title: Iodine status in preschool children and evaluation of major dietary iodine sources: a German experience.
abstract: OBJECTIVE
  Even mild iodine deficiency may negatively affect cognitive performance, especially at a young age. Our aim was to investigate iodine status in very young children and to assess the importance of iodized salt in processed foods of which the use has decreased during the last years in Germany.
  
  
  METHODS
  Twenty-four hours urinary iodine excretion (UIE) as a marker of iodine intake was measured in 378 24 h urine samples collected 2003-2010 by 221 3 to <6 years old participants of the DONALD Study. Parallel 3-d weighed dietary records and measurements of urinary sodium excretion provided data on the daily consumption of the most important iodine sources in the children's diet (iodized salt, milk, fish, meat and eggs). Time trends of UIE (2003-2010) and contributions of the different food groups were analyzed by using linear mixed-effects regression models.
  
  
  RESULTS
  Median UIE of 71 μg/d in boys and 65 μg/d in girls (P = 0.03), corresponding to an iodine intake of 82 and 75 μg/d, respectively (assumption: 15% non-renal iodine losses), was below the recommended dietary allowance (RDA) of 90 μg/d. Milk, salt and egg intake were significant predictors of UIE; milk and salt together accounted for >80% of iodine supply. Between 2003 and 2010, UIE decreased significantly by approximately 1 μg/d per year. The contribution of salt intake to UIE decreased from 2003-2006 to 2007-2010.
  
  
  CONCLUSIONS
  In countries where salt is a major iodine source, already modest decreases in the iodized proportion of salt used in processed foods may relevantly impair iodine status even in preschool children.
authors.affiliation: IEL-Nutritional Epidemiology, DONALD Study at the Research Institute of Child Nutrition, University of Bonn, Heinstück 11, 44225, Dortmund, Germany, johner@fke-do.de.
authors.forename: Simone A
authors.initials: SA
authors.lastname: Johner
authors.forename: Michael
authors.initials: M
authors.lastname: Thamm
authors.forename: Ute
authors.initials: U
authors.lastname: Nöthlings
authors.forename: Thomas
authors.initials: T
authors.lastname: Remer
mesh_terms: D000818:Animals; D000886:Anthropometry; D002675:Child, Preschool; D004531:Eggs; D005260:Female; D005399:Fishes; D005858:Germany; D006801:Humans; D007455:Iodine / Q000008:administration & dosage / Q000097:blood* / Q000172:deficiency / Q000652:urine; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008460:Meat; D008892:Milk / Q000737:chemistry; D015596:Nutrition Assessment; D009752:Nutritional Status; D012964:Sodium / Q000652:urine; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage / Q000652:urine
chemical_list: D017673:Sodium Chloride, Dietary; C034024:iodized salt; D007455:Iodine; D012964:Sodium