You can get plenty of iodine without iodized salt by eating seafood, dairy products, eggs, and seaweed. Adults need 150 mcg of iodine per day, and a single serving of cod or a glass of milk can cover a large portion of that. The key is knowing which foods deliver iodine reliably, because many plant foods contain almost none.
Why Your Body Needs Iodine
Your thyroid gland actively pulls iodine from your bloodstream using a specialized pump on the surface of its cells. Once inside, the thyroid uses that iodine as a raw ingredient to build its two main hormones, which regulate your metabolism, body temperature, heart rate, and brain development. Without enough iodine, the thyroid can’t produce adequate hormones, leading to fatigue, weight gain, sensitivity to cold, and in severe cases, a visible swelling of the thyroid called a goiter.
The recommended daily intake is 150 mcg for adults, 220 mcg during pregnancy, and 290 mcg while breastfeeding. Children need less, ranging from 90 mcg for toddlers to 120 mcg for ages 9 to 13. These are small amounts, but because iodine isn’t evenly distributed in the food supply, people who avoid iodized salt need to be intentional about where they get it.
Seafood: The Most Reliable Source
Ocean fish and shellfish are the most consistently iodine-rich foods available. The standouts, based on USDA data, include:
- Haddock (raw, 4 oz): 250 mcg, more than a full day’s worth
- Cod (baked, 3 oz): 146 mcg, nearly 100% of the daily target
- Lobster (cooked, 3 oz): 157 mcg
- Pollock (raw, 4 oz): 48 mcg
- Salmon (pink, raw, 4 oz): 29 mcg
- Tuna (fresh bluefin, cooked, 3 oz): 20 mcg
- Shrimp (raw, 4 oz): 18 mcg
White fish like cod and haddock contain far more iodine than oily fish like salmon or tuna. A couple of servings of cod per week alone could cover your needs. Canned tuna, on the other hand, provides only about 8 mcg per serving, so it’s a poor iodine source despite being convenient. If you eat seafood regularly, especially white fish and shellfish, iodine deficiency is unlikely.
Dairy and Eggs
Milk, yogurt, cheese, and eggs are significant iodine sources for many people, even though they don’t come from the sea. Dairy cows absorb iodine through their feed and through iodine-based sanitizers used on milking equipment, and that iodine passes into the milk. A single cup of milk typically provides 50 to 80 mcg of iodine, roughly a third to half of the daily goal. Yogurt delivers a similar amount per serving.
Eggs contain iodine mainly in the yolk, with one large egg providing roughly 25 to 30 mcg. Eating two eggs at breakfast gets you about a third of the way there. Cheese has smaller, more variable amounts. If you eat dairy and eggs daily, these foods can form a solid foundation for your iodine intake even without any salt or seafood.
Seaweed: Potent but Easy to Overdo
Seaweed is the most concentrated food source of iodine on the planet, but the amounts vary wildly between types. This is both an opportunity and a risk.
Kombu, the thick kelp used in Japanese broths, contains staggering amounts. Dried kombu ranges from about 2,100 to 4,300 mg per kilogram, which means even a small 1-gram piece could deliver 2,000 to 4,000 mcg of iodine, far exceeding both the daily requirement and the safe upper limit of 1,100 mcg per day. Regular use of kombu can easily push your iodine intake into territory that disrupts thyroid function rather than supporting it.
More moderate options include dried wakame (220 to 280 mg/kg) and dried nori, the sheets used to wrap sushi (9 to 20 mg/kg). A standard nori sheet weighs about 2.5 grams, delivering roughly 25 to 50 mcg of iodine, a safe and useful amount. Wakame falls somewhere in between. Dried dulse flakes contain about 100 mg/kg, making them a practical sprinkle-on option for salads or soups.
If you use seaweed for iodine, nori and dulse are the easiest to dose safely. Kombu, hijiki, and arame are so concentrated that small variations in portion size can mean the difference between a helpful amount and a harmful one. Cooking seaweed and discarding the water also reduces its iodine content significantly, sometimes by 90% or more.
Why Plant Foods Are Unreliable
Fruits, vegetables, grains, and legumes are generally poor iodine sources. The iodine content of any plant food depends almost entirely on the soil it was grown in, and most agricultural soil around the world is low in iodine. Food grown near the coast tends to have somewhat more, but there’s no way to tell from looking at a potato or a bag of beans how much iodine it contains. You can’t build a reliable iodine strategy around these foods.
This matters most for people on vegan or plant-heavy diets. Without dairy, eggs, or seafood, the only consistent plant source is seaweed, and even that requires careful selection. If you eat a fully plant-based diet and don’t use iodized salt, either seaweed (chosen carefully) or a supplement is essentially necessary.
Foods That Block Iodine Uptake
Certain foods contain compounds called goitrogens that interfere with your thyroid’s ability to use iodine. They work by competing with iodine for absorption into thyroid cells, effectively blocking the step where iodine gets built into thyroid hormones.
The main culprits are raw cruciferous vegetables (broccoli, cauliflower, cabbage, Brussels sprouts, bok choy, radishes, and turnips), soy products (tofu, tempeh, edamame, soy milk), and flax seeds. Green, white, and oolong teas also contain goitrogenic flavonoids.
This doesn’t mean you need to avoid these foods. Cooking cruciferous vegetables significantly reduces their goitrogen content. The concern is mainly for people who already have borderline iodine intake and eat large amounts of these foods raw. If your iodine intake is adequate, normal portions of broccoli or tofu won’t cause problems.
Iodine Supplements
If your diet doesn’t reliably include seafood, dairy, or seaweed, a supplement is a straightforward solution. Most iodine supplements come in two forms: potassium iodide (a synthetic, pharmaceutical form) and kelp-derived iodine (extracted from seaweed). Both are well absorbed. Studies show potassium iodide has about 96% absorption, while iodine from brown algae reaches up to 90% absorption in the body.
For most people, a supplement providing 150 mcg (100% of the daily value) is sufficient. Some products contain far more than this, with doses ranging up to 12,500 mcg per capsule. That level of intake is unnecessary for general health and can cause thyroid problems over time. Most adverse reactions from iodine occur at sustained intakes above 1,100 mcg per day. A simple 150 mcg kelp or potassium iodide tablet, taken daily, is the safest approach if you need supplementation.
Putting It Together
Meeting your iodine needs without iodized salt is entirely doable, but it requires some awareness of which foods actually deliver. A practical daily target looks something like this: a cup of milk or yogurt (50 to 80 mcg), one egg (25 to 30 mcg), and a serving of fish once or twice a week (20 to 250 mcg depending on the type). That combination easily hits 150 mcg most days without any salt involved.
If you avoid animal products, two to three sheets of nori per day, a sprinkle of dulse flakes on your meals, or a 150 mcg supplement will cover your needs. The one thing to avoid is guessing. Unlike nutrients that are spread evenly across many foods, iodine is concentrated in a handful of sources and nearly absent from everything else. Picking even one or two reliable sources and eating them consistently is the simplest path to getting enough.