Your thyroid is an essential part of your endocrine system. The endocrine system is responsible for producing hormones that regulate metabolism, growth and development, tissue function, sexual function, reproduction, sleep, and mood, among other things.
Iodine and the thyroid
Iodine is a naturally occurring chemical element like, oxygen and iron. It is an essential mineral that we get naturally from our food supply. Iodine deficiency is caused from not having enough iodine intake in our diet to maintain the body’s cell requirements as the body cannot produce iodine itself.
Everyone needs Iodine for their thyroid to function healthily. Deficiency is one of the most common causes of thyroid disorders. Iron deficiency has significant risks and can cause hypothyroidism, an enlarged thyroid gland and can also affect fertility, pregnancy and neurodevelopment disorders in newborns.
How do I know if I have low Iodine levels?
One of the complications of iodine deficiency may be seen by an enlarged thyroid gland but this can be difficult to detect especially in the earlier stages. Hyperthyroidism are also related to low iodine levels and this can be expressed through lethargy, feeling cold, difficulty concentrating, unusual weight gain, depression as well as puffy skin, hair loss and dry skin.
You may not display or experience any symptoms of low iodine, so the best way to check these levels is to ask your doctor to check your iodine levels this is done either by urine or blood test.
The World Health Organisation recommends that the dietary intake for adult males and females above 12years of age is 150units per day. For pregnant or lactating women they require more at 250units per day.
Where does Iodine come from?
We get our source of iodine through our daily dietary intake. Iodine is present at high amounts in seawater; however distribution over land and fresh water is often uneven. This makes marine sources such as fish, seafood and seaweed high in iodine and is the best dietary source for our daily intake. Other sources include dairy products, Iodised salt, bread/grains and taking iodine supplements.
However in Australia and neighbouring country New Zealand our plant produce are grown in iodine depleted soils that have been mass produced and our livestock are grazed on these iodine depleted soils. This causes our dairy products and fresh produce such as fruit and vegetables to have very low levels of iodine. This causes people to have low iodine intake without even realising. It is also recommended that your daily salt intake should be iodised salt in order to meet these dietary requirements.
How to get your daily quota of iodine intake
This table provides a summary of foods and their iodine content, remember it is recommended that adults have a total of 150units per day.
| Food | Iodine content (units per 100g) |
| Oysters | 160 |
| Sushi (containing seaweed) | 92 |
| Tinned salmon | 60 |
| Bread (made with iodised salt) | 46 |
| Steamed snapper | 40 |
| Cheddar cheese | 23 |
| Eggs | 22 |
| Ice cream | 21 |
| Chocolate milk | 20 |
| Flavoured Yoghurt | 16 |
| Regular milk | 13 |
| Tinned tuna | 10 |
| Bread (without iodised salt) | 3 |
| Beef, pork, lamb | <1.5 |
| Tap water (varies depending on site) | 0.5-20.0 |
| Apples, oranges, grapes, bananas | <0.5 |
In summary, if you want to meet daily requirements, eating marine sourced products will be the most efficient. With a few pieces of seaweed or fish supplying you with the recommended daily units of iodine. A mixture of dairy products and eggs throughout the day will also help contribute.
For more information about iodine for thyroid health visit the websites below
- www.thyroid.com.au/iodine-thyroid-hormones-and-the-thyroid-gland
- www.thyroidfoundation.org.au/iodine-nutrition-iodine-deficiency
- www.betterhealth.vic.gov.au/health/healthyliving/iodine
