Iodine in pregnancy

Iodine in pregnancy

Read time: 3 minutes

Iodine is a trace element found in dairy foods, fish and some other foods¹. One of the less well-known nutrients, it has a vital role to play in your everyday health and your baby’s incredible journey from conception to birth.

Learn more about the importance of iodine in your pregnancy diet, the best sources of iodine and how much iodine you need in your diet.

Why is iodine so important during pregnancy?

Iodine is a key nutrient during pregnancy. For a start, it’s involved in many functions and processes of your body, including making your thyroid hormones. These hormones affect the way your cells function, which in turn affect many processes of your body, such as your heart rate and your metabolism. Having low levels of these hormones has been linked to weight gain, fatigue and mood swings.

Iodine’s also vital for your baby’s brain development. During pregnancy, your baby’s cells rely on your iodine intake, including their rapidly developing brain cells². A good supply of iodine is essential to building this complex organ². A well-balanced pregnancy diet that includes a healthy intake of iodine-rich foods will support your baby’s developing brain, contributing to their learning and motor skills, and helping to set the stage for all future development.

How much iodine do you need when you’re pregnant?

Despite being present in many foods, studies have found that there’s a widespread lack of iodine in our diets³. Because the best sources are all animal-based, if you’re vegetarian, vegan or follow a plant-based diet, you may be at a higher risk of iodine deficiency³. If you’re concerned that you might not be getting enough iodine in your diet, talk to your midwife about taking a pregnancy-safe iodine supplement⁴.

The daily recommended amount for women is 140mcg. If you decide to breastfeed your baby, you shouldn’t need to make any special dietary changes but it’s a good idea to eat healthily. For more advice, you can always talk to your midwife or healthcare professional.

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Which foods contain iodine?

White fish and dairy foods are all excellent sources of iodine⁴. You can also increase your intake by replacing your regular salt with an iodised version (which is salt that has been fortified with iodine³). Although it goes without saying, you shouldn’t increase your salt intake in order to boost your iodine intake.

While seaweed (which absorbs iodine from seawater) can also be an excellent source, the amount of iodine in seaweed is highly variable. Some varieties contain very high levels of iodine, and could be harmful if eaten in large quantities on a regular basis. Some health bodies advise not eating seaweed more than once a week during pregnancy. However, small amounts of powdered or crumbled seaweed can be added to soups, stews and salads.

Learn about other foods to avoid during pregnancy.

Foods high in iodine for pregnancy

Food	Portion	Avergage nutrient quantity (mg)
White fish	100g	115
Oily fish	100g	115
Yoghurt	150g	50-100
Shellfish	100g	90
Cow's milk	200ml	50-80
Organic cow's milk	200ml	30-65
Eggs	1 egg	20
Cheese	40g	20
Meat	100g	10
Poultry	100g	10
Nuts	25g	5
Bread	1 slice	5
Fruit and veg	1 portion	3

It’s worth noting that the iodine content of dairy varies depending on the season, due to variations in how cows are fed throughout the year. Higher levels of iodine have been measured in milk over the winter when cows are fed on winter feed rations, compared with the summer, when lower levels have been measured⁵. These seasonal changes have been linked to the amount of iodine in maternal diets⁶.

Try boosting your intake with these iodine-rich meals and snacks:

Kedgeree made with white fish and boiled eggs
Prawn cocktail made with yoghurt
Jacket potato topped with cottage cheese or sardines
Salmon and haddock sweet potato fish pie
Blackberry and raspberry ginger yoghurt pots

References

NHS. Iodine [Online]. 2017. Available at: www.nhs.uk/Conditions/vitamins-minerals/Pages/Iodine.aspx [Accessed March 2020]
Delange F. Iodine requirements during pregnancy, lactation and the neonatal period and indicators of optimal iodine nutrition. Public Health Nutr 2007;10(12A):1571-1580.
Bath SC, Rayman MP. Is iodine deficiency during pregnancy a public health concern in the UK? Nutr Bulletin 2013;38(4):400-404.
British Dietetic Association. Food fact sheet: Iodine [Online]. 2019. Available at: https://www.bda.uk.com/resource/iodine.html [Accessed March 2020]
Travnicek et al. Iodine content in raw milk [Online]. 2006. Available at: http://vri.cz/docs/vetmed/51-9-448.pdf [Accessed March 2020]
Furmidge-Owen, V. A longitudinal study of iodine status throughout gestation in UK women [Online]. 2013. Available at: http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9266486&fileId=S0029665114000524 [Accessed March 2020]