Can I Eat Salmon on a Low Iodine Diet? A Nutritional Guide

October 8, 2025 •

4 min read

For individuals preparing for radioactive iodine treatment, restricting iodine intake is crucial, with iodine-rich foods like seafood often completely avoided. This raises the important question, can I eat salmon on a low iodine diet?, and requires careful consideration of its iodine content.

Quick Summary

Salmon is generally not permitted on a low-iodine diet because all seafood and seawater fish are considered high in iodine. Adherence to dietary restrictions is vital for treatment.

Key Points

Low-Iodine Diet Rule: All seafood, including salmon, must be avoided on a low-iodine diet due to its high natural iodine content.
Radioactive Iodine Treatment: The diet is a temporary measure designed to maximize the effectiveness of radioactive iodine (RAI) therapy by depleting the body's stored iodine.
Wild vs. Farmed Salmon: While iodine levels can vary based on origin and feed, all marine fish are restricted, so distinctions between wild and farmed salmon don't apply for a strict low-iodine diet.
Safe Protein Alternatives: Approved protein sources include fresh, unprocessed poultry, beef, and pork, as well as egg whites.
Check All Ingredients: Be cautious of hidden sources of iodine, including iodized salt, seaweed derivatives (like agar-agar and carrageenan), and certain food dyes (Red Dye #3).
Non-iodized Salt Is Fine: A low-iodine diet does not restrict non-iodized salt, so you can still add flavor to your cooking.

Understanding the Low-Iodine Diet

Before undergoing radioactive iodine (RAI) therapy for thyroid cancer or certain thyroid tests, patients are typically required to follow a low-iodine diet (LID). The purpose of this short-term, highly restrictive diet is to deplete the body's store of iodine, making the thyroid cells "hungry" for any iodine they can find. This, in turn, makes the radioactive iodine treatment more effective at targeting and destroying thyroid cells. It's crucial to understand that this is not a low-sodium diet, and non-iodized salt is usually permitted. However, many common foods are restricted, especially those from the sea.

The Iodine Content of Seafood and Salmon

Seafood is widely recognized as one of the richest natural sources of dietary iodine. Fish absorb iodine from the seawater they live in, and the concentration can vary depending on the species, geographical location, and whether the fish is wild or farmed.

While some sources suggest salmon might contain less iodine than other marine fish like cod, it is still considered a high-iodine food and is on the list of foods to avoid during a low-iodine diet. Research has shown that the iodine content in wild fish can be higher than in farmed fish, though this can also be influenced by the feed. For example, a study on Norwegian fish found wild fish tended to have higher concentrations of iodine, but no significant difference was noted between wild and farmed Atlantic salmon. However, the variation and overall iodine concentration remain a concern for a strict LID.

Can I Eat Salmon on a Low Iodine Diet? The Consensus

The short and direct answer is no, you cannot eat salmon on a low iodine diet. All types of seafood, including marine fish like salmon, are strictly off-limits. The risks of consuming too much iodine and compromising the effectiveness of your treatment outweigh any potential benefits. Official guidelines from organizations like the American Thyroid Association and Memorial Sloan Kettering Cancer Center explicitly list all seafood and sea products as foods to avoid. This includes fresh, canned, and cured versions, as well as products derived from seaweed.

Navigating the Low-Iodine Diet: A Safer Path

Instead of focusing on what you cannot eat, concentrate on the variety of delicious and safe foods you can enjoy. Here is a brief guide to permitted foods and those to strictly avoid.

Foods to Avoid

Seafood: All fish (including salmon, cod, tuna, and freshwater varieties not explicitly approved), shellfish, and products like kelp, seaweed, carrageenan, algin, and agar-agar.
Dairy: Milk, cheese, yogurt, butter, and ice cream.
Egg Yolks: Only egg whites are permitted.
Iodized Salt and Sea Salt: Use non-iodized salt instead.
Soy Products: Tofu, soy sauce, and soy milk.
Red Dye #3: Found in some red or orange candies, cereals, and beverages.

Foods to Enjoy

Fresh Meat and Poultry: Beef, pork, lamb, and chicken (unprocessed and without added broth).
Egg Whites: An excellent source of protein.
Fresh and Frozen Fruits and Vegetables: Most are fine, though some lists suggest limiting spinach and broccoli.
Grains: Homemade bread without iodized salt, dairy, or eggs; rice; and most pastas.
Unsalted Nuts and Nut Butters.
Oils and Vinegars: Most vegetable oils and vinegars are allowed.

Low-Iodine Fish and Protein Alternatives


Feature	Salmon (Marine Fish)	Cod (Marine Fish)	Freshwater Fish	Poultry (Chicken/Turkey)
Iodine Content	High	High	Low	Low
Recommended for LID?	NO	NO	YES (with confirmation)	YES (fresh, unprocessed)
Source of Iodine	Seawater and feed	Seawater	Naturally low in water	Low in feed, no seawater exposure
Cautions	Varies by species and origin, but always considered too high.	Also varies, but too high for diet.	Check with provider; can vary by water source, but generally safe.	Must be fresh, plain, and not injected with broth.

Conclusion: Prioritizing Your Treatment

While salmon is a healthy fish rich in omega-3s under normal circumstances, it must be excluded from a low-iodine diet. The purpose of the LID is to prepare your body for maximum therapeutic effectiveness with radioactive iodine treatment, and consuming any seafood, including salmon, would undermine this goal. By focusing on approved protein sources like fresh poultry and freshwater fish, alongside a wide variety of other low-iodine foods, you can maintain a nutritious diet without jeopardizing your treatment. Always follow your doctor's specific guidelines to ensure the best possible outcome. For more detailed information on navigating this diet, consult resources like the American Thyroid Association.

How to Find Other Low-Iodine Protein Sources

Fresh, Unprocessed Meats: Buy fresh beef, pork, lamb, or poultry from a butcher and avoid pre-packaged or cured meats that may contain iodized salt or broths.
Egg Whites: Use egg whites in omelets, scrambles, and baking as a versatile and safe protein source.
Plain Nuts and Seeds: Unsalted nuts and seeds are a great snack and addition to meals.
Legumes (with care): Some lists permit certain dried beans and lentils, but it is important to confirm with your doctor, as some types are restricted.
Homemade Broth: Use fresh vegetables and meat scraps (non-iodine-rich) to make your own broth, as store-bought versions often contain iodized salt.

Frequently Asked Questions

Salmon, like all seafood and marine fish, is naturally high in iodine because it absorbs the mineral from seawater. To prepare the body for radioactive iodine treatment, all high-iodine foods must be eliminated, making salmon unsuitable.

No, canned salmon is not allowed on a low iodine diet. While the specific iodine content might vary, canned fish generally comes from seawater sources and is explicitly restricted during this dietary phase.

Studies have shown varied results, but while wild fish often have higher iodine, the difference between farmed and wild Atlantic salmon may not be significant. Regardless, both types of salmon are marine fish and must be avoided.

Yes, some low-iodine diet guidelines permit freshwater fish. However, it is essential to check with your healthcare provider for specific guidance, as iodine content can still vary depending on the fish's source.

If you accidentally consume salmon or another iodine-rich food, you should immediately inform your doctor. They can advise on whether it will affect your treatment schedule, as the goal is to keep iodine intake consistently low.

No, cooking methods do not reliably reduce the iodine content of salmon to a safe level for a strict low-iodine diet. While some boiling may cause a slight reduction, it does not remove enough iodine to make it permissible.

Good low-iodine alternatives to salmon include fresh, unprocessed chicken, beef, or pork. Egg whites are also a versatile protein source that is safe for the diet.