David Murray Cowie pioneered the salt iodation process in America. A professor of pediatrics at the University of Michigan, Cowie was concerned about the widespread problem of goiter in Michigan (nicknamed the "goiter belt" of America). Aware of the Swiss process of adding sodium iodide or potassium iodide to table and cooking salt, Cowie decided that a simple way to address the problem of iodine deficiency would be to merely implement the Swiss solution in America. He had noted that adding iodine to aquatic environments in the Pacific Northwest seemed to decrease the incidence of goiter among fish species. Public opinion also supported his effort in that "important discoveries of vitamins and their roles in food nutrition" were happening during the period. Cowie appealed to the Michigan State Medical Society, a "productive group which concerned itself with the search for answers to difficult medical questions pertaining to the health of the state's residents".
Incorporating iodine into a regular diet would not be an easy process; the salt producers of America had to be persuaded to incorporate sodium iodide into their production process. It was difficult to prove that people who consumed iodized salt were better protected from simple goiter, a difficulty that contributed to resistance to the movement. Cowie and the Michigan State Medical Society turned to the Michigan Salt Producer's Association in 1923. Soon, an iodized salt committee was formed. After several months of meetings and deliberations with physicians and educators, the Executive Council of the Michigan State Medical Society gave Cowie the authority to endorse and implement the production of iodized salt, and the Michigan salt producers agreed to begin producing iodized table salt with labels reading "contains .01 per cent sodium iodide".
On May 1, 1924, iodized salt by Diamond Crystal Salt, Mulkey Salt, Inland Delray Salt, Michigan Salt Works, and Ruggles and Rademaker appeared on Michigan grocers' shelves. By the fall of 1924, Morton Salt Company began distributing iodized salt nationally.
Cowie's efforts to improve the public health environment necessitated broad cooperation. Cowie gained support from the medical board and market support from the Michigan Salt Producers Association, and with this scientific backing, the general public accepted the change. Through this process, we have an early example of an optimal default being created in the field of public health. Cowie's efforts also added a new focus on prevention as well as the advancement and improvement of social and industrial lives as it became more prevalent during the Progressive Era, rather than on merely curing diseases. It was also highlighted by a larger focus on vitamins and in general the possibility of supplementing foods as a way to solve health problems.
Another person who is also credited for the introduction of iodized table salt to America is Dr. William A. Hudson, who devoted much of his time to the study of iodine levels in the blood while at Washington University, the Royal Victoria Hospital in Montreal, and Ford Hospital in Detroit.
Photo of Dr. Cowie's private hospital in Ann Arbor, on Flickr: http://www.flickr.com/photos/vox/2350583240/