By Dr. Jane Smith · Published October 26, 2025 · 10 min read
Iodine foods are easy to overlook — this trace mineral appears in no headline supplement, no protein bar, and no trending diet plan. Yet without adequate iodine, the thyroid cannot produce the hormones that regulate metabolism, energy, brain development, and body temperature.
The good news: most people can meet their 150 mcg daily requirement through a handful of regular foods. This list ranks 20 iodine-rich foods by content per serving, so you can see exactly where your iodine is coming from and whether your current diet is hitting the mark.
⚠️ Medical Disclaimer
This article is for informational purposes only and does not constitute medical advice. If you suspect iodine deficiency or a thyroid condition, consult a healthcare professional before making dietary changes.
Why Iodine Matters for Your Thyroid
Iodine is the raw material your thyroid gland uses to make T3 (triiodothyronine) and T4 (thyroxine) — the two thyroid hormones that regulate nearly every aspect of metabolism. Without enough iodine, the thyroid cannot produce adequate hormone levels, which leads to hypothyroidism: fatigue, cold sensitivity, hair loss, and unexplained weight gain.
According to the NIH Office of Dietary Supplements, iodine deficiency is the leading preventable cause of intellectual disability worldwide. During pregnancy, adequate iodine is essential for fetal brain and skeletal development — which is why the RDA rises sharply for pregnant and breastfeeding women.
Unlike many nutrients, iodine is not naturally abundant in the soil of most regions. Seafood and seaweed are reliable exceptions because marine organisms concentrate iodine from seawater. Dairy is a consistent source due to iodine-based sanitizers used in milk production. Everything else — vegetables, grains, meat — depends heavily on where it was grown or raised.
How Much Iodine Do You Need?
The recommended daily intake varies by life stage:
| Population Group | Daily RDA | Upper Intake Limit |
|---|---|---|
| Adults (19+) | 150 mcg | 1,100 mcg |
| Pregnant women | 220 mcg | 1,100 mcg |
| Breastfeeding women | 290 mcg | 1,100 mcg |
| Children (9–13) | 120 mcg | 600 mcg |
| Children (4–8) | 90 mcg | 300 mcg |
Most adults in the United States exceed the 150 mcg RDA through daily diet — iodized salt, dairy, and seafood are common in the American food supply. Vegans, people who avoid processed foods, and those who have switched from cow's milk to plant-based alternatives are most at risk of falling short.
20 Best Iodine Foods
The values below are drawn from the NIH / USDA collaborative iodine database and reflect typical amounts per standard serving. Note that iodine content can vary based on soil, farming practices, and food processing methods.
Seaweed
1. Kombu kelp — up to 2,984 mcg per 1g serving
The single most concentrated iodine food on the planet. Even a tiny amount can far exceed the 1,100 mcg upper intake limit. Use sparingly; do not consume daily.
⚠️ Caution: Kombu Kelp
A single gram of kombu kelp can contain 2–3× the daily upper intake limit for iodine. Excess iodine can trigger hyperthyroidism or thyroid inflammation, particularly in people with existing thyroid conditions. Enjoy in small portions and not every day.
2. Nori (dried seaweed) — ~232 mcg per 10g serving (155% DV)
The dark sheets used in sushi rolls. Nori is the most practical seaweed choice: high in iodine, easy to find, and far less variable in content than kelp. A single nori sheet wrapping a rice roll provides a meaningful iodine boost.
3. Wakame — ~66 mcg per 1g serving (44% DV)
The soft green seaweed in miso soup. Much gentler than kelp, wakame is a reliable everyday source and easy to add to soups, salads, and grain bowls.
Seafood
4. Cod (baked) — 158 mcg per 3-oz serving (105% DV)
A 3-oz cod fillet meets the entire adult daily requirement in one portion. White, mild fish tends to be higher in iodine than fattier species because iodine concentrates in muscle tissue rather than fat.
5. Scallops (cooked) — 135 mcg per 3-oz serving (90% DV)
One of the highest iodine shellfish. Scallops also provide lean protein and zinc, making them a nutritionally dense choice for anyone building a balanced diet.
6. Oysters (cooked) — 93 mcg per 3-oz serving (62% DV)
Beyond iodine, oysters are one of the richest food sources of zinc. Three ounces provides well over half the daily iodine requirement.
7. Salmon (baked) — ~35 mcg per 3-oz serving (23% DV)
Lower in iodine than white fish, but a consistent source alongside its omega-3 benefits. Wild-caught and farmed varieties deliver similar iodine levels.
8. Shrimp (canned) — ~35 mcg per 3-oz serving (23% DV)
Affordable and versatile. Canned shrimp is a practical way to add both iodine and lean protein to meals without cooking fresh seafood.
9. Tuna (canned in oil) — ~17 mcg per 3-oz serving (11% DV)
Lower than most seafood, but widely consumed. Tuna's contribution to daily iodine intake adds up quickly given how often it appears in lunch meals.
Dairy
10. Greek yogurt (plain, low-fat) — ~116 mcg per 8-oz serving (77% DV)
The richest iodine source in the dairy category, higher per ounce than regular milk because yogurt is more concentrated. Plain varieties have more consistent iodine content than flavored types.
11. Milk (nonfat cow's) — ~85 mcg per 8-oz serving (57% DV)
A reliable, widely available source. One cup covers more than half the daily adult requirement. Note: organic milk averages significantly less iodine because certified organic dairy operations do not use iodine-based sanitizers.
12. Ice cream (vanilla) — ~21 mcg per ½-cup serving (14% DV)
A modest contribution, but it counts. Ice cream is made with milk and cream, which carry iodine through to the finished product.
13. Cheddar cheese — ~14 mcg per 1-oz serving (9% DV)
Lower iodine than fluid milk and yogurt. Cheese is a minor source, but regular consumption across meals adds up over the course of a day.
Eggs and Poultry
14. Egg (hard-boiled) — ~26 mcg per large egg (17% DV)
Most of the egg's iodine is in the yolk. Eggs are one of the most versatile iodine foods — a scramble, a boiled egg at lunch, or a frittata at dinner all contribute meaningfully.
15. Turkey breast (baked) — ~34 mcg per 3-oz serving (23% DV)
Poultry contains moderate iodine because chickens and turkeys fed iodine-supplemented feed pass the mineral through to their meat and eggs. Iodine levels in poultry vary by farming practice.
Fortified and Packaged Foods
16. Iodized salt — ~71 mcg per ¼ tsp (47% DV)
Introduced in the 1920s to prevent widespread goiter, iodized salt remains one of the most cost-effective ways to meet iodine needs globally. Regular table salt is fortified; sea salt, Himalayan pink salt, and kosher salt generally are not.
17. Enriched bread (with iodate dough conditioner) — ~185 mcg per slice (123% DV)
Some commercial bread uses potassium iodate as a dough conditioner, pushing a single slice well above the adult daily requirement. Not all bread is made this way — check the ingredient list for "potassium iodate" or "calcium iodate" to identify enriched varieties.
18. Enriched macaroni (cooked) — ~18 mcg per ½-cup serving (12% DV)
A modest source, but regular pasta meals contribute to overall iodine intake, particularly when combined with dairy-based sauces.
Plant Foods
19. Prunes (dried) — ~13 mcg per 5-prune serving (9% DV)
One of the better plant-based iodine sources outside of seaweed. Prunes also provide fiber and potassium, making them a useful addition to any snack routine. If you're curious about other aspects of your micronutrient intake, learning how to read nutrition labels helps you spot iodine on packaged foods.
20. Lima beans (cooked) — ~8 mcg per ½-cup serving (5% DV)
A modest contribution, but legumes are one of the few reliable plant-based options outside of seaweed and fortified foods. Combined with nori, iodized salt, and dairy, lima beans support a well-rounded intake.
Iodine for Vegans and Vegetarians
Plant-based diets face a genuine iodine challenge. A 2023 systematic review in Nutrients found that vegans averaged only 17–47 mcg of iodine per day — far below the 150 mcg RDA. The reason: the primary iodine sources (seafood, dairy, eggs) are all animal-derived.
If you follow a plant-based diet, focus on:
- Iodized salt — the simplest, most reliable plant-based source
- Nori or wakame seaweed — a few sheets per week provides significant iodine without the excess of kelp
- Fortified plant milks — some brands add iodine to match conventional dairy; check the label
Avoiding iodized salt in favor of sea salt or Himalayan pink salt while also skipping dairy and seafood is a high-risk combination for deficiency. This is especially important for anyone supporting a growing family — the effect on fetal brain development is well-documented. For context on how nutrient deficiencies accumulate with age, see our guide on nutrition for healthy aging.
Signs You May Not Be Getting Enough Iodine
Iodine deficiency develops gradually and is often mistaken for other conditions. Common signs include:
- Goiter — visible swelling in the neck as the thyroid enlarges trying to capture more iodine from the bloodstream
- Unexplained weight gain — slowed thyroid hormone production reduces metabolic rate
- Persistent fatigue — insufficient T3/T4 affects cellular energy production
- Difficulty tolerating cold — thyroid hormones regulate body temperature
- Brain fog and poor concentration — thyroid hormones influence neurological function
- Hair thinning or loss — a common but often overlooked symptom of low thyroid activity
Iodine deficiency shares many symptoms with other nutrient shortfalls. If you suspect a problem, a blood test for TSH (thyroid-stimulating hormone) is the standard first step. Similarly, if you've noticed fatigue and muscle cramps together, it may be worth checking both iodine and electrolyte status — our guide on signs of electrolyte imbalance covers the overlap between these two groups of symptoms.
Start Tracking Smarter
Knowing which foods contain iodine is the first step — consistently eating them is the second. If you want to see how your daily meals stack up against micronutrient targets, Caloria makes it easy: snap a photo of your meal and get an instant nutritional breakdown.
Download Caloria:
Frequently Asked Questions
What foods are highest in iodine?
Seaweed tops the list — nori provides around 232 mcg per 10g, and kombu kelp can exceed 2,000 mcg per gram (use with caution). Among everyday foods, cod (158 mcg per 3 oz) and Greek yogurt (116 mcg per 8 oz) are the most practical high-iodine choices for regular meals.
How much iodine do I need per day?
Most adults need 150 mcg per day. Pregnant women need 220 mcg and breastfeeding women 290 mcg. The tolerable upper limit is 1,100 mcg — difficult to exceed unless you eat kombu kelp frequently.
What are good plant-based iodine foods?
Iodized salt, nori, and wakame are the best plant-based options. Most fruits, vegetables, grains, and legumes contain very little iodine because the mineral must be present in the soil for plants to absorb it. Fortified plant milks that specifically add iodine are also a good option.
Does dairy milk contain iodine?
Yes — a cup of nonfat cow's milk contains roughly 85 mcg of iodine, about 57% of the daily adult requirement. Conventional dairy is a reliable source; organic dairy is typically lower because iodine-based teat dips used in conventional farming are restricted in organic operations.
Can you get too much iodine from food?
Only from kombu kelp in realistic dietary scenarios. Every other food on this list is safe to consume in normal portions. Chronic excess iodine (above 1,100 mcg daily) can paradoxically suppress thyroid function and trigger goiter in susceptible individuals, particularly those with pre-existing thyroid disease.