With the support of the Internal Grant Agency of the Ministry of Health CR in the district of Frýdek-Místek from January till May 1997 iodiuria was assessed in 208 children of both sexes aged 11-13 years in 24-hour urine samples in four fractions. The results indicate that the iodiuria of boys and girls does not differ significantly. 84% of the examined children from the mentioned region are adequately supplied with iodine, in 14% a mild deficiency was found and a clinically serious deficiency was recorded in 2% children. The iodine content of selected foods was assessed. The most significant natural iodine source are sea fish, other commonly consumed foods incl. water participate only to a minor extent in the iodine intake. Iodized table salt is used in food processing only by 25% of 115 addressed regional food manufacturers , iodized table salt accounts for 45% of the total volume of salt used. The mean iodine content in twelve samples obtained in the retail network was 21.5 mg I/kg salt. The mean decline of iodine concentration in salt fortified with potassium iodate in the course of 14 months was 0.4 mg I/kg salt, the iodine content in examined samples varied between 22.7 and 25.9 mg I/kg salt. Even a mild iodine deficiency can have an impact on the somatic, mental and sexual development of entire populations. Therefore at present an intervention programme is implemented to ensure optimal iodine saturation in particular of risk groups - children adolescents , pregnant and lactating women. A comparative examination of ioduria in 11-13-year-old children from the same communities will be made in 1999.

        Key words: iodine saturation - iodiuria - iodine sources - iodine content of foods - changes in iodine concentrartion of salt - intervention