GOITRE PROPHYLAXIS BY ADDITION OF POTASSIUM IODATE TO BREAD: Experience in Tasmania

Abstract

In March/April, 1966, potassium iodate was substituted for some potassium bromate in the bread improver used throughout Tasmania, as a universal prophylactic against endemic goitre. The rate of addition of iodate was 2 parts per million of bread by weight. After a preliminary survey in 1949, tablets containing 10 mg. potassium iodide had been made available to infants, preschool children, and schoolchildren through schools and child-health centres for weekly consumption for approximately sixteen years. State-wide surveys at five-year intervals showed a slow steady reduction in the prevalence of goitre, but in some regions the rates remained high. It was presumed that this was due to ineffective distribution of the tablets. Since 1966 there has been a further striking reduction in the prevalence of goitre, and the 1969 rates for the whole State are similar to these in a non-goitrous region. Some unexplained regional variations were noted in the latest survey. It is concluded that the incorporation of 2 parts per million potassium iodate in bread is an effective prophylactic against endemic goitre.