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Iodine in pregnancy-its role and food sources

During pregnancy, iodine is a very important part of your diet. In general, you should be eating a healthy, varied diet according to the food pyramid, with a special awareness about some of the most vital nutrients that your body needs at this time.

Please refer to our feature: Pregnancy diet and nutrition essentials to ensure you understand these basics. This iodine in pregnancy article walks you through the basics, information from the World Health Organisation, the role it plays in pregnancy and food sources where you can find it.

1. What is Iodine?


There is quite a history behind the vital element, iodine. All aspects of our lives require iodine, which is a water-soluble trace element, that you may remember from your school days, on the periodic table- a chemical element with the symbol I and atomic number 53.


iodine pregnancy food sources eggs

2. Iodine in pregnancy & health – did you know?


Did you know that iodine deficiency is actually a global health issue? The WHO (World Health Organisation) has estimated that over 2 billion people could be suffering from an iodine deficiency. WHO has estimated that one-quarter of these people, 50 million, are actually suffering from serious symptoms, such as brain damage. At one stage this was a rare issue in the western world, but these days the imbalance is on the increase. One of the reasons for this is changes in soil quality, due to the way agriculture is nowadays in comparison to how it used to be.

Modern agricultural methods have resulted in a lack of minerals in the soil. We now have poor iodine content in foods, due to these practices and environmental pollutants.


3. Iodine deficiencies can cause the following:


An iodine deficiency will have a different effect on different people, however here are some of the concerning diseases that have been linked to it: 

  • Mental retardation – can occur in extreme cases, but is more likely to be seen in the offspring of mothers who suffered from an iodine deficiency:
  • Fetal hypothyroidism – this is improper thyroid functioning in unborn children, which can lead to brain damage – Other mental imbalances such as anxiety, depression and panic attacks
  • Goitre – which is thyroid enlargement
  • Autism – In some studies, iodine deficiency has also been linked to breast cancer
  • Higher risk of miscarriage
  • Higher risk of preterm delivery
  • Higher risk of stillbirth


iodine in pregnancy dairy products

4. Iodine in pregnancy

Iodine is absolutely essential for your baby’s developing nervous system and brain, as well as regulating her metabolism. For Mum, iodine plays a central role in regulating your thyroid gland. When this is not well regulated, as mentioned above, there is a higher risk of miscarriage, stillbirth and preterm delivery. Iodine is crucial for normal brain function. In Ireland, it can only be found in a small selection of foods, with fish and dairy foods being key sources of iodine.


5. Sources of iodine


Of course, table salt is iodised in many countries, although in Ireland this isn’t the case across the board, but iodised table salt also comes with a number of chemical additives and has been through a host of processes. Sea salt, on the other hand, is more natural, yet you won’t get enough iodine from this alone, coupled with the fact that it isn’t healthy to overdo your salt intake. Healthier sources of iodine, that can make up part of your healthy, varied pregnancy diet are eggs, dairy products, seafood and vegetables. Of course levels of iodine vary depending on the origin of the food source, the processes involved and the quality of the soil and/or water, where relevant.

The amount of iodine in many types of food varies according to the amount of iodine in the area’s soil or water.

The recommended intake of iodine in pregnancy – 130 mg per day

Good food sources of iodine include:

– Milk
– Dairy products
– 100g of red salmon will give you half the iodine you require for that day
– Tinned sardines
– Tinned mackerel
– Tinned tuna – Shrimp (obviously very well cooked, never raw or undercooked)
– Cod
– Eggs
– Sea vegetables
– Turkey breast
– Baked potato Don’t forget that fish is also a good source of vitamin B12. This aids in normal red blood cell formation, and reduces fatigue and tiredness.

6. Excessive iodine during pregnancy

There have been studies that have revealed health problems caused by excessive iodine during pregnancy. In these cases, we are mostly talking about women who were taking pre-natal vitamins and also deriving iodine from dietary sources.

This study which we refer to here is such an example, and these women were getting 11 times the recommended dose of iodine. Although the average pregnant woman doesn’t need to be especially concerned with this, it is good to have an awareness. If you are taking any supplements, be sure to talk this over with your medical team.


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What Our Patients Say

Gráinne Macken

This is my second visit to Merrion Fetal, I was very pleased on both occasions. Lovely quiet waiting room, appointment was on time. The 20-week scan is very detailed we enjoyed watching our baby on the large TV screen. We got some beautiful photos. The nurse was very pleasant and talked us through all the measurements and anatomy. I would highly recommend this scanning clinic.”

Áine Gibney

I had the best experience at the Merrion Fetal Health clinic for my 20-week big scan. The staff were so friendly and so nice and the lovely lady who did my ultrasound scan was amazing. She was so thoroughgoing to absolutely everything and gave me such reassurance on how my baby was growing and developing. I would recommend any Mother to be to attend here if you are looking for a comfortable, reassuring and super pleasant experience.”

Linda O'Sullivan

Highly recommend! We had an early scan due to a little scare at the start of pregnancy and then another at 12 weeks to make sure all was good again. Helen who was scanning on both days was fantastic. We felt totally relaxed and un-rushed while she took her time finding the best angle of baby to get us the clearest pictures as keepsakes all while making sure everything was perfect with baby. She reassured us throughout and I can honestly say it was the best money we ever spent getting both scans done.

Please let Helen know we are 18 weeks now and flying along Highly recommend!



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All articles on the blog and website are intended as information only. Please do not consider any of the information provided here as a substitute for medical advice. At all times seek medical advice directly with your own doctor and medical team.


This website was formerly Merrion Fetal Health. The clinic has undergone a rebrand and is now known as Merrion Ultrasound.