What is iodine?

Iodine is an essential nutrient for humans.

Why is iodine important for children?

Your child needs iodine to ensure that their thyroid gland works properly. The thyroid gland is important because it produces the hormones that control metabolism, growth and development.

Iodine deficiency

Children need only a small amount of iodine for growth and healthy development, but if they don’t get enough, they might develop iodine deficiency.

Iodine deficiency can cause the thyroid gland to work harder, which makes it get bigger. An enlarged thyroid gland, or goitre, can cause swallowing and breathing difficulties.

Iodine deficiency can also lead to:

• hypothyroidism, which can cause problems like weight gain, dry skin, hair loss, tiredness, intolerance to cold and depression
• stunted growth and intellectual disability.

What are sources of iodine?

Iodine occurs naturally in the sea and in some soils.

Iodine is also found in:

• marine life, including fish, prawns and seaweed
• some plants grown in iodine-rich soil
• the products of animals that have grazed on soil with iodine in it.

Iodine is added to some foods, like salt and commercially baked bread.

How to get enough iodine into your child’s diet

If you include the following foods in your child’s diet each week, it’ll help to ensure that they’re getting enough iodine.

Packaged bread

Bread fortified with iodine can usually give your family enough iodine.

Note that organic bread, salt-free bread, unpackaged bread, and bread mixes for making bread at home might not contain iodine, so either check the food label or ask at the point of sale.

Seafood

Experts recommend 2-3 meals of seafood per week. Tinned salmon and seaweed are the best food sources of iodine.

Eggs and dairy products

Note that the amount of iodine in these foods varies.

Fruit and vegetables

These contain small amounts of iodine and are important for a healthy diet.

Meat

This contains small amounts of iodine.

Vegans might need to consider iodine supplements or iodine-rich vegan foods like fortified soy milks.

Iodised salt is a rich source of iodine and has replaced non-iodised salt in all packaged breads sold in Australia. Bread fortified with iodised salt can provide enough iodine for most people, without the need for extra iodised salt in your diet. Too much salt isn’t good for your health, so it’s best to get iodine from other sources.

Why some children don’t get enough iodine

Some children in Australia – especially those in Victoria, Tasmania and New South Wales – don’t get quite enough iodine.

This might be because several areas of Australia have low iodine levels in the soil, meaning fruit, vegetables and livestock grown or raised in these areas don’t have much iodine.

Also, many families now cut salt out of their diets or don’t use iodised table salt, leading to lower iodine intake.

Can your child have too much iodine?

It’s possible to have too much iodine, but it’s hard to get a dangerously high level of iodine from food alone. For example, to have too much iodine, a child aged 1-3 years would need regularly to eat 1 kg of cheese or 25 whole boiled eggs or drink 4 glasses of milk in a day.

Some medicines and supplements might also contain high doses of iodine.

Some people are particularly sensitive to too much iodine, which might cause difficulties with their thyroid glands.

If you’re concerned about whether your child and family is getting enough iodine, it’s a good idea to talk with a health professional, like your GP or a dietitian.

How much iodine do you need if you’re pregnant or breastfeeding?

You need extra iodine if you’re:

• pregnant
• trying to become pregnant
• breastfeeding.

Iodine recommendations for pregnancy and breastfeeding

If you’re pregnant or breastfeeding, your recommended daily intake of iodine is 220-270 micrograms (μg). To help you meet this daily intake, it’s recommended that you take an iodine supplement of 150 micrograms (μg) per day.

Most pregnancy supplements contain iodine. Check your pregnancy supplement ingredients to make sure you’re getting the recommended amount of iodine per day. You can also ask your doctor, midwife or dietitian about your iodine needs.

Kelp and seaweed iodine supplements aren’t recommended because their iodine content varies.

If you have any pre-existing thyroid problems, check with your doctor before taking a supplement.

Why you need extra iodine in pregnancy

If you’re pregnant, you need extra iodine because your thyroid gland is working extra hard to produce hormones to help the growth of your unborn baby’s brain and nervous system.

Severe iodine deficiency in pregnant women might lead to miscarriage, stillbirth or intellectual disability in babies.

Why you need extra iodine while breastfeeding

After birth, breastfed babies depend on breastmilk as a source of iodine, which keeps their brains and nervous systems developing. This means that iodine deficiency in breastfeeding mothers can also be a risk for babies.

If you’re pregnant, you should be careful when choosing fish. Fish is a good source of iodine, but some larger fish – like flake, swordfish and tuna – have higher levels of mercury than others.