What Is Iodized Salt (and Should You Be Using It)?

Have you ever noticed the words “iodized salt” on your box of table salt and wondered what that meant? Well, it’s exactly what it sounds like: salt, with added iodine. It was introduced in the 1920s, when iodine deficiency was common in the Northwest, Great Lakes, and Appalachian regions of the United States. Although most Americans today are iodine-sufficient, iodized salt is still common on supermarket shelves. But before you pick up that box of iodized salt, there are a few things you should know. Read on to find out.

What Is Iodine (and How Much Do You Need)?

Iodine is a mineral that your body needs for the production of thyroid hormones. “These hormones regulate how the body uses energy, breathing, body temperature, and many other critical functions,” says endocrinologist Dr. Elizabeth Pearce, an associate professor at Boston University School of Medicine. “In pregnant women, thyroid hormones regulate the brain development of the fetus.” In other words, says functional medicine practitioner Dr. Will Cole, “Your body can’t function without thyroid hormones. If your thyroid isn’t working well, nothing is working well.”

Since your body can’t make iodine on its own, iodine is a necessary part of your diet — but you don’t want too much iodine, which is associated with thyroid autoimmune problems and other thyroid disorders. “It’s the ‘Goldilocks’ principle,” Cole says. “You don’t want too much, or too little.” He suggests getting your iodine levels measured before adding more iodine to your diet — or cutting back — to be sure your intake matches your individual needs.

So how much is just right? “Adequate intake is about 150 mcg/day for adult males and females, although more is needed during pregnancy and lactation,” says registered dietitian Eliza Savage of Middleberg Nutrition. Pregnant and lactating women need 220 and 290 mcg/day, respectively.

Should You Be Using Iodized Salt?

While iodized salt may seem like an easy way to incorporate iodine in your diet, Dr. Cole doesn’t recommend it. “I’m not a fan of iodized salt,” he says. “It’s very processed, devoid of most minerals, and I don’t like the anti-caking agents in there, like aluminum.” He also adds that, if someone has a history of autoimmune thyroid issues, getting iodine through food rather than supplements is a good way to keep from overdoing it.

Luckily, even without iodized salt, there are plenty of healthy and delicious ways to make sure you’re getting enough of this essential mineral. “If you’re eating a balanced diet, you should be able to meet your needs quite easily,” Savage says. Produce such as garlic, lima beans, Swiss chard, spinach, and edamame contain iodine, Savage notes, though the amount may vary based on the depletion of minerals in the soil.

Grass-fed beef and pastured eggs have some iodine as well, Cole says. He also recommends wild-caught ocean fish and shellfish, though Pearce notes that as with vegetables, the level of iodine can vary greatly in fish, so it can be hard to gauge exactly how much you’re getting.

Pearce includes dairy as a rich source of iodine, though Cole recommends sticking to fermented varieties such as kefir and yogurt —“grass-fed, full fat, and all that good stuff,”— and only if you tolerate it well.

The Best Way to Get Your Daily Iodine

The foods that have the highest amount of iodine, however, are something you might not normally have hanging around in your pantry: Sea vegetables like dulse, kombu, nori, and kelp, are particularly good sources of iodine. Here are a few ideas for adding sea vegetables into your diet.

1. As a snack: We love Sakara Life’s Nori Chips.
2. In a smoothie: Toss a kelp cube into the blender with your favorite ingredients.
3. In hummus: Whirl it into the blender with chickpeas and avocado for a thoroughly modern, super-healthy take on the spread.
4. In beans: If you cook dried beans, add a strip of kombu to the water for a mineral hit. Bonus: The kombu can help make the beans more digestible
5. In dressings, sauces and sandwiches: Whisk some spirulina into a salad dressing or sauce, or roll up your favorite sandwich fillings in nori instead of a regular wrap.

Pro-Tip: If you’re concerned about iodine intake, avoiding certain foods may be just as important as eating your sea veggies. “It’s interesting to note that thiocyanate-containing foods such as cassava, soy, and brassica veggies may interfere with the uptake of the iodine into the thyroid gland,” Savage notes.