Top 15 Iodine-Rich Foods You Should Add to Your Diet Today

Most people don't know much about this trace mineral other than that it is a salt additive — but it is one of the most essential in the human body. It is the only raw material needed for the manufacture of thyroid hormones, namely thyroxine (T4) and triiodothyronine (T3), which control metabolism, brain development, energy production, body temperature, heart rate and reproductive health. 

IDD is the primary preventable cause of mental disability and most prevalent cause of thyroid disease in the world. Despite decades long iodized salt programmes in India, an estimated 350 million people are still vulnerable to the effects of ID — especially pregnant women, children and populations living inland and, on the mountains, far from the urban centre. 

Knowing about the foods that are rich in iodine, and how much iodine is in each one, is key to a healthy thyroid, brain, hormones and overall metabolism. This iodine rich foods guide provides the top 15 foods high in iodine, an extensive iodine rich foods chart with iodine content per serving, best food source of iodine for vegetarians and non-vegetarians, instructions to use the foods for thyroid health and the top 10 iodine rich foods ranked by content. 

Why Iodine Matters: The Science of a Critical Mineral 

The thyroid is the only tissue in the body that can take up and concentrate the iodine in the bloodstream. It requires iodine to produce thyroid hormones (T4 and T3) and if there is insufficient iodine from food sources, this process does not occur. 

Consequences of Iodine Deficiency 

• Osteoporosis: Low bone mass, which can result in fractures, bone pain, and deformities. 
• Depression: An abnormal condition of the mind characterized by sadness, dismal mood, and a diminished ability to find pleasure or happiness. 
• Goitre: It is thyroid enlargement, due to the inadequate supply of iodine. 
• Cretenism: is an extreme form of mental retardation and low intelligence quotient in children of mothers who have low iodine content. 
• Miscarriage and stillbirth risk: Iodine deficiency during pregnancy is the most preventable cause of intellectual disability worldwide 
• Fibrocystic breast disease: Low iodine is related to painful breast tissue in women in the form of cysts. 
• Infertility: Due to the direct effect on reproduction hormone regulation, impaired fertility can occur. 

How Much Iodine Do You Need? 

Iodine Rich Foods Chart: Top 15 Sources with Iodine Content 

This chart of iodine rich foods is an ordering of the 15 healthiest sources of iodine-containing food, arranged in order of iodine content per serving. Please consult this chart every day as your reference for the amount of iodine in the food (including or excluding iodised salt). 

The iodine content of seaweeds is extremely variable, depending on species and origin. Kombu (kelp) may contain hazardous levels, and should not be eaten for a prolonged amount of time. Nori (used in sushi) is safer and more consistent. In the Indian market, low fat dairy (curd and milk), eggs, fish and iodised salt are the best and most readily available sources of iodine in food. 

Top 10 Iodine Rich Foods for Indian Diets 

The iodine rich foods chart above includes all foods, but many foods such as seaweed, oysters, and cod are not common foods in India. The top 10 iodine rich foods in Indian households that are easiest to come by and use: 

1. Iodised Salt

For Indians, iodised salt is the best and cheapest source of iodine in food. A ¼ teaspoon of iodised salt contains about 71 mcg of iodine – almost the daily adult dose. Make sure you are using actually iodised salt and not sea salt, rock salt/sendha namak or black salt (which has little or no iodine) as well as keeping it in the dark and cold to prevent iodine from evaporating. 

2. Low-Fat Curd

Low fat plain curd is a single best vegetarian food having iodine content in it which is around 75mcg per cup (240g) and is 50% of the daily requirement for Indian diets. Dairy iodine is derived from both the grass and feed eaten by cows, which contain naturally occurring iodine, and the use of sanitising solutions that contain iodine during milk processing. 

During curd making, some of the iodine is concentrated, so curd is slightly better than milk in terms of iodine content and can be used for the benefit of your thyroid. Further, the probiotic property of curd favors the gut health which is tightly associated with thyroid hormone conversion. 

3. Low-Fat Cow's Milk

Low fat Cow's milk contains around 56mcg of iodine (which is about 37% of the daily adult requirement) per cup (240ml). In particular, milk is a good food source throughout the life span and is consistently high in iodine. Full-fat milk has similar levels of iodine. 

Due to the difference in feed and metabolism, buffalo milk is low in iodine as compared to cow's milk which is widely consumed in India. Families who use buffalo milk as their main source of milk should know that the dairy iodine intake may not be as high as the person thinks, based on the information on dairy iodine from around the world. 

4. Eggs

One egg contains about 24 mcg of iodine, which is about 16% of the daily value. The iodine content of the hen's ration is in the egg yolk. Eggs are also an iodine rich food, uniquely so because they contain selenium, which is the mineral needed to convert inactive T4 thyroid hormone into its more active T3 form. Eggs provide 24–48 mcg of iodine daily (1–2 eggs a day), which is a significant amount of iodine, besides dairy and iodised salt. 

5. Tuna (Canned in Water)

Tuna in water is one of the least expensive and easiest-to-serve seafoods high in iodine, and the 17mcg iodine per 85g serving is about what is found in any canned tuna. It is easily accessible in the Indian supermarkets and contains extra selenium and omega-3 fatty acids, which work synergistically with iodine to boost thyroid health. 

6. Prawns and Shrimp

Prawns give about 35 mcg iodine in 85g serving which is 23% of daily requirement. Prawns are also a rich source of B12, zinc and selenium and are a staple food for coastal Indians so iodine is also naturally found in food. Grilled prawns or lightly curried prawns (without heavy cream-based gravies) are some of the most nutritionally efficient iodine rich foods for non-vegetarians in India. 

7. Rohu andCatla(Freshwater Fish)

Marine fish have more iodine concentration than freshwater fish; however, the catla and rohu, which are the most popular species of fish in Bengal, Bihar, Odisha and UP, are a good source of iodine. The amount of iodine in freshwater fish has been reported to vary widely depending on the iodine content of the water where they are raised, but typically ranges from 10–30 mcg of iodine per 100g serve. 

The combination of 2-3 times a week of consumption of rohu or catla, iodised salt and dairy foods is sufficient to provide the adult daily requirement of iodine for inland Indian who doesn't have access to marine fish. 

8. Navy Beans and Rajma

About 32 mcg of iodine are found in 1/2 cup (cooked) of navy beans (haricot beans), one of the better plant-based sources of iodine in the food. Rajma (kidney beans) is a little less, but still is a good source if taken regularly. Legumes grown on soils containing high levels of iodine are more likely to contain high iodine content than those grown on deficient inland soils — the iodine content of legumes is dependent on the soil iodine content. 

9. Nori Seaweed

The seaweed (nori) wrapped sushi is the most iodine rich food available, containing 16-43 mcg per sheet and within a relatively narrow range, compared to kelp (kombu), which can contain thousands of micrograms and is a potential source of iodine toxicity. Nori has become more readily available in Indian grocery stores and online. One or two nori sheets several times a week can make a significant contribution to iodine intake without risk of excess. 

Kombu (kelp) seaweed should NOT be used as a daily iodine rich food as it can contain 2,000–3,000 mcg of iodine per serving, well above the upper tolerable limit of 1,100 mcg/day and may lead to thyroid dysfunction. 

10. Strawberries and Cranberries

Interestingly, strawberries contain about 13 mcg of iodine per cup, which is one of the highest amounts of iodine in foods found in fruit. They are not a significant source of iodine by themselves, but will be important if combined with dairy products, eggs and iodised salt. Dried cranberries (available in India) are also a small but consistent source of iodine. 

Iodine Rich Food for Thyroid: What to Know 

The most clinically relevant use of the information in this nutrition is how foods high in iodine affect the thyroid. Here are some things you should know about eating for a healthy thyroid using iodine: 

For Hypothyroidism (Underactive Thyroid) 

Food is an effective way to replenish iodine to treat hypothyroidism caused by iodine deficiency. In India, however, Hashimoto's thyroiditis, an autoimmune disorder, is the most common cause of hypothyroidism, and it has a paradoxical effect of becoming worse as a result of excess iodine. Before consuming large amounts of iodine rich foods, please discuss this with your endocrinologist if you have Hashimoto's. 

Iodine Deficiency Hypothyroidism: Focus on eating iodine rich food for the thyroid such as iodised salt, dairy, and eggs throughout the day. These give regular, moderate iodine levels but are not likely to cause over-iodisation as can happen with seaweed. 

For Hyperthyroidism (Overactive Thyroid) 

Excess iodine in iodine rich foods can make hyperthyroidism worse (Graves' disease or toxic goitre). Before radioactive iodine therapy, your doctor might advise you to eat a low-iodine diet. Stay away from certain foods high in iodine such as seaweed, too much dairy, and iodine supplements, unless your endocrinologist says to eat them. 

During Pregnancy 

Pregnant women need 220 mcg of iodine each day, which is 47% higher than the iodine needs of non-pregnant adults. The developing foetus solely relies on the mother's iodine intake to make thyroid hormone, the hormone which is essential for brain growth. In 2023, UNICEF reported that IDP in pregnancy is the most prevalent preventable cause of intellectual disability worldwide. 

Combining the following foods at the correct dose is the best way to obtain iodine for thyroid and foetal brain development during pregnancy: iodised salt for all cooking; low fat dairy 2–3 servings daily and a prenatal supplement of 150-200 mcg of iodine (as potassium-iodide) daily. 

Selenium Connection 

The cofactor mineral for the conversion of T4 (inactive thyroid hormone, made from iodine) to T3 (active thyroid hormone) is Selenium. If selenium is not available, eating iodine-rich foods for thyroid health has only partial benefit, since the conversion step doesn't take place. Egg (yolk), fish (tuna, cod, sardines) and low-fat dairy products are the best sources of both iodine and selenium. Vegetarians can get complete thyroid support through pairing up foods rich in iodine with foods rich in selenium (1-2 Brazil nuts a day, or pumpkin seeds). 

Meeting Iodine Requirements on a Vegetarian Indian Diet 

The most difficult group to meet iodine requirements are vegetarians who form a major part of the population of India; the most iodine rich foods tend to be animal based (seafood, dairy, eggs). A practical, day by day plan to get 150mcg of iodine just from vegetable and vegetarian foods that contain iodine: 

A lacto-vegetarian Indian who eats 1 cup of curd and 1 glass of milk per day is likely to be getting sufficient iodine in his diet through the use of iodised salt in food. Vegans (no dairy, eggs), non-iodised salt (rock salt/sea salt/Himalayan pink salt), or plant based milk instead of dairy (may not be fortified with iodine in India). 

Goitrogens: Foods That Interfere with Iodine Absorption 

Some foods contain goitrogenic substances which reduce the uptake of iodine by the thyroid – this is important if iodine levels are already low. It is important to understand these but they do NOT mean all these foods will be eliminated – most goitrogenic activity is neutralised in cooking. 

Goitrogenic foods are a problem only if there is already a deficiency in iodine. If adequate iodine rich food is also consumed, broccoli, tofu or bajra roti does not harm the thyroid. These are healthy foods and they should NOT be eliminated, simply make sure the iodine content of your best food sources of iodine is sufficient. 

Signs You May Need More Iodine Rich Foods 

While many of the symptoms listed below are common to other disorders, some do suggest that there is a lack of iodine and that iodine-rich food intake is inadequate — but may be caused by other factors and should be confirmed by blood testing: 

1. Fatigue and low energy after good sleep 
2. Increase in weight that is not related to an increase in food consumption. 
3. Having low thyroid activity is often indicated by cold intolerance. 
4. Dry skin, flaky skin, and brittle nails. 
5. Hair thinning or hair loss especially around the eyebrows 
6. Trouble focusing or ongoing foggy thinking 
7. The swelling at the base of the neck, which is often seen (i.e. visible goitre) 
8. A decrease in the rate of the heartbeat (bradycardia) 
9. Constipation despite sufficient intake of fibre. 
10. Lack of strength, pain in muscles. 

If you have more than one symptom from this list, ask your doctor to do a blood test for TSH (thyroid stimulating hormone) and, if necessary, a urine test to measure the amount of iodine in your urine (the most accurate test for iodine status). 

Conclusion 

Iodine is a hidden mineral which is important for the thyroid to work, brain development and metabolism to run smoothly. The absence of this impacts a host of issues that have a delayed but hard to correct impact once they occur. For the good news for Indian families, it is so easy to meet an iodine requirement through consuming iodine rich foods, people can use iodised salt in cooking, eat low fat curd and milk daily, eat eggs several times in a week and eat fish 2-3 times in a week (for non-vegetarians). These four habits aim to help prevent the iodine deficiency that is easily avoidable in India with foods that are rich in iodine.