[Eighteen years of universal salt iodization in Iran; the fourth national survey of goiter prevalence and urinary iodine excretion of schoolchildren [2007-2008]]

ABSTRACT

Iodine deficiency disorders [IDD] have been recognized as a major public health problem in Iran for many years. Following the iodine deficiency elimination program, Iran is now an IDD free country in the Middle-East region. This study was performed to evaluate the adequacy of iodine supplementation after 18 years of universal salt iodization and the current status of iodine nutrition in all 30 provinces of Iran. In this descriptive cross-sectional study, [conducted between Oct 2007-February 2008] 36000 schoolchildren, aged 8 to10 years, were randomly selected from all provinces. Goiter prevalence and urinary iodine excretion in schoolchildren and iodine content of salt at household, factory and distribution sites were measured. Total goiter rate [TGR] in the country was 6.5% [6% grade 1 and 0.5% grade 2], and weighted goiter rate was 5.7%. TGR in Hamedan, Zanjan, Kermanshah, Mazandaran and Gilan was over 10%. The median urinary iodine was 140 microg/L, with urinary iodine levels of 20-50, 50-99 and >/= 100 microg/L being 15.3%, 19.8% and 64.9%, respectively. In four provinces, median urinary iodine was lower than100 microg/L. Mean [ +/- SD] and median salt iodine were 23.2 [13.8] and 34.7 ppm at production level and 32.4 [14.7] and 32.3 ppm at distribution level, respectively. Ninety-eight percent of households consumed iodized salt, and 58% of households had appropriate salt storage. The I.R. Iran has made strong progress in the development of universal salt iodization strategy and meets all criteria for sustainable elimination of iodine deficiency. However, lack of adequate iodine nutrition in some provinces necessitates special attention and proper monitoring