Urinary iodine excretion in 389 schoolchildren aged six to ten years in Northern Germany

Objectives: Numerous studies in recent years showed a gradual increase of urinary iodine excretion in Germany due to the use of iodinated salt.

Methods: Therefore the aim of the present study was to determine the iodine concentration in spot urine samples in 389 schoolchildren aged six to ten years from Northern Germany. Iodine was determined by paired-ion reversed phase high performance liquid chromatography (HPLC) with electrochemical detection.

Results: Iodine excretion was measured to be 89.5µg/l (median) or 110.5±85.1µg/l (mean±SD) with a range of 4.9 to 674.5µg/l. There were no statistically significant differences between boys and girls. According to the WHO criteria, no iodine deficiency, defined by an urinary iodine excretion exceeding 100µg/l, was found in 178 children (45.8%). Iodine deficiency grade I existed in 110 children (28.3%; i.e. iodine excretion between 50–100µg/l). 70 children (18.0%) had iodine deficiency Grade II (20–50µg/l), and 31 children iodine deficiency grade III (<20µg/l; 7.9%).

Conclusion: Our data show a further increase of urinary iodine excretion leading to an improved iodine supplementation. This will result in a decrease of goiter prevalence in this age group.