Iodine Deficiency Resurfaces, Raising Concerns Among Doctors

NEW YORK — A 13-year-old boy presented at a clinic with a significantly enlarged neck, baffling doctors.

Initial diagnoses were incorrect. Subsequent testing revealed iodine deficiency as the cause.

A century ago, iodine deficiency was widespread among children nationwide. This was largely eradicated after food manufacturers began adding iodine to salt, bread, and other foods – a major public health triumph.

However, dietary shifts and changes in food production have led to reduced iodine intake.

While most individuals still obtain sufficient iodine, researchers are increasingly observing low iodine levels in pregnant women and others, raising concerns about effects on newborns. Additionally, a small but growing number of pediatric iodine deficiency cases are being reported.

“This issue requires attention,” stated Dr. Monica Serrano-Gonzalez of Brown University, who treated the boy in 2021 in Providence, Rhode Island.

What is iodine?

Iodine, a trace mineral, is found in seawater and certain soils, primarily coastal regions. Its discovery in 1811 by a French chemist, during an experiment with seaweed ash, resulted in a purple vapor, giving rise to its name (from the Greek for violet-colored).

Later, scientists determined iodine’s vital role in metabolism and overall health, particularly for brain development in children.

Neck swelling (goiter) is a symptom of iodine insufficiency. The thyroid gland, using iodine to produce hormones regulating heart rate and other functions, enlarges when iodine is deficient.

At the start of the 20th century, goiter was prevalent among children in inland U.S. areas, notably a “goiter belt” spanning Appalachia, the Great Lakes, and the Northwest. Affected children often exhibited short stature, deafness, intellectual disabilities, and other symptoms of cretinism.

Adding iodine to salt

Public health experts, recognizing the impracticality of widespread seaweed consumption, implemented iodine fortification of table salt. Iodized salt emerged in 1924, achieving over 70% household usage by the 1950s. Bread and other foods were also fortified, making iodine deficiency uncommon.

Dietary habits have evolved. Many processed foods, despite containing significant salt, lack iodine. Leading bread brands have discontinued iodine fortification. The 13-year-old boy, who had mild autism and was a picky eater, consumed primarily specific bread and peanut butter brands.

Consumers increasingly favor non-iodized salts like kosher salt and Himalayan rock salt.

“People have forgotten the reason for iodine in salt,” explained Dr. Elizabeth Pearce of Boston Medical Center and a leader in the Iodine Global Network.

She noted a decline in U.S. iodine levels between the 1970s and 1990s.

How much iodine is enough?

Although overall iodine consumption is decreasing, experts state most Americans still obtain sufficient amounts. However, doctors express concern for women and children, who are more susceptible to deficiency.

The American Academy of Pediatrics and other medical organizations recommend 150 micrograms of iodine daily for pregnant and breastfeeding women, attainable through ½ to ¾ teaspoon of iodized salt.

In recent years, U.S. studies have increasingly reported mild iodine deficiency in pregnant women. A Michigan State University study of approximately 460 pregnant women in Lansing found about 25% had insufficient iodine intake.

Many prenatal vitamins lack iodine, according to Jean Kerver, the study’s lead author. She recommends pregnant and breastfeeding women check labels to ensure their supplements contain iodine.

Some studies associate even mild iodine deficiency with lower IQs and language delays in children, though the exact threshold for problems remains debated, Pearce noted.

Experts cite insufficient research on the impact of iodine deficiency on the U.S. population in recent years.

Serrano-Gonzalez reported observing four additional pediatric cases in their Providence clinic.

“We are concerned about a potential increase, particularly in individuals with restricted diets,” she stated.

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