BACKGROUND: An epidemiologic survey showed in 1992 iodine deficiency and endemic goiter in schoolchildren from the Basque Country. OBJECTIVES: (1) To determine the percentage of homes of schoolchildren where iodized salt (IS) is used; (2) to assess iodine nutrition status in schoolchildren and to compare the data collected to those available from previous epidemiological studies. DESIGN AND METHODS: A cross-sectional study in 720 randomly selected schoolchildren. Urinary iodine concentration (UIC) was measured using high-performance liquid chromatography(HPLC) with electrochemical detection. RESULTS: IS was used at 53.0% of the homes (95% confidence interval [CI], 49.2-56.7%). Median UIC has increased by 226%, from 65 μg/L in 1992 to 147 μg/L (percentile [P], P(25), 99 μg/L; P(75), 233 μg/L) today. Both schoolchildren consuming IS and those using unfortified salt at their homes had UICs corresponding to adequate iodine intakes (165 and 132 μg/L respectively). UICs experienced great seasonal fluctuations, being 55% higher during the November-February period than in June-September period (191 μg/L vs 123 μg/L; p<0.001) CONCLUSIONS: Schoolchildren from the Basque Country have normalized their iodine nutrition status. The strong seasonal pattern of UICs suggests that consumption of milk and iodine-rich dairy products coming from cows feed iodized fodder is one of the most significant factors involved in the increase in iodine intake since 1992.
BACKGROUND: An epidemiologic survey showed in 1992 iodinedeficiency and endemic goiter in schoolchildren from the Basque Country. OBJECTIVES: (1) To determine the percentage of homes of schoolchildren where iodized salt (IS) is used; (2) to assess iodine nutrition status in schoolchildren and to compare the data collected to those available from previous epidemiological studies. DESIGN AND METHODS: A cross-sectional study in 720 randomly selected schoolchildren. Urinary iodine concentration (UIC) was measured using high-performance liquid chromatography(HPLC) with electrochemical detection. RESULTS: IS was used at 53.0% of the homes (95% confidence interval [CI], 49.2-56.7%). Median UIC has increased by 226%, from 65 μg/L in 1992 to 147 μg/L (percentile [P], P(25), 99 μg/L; P(75), 233 μg/L) today. Both schoolchildren consuming IS and those using unfortified salt at their homes had UICs corresponding to adequate iodine intakes (165 and 132 μg/L respectively). UICs experienced great seasonal fluctuations, being 55% higher during the November-February period than in June-September period (191 μg/L vs 123 μg/L; p<0.001) CONCLUSIONS: Schoolchildren from the Basque Country have normalized their iodine nutrition status. The strong seasonal pattern of UICs suggests that consumption of milk and iodine-rich dairy products coming from cows feed iodized fodder is one of the most significant factors involved in the increase in iodine intake since 1992.