science · 01 May 1924 · 100 years ago
In 1924, the first iodized table salt in the U.S. went on sale at grocers in Michigan state. The table salt contained 0.01% sodium iodide as a dietary supplement, since an adequate intake of iodine reduces the incidence of goitre (major swelling of the thyroid gland in the neck.) Diamond Crystal Salt, and four other Michigan table salt companies agreed to add the trace of iodine compound to their product at the urging of the Michigan State Medical Society, initiated and led by David Murray Cowie. At first reluctant, later in the year, Morton Salt Company supplied the national market. The significant value of iodine for this purpose had been determined by David Marine, as a result of a trial (1917-22) on a large group of schoolgirls.