When it comes to supporting a baby’s developing brain during pregnancy, most people think of folate. Folate is a B vitamin that helps prevent serious problems within the brain and spinal cord called neural tube defects.
But folate isn’t the only key nutrient that deserves the spotlight. Iodine is critical for a baby’s developing brain and nervous system too. Yet data indicates that a growing number of people do not get enough iodine when pregnant.
You need about 50% more iodine during pregnancy. That number climbs even higher while breastfeeding.
Keep reading to learn if you’re at risk for having low iodine levels and what you can do to make sure you and your baby are getting the right amount of this important nutrient.
Why is iodine important during pregnancy?
Iodine is a trace mineral that’s essential for healthy fetal development. Like folate, iodine supports fetal brain and nerve development. Iodine also helps maintain healthy function of the thyroid, a gland in the base of the neck.
The thyroid gland uses iodine to make hormones. These thyroid hormones regulate important body functions and impact how well the bones, brain, heart and other organs work.
You need extra iodine during pregnancy because both you and your baby are making thyroid hormones. A growing fetal brain needs the right level of thyroid hormones to properly develop. The right level also supports healthy bone growth and nerve development.
Severe iodine deficiency can have devastating effects on fetal brain development. The result can be lifelong developmental delays and intellectual disability. In fact, iodine deficiency is the most common cause of preventable intellectual disability worldwide.
The impact of mildly-to-moderately low iodine levels is less clear. But some evidence suggests these lower levels may still affect fetal brain development. Keep in mind that getting too much iodine can cause its own set of serious health issues as well. The key is to get the right amount, without overdoing it.
Are you at risk for being iodine deficient?
Iodine deficiency might seem like a problem of the past or something that mainly affects people outside the United States. But data shows that a substantial number of pregnant women in the United States are not getting enough iodine in their diets.
Changes in how food is grown and processed may be factors. Using less iodized salt in home-cooked meals may be another factor. Many people cook with sea salt or kosher salt, which are not iodized. People who do not eat dairy foods, eggs or fish might be particularly at risk.
To keep you and your baby supplied with enough iodine, you need 220 micrograms (mcg) a day while pregnant. During breastfeeding, you need 290 mcg of iodine a day.
Are you eating enough food that contains iodine?
Good food sources of iodine include:
- Fish and seafood. Fish naturally contains iodine. While you’re pregnant, eat 8 to 12 ounces of fish or shellfish a week. Choose seafood that’s lower in mercury. Examples include salmon, sardines, tilapia, shrimp, crab and cod. And avoid raw and undercooked seafood.
- Dairy foods. Milk, cheese and yogurt are good sources of iodine. Have three servings of nonfat or low-fat dairy every day. An example of a serving is one cup of milk. Milk substitutes, such as almond milk, usually have little to no iodine.
- Kelp, nori, wakame and kombu are good sources of iodine, although the amount varies greatly among the different types of seaweed. Some commercially available seaweeds have high levels of iodine in small portions. Read the product label and be mindful about how many servings you eat.
- Eggs. Eggs are a natural source of iodine, but it’s mostly found in the yolks. Choose whole eggs over egg whites for the iodine.
- Fortified bread and soy products. These foods have added iodine. The U.S. Food and Drug Administration (FDA) requires iodine to be listed on the label when it’s added to food. But iodine that’s found naturally in food does not have to be listed.
- Iodized table salt. If you use salt, choose salt containing iodine. Using iodized table salt usually gives you enough iodine. Generally, sea salt, Himalayan salt, fleur de sel and kosher salt have only trace amounts of iodine. Check the label to see if more iodine is added. Most fast and processed foods that contain salt use noniodized salt. The Dietary Guidelines for Americans recommends that pregnant and non-pregnant adults consume less than 2,300 milligrams (mg) of sodium a day — that’s about a teaspoon of table salt — and less if you have a medical reason to limit salt.
Here are some examples of iodine levels in food:
- Baked cod, three ounces — 158 mcg.
- Greek fat-free yogurt, six ounces — 87 mcg.
- Fat-free milk, one cup — 85 mcg.
- Iodized table salt, one-quarter teaspoon — 76 mcg.
- Hard-boiled egg, one — 26 mcg.
- Cheddar cheese, one ounce — 15 mcg.
- Cooked shrimp, three ounces — 13 mcg.
Do you need an iodine supplement?
Even if you eat a healthy diet, you can miss out on key nutrients. Taking a daily prenatal vitamin and mineral supplement can help fill any gaps. The American Academy of Pediatrics and the American Thyroid Association recommend that people who are planning to become pregnant and those who are pregnant or lactating consume a supplement with 150 mcg of iodine a day.
Some prenatal vitamins contain iodine, but not all do, so be sure to check the label. In dietary supplements, iodine may appear on the label as potassium iodide or sodium iodide.
Taking too much of some supplements can be harmful to you and your baby. This goes for iodine too. Talk with your healthcare professional about what vitamins or mineral supplements you need during your pregnancy.