THE IODINE SUPPLY OF HUMANS DEPENDING ON SITE, FOOD OFFER AND WATER-SUPPLY

In Central Europe, the iodine content of weathered soils of new red sandstone, Muschelkalk, keuper and lower strata of new red sandstone, which developed from marine sediment is low. Boulder clays and diluvial sands also exhibit low iodine concentrations. In the same areas, the iodine concentration of drinking water decreases from 9 to 1 mu g/l with increasing distance from the oceans. Cereals and foodstuffs produced from them are extremely iodine-poor. The iodine content of plants increases with the proportion of leaves. Soil contamination raises the iodine content of foodstuffs and improves the iodine supply of animals. The iodination of mineral mixtures increased the iodine content of cow's milk from 17 to 81 mu g/l. The iodination of packed cooking salt and of the mineral mixtures for cattle and pigs resulted in a mean increase of the iodine intake of adults from about 30 mu g/day to 48 and 59, respectively. Although iodine intake remained considerably below the calculated requirement for adults (100 to 150 mu g/day), it led to the disappearance of Struma konnata and reduced the frequency of struma in children.