Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com Original Paper Ann Nutr Metab 2007;51:439–447 DOI: 10.1159/000111164 Iodine Intake of Slovenian Adolescents Matevž Štimec a Nataša Fidler Mis a Katarina Smole a Andreja Širca-Čampa a Primož Kotnik b Mirjana Zupančič c Tadej Battelino b Ciril Križišnik b a Centre for Nutrition, b Department of Endocrinology, Diabetes and Metabolism, and c Biochemical Laboratory, University Children’s Hospital, Ljubljana, Slovenia Introduction Adequate iodine consumption in a population is ex- tremely important for public health, as both low and high iodine intakes are associated with various thyroid diseas- es [1, 2]. The dietary iodine supply is influenced by a num- ber of agricultural, commercial and cultural factors. In a previous publication we described the history of goiter prevalence, changes in urinary iodine excretion, and regulatory changes in salt iodization in Slovenia [3]. Briefly, iodized table salt (salt added in cooking and at the table) was introduced in Slovenia in 1953 (10 mg KI/kg salt). In 1999 the obligatory supplementation of table salt with iodine was increased to 25 mg KI/kg salt (or 32 mg KIO 3 /kg salt which is equal to 19 mg iodine/kg salt). Reg- ulations from 1999 [4] did not define the iodization of salt used in the food industry; therefore, in 2003 a new regula- tion came into force. It defines that all salt, except sea salt, traded on the Slovenian market for human consumption and production of foods has to be iodized (25 mg KI/kg salt or 32 mg KIO 3 /kg, which corresponds to 19 mg io- dine/kg salt). Additionally all table salt, whether evapo- rated, sea or mineral, used in households has also to be iodized (25 mg KI/kg salt or 32 mg KIO 3 /kg) [5]. In 2004 an appendix was added to the 2003 law mandating that all imported salt sold in Slovenia has to be in accordance with Slovenian law [6] . Thus all salt in Slovenia, except sea salt, used in the food industry has to be supplemented with iodine (25 mg KI/kg salt or 32 mg KIO 3 /kg). However, it was unknown what effect this increase in table salt iodization would have on Slovenian iodine nu- Key Words Nutrition  Iodine intake  Salt  Food frequency questionnaire  Dietary protocol Abstract Background: Slovenia is classified as being iodine-deficient. We recently found that Slovenian adolescents are iodine- sufficient (median urinary iodine concentration of the popu- lation 140 g/l) and the prevalence of goiter is low (0.9%). The objective of this study was to evaluate iodine intake, the prevalence of marginal, low and excessive intake ( !50, 50– 100 and 6300 g/day), as well as the main sources of iodine in the diet of Slovenian adolescents. Methods: A cross-sec- tional study included 2,581 adolescents (1,415 girls, 1,166 boys, mean age 8 SD 15.6 8 0.5 years) representing 10% of 15-year-old Slovenian adolescents. Iodine intake was deter- mined using a food frequency questionnaire (FFQ) in the whole population studied (n = 2,485) and weighted 3-day dietary protocols (3DPs) in a subgroup of participants (n = 191). Results: Median iodine intake determined from FFQ was 155.8 g/day. There was no significant difference be- tween genders. Marginal, low and excessive iodine intake was observed in 3.3, 20.3 and 11.3% of the adolescents, re- spectively. The major food sources of dietary iodine includ- ed table salt (39 % of the mean daily iodine intake), bever- ages (22%) and milk/milk products (19%). Conclusions: Dietary iodine intake in Slovenian adolescents is adequate, illustrating the effective salt iodization program. Copyright © 2007 S. Karger AG, Basel Received: November 7, 2006 Accepted: April 20, 2007 Published online: November 20, 2007 Nataša Fidler Mis University Medical Centre Ljubljana, University Children’s Hospital Centre for Nutrition, Vrazov trg 1 SI–1000 Ljubljana (Slovenia) Tel. +386 1 522 9308, Fax +386 1 522 9357, E-Mail Natasa.Fidler@guest.arnes.si © 2007 S. Karger AG, Basel 0250–6807/07/0515–0439$23.50/0 Accessible online at: www.karger.com/anm