In university, I had a passionate biology lecturer dedicated to resolving global iodine deficiencies. He always advocated for iodized salt, claiming it plays a pivotal role in enhancing public health. His emphasis on its significance still resonates with me whenever I browse the salt aisle at the supermarket.

Recently, I’ve observed a decline in the availability of iodized salt. Fancy varieties like Cornish sea salt, Himalayan pink salt, and gourmet kosher salts are dominating the shelves. The remaining iodized salt products are often unattractive, posing the question: Are we risking the benefits brought by this simple yet vital mineral?

Iodine is a crucial mineral that the thyroid uses to produce hormones essential for metabolism, growth, digestion, heart rate, and body temperature regulation.

Ensuring adequate iodine intake during pregnancy is especially critical, as thyroid hormones influence fetal brain development. Mild iodine deficiency can diminish intelligence significantly—by as much as 13 IQ points. It is equally important for children, supporting both brain development and thyroid functionality. Reports exist of children suffering from iodine deficiency displaying poor school performance and fatigue due to extreme pickiness in food choices. Additionally, both adults and children can develop goiter, an enlargement of the thyroid gland, due to insufficient iodine intake.

Natural sources rich in iodine include seaweed, seafood, and dairy products. Milk contains iodine due to iodine being added to cow feed and the use of iodine-based disinfectants during milking. Fruits, vegetables, and grains can capture minimal amounts of iodine from soil, which varies significantly in iodine content. Regions like Switzerland and Michigan historically had iodine-poor soil, resulting in high incidences of goiter among children.

In 1922, Switzerland pioneered iodized salt by adding iodine to table salt. This initiative led to a near elimination of goiters and remarkable increases in children’s height and IQ, as economist Dimitra Politi described it. High school graduation rates soared as a result of this public health intervention.

Iodized salt made its way to Michigan in 1924, followed by widespread adoption across the U.S. and other countries. Its introduction significantly contributed to the global rise in IQ witnessed in the 20th century. Rarely has such an inexpensive invention delivered such monumental benefits. Endocrinologist Gerald Barrow famously stated, “Five cents per person per year can make the entire population smarter than before.”

Despite these gains, iodized salt faces a popularity crisis today. The allure of pink Himalayan sea salt often overshadows the practical benefits of iodized options. Many consumers avoid iodized salt, mistakenly believing it contains harmful additives, despite iodine being a natural element.

As people reduce their use of iodized salt at home, they increasingly rely on processed foods, which typically contain non-iodized salt. The growing popularity of vegan diets and plant-based milk alternatives further diminishes iodine intake.

A recent study indicates that Americans not consuming enough iodine has doubled since 2001, with alarming findings showing that 46% of pregnant women are iodine deficient.

This trend is mirrored in the UK, where women of reproductive age show average iodine levels below recommended standards. In Australia, 62% of pregnant and breastfeeding women lack sufficient iodine. Conversely, some regions in Japan report excessive iodine intake leading to thyroid complications.

Consequently, public health experts urge residents of the U.S., U.K., and Australia to reintroduce iodized salt into their diets to safeguard against cognitive impairments, thyroid issues, and the potential return of goiter.

It’s perplexing. The supplement industry thrives, with people consuming large doses of zinc, selenium, and ginkgo biloba for brain health, often despite minimal evidence supporting these benefits. In contrast, iodine supplements and iodized salt remain overlooked, despite the risks associated with iodine deficiency.

Regardless of current trends, I will persist in my quest for iodized salt at the supermarket, wary of the judgment that may accompany a purchase of those appealing pink flakes.