High iodine intake by preschool children in Miyagi prefecture, Japan

Environ Health Prev Med. 2014 Sep;19(5):330-8. doi: 10.1007/s12199-014-0394-6. Epub 2014 Jun 28.

Abstract

Objectives: Standard Tables of Food Composition in Japan 2010 (FCT) remain incomplete for iodine contents. This survey was initiated to develop a method to cope with this shortage and to find daily iodine intake of preschool children in Japan.

Methods: Data were available for one-day food intake for 296 3- to 6-year-old children (the total cases). 128 samples (the selected cases) were analyzed by ICP-MS for iodine (the measured values). Iodine intake was also calculated using FCT assuming that iodine contents in missing items were zero (the calculated values).

Results: Measured and calculated values for the selected 125 cases (after exclusion of 3 extreme cases) gave geometric means (GM) of 117.6 and 101.8 μg/day. The measured/calculated ratio in GM, 117.6/101.8 = 1.155, was applied to the calculated values for total 296 cases to estimate iodine intake (the estimated values). GM for the estimated value was 175.2 μg/day and it was 8.93 μg/kg/day after adjustment for body weight for 296 children. There was no significant difference between boys and girls.

Discussion: The GM values for both the measured and estimated values (n = 125 pairs) were 117.6 μg/day. The agreement suggested that the factor employed, 1.155, was proper and adequate. Literature survey suggested that values on a body weight basis were comparable between the children and adults in Japan. The levels were higher than levels in east Asian countries.

Conclusions: A correction method was developed for estimation of daily dietary iodine intake. The iodine intake level for preschoolers was comparable to levels for adult population.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Child
  • Child, Preschool
  • Diet Surveys*
  • Eating*
  • Female
  • Humans
  • Iodine / metabolism*
  • Japan
  • Male
  • Mass Spectrometry

Substances

  • Iodine