones that come from the sea. Seaweed is an especially good source. Other seafood sources include:

  • Tuna
  • Sardines
  • Salmon
  • Lobster
  • Shrimp

Iodine is also in foods such as:

  • Dairy products
  • Grains
  • Eggs
  • Vegetables

Iodine is in breast milk and added to baby formula. It's also added to many brands of table salt.

Tell your doctor about any supplements you're taking, even if they're natural. That way, your doctor can check on any potential side effects or interactions with medications.

Side effects. More than 1,100 micrograms of iodine a day for adults can be dangerous. It could cause thyroid problems and other issues.

Iodine supplements can also cause:

Risks. Don't use an iodine supplement if you have thyroid problems unless a doctor recommends it. Pregnant women sometimes need iodine supplements. Ask your doctor about it.

Interactions. If you take any medications regularly, talk to your doctor before you start using iodine supplements. They could interact with lithium and drugs for heart problems, high blood pressure, and thyroid problems.

The U.S. Food and Drug Administration (FDA) does regulate dietary supplements; however, it uses different regulations than for foods or drugs. Manufacturers are responsible for making sure they are safe and labeled correctly.