The 13-year-old boy came to the clinic with a rapidly ballooning neck. Doctors were puzzled.
Testing ruled out their first suspicion. But further tests pinpointed what they – and the boy – had been missing: iodine.
A century ago, iodine deficiency affected children across large swathes of the United States and the rest of the world. It essentially disappeared after some food makers started adding it to table salt, bread and other foods, in one of the great public health success stories of the 20th century.
But today, people are getting less iodine because of changes in diet and food manufacturing.
Although most people are still getting enough, researchers have increasingly been reporting low levels of iodine in pregnant women and other people, raising concerns about an impact on their newborns.