Are you getting enough iodine?
Iodine is a vital trace element that we all need for good health. Find out how you can add more to your diet.
Words: Janine Phillipson
Our bodies need iodine for the development of essential thyroid hormones thyroxine and triiodothyronine, which regulate many metabolic processes, such as brain function and the growth and development of tissues.
Because the body doesn’t produce iodine naturally, if you don’t have enough in your diet, it can lead to a number of problems, depending on your life stage.
Iodine deficiency in an adult can lead to an enlarged thyroid gland (goitre) or other disorders that can significantly affect a person’s health, such as hypothyroidism. For pregnant women, in particular, iodine deficiency can increase the risk of stillbirth, miscarriage or premature delivery, as well as result in congenital abnormalities in their babies.
In fact, iodine deficiency is the world’s leading cause of preventable intellectual disability or mental retardation in children and, on a wider level, can “reduce intellectual capacity at home, in school and at work”, according to the World Health Organization.
Iodine deficiency is the world’s leading cause of preventable intellectual disability or mental retardation in children.
Research has shown that iodine deficiency among Australians living in Tasmania, the Australian Capital Territory, New South Wales and Victoria is quite common, with nearly half the population thought to have inadequate intakes. This has been attributed to the iodine-deficient soils of these regions, and, in the past, various initiatives have been put in place to address this problem, including supplementation and fortification schemes1. In 2009, Food Standards Australia and New Zealand made it compulsory for bakers to use iodised salt in all commercial bread, going a long way to help increase nationwide intakes.
How much iodine do I need?
Dietitian and clinical consultant at Australian Unity Remedy Healthcare Julie Martin says pregnancy is the most vital time to make sure you are getting enough iodine to maintain your own normal thyroid hormone levels, while also producing enough thyroid hormones to transfer to the developing baby.
“Pregnant women have a higher iodine requirement and it would be incredibly difficult to get the correct amount through diet alone,” she says.
The National Health and Medical Research Council (NHMRC) recommends pregnant women take 220µg of iodine per day and breastfeeding mothers take 270µg per day (µg is the same as mcg, both meaning ‘microgram’).
As a child, iodine deficiency can impair the development of the brain and nervous system, with the most crucial period being from foetal development to the third year of life. The recommended daily intake (RDI) for iodine by age is useful to know: younger children (1 to 8 years) – 90µg; older children (9 to 13 years) – 120µg; adolescents (14 to 18 years) – 150µg.
The RDI for iodine for adult men and women is 150µg, although women with pre-existing thyroid conditions should not take iodine supplements until they have checked with their doctor.
Iodine is not stored anywhere in the body, so, while we only need it in small amounts, we need it regularly. The following foods are rich in naturally occurring iodine and can be implemented into a balanced diet. If using salt, opt for the iodised variety, as sea salt does not contain iodine.
- Bread (2 slices/60g): 28µg
- Oysters (6 oysters/90g): 144µg
- Sushi (1 roll/100g containing seaweed): 92µg
- Milk (1 large glass/250ml): 57µg
- Canned tuna (1 small tin/95g): 10µg
Information provided in this article is not medical advice and you should consult with your healthcare practitioner. Australian Unity accepts no responsibility for the accuracy of any of the opinions, advice, representations or information contained in this publication. Readers should rely on their own advice and enquiries in making decisions affecting their own health, wellbeing or interest.
- Australian Academy of Science, science.org.au/resources/iodine-deficiency