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.
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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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)|
|Organic cow's milk
|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.
- 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]
Questions about feeding and nutrition?
Our midwives, nutritionists and feeding advisors are always on hand to talk about feeding your baby. So if you have a question, just get in touch.