What is iodine?
Iodine is an element that is essential for normal growth and for the development of the brain.
A healthy diet needs enough iodine, but too much can cause health problems. Many Australians have enough iodine in their diet, but some don’t.
What does iodine do?
Iodine helps the thyroid gland, in the neck, to make the hormone thyroxine. Thyroxine controls many of the ways certain cells work.
Iodine is important before birth and in babies and young children. It is essential for the development of the brain and nervous system, the 5 senses, alertness and coordination.
How much iodine do I need?
How much iodine you need depends on your age and stage of life:
|Stage of life||Recommended daily intake for iodine (micrograms per day)|
|Babies 0 to 6 months||90|
|Babies 7 to 12 months||110|
|Children aged 1 to 8||90|
|Children aged 9 to 13||120|
|Adolescents aged 14 to 18||150|
Too little or too much iodine can cause problems.
Too little iodine may cause extreme tiredness, feeling cold, problems concentrating and hair loss. And without enough iodine, the thyroid gland may enlarge to form a goitre. It shows up as a lump in the neck.
Too much iodine (usually from supplements) can be dangerous for people with thyroid disorders.
How do you get enough iodine?
You get iodine from food. Foods high in iodine include seafoods such as oysters, snapper and seaweed. Tinned salmon, bread, eggs, milk and milk products such as yoghurt also contain iodine.
Iodine is also added to many types of salt. You can check on the label.
Iodised salt is now used in bread making. The packaging will tell you how much iodine the bread contains.
Iodine and pregnancy
If you are pregnant, check if you are eating enough iodine. Low iodine levels can increase the risk of a miscarriage. It can also lead to stunted growth and intellectual disability or reduced IQ in the baby.
The National Health and Medical Research Council recommends that all women who are pregnant, breastfeeding or considering pregnancy take an iodine supplement of 150 micrograms a day to top up their intake as otherwise they are unlikely to get all the iodine they need every day. Talk to your doctor about this. Women who have a thyroid condition should not take iodine supplements until they have checked with their doctor.
Many Australian women don’t get enough iodine for pregnancy, so it’s important to take a supplement from when you are planning pregnancy, right through until after you have had the baby and finished breastfeeding. If you are pregnant, avoid kelp (seaweed) supplements as these may contain varying levels of iodine and may contain heavy metals such as mercury.
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Last reviewed: March 2021