What is iodine?

Iodine is an element that is essential for normal growth and for brain development. The body needs iodine to make thyroid hormones in the thyroid gland. Thyroid hormones influence metabolism. They are essential for the development and function of the brain, nerves and bones.

A healthy diet needs enough iodine to function well, but too much may cause health problems. Many Australians have enough iodine in their diet, but some don’t. Do not take more than the recommended dose of supplements. If you have a thyroid condition, speak to your doctor before taking iodine supplements.

Find out more here about iodine and recommended iodine daily intake.

Where does iodine come from?

Iodine is found naturally in the sea and in some soils. Foods high in iodine include fish, prawns and seafood, as well as iodised salt and packaged bread.

What are the best sources of iodine?

Iodine is found in many foods. The amount of iodine that different foods contain, depends on where they are grown and how they are made.

Bread

Since 2009, it has been a requirement in Australia and New Zealand that commercial bread is made with iodised salt (salt that contains iodine). Eating packaged bread as part of a normal diet provides enough iodine for most people, but not enough if you are pregnant or breastfeeding.

Organic, salt-free and unpackaged bread and bread mixes might not contain iodine, so it’s important to check the food label.

Salt

Iodised salt is a good source of iodine. However, most Australians eat too much salt, which can increase the risk of heart disease and stroke, so it’s best to get iodine from other foods.

It’s a good idea to reduce the amount of salt you add to food to as low as possible, but to make sure any salt you do use is iodised. If you have a low-salt diet for health reasons, it may be better to get iodine from a supplement. You can discuss this with your doctor if you aren’t sure.

Specialty salts such as sea salt, Himalayan salt and kosher salt usually don’t contain iodine — check the label before you buy it.

Seafood

Seafoods such as oysters, snapper, tinned salmon and seaweed contain lots of iodine.

It’s a good idea to eat seafood 2 to 3 times a week, but be careful not to eat too much fish that contains mercury (such as swordfish and tuna), especially if you are pregnant or breastfeeding.

Other foods

Eggs, milk and dairy products such as yoghurt also contain iodine.

How can I make sure I get enough iodine?

How much iodine you need depends on how old you are. Most adults need 150 micrograms of iodine daily, but you need more if you are pregnant or breastfeeding.

Eating the 5 food groups should provide most people with enough iodine from their regular diet.

Here are some common foods and how much iodine they contain:

Iodine and pregnancy

If you are pregnant or breastfeeding, getting enough iodine is especially important to ensure your baby has what they need for their brain and nervous system to develop properly. The National Health and Medical Research Council recommends that you take an iodine supplement of 150 micrograms a day. Ask your doctor or midwife for more information.

Resources and support

• Visit Nutrition Australia for more information about iodine and your health and for recipes that are rich in iodine.
• The Thyroid Foundation has a factsheet about iodine supplementation during pregnancy and breastfeeding.
• Read more on the essential vitamins and minerals you need during pregnancy (including iodine, folate and iron) on the Pregnancy, Birth and Baby website.