Simulation of total dietary iodine intake in Flemish preschool children

The aim of the present study was to calculate the distribution of total iodine intake among Flemish preschoolers and to identify the major sources contributing to iodine intake. A simulation model using a combination of deterministic and probabilistic techniques was utilised. Scenario analyses were performed to assess iodine intake via dairy products, industrially added iodised salt in bread and discretionarily added iodised household salt. Relevant data from 3-d estimated dietary records of 696 preschoolers 2·5-6·5 years old were used. Usual iodine intakes were calculated using the Iowa State University method. With a more generalised utilisation of iodised salt in bread (44 % of the bakers in 2011 instead of 12 % in 2002), mean iodine intake increased from 159 to 164 μg/d using the McCance and Widdowson's food composition table and from 104 to 109 μg/d using the German food composition table. The percentage of preschoolers with an iodine intake below the estimated average requirement (65 μg/d) decreased from 5-12 to 4-9 %, while the percentage of preschoolers with an iodine intake above the tolerable upper intake level (300 μg/d) remained constant (0·3-4 %). Mean iodine intake via food supplements was 4·2 μg/d (total population) and 16·9 μg/d (consumers only). Both in 2002 and 2011, sugared dairy products, milk and iodised salt (21·4, 13·1, and 8·7 %, respectively in 2011) were the main contributors to total iodine intake. In conclusion, dietary iodine intake could still be improved in Flemish preschoolers. The use of adequately iodised household salt and the more generalised use of iodised salt by bakers should be further encouraged.