Is Your Favorite Salt Causing an Iodine Deficiency?

There’s a surprising amount of options when it comes to buying salt. There’s table salt, Kosher salt, sea salt, and Himalayan salt—just to name a few. But while all these salts contain sodium, only one—table salt—has been fortified with iodine, an essential nutrient. The practice of iodizing salt began in the 1920s as a way to address widespread iodine deficiencies in Switzerland. Just a few years later, iodized salt was introduced in America. 

Recently, gastroenterologists on TikTok are claiming that the rising popularity of non-iodized salts, like sea salt and Himalayan salt, is contributing to an increase in iodine deficiencies. So, should we be chucking our fancy sea salt in favor of iodized table salt? Before you reach for the salt shaker, here’s what you need to know about iodine deficiencies and salt. 

What is iodine and why do we need it? 

“Iodine is a trace element that is important for thyroid function,” says Emily Truscott, a clinical dietitian at the University of Florida’s Food Science and Human Nutrition Department. “The thyroid helps regulate various bodily functions, such as metabolism, heart rate, and the nervous system.” Since iodine is also crucial when it comes to human growth and development, Truscott says it's especially important to get enough iodine during pregnancy and early infancy. 

According to the World Health Organization (WHO), young children are also at a higher risk for the effects of iodine deficiency, which can impact brain development in the first two years of life. 

Besides salt, what foods contain iodine?

Lots of foods naturally contain iodine. The National Institutes of Health (NIH) names seaweed as one of the best natural sources of iodine. Other iodine-rich foods include seafood and eggs. Dairy products like milk and yogurt can also be a great source of iodine, but this depends on the diet of the cows as well as how the products are processed. 

Additionally, certain foods actually interfere with the body’s ability to use iodine; these foods are called goitrogens. Some examples include soy, cruciferous vegetables, lima beans, and sweet potatoes.

What are the symptoms of an iodine deficiency? 

The first symptom of an iodine deficiency is typically an enlarged thyroid—a condition referred to as a goiter. “Other signs of severe iodine deficiency are hypothyroidism (low levels of thyroid hormones), and decreased fertility,” says Truscott. 

Truscott tells me that while iodine deficiency is uncommon in North America, some groups are more at risk than others. Pregnant people need more iodine and are therefore at greater risk for iodine deficiency. The risk is also increased for people living in areas with low levels of iodine in the soil (like mountainous regions or areas that experience frequent flooding).

Not using iodized salt can put you at risk for iodine deficiency, but other personal food choices are also a factor. “Since seafood and dairy products are sources of iodine, vegans or people who do not consume much of these foods are more at risk,” explains Truscott. She also notes a potential risk for those who eat a diet that’s high in the foods that interfere with the body’s ability to use iodine (goitrogens). 

Should you take an iodine supplement? 

“I typically recommend a multivitamin to ensure you are meeting your vitamin and mineral needs on a daily basis,” says Truscott, adding that most multivitamins will provide sufficient amounts of iodine. That said, she also emphasized that an iodine supplement may not be for everyone. “Talk with your doctor and/or registered dietitian before making changes to your diet and/or supplement regimen,” she cautions. "Iodine supplements can interact with some medications and might not be appropriate for some people.”

There is *also* such a thing as too much iodine. In fact, according to the NIH, excessive iodine can cause a lot of the same symptoms as an iodine deficiency. Luckily, the organization states that for most people, the amount of iodine generally found in food and supplements is unlikely to cause any problems. 

So, are iodine deficiencies actually on the rise?

Truscott assures that, while certain subgroups of people are more at risk (including those who are pregnant), there's no recent data suggesting that iodine deficiency is a widespread issue in the United States. "The National Health and Nutrition Examination Survey (NHANES) helps monitor the nutrition status of Americans,” she says. “Based on the most recent data from 2011 to 2014, iodine levels are generally sufficient.” 

However, recently, doctors have been noticing an upswing in iodine deficiencies and hypothyroidism in children worldwide. Two likely contributing factors are decreased use of iodized salt and the rising popularity of plant-based diets. In fact, the WHO has put out a call-to-action to fortify plant-based dairy alternatives, specifically in European regions.

Do you need to swap your sea salt for table salt again? 

“In short, it depends on the individual,” explains Truscott. “Historically, using iodized table salt is the most practical, cost-effective method for reducing your risk for iodine deficiency.” 

That said, if you’re a fan of sea salt or pink Himalayan salt, heed Truscott’s advice to take a multivitamin, which should provide all the iodine you need. It’s an easy way to make sure you’re getting all of your essential nutrients, no matter what type of salt you prefer.