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Why do I need iodine in my diet?

Updated: Dec 20, 2020

What is iodine?

Iodine is a mineral that is important for health. It is a key part of the thyroid hormones that are needed for many functions including growth, metabolism and for the development of a baby’s brain during pregnancy and early life.

How much Iodine do I need?

According to European Food Safety Authority (EFSA) recommendations.

  • Adult 150 mcg*

  • Pregnant woman 200 mcg*

  • Breastfeeding woman 200 mcg*

Iodine is found in fish, dairy products and milk. White fish tends to have more iodine than oily fish.

It is important to be aware that most milk-alternative drinks (e.g. soya/almond/oat) are not fortified with #iodine and have a low iodine content. Some milk-alternative drinks are fortified so it is important to check the food label.

Iodine in seaweed?

Who doesn't love sushi? Seaweed is a good source of iodine but is only recommended once per week especially during pregnancy.

The reason being seaweed is a very concentrated source of iodine, but it can also provide excessive amounts (particularly so in the case of brown seaweed such as kelp). Basically it is hard to determine how much iodine is in seaweed as it varies depending on the type of seaweed consumed.

Can I have too much iodine?

Too much #iodine can cause thyroid problems. Kelp and seaweed are food sources that are likely to lead to excessive iodine intake. Iodine tolerance varies between people so it is difficult to say how much is too much. A rough guide should not exceed 600 mcg/day.

In some countries iodine is added to salt “iodized salt”. It is not widely available in Ireland and the UK. As #salt intake is high in the population iodized salt should not be relied on as a means of increasing iodine intake.

It is very difficult to estimate the amount of iodine in food. As the actual amount of iodine in food varies for a number of reasons, including the iodine content of the soil, farming, season dependent and type of fish.

Insufficient level of iodine?

A low intake of iodine over a long period of time will cause your thyroid to work harder to try to keep the right amount of #thyroid hormones in your blood. Your thyroid may then increase in size in order to trap iodine – this swelling, or “goitre”, may be visible in your neck.

If you have an iodine deficiency during pregnancy, there may be effects on the baby’s brain development, which could lead to problems such as lower IQ or reading ability in later life.

Who is at risk of iodine deficiency?

Anyone who avoids fish and/or dairy products (e.g. due to allergy or intolerance, personal choice) could be at risk of iodine deficiency. Vegetarians and particularly vegans are at risk of iodine deficiency as they do not eat most iodine rich foods, and therefore may need to consider a suitable iodine-containing supplement.

What about an iodine supplement?

There are currently no official UK and Ireland recommendations for adults or pregnant women to take an iodine supplement. It is better to meet iodine recommendations through diet where possible. Most adults following a healthy, balanced diet that contains milk, dairy products and fish, should be able to meet their iodine requirements.

If there is adequate intake before and during pregnancy, an iodine supplement may not be needed. Some but not all, pregnancy multivitamin and mineral supplements contain iodine. For those who do not consume sufficient iodine-rich a supplement containing iodine may be useful.

Iodine in supplements should be in the form of “potassium iodide” or “potassium iodate” and should not exceed the daily adult requirement of 150 mcg per day.

Do not use seaweed or kelp supplements as an iodine source; the amount of iodine in such supplements can vary considerably from the value claimed on the label and can provide excessive quantities of iodine.

If you have any questions regarding iodine, feel free to drop me and email or you can find me at over on Facebook and Instagram @coleman_nutrition.

Check the below link for more details on eating #sushiduringpregnancy

*mcg = microgram

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