Brief answer: Iodine is a nutrient that the body needs to produce thyroid hormones, which among other things control metabolism and are important for fetal brain development. The need for iodine increases during pregnancy and breastfeeding. Research suggests that even mild iodine deficiency can affect fetal development, but the evidence varies. The Swedish Food Agency recommends pregnant women consume around 175 micrograms of iodine per day.
Why does the body need iodine?
Iodine is a building block in the thyroid hormones that regulate metabolism throughout the body. According to 1177 and the Swedish Food Agency, these hormones are particularly important during pregnancy, as they play a role in fetal brain and growth. The fetus is dependent on the mother's iodine, especially early in pregnancy, and can therefore be affected if intake is too low. Evidence indicates that sufficient iodine intake is important even before and early in a pregnancy.
How much iodine is needed before and during pregnancy?
The Swedish Food Agency recommends pregnant women consume approximately 175 micrograms of iodine per day and breastfeeding women around 200 micrograms per day, which is more than the general need for adults. International guidelines, such as WHO's, suggest a slightly higher intake of around 250 micrograms per day during pregnancy. The difference in figures is due, among other things, to how the need is calculated. The increased need is explained by the thyroid working harder, the fetus needing iodine, and more iodine being excreted by the kidneys during pregnancy.
What does research say about iodine deficiency and fertility?
Review articles suggest that moderate to severe iodine deficiency during pregnancy can be linked to impaired neurocognitive development in the child, and in severe cases to more pronounced damage. The picture for mild deficiency is less clear – some studies have not been able to show a clear benefit of iodine supplements for only mild deficiency, meaning the evidence here is limited. At the same time, research describes that women in parts of Europe and the USA once again appear to have a lower iodine intake, including women undergoing fertility treatment. The correlations should be interpreted cautiously, but they suggest that iodine is worth paying attention to.
Where do you get iodine – and can you get too much?
Common sources of iodine in the Swedish diet are iodized salt, milk and dairy products, fish, and eggs. Those who eat few or no animal products, for example, on a vegan diet, may, according to the Swedish Food Agency, find it harder to meet the recommendations and may need to review their intake. At the same time, balance is important: too much iodine can also be detrimental, and the Swedish Food Agency advises pregnant and breastfeeding women against eating large quantities of sea algae and seaweed, which can contain very high levels of iodine. If you want to use a dietary supplement, it is wise to check the dose and need with a midwife or healthcare provider.
Frequently Asked Questions
Question: Do all pregnant women need an iodine supplement?
Answer: Not necessarily. The need depends on your diet. Those who use iodized salt and eat dairy products, fish, and eggs often get a good deal of iodine through their food. For vegan or very restrictive diets, the need may be greater. Feel free to consult healthcare providers about what suits you.
Question: Can you get too much iodine?
Answer: Yes. Both too little and too much iodine can be detrimental. The Swedish Food Agency advises pregnant and breastfeeding women against high intakes, for example, through sea algae and seaweed products. Stick to recommended levels unless advised otherwise by healthcare providers.
Question: Is iodized salt enough to cover the need?
Answer: Iodized salt contributes a significant part of iodine intake for many, but how much depends on the rest of the diet. Since one should also be moderate with salt, it is good to get iodine from other foods such as dairy, fish, and eggs.
This article provides general information and is not medical advice. It does not replace individual assessment by a midwife, doctor, or other healthcare professional. Always consult healthcare providers about your situation, especially before and during pregnancy or if you have a thyroid condition.