[Iodine supply in school children three years after introduction of obligatory salt iodization]

Three years after introduction of obligatory salt iodization in Poland we evaluated iodine supply in children from Mazovia region. Urinary iodine concentration (UIC) was estimated in morning samples from 779 schoolchildren aged 6-14 years. Previous investigation 7 years ago revealed mild or moderate iodine deficiency in this area. UIC was lower than 100 micrograms/l in 80% of samples and mean UIC was 56.9 +/- 42.3 micrograms/l. According to WHO and ICCIDD recommendations median value of UIC at least 100 micrograms/l in the representative sample of population indicates satisfactory iodine supply. Recent data revealed that UIC was much higher than in the first phase of study, 7 years ago--mean 115.5 +/- 76.6 micrograms/l and median 100.69 micrograms/l. UIC lower than 100 micrograms/l occurred in 48% of samples, more frequently in rural regions. Iodine supply in the region was diversified--we revealed rural cohort where mean and median values of UIC (corresponding 78.96 +/- 47 micrograms/l and 67.8 micrograms/l) were unexpectedly low. Our results confirm the improvement of iodine supply in Poland after 1997. Nevertheless, taking under consideration that daily iodine supply in children and adolescents should reach 120-150 micrograms, the situation is not fully satisfactory--almost in half of schoolchildren iodine consumption hardly reaches recommended value for the whole population. We stress the necessity of continuous monitoring of the adequacy of iodine supplementation and its results.