Iodine during pregnancy – Dosage and food sources

A dish composed of fish fillet which is rich in iodine.
Seafood provide iodine

Pregnancy is a transformative journey, and the health of both the mother and the developing baby is important. One often overlooked but crucial element in this journey is iodine. Iodine is an essential mineral that plays a vital role in the development of the baby's brain and overall health. 

This article will delve into the significance of iodine during pregnancy, recommended dosages, and the best food sources to ensure your and your baby's well-being.

MEDICAL DISCLAIMER: The information included in this material is for informational purposes only. Always seek medical advice for any concerns about health and nutrition.

What is iodine?

Iodine is a crucial chemical element essential for maintaining the proper function of the thyroid gland. It is used by the thyroid to produce hormones that regulate metabolism, energy production, and the development of the brain and nervous system. 

This is commonly found in everyday foods, especially in seafood such as fish, such as cod or tuna. A further source of iodine is iodized table salt. During pregnancy and breastfeeding, an adequate intake of iodine is strongly recommended to ensure the health of your baby.

Why is it important for pregnant women?

Iodine is vital for pregnant women due to its essential role in the healthy development of the baby. Here are the key reasons why iodine is vital during pregnancy.

  • Brain and nervous system development: Iodine is a fundamental component for the synthesis of thyroid hormones. These hormones play a central role in the formation of neural connections, which are essential for cognitive function, motor skills, and overall neurological health.
  • Preventing iodine deficiency: Iodine deficiency during pregnancy can result in developmental issues, including intellectual disabilities, delayed physical growth, fetal hypothyroidism, and neurological impairments in the baby.
  • Thyroid function: Iodine is necessary for maintaining the thyroid gland's proper function in both the mother and the developing baby. A healthy thyroid is essential for regulating the metabolism and energy production of both the mother and the fetus.

How much is recommended before, during, and after pregnancy?

Iodine recommendations for women differ based on their life stage. Before pregnancy, the recommended daily intake is around 150 micrograms (mcg). The World Health Organization (WHO) recommends a higher iodine intake of 250 mcg daily in pregnant women and while breastfeeding, it remains elevated at 250-290 mcg daily. 

After breastfeeding, iodine intake can return to the standard 150 mcg per day. These guidelines ensure the baby's proper brain and nervous system development and help prevent iodine deficiency. Women need to discuss their iodine needs with a doctor, as individual requirements may vary based on factors like diet, regional iodine availability, and health conditions.

Can you take too much iodine? 

Chronic overconsumption of iodine, often referred to as iodine toxicity, can disrupt thyroid function and lead to thyroid disorders such as hyperthyroidism. Additionally, excessive iodine can have adverse effects on other organs and systems in the body. 

The recommended daily intake of iodine is established to strike a balance between preventing deficiency and avoiding excessive intake. Individuals must adhere to recommended iodine guidelines and consult with doctors, especially during pregnancy, where an excess of iodine can have detrimental effects on both the mother and the developing baby.

Best food sources that are high in Iodine

Several foods are rich sources of iodine, making them valuable additions to your diet to ensure adequate iodine intake. Here are some of the best food sources high in iodine.

  • Seafood: Seafood, particularly saltwater fish like cod, tuna, and shrimp, is exceptionally rich in iodine due to the iodine content in seawater.
  • Iodized Salt: Regular table salt that is iodized is a common and easily accessible source of iodine. It is widely used for seasoning and cooking.
  • Seaweed and kelp: These oceanic vegetables are among the most iodine-rich foods available. They can be consumed as part of salads, sushi, or used as a seasoning.
  • Dairy products: Milk, yogurt, and cheese can be good sources of iodine, as it is often used to clean the udders of dairy cows and in dairy equipment.
  • Eggs: Eggs, particularly when the hens are fed iodine-fortified feed, can be a source of iodine.
  • Prunes and prune juice: These fruits are known to contain moderate levels of iodine.
  • Cranberries: Cranberries and cranberry juice can also provide a modest amount of iodine.

It's important to maintain a balanced diet that includes these iodine-rich foods to ensure you meet your daily iodine requirements, especially during pregnancy or if you live in an area with low iodine levels in the soil or water. However, it's advisable to consult with your doctor to determine your specific iodine needs and whether supplementation is necessary.

Should you supplement iodine during pregnancy?

The need for iodine supplementation depends on individual factors such as dietary habits, regional iodine levels in food and water, and specific health conditions. 

One study says that women with a median urinary iodine concentration (UIC) at or above 100 µg/l do not need iodine supplementation during pregnancy. On the other hand, if the UIC is below 100 µg/l, pregnant women should take iodine-containing supplements.

Frequently asked questions on iodine:

Why is iodine important for pregnant women?

Iodine is crucial for pregnant women because it plays a vital role in the development of the baby's brain and nervous system. It helps prevent iodine deficiency, which can lead to intellectual disabilities and developmental issues. Additionally, iodine supports thyroid function and overall health for both the mother and the developing baby.

What foods are rich in iodine?

Foods rich in iodine include seafood like cod, tuna, and shrimp, which are excellent sources due to the iodine content in seawater. Seaweed and kelp, often used in sushi or as seasonings, are exceptionally high in iodine. Iodized salt is a common source, while dairy products, eggs, and certain breads and cereals can also contribute to iodine intake.

What are the symptoms of low iodine in pregnancy?

Low iodine levels during pregnancy can lead to various symptoms and potential complications. Common symptoms include fatigue, weight gain, cold intolerance, and swelling of the thyroid gland (goiter). In more severe cases, iodine deficiency can result in developmental issues in the baby, such as intellectual disabilities, delayed physical growth, and neurological impairments.

How much is too much iodine in pregnancy?

Generally, it is recommended not to exceed 1,100 micrograms (mcg) of iodine per day during pregnancy. Intake above this limit can lead to thyroid dysfunction and other health issues, so it's important to consult with a doctor before taking iodine supplements.


[1] Zimmermann, M.B. (2016). The Importance of Adequate Iodine during Pregnancy and Infancy. World Review of Nutrition and Dietetics, [online] 115, pp.118–124. doi:

[2] (n.d.). Iodine supplementation during pregnancy. [online] Available at:

[3] Bellefonds, C. (n.d.). What Types of Fish Are Safe to Eat During Pregnancy? [online] Available at:

[4] Andersen, S.L. and Laurberg, P. (2016). Iodine Supplementation in Pregnancy and the Dilemma of Ambiguous Recommendations. European Thyroid Journal, 5(1), pp.35–43. doi:

[5] MotherToBaby. (n.d.). Iodine. [online] Available at:

[6] Frontiers. (2019). Consequences of Iodine Deficiency in Pregnancy. [online] Available at:


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