You may have heard recently that Americans aren’t getting enough iodine in their diets. An article in the March/April 2006 issue of The Saturday Evening Post reported that “Government experts … warn that iodine deficiency—a serious health threat in developing nations—could resurface in this country.” The problem is this: Americans are eating more fancy salt—like kosher salt, sea salt, and fleur de sel — that don’t contain iodine, and less table salt, like Morton’s, which is typically fortified with iodine. Americans are also eating more meals in restaurants, and most pro kitchens use kosher salt.
Table salt companies began fortifying their products in the 1920s specifically to address what was then a common problem. Thousands of people—as well as livestock—suffered from iodine deficiency–induced goiter, an unsightly swelling of the throat due to an enlarged thyroid gland. In fact, iodine deficiency was the number one cause for young men to be discharged from the army during World War I. Besides goiter, mothers who are deficient are also at risk of giving birth to babies with a lower IQ, or even mental retardation.
Thousands of people suffered from iodine deficiency–induced goiter, an unsightly swelling of the throat due to an enlarged thyroid gland.
Despite the Saturday Evening Post report, the government, so far, has not warned about the risk of iodine deficiency. According to a National Health and Nutrition Examination Survey conducted in 2001–2002, Americans’ iodine levels were right where they should be. The average adult needs roughly 150 micrograms per day, or less than one-sixth of a milligram, and the study showed us at 167.8. An earlier NHANES survey conducted from 1988 to 1994 showed us at 145 micrograms.
Still, these numbers are much lower than they were a decade earlier. An NHANES survey from 1971 to 1974 revealed that average adults were getting 320 micrograms daily. Plus, there’s no data from the last four years.
“The  data shows that we’re probably OK, but my own personal feeling is that we need to keep a closer look at this,” says Kevin Sullivan, associate professor of epidemiology at Emory University, and a fellow at the Centers for Disease Control and Prevention. “We can’t afford to go any lower.”
Besides table salt, 70 percent of which is fortified, you can get iodine in your diet other ways. Trace amounts of iodine are also found in milk, as it’s a common practice in the dairy industry to swab iodine on a cow’s teats after milking to prevent inflammation.
There’s iodine in a lot of the meat and fresh produce we consume, passed on from the dirt in which the plants and livestock feed grow. How much depends on where it comes from. Parts of the country—the Great Lakes region, the Midwest, and the intermountain region—have iodine-deficient soil. This is why people living in the middle of the country before the 1920s had a higher incidence of goiter: At that time, Americans ate food that was locally grown and raised by necessity.
Most multivitamins contain it, as do ocean fish, kelp, and other seaweeds.
“We actually see many cases of excess iodine,” says Dr. Valerie Peck, an endocrinologist and clinical associate professor of medicine at New York University. “A lot of my patients are really into eating kelp these days,” she says.
But if you’re not on a macrobiotic diet, don’t eat much fish, and don’t take multivitamins, you could be at risk of iodine deficiency. Levels in meat, produce, and milk vary widely, and, according to Sullivan, they shouldn’t be depended on as one’s sole source of the micronutrient.
“If somebody really does not use any iodized salt, and doesn’t eat foods that contain iodine, they should be taking multivitamins,” says Sullivan. “If they don’t, I would be concerned.”