Iodine in Salt – the First Fortification
During the 1921 American Medical Association (AMA) convention, two Ohio doctors presented findings from their clinical trial demonstrating the effectiveness of sodium iodide treatments for the prevention of goitre. It was found that without iodine the body could not properly synthesize thyroid hormones, which often resulted in an unsightly neck goitre or in more serious cases, mental retardation. Iodine deficiency generally occurs in areas where the soil has been depleted of iodine because of flooding, heavy rainfall, or glaciation. Shortly after the publication of the results, Michigan became the first state to institute a public campaign to provide dietary iodine via salt. An extensive educational campaign that involved schoolteachers, industry as well as medical and public health communities helped increase consumer awareness about, and demand for, iodized salt so that by 1924 iodized salt was commonplace, despite the fact that iodization was never mandatory. Epidemiological studies following the implementation recorded a significant decline in the incidence of goitre, confirming the success of the programme. Most table salt continues to be fortified with iodine today.