On May 1, 1924, iodized salt first became available on grocery shelves in Michigan, spurred largely by the series of reports by David Cowie, chair of the Pediatrics Department at the University of Michigan, David Marine, a U.S. physician in Ohio, and others in the preceding years.

In 1922, Cowie proposed at a Michigan State Medical Society thyroid symposium that the U.S. adopt salt iodization to eliminate simple goiter. The region had largely been severely iodine deficient, and Hartsock in 1926 described an outbreak of thyrotoxicosis in adults who took iodized salt living in the Great Lakes region of the goiter belt. Iodine is a micronutrient required for thyroid hormone production.