Iodine is a micro-mineral that we need in our diet. Micro-minerals are minerals that our bodies need in very small amounts to stay healthy and function at their best. Although we only need a tiny amount of these minerals, our bodies can go haywire if we do not consume enough of them.

Role of Iodine in the Body

Iodine plays an essential role in the production of thyroid hormones, thyroxine (T4) and triiodothyronine (T3). Our bodies use these thyroid hormones to regulate many reactions, including building proteins and metabolism. Additionally, thyroxine and triiodothyronine are required for the proper growth and development of skeletal and nervous systems in fetuses and young children. Research also suggests that iodine supports our immune response to infections. 

How Much Iodine Do I Need?

The amount of iodine our bodies need can vary based on a number of factors. Health Canada recommends healthy individuals over the age of 14 consume 150 micrograms daily while children between the ages of 1 and 8 should consume 90 micrograms daily. Check out Health Canada’s website for a complete list of iodine intake recommendations.

Am I At Risk of Deficiency?

Iodine deficiency is rare in Canada and the United States. But this does not mean that deficiency never happens. Some populations have a higher risk of developing iodine deficiency. These higher-risk populations include,

    • Pregnant women
    • People who do not use iodized salt
    • Vegans
    • People avoiding dairy products and eggs
    • People with low iodine levels who eats goitrogen-containing foods
      • Goitrogens are compounds that interfere with the production of thyroid hormones and can lead to the development of goitres

As I mentioned earlier, our bodies use iodine to make thyroid hormones which are needed for the development of our nervous system. As a result, iodine deficiency can impact our ability to focus on tasks and think clearly and may cause below-average IQs in children. Some signs and symptoms of iodine deficiency include,

Can I Have Too Much?

Although our bodies need iodine to function at their best, too much iodine is a bad thing. Consuming large amounts of iodine at a one time can cause unpleasant symptoms such as,

    • Goitre
    • Stomach pain
    • Nausea and vomiting
    • Diarrhea

Additionally, it might surprise you to know that consuming too much iodine for long periods can have similar signs and symptoms as iodine deficiency. Consuming large amounts of iodine-rich foods can lead to the development of goitres and increase our risk of developing thyroid cancer.

Where Can I Find Iodine?

Iodine can be found in a variety of animal-based foods, as well as in some plant-based options. Some iodine-rich sources of food include,

    • Seaweed
    • Cod
    • Milk
    • Iodized table salt
    • Eggs
    • Shrimp
    • Cheddar cheese
    • Greek yogurt
    • Beef liver
    • Chicken breasts
    • Bananas
    • Broccoli
    • Green beans

For more iodine-rich foods, check out Harvard’s School of Public Health website.

Two fried eggs. Eggs are a great source of iodine. Image from Pexels.

Dietary Supplements for Iodine

Like many other micronutrients, iodine is available in dietary supplements. It can be found in many multivitamins as well as in individual supplements, such as sodium iodide or potassium iodide. Iodine-containing kelp is also available as a dietary supplement.

Interaction with Medications

Iodine is known to interact with some medications including, thyroid medications, some diuretics medications and select heart medications. You should always chat with your doctor or dietitian before starting any new supplements to prevent any unwanted interactions and side effects.

For more on the role of vitamins and minerals in promoting health and supporting our bodies, check out the Micronutrient Monday series.


Bertinato, J. (2021). Iodine nutrition: Disorders, monitoring and policies. In Advances in Food and Nutrition Research(Vol. 96).

Harvard T.H. Chan School of Public Health. (n.d.). Iodine. Retrieved January 3, 2022, from

Health Direct. (n.d.). Iodine deficiency. Retrieved January 3, 2022, from

National Institutes of Health. (n.d.). Iodine – Health Professional Fact Sheet. Retrieved January 3, 2022, from