Chapter 37 - The Iodine Content of Foods and Diets: Norwegian Perspectives

Abstract

Dietary sources of iodine vary with country and population. Determination of the iodine content in Norwegian foods shows that fish and seafood, milk and dairy products, and eggs have the highest iodine concentration. Dietary studies in the Norwegian population show that the amount and frequency of intake of these iodine rich sources are of great importance to achieve sufficient dietary iodine intake. Dietary iodine intake of adults is in the range of 50–250 μg/day. Dietary iodine intake is in the range of the recommended level among children, and below the recommendation among adolescents and subgroups of pregnant women. Regular intake of fish and seafood and/or milk and dairy products is of great importance to achieve a sufficient iodine intake in the Norwegian diet. Urinary iodine concentration in small groups of adults indicates sufficient iodine intake. Mandatory iodization of cow fodder has been more important for iodine intake than iodized table salt in Norway. Increase in the iodine content of milk and dairy products through fodder supplement, and also the more widespread use of fish and seafoods, explains the eradication of iodine deficiency in Norway in the 1950s. To secure sufficient iodine intake in the population of Norway today, a continued monitoring of iodine concentration in foods, together with surveys of iodine nutrition and status in the population is necessary.