Recently, I have started to use sea salt a lot more in my cooking. But as I replaced the classic iodized table salt with things like Himalayan pink sea salt, I began to wonder, were my iodine levels being affected by this change? Were there foods high in iodine I could be eating more of?

Iodine is quite essential for your health, so it is important that you make sure you are getting enough in your diet each day. If you are wondering how much iodine you need, the guidelines below can help you out. You’ll also learn why pregnant women need a lot more iodine than usual.

Why do you need iodine?

The major use of iodine in the body is in making thyroid hormones. The thyroid is in charge of controlling metabolism and impacts many important functions in the body. If the thyroid gland doesn’t have enough iodine to make the thyroid hormones, it can become enlarged (goiter) and thyroid disorders can occur.

Iodine is also extremely important for the proper growth and development of a baby, and so it is especially important during pregnancy.

How much iodine you need daily

Normally, people 14 and older are recommended to consume 150 μg of iodine per day, while children one to eight years old should consume 90 μg per day, and nine to 13 year olds should consume 120 μg per day.[1]

To get enough, you’ll want to consume iodine-rich foods.

Foods high in iodine

Iodine is added to salt, making iodized salt a major source of iodine in many diets. There is approximately 71 μg iodine in 1/4 teaspoon of iodized salt.[1] But if you don’t use iodized salt, you’ll want to be extra careful to eat other iodine-rich foods.

Iodine is found naturally in many foods:

• Seaweed (for example nori, kombu, and wakame)
• Seafood
• Dairy
• Eggs
• Grains

For example, a serving of cod contains about 99 μg, a serving of low-fat plain yogurt contains about 75 μg, and one egg contains about 24 μg. A sheet of seaweed can have anywhere from 16 to thousands of μg iodine.[1]

Some people may not be getting enough iodine daily and can be at increased risk of iodine deficiency. These include people who don’t eat iodized salt and pregnant women.

Iodine requirement increases by 50% during pregnancy

Iodine is a vital part of making thyroid hormones, which are crucial for proper brain and neurological development during gestation. These iodine benefits are particularly important during early pregnancy (the first trimester).[2-4] Studies show that children of iodine-deficient mothers tend to show lower cognitive function.

Because of this, the iodine requirement for a woman increases by at least 50% during pregnancy.[2] Pregnant women are advised to consume at least 250 μg per day, compared to the normal 150 μg per day.[5]

Iodine deficiency during pregnancy can lead to cognitive impairments in the child

It is well established that moderate to severe iodine deficiency during pregnancy can impair neurological development of the fetus. Severe deficiency can lead to extreme developmental problems like cretinism, a condition of severely delayed and impaired physical and mental growth.[2,3]

What is less known is that mild iodine deficiency during pregnancy can be very dangerous, too.[1] A large study on over 1000 pregnant women was published in the journal Lancet in 2013. Children of women who had urinary levels of iodine less than 150 μg/g (considered mildly deficient) were more likely to have scores in the lowest quartile for verbal IQ, reading accuracy, and reading comprehension compared to those with levels above 150 μg/g. The farther iodine levels dropped below 150 μg/g, the worse the scores became.[3]

Another study used a nine-year follow up period after pregnancy to assess academic performance in children. They found that children of mothers with iodine levels less than 150 μg/g showed reductions in scores of 10% in spelling, 7.6% in grammar, and 5.7% in English literacy.[6] These results of these studies show that moderate deficiency can result in less severe, but still significant, impacts on brain development and cognition.

Getting enough iodine during pregnancy

Unfortunately, many women don’t get enough iodine during pregnancy.[7] A study published in August 2015 on Swedish women found that the median iodine level of the 459 women was only 98 μg/g, far below the recommended 150 to 250 μg/g.[2]

Pregnant and lactating women should consume 250 μg of iodine per day. Anywhere between 250 μg to 500 μg is considered more than adequate, and over 500 μg is excessive. The minimum daily requirement is 150 μg per day.[5]

Women are recommended to use iodized salt, and to take a supplement that contains 150 μg iodine while pregnant.[7] Talk with your doctor about how to safely get enough iodine into your daily diet to be sure you are helping your baby form a healthy brain.

For more tips on having a healthy pregnancy, read these articles:

• Yoga Found Effective for Pregnancy Anxiety
• The Benefits of Working Out While Pregnant: How to Prevent Gestational Diabetes and Weight Gain
• Natural Tips for Recovering from C-Section Surgery

Share your experience

How do you make sure you get enough iodine daily? Do you use iodized salt? Have you ever been iodine deficient? Please share your thoughts in the comments section below.

[1] National Institutes of Health Fact Sheet: Iodine.

[2] Acta Obstet Gynecol Scand. 2015 Aug 20. [Epub ahead of print]

[3] Lancet. 2013 Jul 27;382(9889):331-7.

[4] J Trace Elem Med Biol. 2013 Jul;27(3):174-83.

[5] Paediatr Perinat Epidemiol. 2012 Jul;26 Suppl 1:108-17.

[6] J Clin Endocrinol Metab. 2013 May;98(5):1954-62.

[7] J Clin Endocrinol Metab. 2008 Jul; 93(7): 2466–2468.

Originally published in 2015, this post has been updated.