11 Iodine-Rich Foods You Wouldn’t Have Known About

Reviewed By Registered Dietitian Nutritionist Rachelle Caves, RDN, CNSC, CPT
11 Iodine-Rich Foods You Wouldn’t Have Known About January 22, 2019

Around 2 billion people in the world suffer from iodine deficiency (1). This deficiency, if not corrected, can lead to brain damage and irreversible mental retardation (2).

We are sure you don’t want to be one of them. Your body needs iodine to produce thyroid hormones. These hormones help regulate your metabolism and a host of other functions. Not getting enough of iodine can lead to severe consequences – and in adults, it can mean extreme mental fogginess and inability to think clearly. The best way to prevent this is to consume enough of foods rich in iodine.

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Why Is Iodine Important?

To understand this, we need to look at the functioning of the thyroid gland. This organ is located at the front of the neck, under the voice box. It plays an important role in the metabolism, growth, and development of the human body. The gland achieves this by releasing a steady amount of thyroid hormones (T3 and T4) into the blood.

The thyroid gland needs adequate iodine to function at its optimum levels. Deficiency of iodine can lead to an underactive thyroid, where the gland doesn’t produce enough hormones. This leads to undesirable effects. When the thyroid gland doesn’t receive enough iodine for prolonged periods, it becomes enlarged – in an attempt to compensate for the deficiency. This condition is known as goiter, characterized by an abnormally swollen neck.

One way to prevent any of this is ensuring you consume adequate amounts of iodine. Let’s look at the foods replete with this nutrient.

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What Are The Foods Rich In Iodine?

1. Seaweed

Seaweed Pinit


1 g of seaweed can contain anywhere between 16 to 2,984 mcg of iodine, which meets 11% to 1,989% of the RDA of the nutrient.*

Studies show that seaweed supplementation can boost iodine status, more so in iodine-deficient women (3). Post supplementation, the serum concentrations of thyroid hormones had increased. Seaweed is also palatable, and you can consume it as a whole food to fight iodine deficiency.

The Japanese happen to consume the most iodine (in the form of seaweed) in the world. According to studies, this could be the reason behind their high life expectancy and astonishingly lower incidences of some forms of cancer (4).

The different types of seaweed rich in iodine include Nori, Kombu Kelp, and Wakame.

2. Cod

3 ounces of cod contains 99 mcg of iodine, which meets 66% of the RDA of the nutrient.*

Cod is relatively low in fat and calories, but it is rich in iodine. But the amount of iodine in cod depends on the region where the fish is caught (5).

Cod liver is also known for its omega-3 content. Though it doesn’t contain as much omega-3 fatty acids as salmon or mackerel, studies show that it can also help in preventing cardiovascular disease (6).

3. Milk

1 cup of milk contains 56 mcg of iodine, which meets 37% of the RDA of the nutrient.*

Milk happens to be one of the major contributors of iodine to the American diet. As per a study conducted on 18 brands of milk marketed in the Boston area of the US, all the brands had a minimum of 88 mcg of iodine in 8 ounces of milk (7).

Iodine is also present in breast milk. Infants receive the iodine they need from their mothers. The nutrient aids the neurological development of the infant (8).

4. Iodized Salt

1.5 g of iodized salt contains 71 mcg of iodine, which meets 47% of the RDA of the nutrient.*

It was around 1920 that countries across the globe started iodizing their nation’s salt. This helped eliminate iodine deficiency to a large extent (there is still a long way to go, though). Today, 90% of the US population has access to iodized salt. Salt iodization is now considered a useful approach towards decreasing iodine deficiency in populations (9).

The upper limit of iodine is 1,100 mcg, and this is equivalent to about four teaspoons (23 grams) of iodized table salt. But, we don’t recommend you depend too much on salt for your daily dose of iodine.

5. Shrimp

3 ounces of shrimp contains 35 mcg of iodine, which meets 23% of the RDA of the nutrient.*

This popular seafood is rich in iodine too. But ensure you consume shrimp along with the shell as it is the shell that contains higher concentrations of iodine (10).

Shrimp also contains astaxanthin, an important antioxidant that gives it its characteristic red color. Astaxanthin scavenges free radicals and is more effective in doing so than beta-carotene, a potent carotenoid. Dietary supplementation with astaxanthin prevents cardiovascular disease (11).

6. Macaroni

Macaroni Pinit


1 cup of boiled and enriched macaroni contains 27 mcg of iodine, which meets 18% of the RDA of the nutrient.*

This dry pasta made of durum wheat can benefit you in other ways too. Macaroni contains another important nutrient – fiber (as it is prepared with whole wheat). Fiber helps lower bad cholesterol levels and regulates blood sugar.

Most brands of macaroni may also be enriched with iron, which boosts immunity and promotes the transportation of oxygen throughout the body.

7. Eggs

1 large egg contains 24 mcg of iodine, which meets 16% of the RDA of the nutrient.*

Eggs are one of the most nutritious foods on the planet. Egg consumption in healthy populations was associated with improved cardio-metabolic health (12). Regular intake of eggs was also found to increase the levels of good cholesterol (13).

Studies show that the majority of iodine in eggs is present in the yolk (14).

8. Tuna

1 canned tuna contains 17 mcg of iodine, which meets 11% of the RDA of the nutrient.*

Tuna is also a great source of omega-3 fatty acids, which can help prevent heart disease (15). The omega-3 fatty acids in tuna also boost brain health and may help prevent brain-related ailments like depression (16).

Fish low in fat are found to have the highest iodine content (5). But tuna is a fattier fish, so it contains comparatively less iodine than cod.

9. Corn

½ cup of corn contains 14 mcg of iodine, which meets 9% of the RDA of the nutrient.*

Corn can be enjoyed as a snack. It is quite nutritious too. In a study, corn turned out to be the most nutritious among other grains. It had the highest phenolic content. It also exhibited the highest antioxidant activity (17).

10. Prunes

5 dried prunes contain 13 mcg of iodine, which meets 9% of the RDA of the nutrient.*

Prunes also serve as a good source of energy, thanks to the simple sugars they contain. But these sugars don’t lead to blood sugar spikes, possibly because of their high fiber, fructose, and sorbitol content. They also contain certain phenolic compounds that also may delay glucose absorption (18).

These phenolic compounds in prunes were also found to prevent the oxidation of LDL cholesterol, thereby reducing the risk of chronic diseases.

11. Lima Beans

Lima Beans Pinit


½ cup of boiled Lima beans contains 8 mcg of iodine, which meets 5% of the RDA of the nutrient.*

Additionally, among legumes, lima beans contain the highest concentration of iron (19). The mineral boosts immunity and promotes blood production.

The fiber in lima beans keeps you full and can aid weight loss. This fiber may also help lower bad cholesterol levels, cutting down the risk of heart disease.

As you saw, excluding salt, all foods in the above list offer great benefits. This means, as you try to include more iodine in your diet, you also consume more of the other healthful nutrients. As a result, you will be healthier and free from any deficiency.

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Talking about that, what is iodine deficiency?

What Is Iodine Deficiency?

Iodine deficiency is rare – given that we use iodized salt in most of our food preparations. Individuals who don’t consume enough of foods rich in iodine can suffer from a deficiency. Pregnant women are at a higher risk as they need a higher dose of iodine.

The most important function of iodine in the human body is to promote optimal functioning of the thyroid gland. Iodine deficiency can cause hypothyroidism, a condition where a person’s thyroid glands don’t produce enough of the thyroid hormone. This hormone plays a role in brain development, growth, healing, and metabolism.

Iodine deficiency can lead to the following symptoms:

  • weakness
  • frequent fatigue
  • hair loss
  • dry skin
  • issues with learning or memory
  • complications during pregnancy
  • swollen neck (in extreme cases)

Consuming foods rich in iodine can prevent iodine deficiency. Here’s the required dosage*:

Birth to 6 months110 mcg
7 to 12 months130 mcg
1 to 3 years90 mcg
4 to 8 years90 mcg
9 to 13 years120 mcg
14 to 18 years150 mcg
19+ years150 mcg220 mcg290 mcg

Not meeting the daily requirement can lead to iodine deficiency, and the most common complication associated with it is hypothyroidism. Five out of every 100 people in the US suffer from hypothyroidism, though most cases are mild (20). Severe cases of the disease can lead to more pronounced symptoms of iodine deficiency. In such an instance, what can you do?

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A Note On Hypothyroidism

Hypothyroidism is a common ailment. But there are cases when the symptoms can turn severe. If you are one among them, don’t worry – because you can easily deal with hypothyroidism.

Reduce Stress. Stress can hurt your thyroid gland. Several studies have demonstrated that psychological and physiological stressors can induce immunologic changes (21). Stress affects one’s immune system – and this may contribute to autoimmune diseases, like hypothyroidism.

Get Proper Sleep. When you wake up, you need to feel refreshed and well-rested. Studies show that slow wave sleep (one of the deepest phases of sleep) is affected in people with hypothyroidism (22). Cutting back on sleep can further aggravate your condition. Lack of adequate sleep can also cause stress, which can also exacerbate the symptoms (23).

Get Moving. Exercise is important, and more so when you are diagnosed with hypothyroidism. Thyroid disease affects your metabolism. Regular exercise boosts your metabolism, helping you deal with the condition better. Studies also show that regular aerobic exercise can improve the levels of circulating thyroid hormones (24).

Eat Right. Include more of fruits and veggies (you might have to exclude goitrogenic veggies like broccoli or cabbage) and whole grains in your diet. Switch to a healthy diet if you haven’t done so already. Stay away from all forms of processed foods. Adopting a healthy diet ups your metabolism and helps you feel normal (25).

Take support from your family and friends too. This can help boost your mood and stave away sluggish or depressive symptoms. Include the iodine-rich foods in your diet, on top of your medication. Also, include foods rich in selenium (like Brazil nuts), as it is an important mineral that supports thyroid function (26).

Dealing with hypothyroidism is easy. With proper care, you can even be healthier than your peers!

Before we close, there is something else you must know. Iodine sure is important. But excess of it can be detrimental.

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What Are The Side Effects Of Consuming Excess Iodine?

  • Issues During Pregnancy And Breastfeeding

The intake of excess iodine can increase the risk of thyroid problems, more so during pregnancy and breastfeeding. Please keep your iodine dosage in check.

  • Aggravated Symptoms In People With Thyroid Disease

Excess iodine can lead to aggravated symptoms in people with thyroid disease – both hypothyroidism and hyperthyroidism. Please consult your doctor and don’t exceed the recommended dosage.

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Like any other nutrient, iodine has its role to play. Including the foods mentioned in this article in your diet not only cuts the risk of iodine deficiency but also offers other beneficial nutrients.

When are you heading to the nearest market? What foods are you going to pick? Tell us in the box below.

*Sourced from National Institutes of Health Office of Dietary Supplements

Disclaimer: “The content in this article is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician before starting a diet, exercise, or supplement regimen. This article is intended for educational purposes only.”


  1. The changing epidemiology of iodine deficiency”. Nature Reviews. Endocrinology, US National Library of Medicine.
  2. Health consequences of iodine deficiency”. Sultan Qaboos University Medical Journal, US National Library of Medicine.
  3. Low-level seaweed supplementation improves...”. The British Journal of Nutrition, US National Library of Medicine.
  4. Assessment of Japanese iodine intake based on...”. Thyroid Research, US National Library of Medicine.
  5. Iodine content of six fish species...”. Food & Nutrition Research, US National Library of Medicine.
  6. Seafood consumption and components of health”. Global Journal of Health and Science, US National Library of Medicine.
  7. Sources of dietary iodine...”. The Journal of Clinical Endocrinology and Metabolism, US National Library of Medicine.
  8. Iodine”. Centers for Disease Control and Prevention.
  9. History of US iodine fortification and...”. Nutrients, US National Library of Medicine.
  10. Bromine and iodine contents in raw and cooked...”. Journal of Agricultural and Food Chemistry, US National Library of Medicine.
  11. Astaxanthin: A potential therapeutic agent in...”. Marine Drugs, US National Library of Medicine.
  12. Egg consumption and human cardio-metabolic...”. Nutrients, US National Library of Medicine.
  13. Egg consumption and high-density-lipoprotein...”. Journal of Internal Medicine, US National Library of Medicine.
  14. Investigation of iodine bioavailability...”. European Food Research and Technology.
  15. Omega-3 fatty acids and cardiovascular disease…”. Current Treatment Options in Cardiovascular Medicine, US National Library of Medicine.
  16. Omega 3 fatty acids and the brain...”. Asia Pacific Journal of Clinical Nutrition, US National Library of Medicine.
  17. Antioxidant activity of grains”. Journal of Agricultural and Food Chemistry, US National Library of Medicine.
  18. Chemical composition and potential health effects…”. Critical Reviews in Food Science and Nutrition, US National Library of Medicine.
  19. The potential health benefits of legumes as a…”. The British Journal of Nutrition, US National Library of Medicine.
  20. Hypothyroidism (Underactive Thyroid)”. National Institutes of Diabetes and Digestive and Kidney Diseases.
  21. Stress and thyroid autoimmunity”. Thyroid: Official Journal of the American Thyroid Association, US National Library of Medicine.
  22. Thyroid gland and sleep”. Acta medica Austriaca, US National Library of Medicine.
  23. Interactions between sleep, stress, and...”. Sleep Science, US National Library of Medicine.
  24. Exercise intensity and its effects on...”. Neuro Endocrinology Letters, US National Library of Medicine.
  25. Healthy eating for a healthy thyroid”. Harvard Medical School.
  26. Selenium and the thyroid gland...”. Clinical Endocrinology, US National Library of Medicine.
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