<P> In the U.S. in the early 20th century , goitre was especially prevalent in the region around the Great Lakes and the Pacific Northwest . David Murray Cowie , a professor of paediatrics at the University of Michigan , led the U.S. to adopt the Swiss practice of adding sodium iodide or potassium iodide to table and cooking salt . On May 1 , 1924 , iodised salt was sold commercially in Michigan . By the fall of 1924 , Morton Salt Company began distributing iodised salt nationally . There was a gradual increase in average intelligence of 1 standard deviation , 15 points , in iodine - deficient areas and 3.5 points nationally . </P>
<P> In the U.S. in the early 20th century , goitre was especially prevalent in the region around the Great Lakes and the Pacific Northwest . David Murray Cowie , a professor of paediatrics at the University of Michigan , led the U.S. to adopt the Swiss practice of adding sodium iodide or potassium iodide to table and cooking salt . On May 1 , 1924 , iodised salt was sold commercially in Michigan . By the fall of 1924 , Morton Salt Company began distributing iodised salt nationally . There was a gradual increase in average intelligence of 1 standard deviation , 15 points , in iodine - deficient areas and 3.5 points nationally . </P>
when did they start putting iodine in salt
when did they start putting iodine in salt
1924
1924