Iodine helps make thyroid hormones. These help keep cells and the metabolic rate (the speed at which chemical reactions take place in the body) healthy.

You should be able to get all the iodine you need by eating a varied and balanced diet.

If you take iodine supplements, do not take too much as this could be harmful. Taking 0.5mg or less a day of iodine supplements is unlikely to cause any harm.

Good sources of iodine

Good food sources of iodine include:

  • sea fish
  • shellfish

Iodine can also be found in plant-based foods, such as cereals and grains. But the levels vary depending on the amount of iodine in the soil where the plants are grown.

How much iodine you need

Adults need 140 micrograms (μg) of iodine a day.

If you are following a strict vegetarian or vegan diet and do not eat any fish then you may want to consider taking an iodine supplement. Some types of plant-based milk are also fortified with iodine. Talk to your GP or a healthcare professional about supplements

The Vegan Society has more information about iodine and vegan diets

Effects of taking too much iodine

Taking high doses of iodine for a long time could change the way your thyroid gland works.

This can lead to a wide range of different symptoms, such as weight gain.

If you take iodine supplements, do not take too much as this could be harmful.

Taking 0.5mg or less a day of iodine supplements is unlikely to cause any harm.


Content supplied by the NHS and adapted for Ireland by the HSE

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This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.

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