Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

beginning of content

Iodine deficiency

7-minute read

Key facts

  • Iodine is an element essential for normal growth and for the development of the brain.
  • Iodine deficiency is the most common cause of thyroid disease, specifically hypothyroidism (underactive thyroid).
  • Hypothyroidism can cause symptoms including severe tiredness, feeling cold, weight gain and an enlarged thyroid (goitre).
  • While anybody can develop iodine deficiency, it’s more common in people who are pregnant or breastfeeding (who have higher iodine requirements), and unborn or newborn babies.
  • Iodine deficiency is usually treated by eating more iodine-rich salt, using iodised salt and taking iodine supplements.

What is iodine?

Iodine is an element that is essential for normal growth and for the development of the brain. 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, but too much can cause health problems.

Read more on the role of iodine and your health.

What is iodine deficiency?

Iodine deficiency occurs when you don’t have enough iodine in your body. This usually occurs because you don’t consume enough iodine in your diet.

Iodine deficiency is the most common cause of thyroid problems. Iodine deficiency is a growing problem in Australia, especially among children and people who are pregnant or breastfeeding. These groups are at risk of thyroid problems and other serious consequences.

What are the symptoms of iodine deficiency?

Many people with iodine deficiency don’t have symptoms.

In other people, low iodine causes hypothyroidism (underactive thyroid).

Symptoms of hypothyroidism include:

Who is at risk of iodine deficiency?

While anybody can develop iodine deficiency. It’s more common in people who are pregnant or breastfeeding (who have higher iodine needs), and unborn or newborn babies.

In some parts of Australia, there isn’t enough iodine in the soil, so foods grown there won’t contain as much iodine. This means that people eating these foods may be at a greater risk of iodine deficiency.

To address this problem, iodine is added to most table salts (known as ‘iodised’ salt). Since 2009, all breads in Australia that are not organic must contain iodised salt. This helps ensure that most people get enough iodine.

Some people don’t get enough iodine because the foods that contain it, such as seafood, tend to be more expensive. Eating organic bread or specialty salt may also mean people are missing out on iodine in their diet.

How is iodine deficiency diagnosed?

Your doctor will do a physical examination and order a urine test or a thyroid stimulating hormone (TSH) blood test. If the results show abnormal levels of TSH, you may have further tests such as an ultrasound to look at the thyroid gland.

In Australia, all newborn babies have a screening blood test. This is known as the neonatal screening test (NST) or ‘heel prick’ and tests for a range of rare medical conditions. This includes low thyroid hormone levels, which can in some circumstances be a sign of iodine deficiency. Identifying thyroid problems early in life ensures affected babies can receive treatment before complications occur.

If you are diagnosed with iodine deficiency, your doctor may refer you to an endocrinologist (a doctor who specialises in metabolism and hormones).

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

How is iodine deficiency treated?

Iodine deficiency is usually treated by:

People with hypothyroidism may need treatment with a synthetic form of thyroid hormone.

How is iodine deficiency prevented?

Most people can get enough iodine from eating iodine-rich foods such as seafood. Seasoning your food with small amounts of iodised salt and eating packaged bread will also help increase iodine in your diet.

The National Health and Medical Research Council recommends that you take an iodine supplement of 150 micrograms a day if you are:

  • pregnant
  • breastfeeding
  • planning a pregnancy

Ask your doctor for more information.

It’s important that you don't take more than the recommended dose of supplements. If you have a thyroid condition, speak to your doctor before taking iodine supplements.

Read more about iodine and recommended iodine daily intake.

ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.

What are the complications of iodine deficiency?

Iodine deficiency can cause hypothyroidism (underactive thyroid).

In females, iodine shortage can also cause:

Unborn babies and young children who have iodine deficiency are at a higher risk of:

  • brain damage
  • intellectual disability
  • stunted (poor) growth

Resources and support

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: June 2023

Back To Top

Need more information?

These trusted information partners have more on this topic.

Top results

Iodine -

Iodine is important for your thyroid gland, and iodine deficiency can cause problems, especially in unborn and newborn babies. Find out how to ensure your iodine intake is adequate.

Read more on myDr website

Iodine | Nutrition Australia

Learn what iodine is, why is it important for health, iodine requirements and food sources.

Read more on Nutrition Australia website

Iodine - Better Health Channel

Good sources of iodine include fortified bread and any type of seafood, including seaweed.

Read more on Better Health Channel website

Iodine: how much does your family need? | Raising Children Network

Children need iodine for growth, development and good health. They can get iodine from packaged bread, seafood, eggs, fruit and vegetables, meat and dairy.

Read more on website

Folic acid & iodine fortification, Summary - Australian Institute of Health and Welfare

Mandatory folic acid and iodine fortification of bread resulted in increased levels of folic acid and iodine in the food supply, increased folic acid and iodine intakes, a decreased rate of neural...

Read more on AIHW – Australian Institute of Health and Welfare website

Iodine supplementation - Maternal and newborn

iodine supplementation for women thinking of having a baby, during preganancy and breastfeeding

Read more on NSW Health website

Pregnancy supplements: Folate and iodine - Pregnancy

Babies need folate and iodine for the healthy development of their spine, brain, and nervous system. Sometimes our diet does not have enough folate and iodine, and a supplement is needed. It can take time to build up these nutrients.

Read more on NSW Health website

Goitre - Better Health Channel

Symptoms of a goitre can include enlargement of the throat, swallowing problems and breathing problems.

Read more on Better Health Channel website

The thyroid gland

Information on the thyroid gland and its function in regulating your body’s metabolism.

Read more on WA Health website

Hypothyroidism - Hormones Australia

Hypothyroidism is the most common thyroid disorder in Australia, affecting around 1 in 33 Australians. It is usually a permanent condition where the thyroid

Read more on Hormones Australia website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Queensland Government logo Government of South Australia, health department logo Tasmanian government logo Victorian government logo Government of Western Australia, health department logo

Healthdirect Australia acknowledges the Traditional Owners of Country throughout Australia and their continuing connection to land, sea and community. We pay our respects to the Traditional Owners and to Elders both past and present.