Objective: To determine how iodine deficiency and endemic goitre disappeared in Britain.
Design: Review of surveys of endemic goitre and iodine nutrition.
Main results: Endemic goitre was widespread in Britain but has declined, most notably since the 1960's. Its disappearance was probably due to changes in farming practice, especially iodine supplementation in dairy herds which has resulted in iodine contamination of milk and dairy produce.
Conclusions: Although iodization of dairy herds offers an indirect method of counteracting iodine deficiency, it is haphazard and there should be careful and continuous monitoring of iodine intakes in the population.