A Short History of Iodized Salt in the United States

Iodized salt became standard in American kitchens in the 1920s. We look at the public health campaign behind it, how it changed iodine intake nationwide, and what it tells us about population-level nutrition strategy.

The "Goiter Belt"

In the early 20th century, doctors and public health officials noticed that an enlarged thyroid, then called goiter, was far more common in certain parts of the United States. The pattern was strongest around the Great Lakes, across the upper Midwest and in the Pacific Northwest. These regions became known as the "goiter belt." Their common thread was soil and water naturally low in iodine, far from ocean sources.

Studies in the 1910s, including school-based research in Ohio led by David Marine, showed that iodine intake made a measurable difference in these communities. That research laid the groundwork for a population-wide approach.

1924: Iodized Salt Arrives

Michigan led the way. Working with the Michigan State Medical Society, salt producers began selling iodized table salt in Michigan in 1924. Salt made a logical carrier: almost everyone used it, they used it in fairly steady amounts every day, and adding iodine to it was simple and inexpensive.

That same year, Morton Salt began distributing iodized salt nationally, and other brands soon followed. Notably, the U.S. program was voluntary. Salt makers were never required to iodize, and consumers could always choose plain salt.

The Results

Over the following decades, goiter rates in the goiter belt fell sharply, and iodized salt became one of the most cited successes in American public health. It also became a model for food fortification more broadly, alongside later programs such as adding vitamin D to milk and folic acid to enriched grains.

What's Changed Since

The salt aisle and the American diet look very different today:

• Most of the salt people eat now comes from processed and restaurant food, which is usually made with non-iodized salt.
• Sea salt, kosher salt and pink Himalayan salt have become popular, and most of these are not iodized.
• Many people deliberately cut back on salt for other health reasons.

National survey data show U.S. iodine intake fell from the 1970s to the 1990s and then leveled off. That is one reason iodine has come back into the conversation. See Is Iodine Deficiency Coming Back? for the latest research.

What This Means Today

Iodized salt still works as it always has, but it only helps the people who actually use it. Checking whether the salt at home is iodized, and paying attention to other iodine sources like dairy, eggs and seafood, is a simple first step. For more on how fortification works around the world, read Iodine and Salt: How Fortification Programs Work.

Frequently Asked Questions

Is this historical formula still relevant, or just a marketing story?
It's both. The historical formula has held up because the underlying chemistry works, not just because it's old — but longevity alone isn't a health claim, and any supplement decision should be made with your own health context in mind.

Is iodized salt enough on its own, or do people still supplement?
Many people still choose a supplement for more consistent, controllable intake — see Daily Iodine Intake, Food Sources, and Supplementation, Explained.

Shop Lugol's Solution — the traditional, trusted way people have supported their iodine intake for over 200 years.

Arjun Malhotra writes the research- and history-focused pieces for the Iodine Journal.

This article is for general educational purposes only and has not been evaluated by the FDA. It is not intended to diagnose, treat, cure, or prevent any disease, and is not a substitute for advice from a qualified healthcare provider — especially if you are pregnant, nursing, taking thyroid medication, or managing a thyroid condition.