Progress towards eliminating iodine deficiency in South Africa

Before the introduction of salt iodisation in 1954, South Africa was one of the many countries of the world with a lack of iodine in most of its territory and hence there was a need for a salt iodisation programme. The understanding of the iodine situation in South Africa, the basics of iodine nutrition and progress toward eliminating iodine deficiency internationally and in South Africa are reviewed in this paper. Voluntary salt iodisation in the country at 10-20 ppm introduced in 1954 failed to eliminate endemic goitre and iodine deficiency. In contrast, considerable progress has been achieved in South Africa in eliminating iodine deficiency by introducing mandatory iodisation of table salt at 40-60 ppm in 1995. A 1998 survey showed that optimal iodine nutrition was achieved nationally and in seven of the nine provinces, with more than adequate iodine intake in two provinces. At that time, 86.4% of households used iodised salt and 62.4% used adequately iodised salt that contained more than 15 ppm of iodine, with low coverage rates (<50%) in the three northern provinces (Limpopo, Mpumalanga and North West). Closer collaboration between the South African Iodine Deficiency Disorders Network and the salt industry resulted in improved accuracy of salt iodisation. Knowledge of iodine nutrition amongst adults is low, particularly in low socioeconomic households, leading to the vulnerability of these groups to obtain non-iodised salt for cooking via unconventional sources. In South Africa a sound scientific data base should be used to maintain the strengths of the national salt iodisation programme and improve on any aspects of the programme in need of attention.