Iodine is a mineral that is essential for thyroid health. Although many types of seafood are rich in iodine, it is also found in eggs, dairy products, and some plant foods.
In addition to foods that contain naturally occurring iodine, people can also consume the mineral from fortified sources. Iodized salt is a common source.
Adequate iodine intake is important for a healthy thyroid. The thyroid is responsible for hormone regulation, metabolism, nervous system health, and more.
An iodine deficiency can be harmful to health. Deficiency is particularly dangerous for pregnant women.
Algae are full of naturally occurring iodine and contain around 232 micrograms (mcg) per serving. That is more than the recommended daily allowance of 150 mcg (RDI) for men and non-pregnant women.
The high iodine content of the algae is due to their ability to absorb concentrated iodine from the sea.
In general, seafood is a good source of iodine. However, cod is particularly rich in this essential mineral. One serving, or 3 ounces (ounces) of cod, contains approximately 158 mcg of iodine, which is the RDI for most adults.
Researchers have found that the body of water the fish lives in determines how much iodine cod contains. Cod from the Norwegian Sea, for example, had more iodine than Atlantic cod from the North Sea.
Halibut is another iodized fish. Research shows that Atlantic halibut contains around 21 µg iodine per serving. Although this is less than some other fish, it still provides a good amount of iodine.
Pollock is a member of the cod family who frequent the cold waters of the North Pacific. A serving of 120 grams (g) Alaska pollock provides about 67 mcg of iodine, which is about half the recommended daily allowance.
It also contains omega-3 fatty acids, phosphorus, selenium, and niacin, all of which contribute to immune and nervous system health.
Although crabs contain less iodine than other seafood, they still provide between 26 and 50 mcg in a 100 g serving.
In addition to being a great source of protein, crabs contain many other essential nutrients. It supplies selenium, B12 and zinc.
Scallops are a great source of iodine. They provide 135 mcg per serving, which is 90% of the RDI. They can also be beneficial for heart health and the central nervous system.
Often consumed as a calamari, squid contains around 65 mcg per serving. It’s also a good source of vitamin C, iron, and calcium, as well as omega-3 fatty acids.
Because tuna is a fatter fish than other varieties, it contains less iodine. At 17 mcg per 3 oz. Serving, it’s still a decent source of the mineral.
Tuna is an easily accessible, relatively affordable source of iodine that people can add to their diet more easily than other seafood.
Dairy products are also a good source of iodine. For example, one cup of low-fat cow’s milk contains an average of 85 mcg, which is more than half the RDI.
Nevertheless, a summary of a study from 2017 states that the actual iodine concentration in dairy products fluctuates widely. Factors influencing the total concentration are the milk yield, the season and whether the farmer immerses the teats with disinfectants containing iodine. This means that milk contains different amounts of iodine.
Certain types of cheese provide more iodine than others. On average, however, cheese contains 37.5 µg iodine per 100 g cheese.
Like other dairy products, yogurt is a good source of iodine. Just one cup of Greek plain yogurt provides up to 116 mcg of iodine.
Eggs – especially egg yolks – are a good source of iodine. A large egg normally contains 26 µg of iodine.
13. Iodized salt
Perhaps the most popular and abundant 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 inexpensive ways to prevent iodine deficiency. It is an especially good source of iodine for people on a plant-based diet, as plant-based foods are generally a poor source of iodine.
Iodine is an essential mineral for thyroid regulation. Without enough iodine, problems like weight gain, excessive fatigue, hair loss, dry skin, and cognitive impairment can occur.
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, such as sea salt and pink Himalayan salt, do not contain iodine.
According to the National Institutes of Health (NIH), the recommended daily dose for iodine is 150 µg in adult men and women. In the United States and Canada, only one teaspoon of iodized salt contains 250 mcg. This makes it relatively easy to meet the RDI.
It is important to note that the iodine recommendation for pregnant women is significantly higher at 220 mcg.
Because the risk of iodine deficiency increases dramatically during pregnancy, the American Thyroid Association recommends that people planning pregnancy take a prenatal vitamin containing at least 150 micrograms of iodine daily.
The most vulnerable to iodine deficiency are pregnant women and people who eat a low-sodium diet.
Failure to consume enough iodine each day can lead to long-term thyroid problems. Goiter, hypothyroidism, and pregnancy complications can all result from an iodine deficiency.
Learn more about the signs of iodine deficiency.
Consuming too much iodine can also be problematic. Diets high in iodine have been linked to thyroid inflammation and thyroid cancer. The damage from an iodine-rich diet occurs over time.
In addition, consuming a very large serving of iodine at once can cause short-term discomfort. A person may experience burning in the mouth and stomach, fever, nausea, and diarrhea.
Individuals taking iodine supplements should ensure that the product contains only the RDI or less to avoid consuming too much iodine.
Iodine is a mineral found in foods like seafood, dairy products, and seaweed. It is important for the regulation of thyroid function.
An iodine deficiency can cause serious long-term illnesses and side effects such as goiter and hyperthyroidism.
Pregnant women or those who are planning a pregnancy are particularly at risk. They should take a prenatal vitamin with iodine and include a variety of sources of iodine in their diet to ensure they do not develop deficiencies.
Usually, including just a teaspoon or less of iodized salt in a person’s diet provides sufficient iodine.