“Red Dye number 3 contains four iodine atoms in the molecule. And iodine acts on the thyroid. And so when you’re ingesting large amounts of iodine, it stands to reason that it would affect the ...

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 kids across large swaths of ...