Iodine is one of the essential minerals that has to come from your diet. It is important for the normal health of your thyroid gland.

According to one study findings published by Oxford University Press, iodine promote the production of thyroid hormones which majorly regulates metabolism. Iodine can be obtained from many foods where it occurs naturally. Additionally, iodine can also be sourced by consuming mineral foods like iodized salt.

The United States Department of Agriculture recommends that an adult person should consume 150 mcg of iodine per day as a recommended daily intake (RDI). Lactating and pregnant women may need to consume a higher value than that.

Iodine deficiency can lead to goitre and hypothyroidism characterized by fatigue, prostration, and weight gain.

This article will discuss some of the rich sources of iodine you can use to prevent deficiency.

1.      Iodized Salt

In many shops and supermarkets, iodized and unionized salt is sold. A naturally-occurring salt in the rocks has no iodine and if iodine is added, then it’s called iodized salt.

This practice dates way back to early 1920s since it began, specifically in the United States. According to one published study, it was stated categorically to reduce the incidences of goiter which is the swelling of the thyroid gland.

It is believed that in every quarter teaspoon of iodized salt, there is 71 mcg of iodine which is up to 47% of the daily recommended value. Additionally, salt is composed of sodium.

Interestingly, the intake of sodium in some countries like the United States has been reduced. This is because some health organizations and medical practitioners push for daily restrictions of sodium intake to minimize the likelihood of developing high blood pressure.

However, a study by the National Center for Biotechnology Information has shown that the chances of salt raising blood pressure are minimal, and only possible in individuals who are sensitive to salt, approximately to be about 25% of the world population.

2.      Cod

If you are looking for a fish with a mild flavor and delicate texture, then cod is for you. It has also been shown to be low in fat and calories. However, eating cod offers various minerals iodine included. The Icelandic Food Content Database says that any fish that has low-fat content, automatically have higher amounts of iodine.

For example, according to the National Institutes of Health, a cod that weighs 85 g (3 ounces) contains about 63-99 mcg of iodine. This is approximately 42-66% of the daily recommended intake of iodine.

It is worth noting that some factors can make the amount of iodine in cod vary including where it was caught, farm-raised or wild-caught.

3.      Seaweed

Apart from being a good and natural source of iodine, seaweed provides antioxidants, vitamins, and minerals. They are particularly low in calories.

According to Science Direct, the amount of iodine in seaweed may vary depending on the type of seaweed, how it has been prepared, and its region of growth. Best seaweed that can provide iodine includes nori, kombu kelp, and wakame.


This type of seaweed has a lower amount of iodine. It is a seaweed that is typically red. Nori is most commonly used in dishes like sushi rolls.

According to the National Center for Biotechnology Information, the content of iodine in nori is 16-43 mcg for every nori gram. This is about 11-29% of the daily recommended intake.

Kombu Kelp

Unlike nori, kombu kelp is a type of seaweed that is brown. In the market, it can be found dried or sold as a fine powder. This seaweed is commonly used in the preparation of dashi, a Japanese soup stock.

According to one study that examined iodine content in seaweed from different Asian countries, kombu kelp contains the highest amount of iodine than other seaweed.

In just 1 g of kombu kelp seaweed, there is about 2,982 mcg of iodine. This is approximately 2,000% of the daily recommended value which is far beyond the recommendations.


Wakame is also a good source of iodine. And just like kombu kelp, it is a brown seaweed. It used commonly to flavor miso soup.

The region where wakame grows normally makes the amount of iodine in it vary. For example, wakame from New Zealand and Australia have a lower amount of iodine compared to those from Asia.

However, the average iodine content in wakame is approximately 66 mcg which is 44% of the daily recommended value.

4.      Dairy

According to one research published by Oxford University Press, iodine is majorly sourced from dairy products. However, a few things can make the amount of iodine in dairy products vary including the iodine-based disinfectants used when milking and the amount of iodine contained in the cattle feed.

One study by the National Center for Biotechnology Information found that the average iodine content in most brands of milk products is 88 mcg per 1 cup although some brands may contain up to 168 mcg per cup. This is on average 52-112% of the daily recommended value of iodine.

The National Institutes of Health also claims that yogurt can be a good source of iodine among dairy sources. It says that in just one cup of yogurt, there is approximately 50% of the daily recommended intake of iodine.

5.      Shrimp

Shrimp is another excellent source of iodine and contains a high amount of protein but is packed with fewer calories. Other nutrients found in shrimp include phosphorus, vitamin B12, and selenium. About 35 mcg of iodine or 23% of the daily recommended intake is contained in 3 ounces of shrimp.

6.      Tuna

Apart from providing 17 mcg of iodine in 3 ounces, tuna is also a great source of protein, omega-3 fatty acids, iron, potassium, and B vitamins. Tuna contains lower amounts of iodine because it is fattier, but still, it remains to be a good source of it.


Your body needs iodine, especially for good thyroid health and function. Adequate consumption of iodine prevents the occurrence of goiter and hypothyroidism. Iodine can be sourced from seaweed, shrimp, and iodized salt among other mentioned sources above.

Latest posts by Marie Salbuvik (see all)

MS, Lund University, Sweden

Nutrition plays an important role in human life. Eating habits are one of the factors that affect our health. There is often a misconception among people that nutritionists force a very restrictive diet, but that is not true. In fact, I don't ban any products, but I point out dietary mistakes and help change them by giving tips and new recipes that I've tried myself. I advise my patients not to resist change and to be purposeful. Only with willpower and determination can a good result be achieved in any area of life, including changing eating habits. When I don't work, I love to go climbing. On a Friday evening, you are most likely to find me on my couch, cuddling with my dog and watching some Netflix.

Latest from Health