Read more to learn about 13 iodine-rich foods, how much iodine a person should consume, and the risks of consuming both too much and too little of this mineral.
Iodine is a mineral essential for thyroid health. Although many types of seafood are rich in iodine, it is also present in eggs, dairy products, and some plant foods.In addition to foods containing naturally occurring iodine, people can consume the mineral through fortified sources. Iodized salt is a common source.Consuming enough iodine is important for a healthy thyroid. The thyroid is responsible for hormone regulation, metabolism, nervous system health, and more.If a person is deficient in iodine it can harm their health. Adeficiency is particularly dangerous for pregnant women.
People looking to include more iodine in their diet can increase their intake of the following foods:
Seaweed is full of naturally occurring iodine and contains about 232 micrograms (mcg) per serving. That’s more than the 150 mcg recommended daily intake (RDI) for men and non-pregnant females.Seaweed’s high iodine content is thanks to its ability to absorb concentrated iodine from the ocean.
In general, seafood is a good source of iodine. However, cod is particularly high in this essential mineral. One serving, or 3 ounces (oz.) of cod contains roughly 158 mcg of iodine, meeting the RDI for most adults.
Researchers have found that the body of water the fish lives in determines how much iodine cod contains. For example, cod from the Norwegian Sea had more iodine than Atlantic cod from the North Sea.
Halibut is another seafood high in iodine. Research shows that Atlantic halibut contains about 21 mcg of iodine per serving. Although that is less than some other fish, it still provides a good amount of iodine.
Pollock is a member of the cod family that frequents the cold waters of the North Pacific. A 120 gram (g) serving of Alaskan pollock provides around 67 mcg of iodine, which is about half of the RDI.
It also contains omega-3 fatty acids, phosphorus, selenium, and niacin, which all contribute to immune and nervous system health.
Though crab contains less iodine than other seafood, it still provides 26–50 mcg in a 100-g serving.
Besides being a good source of protein, crab also contains many other essential nutrients. It provides selenium, B12, and zinc.
Scallops are a great source of iodine. They provide 135 mcg per serving, which is 90% of the RDI. They may also be beneficial for heart health and the central nervous system.
Squid, commonly consumed as calamari, contains about 65 mcg per serving. It is also a good source of Vitamin C, iron, and calcium, and omega-3 fatty acids.
Because tuna is a fattier fish than other varieties, it contains less iodine. However, at 17 mcg per 3 oz. serving, it is still a decent source of the mineral.
Tuna is an accessible, relatively affordable source of iodine that people may find easier to add to their diet than some other seafood.
Dairy products are also a good source of iodine. For example, one cup of nonfat cow’s milk on average contains 85 mcg, which is more than half the RDI.
Despite this, an abstract from a 2017 study states that the actual iodine concentration in milk products varies greatly. Factors influencing the total concentration include milk yield, season, and whether the farmer engages in teat-dipping with iodine-containing disinfectants. This means milk has a variable amount of iodine.
Certain types of cheese provide more iodine than others. However, on average, cheese contains 37.5 mcg of iodine per 100 g of cheese.
Like other dairy products, yogurt is a good source of iodine. Just one cup of plain Greek yogurt provides up to 116 mcg of iodine.
Eggs — specifically egg yolks — are a good source of iodine. Typically, one large egg contains 26 mcg of iodine.
13. Iodized salt
Perhaps the most popular and plentiful source of iodine in the average person’s diet is iodized salt. It takes just over half a teaspoon of iodized salt to get the RDI of iodine.
This is one of the most convenient and affordable ways to prevent iodine deficiency. It is a particularly good source of iodine for people who follow plant-based diets, as plant foods are generally a poor source of iodine.
Iodine is an essential mineral for thyroid regulation. Without sufficient iodine, people may experience issues like weight gain, excessive fatigue, hair loss, dry skin, and cognitive impairment.
The presence of the mineral in iodized salt makes some people think that sodium and iodine are synonymous. However, this is not true. Classic table salt is available with and without iodine, and many popular salts, like sea salt and pink Himalayan salt, do not contain iodine.
Iodine is an essential mineral you must get from your diet.
Interestingly, your thyroid gland needs it to produce thyroid hormones, which have many important responsibilities in your body
The recommended daily intake (RDI) of iodine is 150 mcg per day for most adults. For women who are pregnant or nursing, the requirements are higher
In fact, one-third of the population is at risk of deficiency, particularly those who live in areas that have only a small amount of iodine in the soil, including European countries (1Trusted Source).
Iodine deficiency can lead to swelling of the thyroid gland, known as goiter, and hypothyroidism, which can cause fatigue, muscle weakness and weight gain
This article explores 5 iodine-rich food sources that can help prevent a deficiency.
1. Seaweed :
Seaweed is a good source of antioxidants, vitamins and minerals. It’s also low in calories.
Seaweed is one of the best natural sources of iodine. However, the amount can vary significantly based on seaweed type, the region in which it grew and its preparation
Three popular seaweed varieties include kombu kelp, wakame and nori.
Kombu kelp is a brown seaweed sold dried or as a fine powder. It is often used to make a Japanese soup stock called dashi.
In a study that surveyed seaweed samples from various Asian countries for their iodine content, it was found that kombu kelp contains, by far, the highest amount of iodine compared to other species of seaweed
Kombu kelp can contain up to 2,984 mcg of iodine per seaweed sheet (1 gram). This provides almost 2,000% of the recommended daily intake (6Trusted Source).
Excess iodine consumption is well-tolerated in the majority of people but could result in thyroid dysfunction for those who are susceptible (7Trusted Source).
Wakame is another type of brown seaweed that is slightly sweet in flavor. It is commonly used to make miso soup.
The amount of iodine in wakame seaweed depends on where it is grown. Wakame from Asia has higher amounts of iodine than wakame from Australia and New Zealand
One study found that the average amount of iodine in wakame seaweed from various parts of the world was 66 mcg per gram, or 44% of the daily recommended intake
Nori is a type of red seaweed. Unlike brown seaweeds, it has a much lower content of iodine.
Nori is the type of seaweed that is commonly used in sushi rolls.
The iodine content in nori varies between 16–43 mcg per gram, or about 11–29% of the daily value
Dairy products are major sources of iodine, especially in American diets .The amount of iodine in milk and dairy differs greatly based on the iodine content in the cattle feed and the use of iodine-containing disinfectants during milking .A comprehensive study measured the iodine content in 18 different brands of milk sold in the Boston area. It found that all 18 brands had at least 88 mcg in 1 cup (8 ounces) of milk. Some brands even contained up to 168 mcg in one cup. Based on these results, 1 cup of milk can provide 59–112% of the recommended daily amount of iodine.Yogurt is also a good dairy source of iodine. One cup of plain yogurt provides approximately half of the daily recommended amountThe amount of iodine in cheese varies depending on the type.Cottage cheese is one of the best sources of iodine. One cup of cottage cheese provides 65 mcg, while one ounce of cheddar cheese provides about 12 mcg (15).
3. Iodized Salt:
Currently, both iodized and uniodized salt are sold in the United States.The addition of iodine in table salt began in the US in the early 1920s to help decrease the occurrence of goiters, or swelling of the thyroid gland .There is approximately 71 mcg of iodine in 1/4 teaspoon of iodized salt, which is 47% of the daily recommended intake. However, salt also contains sodium .In the last few decades, iodine intake has decreased in the US. This is likely due to the push of major health organizations to restrict daily sodium intake to prevent or treat high blood pressure.Nevertheless, salt only seems to raise blood pressure in salt-sensitive individuals, which is about 25% of the population
4. Shrimp :
Shrimp is a low-calorie, protein-rich seafood that is a very good source of iodine .Additionally, shrimp provides key nutrients such as vitamin B12, selenium and phosphorus .Shrimp and other seafood are good sources of iodine because they absorb some of the iodine that is naturally present in seawater .Three ounces of shrimp contain about 35 mcg of iodine, or 23% of the daily recommended intake
5. Tuna :
Tuna is also a low-calorie, high-protein, iodine-rich food. Furthermore, it is a good source of potassium, iron and B vitamins .Tuna is also a good source of omega-3 fatty acids, which may lower your risk of heart disease.Fish higher in fat offer lower amounts of iodine. Since tuna is a fattier fish, the amount of iodine found in tuna is lower than leaner fish varieties, such as cod .However, tuna is still a relatively good source of iodine, as three ounces provide 17 mcg, or about 11% of the recommended daily intake.Iodine is a chemical element essential for the production of thyroid hormones that regulate growth and metabolism. Diets deficient in iodine increase the risk of retarded brain development in children (cretinism), mental slowness, high cholesterol, lethargy, fatigue, depression, weight gain, and goiter: a swelling of the thyroid gland in the neck. Please note that both too much and too little iodine can cause hypothyroidism, for more information, see the section on hypothyroidism.
What foods are naturally high in iodine? Iodine is a component of almost every living plant and animal. No standard measurements of iodine in food exist because iodine concentrations vary across the world. In general, foods from the sea contain the most iodine, followed by animal foods, then plant foods. Of all foods, seaweed (like kelp), is the most well-known and reliable source of natural iodine. Egg and dairy products can also be good sources.
Foods That Are Rich in Iodine
Other than fortified salt, the concentrations of iodine in these foods can vary widely and this table should be taken as a rough guide.
16-2984μg (11% – 1989% DV)
99μg (66% DV)
Iodized Salt (Fortified)
77μg (51% DV)
Baked Potato with peel
60μg (40% DV)
1 cup (8 fluid ounces)
56μg (37% DV)
35μg (23% DV)
2 fish sticks
35μg (23% DV)
Turkey breast, baked
34μg (23% DV)
Navy beans, cooked
32μg (21% DV)
Tuna, canned in oil
3 ounces (1/2 can)
17μg (11% DV)
12μg (8% DV)
*A three-ounce serving of meat is about the size of a deck of cards.
Source: Linus Pauling Institute Article on IodineHow much iodine do I need? In your entire lifetime you will need less than a teaspoon of iodine to ensure good health, however, since it is dangerous to consume that much iodine at once, it is best to eat a little each day. You only need 150 micrograms (mcg, μg), or 20,000th of a teaspoon, to meet your daily requirement.
If iodine is in most plant and animal foods how can anyone be deficient? According to the World Health Organization, iodine deficiencies exist in 54 countries as of 2003. Map provided by the World Health Organization
There is no exact answer as to why iodine deficiencies occur, however, two theories exist:
People live in a part of the world with low levels of iodine in the soil or sea.
People eat high amounts of refined foods that lose their iodine content during refinement. Refined sugar, for example, contains no iodine.
Some countries, like the U.S., show a risk of excess iodine intakes which suggests overconsumption of foods fortified with iodine, such as iodized salt.
Is too much iodine good or bad? The tolerable upper intake for iodine is set at 1.1mg (1,100μg) for adults 19 years and older. Risks of high iodine intake include hypothyroidism, hyperthyroidism, and goiter. Really acute iodine poisoning can lead to burning of the mouth, throat, and stomach, fever, abdominal pain, nausea, vomiting, diarrhea, weak pulse, and even coma.(5) With that said, some studies suggest that intakes of iodine is up to 1.2mg (1,200μg) per day, and can confer health benefits, including cancer protection. Japanese people get most of their iodine from kelp seaweed. Please consult your doctor before taking high doses of iodine, do so with caution, and for limited time periods.
Is there Iodine in Breast Milk? New mothers should be aware that their breast milk contains iodine for their newborn children. The amount of iodine in breast milk will depend on the mother’s diet. A 1984 sample of women from the United States found the average concentration of iodine excreted in breast milk to be 114μg per day. This more than meets the adequate intake requirement of 110μg per day for infants ranging 0-6 months, but falls a little short of the 130μg per day requirement for infants ranging 7 months to 1 year. This should not necessarily be taken as a cause to eat a lot more iodine on the part of lactating women, as too much iodine can also be harmful.
I don’t eat salt, meat, or seaweed, where can I get iodine? Your options are to consider supplements, buy foods enriched in iodine, or ensure that the plant foods you consume come from parts of the world where the soil is rich in iodine.
I have hypothyroidism, can I consume iodine foods, or take iodine supplements? Worldwide, iodine deficiency is the number one cause of hypothyroidism, however, iodine deficiency rarely causes hypothyroidism in the U.S. The only time you should consume iodine is if the cause of your hypothyroidism is from iodine deficiency, and even then, only consume moderate amounts. Note: Too little or too much iodine can cause hypothyroidism. Other causes of hypothyroidism include Hashimoto’s disease, thyroiditis (inflammation of the thyroid), congenital hypothyroidism, surgical removal of part or all of the thyroid, radiation treatment of the thyroid, and some medications. If you have hypothyroidism from these causes, the U.S. National Institute of Health cautions that: “…taking iodine drops or eating foods containing large amounts of iodine – such as seaweed, dulse, or kelp – may cause or worsen hypothyroidism or hyperthyroidism.” As such, only consume iodine in moderate amounts to maintain a proper level.