10 Best Iodine-Rich Foods to Support Your Thyroid Health

Iodine is a crucial trace mineral that plays a vital role in maintaining optimal health, particularly for thyroid function. Despite its importance, iodine deficiency remains a significant concern worldwide, affecting approximately one-third of the global population. Understanding which foods are rich in iodine can help you meet your daily requirements and support your overall well-being.

The thyroid gland relies on iodine to produce essential hormones that regulate metabolism, growth, and development. Adults need approximately 150 micrograms (mcg) of iodine daily, while pregnant and breastfeeding women require higher amounts—220 mcg and 290 mcg respectively.

Insufficient iodine intake can lead to serious health complications, including goiter (thyroid gland enlargement), hypothyroidism, fatigue, weight gain, and developmental issues in children. This comprehensive guide explores the best iodine-rich foods to help you maintain adequate levels of this essential mineral.

Why Iodine Is Essential for Your Health

Before diving into specific foods, it’s important to understand why iodine is so crucial. Your thyroid gland uses iodine to produce thyroid hormones—thyroxine (T4) and triiodothyronine (T3)—which influence nearly every cell in your body. These hormones regulate your metabolic rate, heart function, digestive processes, muscle control, brain development, and bone maintenance.

Iodine deficiency can impair these functions, leading to symptoms such as persistent fatigue, unexpected weight gain, difficulty concentrating, dry skin, hair loss, and sensitivity to cold temperatures. For pregnant women, adequate iodine is particularly critical for fetal brain development and preventing intellectual disabilities in children.

1. Seaweed and Sea Vegetables

Seaweed stands as nature’s most concentrated source of iodine, with content varying dramatically depending on the variety, growing location, and preparation method. These marine vegetables absorb iodine naturally from seawater, making them nutritional powerhouses.

Kelp (Kombu)

Kelp, particularly kombu kelp, contains exceptionally high iodine levels. A single gram can provide up to 2,984 mcg of iodine—nearly 2,000% of the daily requirement. This brown seaweed is commonly used in Japanese cooking, especially for making dashi broth. However, due to its extremely high iodine content, kelp should be consumed in moderation to avoid excessive intake.

Wakame

Wakame, another brown seaweed with a subtly sweet taste, is frequently used in miso soup and seaweed salads. It typically contains about 66 mcg of iodine per gram, providing approximately 44% of your daily needs. The iodine content varies based on where it’s harvested, with Asian-sourced wakame generally containing more iodine than varieties from other regions.

Nori

Nori, the red seaweed used in sushi rolls, contains less iodine than brown seaweeds but remains a valuable source. Each gram provides 16-43 mcg of iodine, or about 11-29% of the daily value. Nori sheets are convenient and versatile, making them easy to incorporate into various dishes beyond sushi.

2. Fish and Seafood

Ocean fish and seafood naturally accumulate iodine from seawater, making them excellent dietary sources. The iodine content varies based on species, whether the fish is wild-caught or farm-raised, and the water’s iodine concentration.

Cod

Cod, a mild-flavored white fish, is particularly rich in iodine. Three ounces (85 grams) of cod provides approximately 63-99 mcg of iodine, meeting 42-66% of your daily requirement. As a lean fish with low fat content, cod concentrates more iodine than fattier fish species. It’s also an excellent source of protein, vitamin B12, and selenium while being relatively low in calories.

Tuna

While tuna contains less iodine than leaner fish due to its higher fat content, it remains a worthwhile source. Three ounces of tuna provide about 17 mcg of iodine, or 11% of the daily value. Beyond iodine, tuna offers high-quality protein, omega-3 fatty acids that support heart health, and essential nutrients like potassium, iron, and B vitamins.

Shrimp

Shrimp is a low-calorie, protein-rich shellfish that delivers a solid dose of iodine. A three-ounce serving contains approximately 35 mcg of iodine, providing 23% of your daily requirement. Shrimp also supplies vitamin B12, selenium, and phosphorus, making it a nutritionally dense food choice.

3. Dairy Products

Dairy products have become major iodine sources in Western diets, particularly in the United States. The iodine content in dairy varies based on several factors, including the iodine levels in cattle feed and the use of iodine-containing sanitizing solutions during milking processes.

Milk

One cup of milk can provide anywhere from 59-112% of your daily iodine requirement, with amounts typically ranging from 88-168 mcg per eight-ounce serving. This variation depends on the brand, processing methods, and dairy farming practices. Both whole and low-fat milk contain similar iodine levels.

Yogurt

Plain yogurt is another excellent dairy source, with one cup typically providing about 75 mcg of iodine, or roughly half of the daily recommended amount. Greek yogurt and regular yogurt contain comparable amounts, though exact levels vary by brand and production methods.

Cheese

The iodine content in cheese varies significantly by type. Cottage cheese ranks among the best sources, with one cup delivering approximately 65 mcg of iodine. Hard cheeses like cheddar contain less, with one ounce providing about 12 mcg. Soft cheeses typically fall somewhere in between.

4. Iodized Salt

The introduction of iodized salt in the 1920s marked a major public health achievement in combating iodine deficiency and preventing goiter. This fortified salt remains one of the most accessible and affordable sources of iodine.

Just one-quarter teaspoon of iodized salt contains approximately 71 mcg of iodine, meeting 47% of the daily requirement. However, it’s important to balance iodine intake with sodium consumption. The American Heart Association recommends limiting sodium to 2,300 mg daily, and ideally no more than 1,500 mg for most adults.

Not all salt is iodized—sea salt, Himalayan pink salt, and kosher salt typically don’t contain added iodine unless specifically labeled as such. If you’re restricting salt intake for blood pressure management or other health reasons, ensure you’re getting iodine from other dietary sources.

5. Eggs

Eggs are convenient, affordable, and nutritious sources of iodine. One large egg contains approximately 24 mcg of iodine, providing 16% of the daily value. Importantly, the iodine is concentrated in the yolk, not the white.

The iodine content in eggs depends on the iodine levels in chicken feed, which can vary between farms and regions. Beyond iodine, eggs provide high-quality protein, healthy fats, vitamin D, B vitamins, selenium, and choline—all essential nutrients that support various bodily functions.

6. Prunes (Dried Plums)

For those following vegetarian or vegan diets, prunes offer a plant-based iodine source. Five dried prunes contain about 13 mcg of iodine, meeting 9% of the daily requirement.

Prunes are well-known for supporting digestive health due to their high fiber content and natural sorbitol. They’re also rich in vitamin K, vitamin A, potassium, iron, and antioxidants. Research suggests that regular prune consumption may support bone health, improve heart health markers, and aid in weight management by promoting satiety.

7. Lima Beans

Lima beans, also known as butter beans, provide a vegetarian-friendly iodine source. One cup of cooked lima beans contains approximately 16 mcg of iodine, or 10% of the daily value.

However, the iodine content in beans and other plant foods can vary considerably based on soil iodine levels, irrigation water composition, and fertilizer use. Despite this variability, lima beans remain valuable for their fiber, magnesium, folate, and plant-based protein content, all of which support cardiovascular health.

8. Cranberries

Cranberries are among the few fruits that contain notable amounts of iodine. Four ounces of cranberries provide approximately 400 mcg of iodine, though this can vary based on where they’re grown. Fresh cranberries are generally better sources than processed cranberry products.

Beyond iodine, cranberries are packed with antioxidants, vitamin C, and compounds that may help prevent urinary tract infections. They can be enjoyed fresh, dried (watch for added sugars), or as unsweetened cranberry juice.

9. Navy Beans

Navy beans are another legume that can contribute to your iodine intake, though like lima beans, their content varies based on growing conditions. Half a cup of navy beans provides approximately 32 mcg of iodine, or about 21% of the daily value.

These small white beans are excellent sources of plant-based protein, fiber, folate, manganese, and thiamine. They support digestive health, help stabilize blood sugar levels, and may reduce cholesterol levels when consumed regularly.

10. Turkey Breast

Turkey breast is a lean protein source that also provides iodine. Three ounces of baked turkey breast contain approximately 34 mcg of iodine, meeting about 23% of the daily requirement.

Turkey is also rich in B vitamins, selenium, phosphorus, and zinc. It’s a versatile meat that can be included in various dishes, from sandwiches to salads to main courses. Choosing organic or pasture-raised turkey may provide additional nutritional benefits.

How Much Iodine Do You Need?

The recommended daily intake of iodine varies by age and life stage:

• Infants 0-6 months: 110 mcg
• Infants 7-12 months: 130 mcg
• Children 1-8 years: 90 mcg
• Children 9-13 years: 120 mcg
• Adults 14+ years: 150 mcg
• Pregnant women: 220 mcg
• Breastfeeding women: 290 mcg

Most healthy individuals can safely consume up to 1,100 mcg of iodine daily. However, consistently exceeding this upper limit may lead to thyroid dysfunction, particularly in those with pre-existing thyroid conditions.

Signs of Iodine Deficiency

Recognizing the symptoms of iodine deficiency can help you address the issue promptly. Common signs include:

• Visible neck swelling (goiter): The thyroid gland enlarges in an attempt to capture more iodine from the bloodstream
• Unexpected weight gain: Insufficient thyroid hormones slow metabolism
• Chronic fatigue and weakness: Low thyroid function reduces energy production
• Hair loss: Thyroid hormones help regulate hair follicle growth
• Dry, flaky skin: Reduced thyroid function affects skin cell regeneration
• Feeling cold: Low metabolism generates less body heat
• Memory problems and difficulty concentrating: Thyroid hormones support brain function
• Irregular or heavy menstrual periods: Thyroid hormones influence reproductive hormones

If you experience these symptoms, consult a healthcare provider. They can perform blood tests to check your thyroid function and iodine status.

Who Is at Risk for Iodine Deficiency?

While iodine deficiency has decreased significantly in developed countries following salt iodization programs, certain groups remain at higher risk:

• Pregnant and breastfeeding women: Their iodine requirements increase substantially
• People who don’t use iodized salt: Those using sea salt, Himalayan salt, or limiting salt intake
• Vegans and vegetarians: They may consume fewer iodine-rich foods if not carefully planning meals
• People living in regions with iodine-depleted soil: This affects the iodine content of locally grown produce
• Individuals with increased iodine needs: Those with certain thyroid conditions or taking medications that interfere with iodine absorption

Can You Get Too Much Iodine?

While iodine deficiency is concerning, excessive intake can also cause problems. Most people tolerate high iodine intake well, but some individuals—particularly those with pre-existing thyroid disorders—may experience adverse effects.

Consuming more than 1,100 mcg daily on a regular basis may cause:

• Thyroid inflammation
• Thyroid gland enlargement
• Hypothyroidism or hyperthyroidism
• Increased risk of thyroid cancer (with very excessive, prolonged intake)

This is particularly relevant when consuming seaweed, especially kelp, which can contain extremely high iodine levels. If you regularly eat seaweed or take iodine supplements, discuss this with your healthcare provider to ensure you’re not exceeding safe limits.

Tips for Incorporating Iodine-Rich Foods Into Your Diet

Meeting your daily iodine requirements doesn’t have to be complicated. Here are practical strategies:

• Start your day with eggs: Include whole eggs in breakfast to get iodine and other essential nutrients
• Choose iodized salt: When you do use salt, make it iodized (but still moderate your overall sodium intake)
• Include dairy at meals: Add yogurt to breakfast, milk to coffee, or cheese to lunch
• Eat seafood twice weekly: Include fish or shrimp in your meal plan at least two times per week
• Try seaweed snacks: Nori sheets make convenient, crunchy snacks with a savory flavor
• Add seaweed to soups and salads: Wakame works wonderfully in miso soup or mixed into green salads
• Enjoy beans regularly: Lima beans and navy beans add fiber, protein, and iodine to meals
• Snack on prunes: Keep dried prunes handy for a sweet treat that provides iodine and fiber

Special Considerations for Different Diets

Vegetarian and Vegan Diets

Those following plant-based diets need to be more intentional about iodine intake since many top sources are animal-based. Focus on:

• Iodized salt (in moderation)
• Seaweed and sea vegetables
• Beans (lima beans, navy beans)
• Prunes and cranberries
• Potatoes with skin
• Fortified plant-based milk (check labels)

Some vegans may benefit from iodine supplements, but consult with a healthcare provider or registered dietitian before starting supplementation.

Gluten-Free Diets

Individuals with celiac disease or gluten sensitivity who avoid processed foods may inadvertently reduce iodine intake, as many processed foods use iodized salt. Ensure adequate intake through naturally iodine-rich foods or consider supplementation under medical guidance.

Pregnancy and Breastfeeding

Adequate iodine is crucial during pregnancy and lactation for fetal and infant brain development. Since requirements increase to 220-290 mcg daily, pregnant and nursing women should discuss their iodine intake with their healthcare provider. Many prenatal vitamins contain iodine, but not all do—check labels carefully.

Should You Take Iodine Supplements?

Most people in developed countries can meet their iodine needs through diet alone, particularly when consuming a varied diet that includes some of the foods mentioned above. However, supplements may be appropriate for:

• Pregnant and breastfeeding women not meeting needs through diet
• Vegans and vegetarians with limited iodine-rich food intake
• People with documented iodine deficiency
• Those living in regions with severe iodine deficiency

If you’re considering iodine supplements, consult a healthcare provider first. They can test your iodine status and recommend appropriate dosages if needed. Taking unnecessary supplements can lead to excessive intake and potential thyroid problems.

Foods That Interfere with Iodine Absorption

Certain foods contain goitrogens—compounds that can interfere with thyroid function and iodine utilization when consumed in very large amounts. These include:

• Cruciferous vegetables (broccoli, cauliflower, cabbage, kale)
• Soy products
• Cassava
• Sweet potatoes
• Lima beans (which also contain iodine)

For most people with adequate iodine intake, these foods pose no problem and should not be avoided—they offer numerous health benefits. Cooking these foods significantly reduces their goitrogenic effects. However, if you have thyroid issues or iodine deficiency, discuss your intake of these foods with a healthcare provider.

The Bottom Line

Iodine is an essential mineral that plays a critical role in thyroid function, metabolism, and overall health. While iodine deficiency remains a global concern, it’s easily preventable through dietary choices.

The best iodine-rich foods include seaweed, fish and seafood, dairy products, eggs, iodized salt, and certain beans and dried fruits. By incorporating a variety of these foods into your regular diet, you can maintain healthy iodine levels and support optimal thyroid function.

Pay attention to your body’s signals, and if you experience symptoms of iodine deficiency or thyroid dysfunction, consult with a healthcare provider. They can perform appropriate tests and provide personalized recommendations for your situation.

Remember that balance is key—both too little and too much iodine can cause problems. A varied, whole-foods-based diet that includes several iodine-rich options throughout the week is the best approach for most people to meet their needs naturally and safely.

Sources:

• National Institutes of Health – PubMed Central
• NIH Office of Dietary Supplements – Iodine Fact Sheet
• USDA National Agricultural Library
• World Health Organization
• American Heart Association