13 Foods Rich in Iodine

Iodine is an essential trace mineral that helps the brain function properly; it helps your body properly metabolize the energy from food. In women, it ensures breast and ovarian health, as well. The thyroid hormones T3 and T4 contain the iodine molecule, and these hormones regulate your body’s metabolism.^[1]

Eating foods rich in iodine helps the thyroid to manage metabolism, detoxification, growth, and development. Although most people think of seaweed and seafood as foods that contain high levels of iodine, there are also many delicious plant-based foods high in iodine, from berries to potatoes.

The Recommended Daily Allowance (RDA) for iodine is provided below.^[2] However, given the many critical bodily functions iodine supports, many healthcare specialists believe that these recommendations are too low. Note that if you have a thyroid condition, whether hypothyroidism or hyperthyroidism, your healthcare provider’s specific recommendations for iodine intake may vary from these standard recommendations. In some cases, taking iodine can worsen your condition so be sure to check with your provider.

Life Stage	Serving Size
Infants birth-6 months	110 mcg (if not breastfeeding)
Infants 7-12 months	130 mcg (if not breastfeeding)
1-8 years	90 mcg (if not breastfeeding)
9-13 years	120 mcg
Teens >14 and adults	150 mcg
Pregnant women	220 mcg
Breastfeeding women	290 mcg

Iodine-Rich Foods

Sea vegetables and seafood are naturally high in iodine. The fruits and vegetables listed below can vary in iodine levels depending on the soil in which they were grown. Vegetables and fruit grown near the coasts will have higher iodine levels, whereas produce grown inland will have lower levels if any. So while these values give an estimate, iodine content will vary.

The most reliable sources of natural iodine are sea vegetables and seafood. Other common sources are typically high in iodine because they were grown in iodine-rich soil, fed fish in their diet (i.e., chickens and eggs), or fortified (i.e., grains). While milk is a natural source of iodine, its levels were substantially higher in the past because dairy farmers use antiseptic iodine solution to clean equipment as well as the cow teats.^[3] This practice has declined, and as a result, dairy is not as reliable a source of iodine as it used to be.^[2]

Eggs contain iodine because commercially raised chickens are fed fish in their diets.^[4] Bread typically contains iodine because bread conditioners containing potassium iodate or calcium iodate are added; grains are not generally good sources of iodine.^[4]

Below are the top ten sources of iodine for your diet.

1. Sea Vegetables

The ocean is the source of most iodine-rich foods, including seafood and seaweed (sometimes called sea vegetables). The most common use of seaweed in the U.S. is, of course, as a sushi wrapper, but they are common in macrobiotic dishes and in Japanese cuisine. Seaweeds tend to store heavy metals, so be cautious in consuming too much. They can be dried, pickled, or used as a condiment. I recommend sprinkling these into soups or salads: since they are high in salt, flaked seaweed easily substitutes as a tasty alternative to salt. Some common seaweeds used for cooking and snacking are below.

Nori

You probably know nori as the dark greenish-black seaweed used as a sushi roll wrapper. It comes in sheets and is one of the lower-iodine seaweeds. One sheet provides 16 micrograms (mcg) of iodine.^[5] It is a red algae of the genus Porphyra.

Arame Kelp

Kelps have relatively high iodine content, but there are several varieties. Arame (Eisenia bicyclis) has a mild, semi-sweet flavor and comes in dark brown strands. One tablespoon of Arame contains about 730 mcg of iodine

Kombu Kelp

Kombu kelp (Saccharina japonica) is widely cultivated on floating oceanic ropes off of Japan and Korea. It's one of the most popular sea vegetables in Asia. A one-inch piece of kombu contains about 1,450 mcg of iodine

Wakame Kelp

Wakame kelp (Undaria pinnatifida) has a sweet but strong flavor. Japanese sea farmers have cultivated wakame for centuries. It was popular during the macrobiotic movement and is used in traditional Chinese medicine for various health issues. One tablespoon of Wakame contains about 80/mcg of iodine.

Hiziki

In the scientific genus Sargassum, one tablespoon of hiziki — sometimes called hijiki — not only contains about 780 mcg of iodine, but it also has high amounts of calcium, iron, and magnesium. However, studies have also found it may contain toxic amounts of inorganic arsenic at 67 to 96 mg/kg (other species tested had less than 0.3mg/kg),^{[6, 7]} and several countries have warned against consuming it.^[8]

2. Cape Cod Cranberries

This antioxidant-rich fruit is another great source of iodine. According to one analysis from 1928, cranberries had 26 to 35 parts per billion (ppb) of iodine (in comparison, potatoes had 11 to 18 ppb, and cabbage and lettuce 6 to 20 ppb, cored apples had 1 ppb).^[9] These cranberries grow close to the ocean, and the varieties closest to the sea had higher iodine. One website reports that four ounces of cranberries (approximately three-quarters cup) contain approximately 400 mcg of iodine. I recommend buying fresh organic berries or juice.^[10] If you buy processed cranberry juice, be aware of how much sugar it contains.

3. Raw Milk

Most dairy contains iodine, especially raw milk since it is the raw, pre-processed state before making other products like cheese, yogurt, or ice cream. One serving is 250 mL or one cup, and that contains anywhere from 56 to 110 mcg iodine per serving.^{[2, 11]} If you do partake in dairy, raw unpasteurized milk provides a healthier option, and contains 20 amino acids, calcium, and beneficial probiotic bacteria. Pasteurization may reduce the amount of available iodine in dairy, although it's not totally clear.^[12]

4. Yogurt

Since dairy is often high in iodine, dairy yogurt is also an excellent iodine food (this does not hold for non-dairy yogurts). Yogurt also contains beneficial probiotic bacteria. One serving holds more than half of your daily needs of iodine: one cup contains approximately 90 mcg of iodine. Other than yogurt, here is a list of probiotic foods you should consider incorporating into your diet for added health benefits.

5. Raw, Organic Cheese

Raw, unpasteurized cheese is relatively high in iodine, along with essential B vitamins, calcium, and protein. One ounce of raw cheddar cheese contains around 10 to 15 mcg of iodine.^[2] Goat's milk cheese is easier on the digestive system and contains slightly higher levels of calcium and protein.

Dairy, whether raw or pasteurized, may not be the best choice for some people, especially those with sensitive digestive systems or individuals adhering to a vegan or vegetarian diet.

6. Organic Lima Beans

Lima beans, also called butter beans, have moderate amounts of iodine at 8 mcg per serving.^[2] But lima beans aren't just an iodine food, they are also incredibly high in cholesterol-reducing fiber, folate, and other B vitamins.

7. Organic Potatoes

The common potato is an easy addition to most meals and, since many have been biofortified with iodine, they are one of the richest sources of this mineral. Even after cooking, studies indicate that potato dishes can provide between 33.3 percent to 52.7 percent of your daily recommended intake.^[13] Be sure to get organic only as potatoes tend to suck up pesticides very easily!

8. Ocean Seafood

Although it’s not appropriate if you subscribe to a plant-based diet, seafood is a good source of iodine. If you do eat seafood, check out sustainable online guides to ensure you select varieties that are low in ocean contaminants and are harvested in an environmentally-sensitive way. Here are some popular options:

• Cod. Three ounces of baked cod contains 99 mcg per serving.
• Snapper. One fillet of steamed snapper (125 grams) contains 50 mcg of iodine.^[14]
• Canned Salmon. One small tin of canned salmon contains 63 mcg of iodine.
• Canned Albacore Tuna. Three ounces of canned tuna fish (one small tin) in oil contains 17 mcg of iodine.

9. Eggs

Interestingly, eggs contain iodine because poultry farmers feed chickens fishmeal. This also means the iodine content of eggs varies. On average, a large egg contains about 24 mcg of iodine. All of the iodine is contained within the yolk.^[15] If possible, choosing organic, pasture-raised eggs is the best option for your health.

10. Prunes

A serving of five prunes or dried plums contains 13 mcg of iodine. Of course, prunes and prune juice are well known for stimulating digestion. They’re also high in potassium, iron, and retinol (vitamin A).

11. Creamed Corn

According to the U.S. National Institutes of Health, just a half-cup of canned creamed corn contains 14 mcg of iodine. As with other vegetables, this level may vary depending on where the corn was grown. Additionally, be aware that most corn is genetically modified. If you select organic varieties of corn and corn products, they will be GMO-free.

12. Himalayan Pink Salt

The iodine content of Himalayan pink rock salt varies because it is a natural, unprocessed product that comes from — where else — the Himalayan foothills. Some salt may have more and some may have less than iodized table salt. However, Himalayan crystal salt is all-natural and a better option to pep up your food.

13. Chocolate

Chocolate lovers rejoice, chocolate is a high-iodine food! This is primarily because of the milk, but also because cacao typically is grown in coastal regions. One study found chocolate had 70 ppb of iodine.^[4]

Iodine Supplements

If you're not a fan of the iodine foods listed above, you can take iodine supplementally. There are many different types of iodine supplements on the market, so knowing the differences between each is vital. I recommend a nano-colloidal nascent iodine supplement which the body can quickly absorb and use effectively.

Research has shown that a lack of dietary iodine may lead to enlargement of the thyroid gland,^[16] lethargy,^[17] fatigue,^[18] weakness of the immune system,^[19] slow metabolism,^[20] autism,^[21] weight gain,^[22] and possibly even mental states such as anxiety and depression.^[23] Ensuring your body has adequate iodine to avoid a deficiency and to remain in a healthy state can help your energy, metabolism, and more.

Points to Remember

The most reliable sources of natural iodine are sea vegetables (seaweed) and marine fish and shellfish, but they’re also prone to contamination from pollutants. Dairy products have long had iodine because dairy farmers use iodophor cleaning solutions, but this practice is declining. Eggs have iodine because poultry farmers feed chickens fish meal (and fish contains iodine). Of course, if you follow a plant-based diet, these are not appropriate solutions for iodine.

Many lists of iodine foods include bread, but this is only due to the use of iodine-containing bread conditioners. Grains themselves do not contain significant iodine. Vegetables and fruits that are listed as having iodine must be grown in iodine-rich soils, so their values may be inconsistent in practice.

While the best way to get iodine is from a balanced diet, but if you eat a plant-based diet or if you find yourself unable to eat enough iodine-rich foods, a nascent iodine supplement can ensure a regular, steady intake. Nascent iodine offers the best bioavailability in a supplement.

References (23)

1. Nussey S, Whitehead S, eds. "The thyroid gland." In: Endocrinology: An Integrated Approach Edi. Oxford, UK: BIOS Scientific Publishers; 2001.
2. National Institute of Health. "Iodine." Office of Dietary Supplements. Fact Sheet for Health Professionals.
3. Vance KA, et al. "Dairy’s Inadvertent Contribution to Sustaining Optimal Iodine Nutrition." In: Watson RR, et al, eds. Nutrients in Dairy and Their Implications for Health and Disease. 1st Ed. San Diego, CA:Academic Press. 2017:139-147.
4. Fordyce FM. "Database of the Iodine Content of Food and Diets Populated with Data From Published Literature." British Geological Survey, Natural Environment Research Council. 2003.
5. Wilde M. "How much Iodine is in Seaweed?." Napiers Herbalists Limited. Jan 2015. Accessed 23 Jul. 2018.
6. Rose M, et al. "Arsenic in seaweed—Forms, concentration and dietary exposure." Food Chem Toxicol. 2007;45(7),1263-1267.
7. Nakamura Y. "Cancer risk to Japanese population from the consumption of inorganic arsenic in cooked hijiki." J Agric Food Chem. 2008 Apr 9;56(7),2536-40.
8. Curran L. "Food Standards Agency Issues Seaweed Warning." Food Safety News. 6 Aug. 2010.
9. Morse FW. "The iodine content of cranberries." J Biol Chem. 1928;79,409-411.
10. "Foods high in iodine." Hyperthyroidism & Hypothyroidism. 2017. Accessed 24 Jul. 2018.
11. Travnicke J, et al. "Iodine content in raw milk." Veterinarni Medicina, 2006;51(9),448-453.
12. "The effect of heat treatment on the nutritional value of milk and milk products." The Consumer Education Project of Milk, South Africa. Sep. 2016. Accessed 24 Jul. 2018.
13. Cerretani L, et al. "Evaluation of iodine content and stability in recipes prepared with biofortified potatoes." 2014;65(7),797-802.
14. "Iodine in food and iodine requirements." June 2016. Australia and New Zealand Food Standards. Accessed 24 Jul. 2018.
15. "Low-Iodine Diet." Jan 2014. Accessed 24 Jul. 2018.
16. Medline Plus. "Goiter - simple." U.S. National Library of Medicine. Updated 9 July 2018. Accessed 24 Jul. 2018.
17. Gastaldi R, et al. "Iodine deficiency and its consequences for cognitive and psychomotor development of children." Ital J Pediatr. 2014;40(Suppl 1):A15.
18. Zimmermann MB, Boelaert K. "Iodine deficiency and thyroid disorders." Lancet Diabetes Endocrinol. 2015;3(4),286-95.
19. Ahad F, Ganie SA. "Iodine, Iodine metabolism and Iodine deficiency disorders revisited." Indian J Endocrinol Metab. 2010;14(1),13-17.
20. "Iodine in diet." Medline Plus. U.S. National Library of Medicine. Updated 9 July 2018. Accessed 24 Jul. 2018.
21. Hamza RT, et al. "Iodine deficiency in Egyptian autistic children and their mothers: relation to disease severity." Arch Med Res. 2013;44(7),555-61.
22. "Hashimoto's Disease." National Institute of Diabetes and Digestive and Kidney Diseases. Sep 2017 Accessed 24 Jul. 2018.
23. Melish JS. "Thyroid Disease." In: Walker HK, et al, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd ed. Boston, MA: Butterworths; 1990.

†Results may vary. Information and statements made are for education purposes and are not intended to replace the advice of your doctor. If you have a severe medical condition or health concern, see your physician.