Iodine on a Plant-Based Diet: How to Get Enough

Iodine from seaweed

Why is iodine important?

If you’re eating fully (or mostly) plant-based, you might wonder: how do I get enough iodine on a plant-based diet?

Iodine is a trace element that plays a crucial role in:

  • the production of thyroid hormones
  • a healthy metabolism
  • brain development and growth
  • a strong immune system

The recommended daily intake (RDI) is 150 mcg for adults and 200 mcg for pregnant or breastfeeding women.

Too much or too little iodine?

An iodine deficiency can lead to hypothyroidism (underactive thyroid), with symptoms such as:

  • weight gain
  • fatigue
  • constipation

An excess of iodine can result in hyperthyroidism (overactive thyroid), causing:

  • diarrhea
  • heart palpitations
  • weight loss

The goal is to get enough iodine—but not too much.

Where is iodine found?

Iodine naturally occurs in:

  • fish
  • eggs
  • dairy products
  • seaweed

Depending on the iodine content of the soil in your country, foods may naturally contain little iodine. That’s why in many countries iodine is added to salt and baker’s salt, which is often used in bread.

Be aware: organic bread is often baked without baker’s salt and therefore contains almost no iodine. Always check with your baker or look on the label for “iodized salt” or “baker’s salt.”

Iodine on a plant-based diet: plant-based sources

Even without animal products, you can still meet your iodine needs. Important plant-based sources of iodine include:

1. Iodized salt

1 gram of iodized salt contains about 21 mcg of iodine.

Add a pinch to your meals to easily boost your intake.

2. Bread baked with baker’s salt

1 slice of whole-grain bread provides about 20–25 mcg of iodine.

With 6 slices per day, you’ll reach the RDI.

3. Nori

Known from sushi, but also tasty in salads or soups.

Half a nori sheet provides about 75 mcg of iodine.

4. Seaweed flakes

A mix of different seaweeds (e.g., “salade du pêcheur”).

Sprinkle a teaspoon over your meal 2–3 times per week for extra iodine.

What to watch out for

Some seaweeds, such as kombu (kelp) and dulse, contain extremely high levels of iodine. Eating these daily can quickly lead to excessive intake, which may disrupt thyroid function.

Iodine levels in seaweed can vary widely. For this reason, seaweed-based supplements (such as kelp tablets) are not recommended.

Do you eat little bread and salt?

If you eat plant-based but generally consume little bread or iodized salt, here are good options:

  • Use nori or seaweed flakes regularly.
  • Consider a supplement with potassium iodide.

Conclusion: iodine on a plant-based diet is achievable

With the right choices, it’s entirely possible to get enough iodine on a plant-based diet.

  • Use iodized salt or bread baked with baker’s salt.
  • Add nori or seaweed flakes a few times per week.
  • Consider a potassium iodide supplement if your intake is low.

This ensures your thyroid, brain, and metabolism stay healthy.

Discover Plants for Health

Want to make sure you’re meeting all your nutritional needs on a plant-based diet?

In our Plants for Health program, we guide you step by step with weekly meal plans, practical tips, and expert support. Learn more about the lifestyle program here.

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