Journal List > Int J Thyroidol > v.8(2) > 1082720

Int J Thyroidol. 2015 Nov;8(2):170-182. Korean.
Published online November 30, 2015.  https://doi.org/10.11106/ijt.2015.8.2.170
Copyright © 2015. the Korean Thyroid Association. All rights reserved.
An Iodine Database for Common Korean Foods and the Association between Iodine Intake and Thyroid Disease in Korean Adults
Mi-Rhan Han,1 Dal Lae Ju,2 Young Joo Park,3 Hee-Young Paik,4 and YoonJu Song1
1Major of Food & Nutrition, School of Human Ecology, The Catholic University of Korea, Bucheon, Korea.
2Department of Food Service and Nutrition Care, Seoul National University Hospital, Seoul, Korea.
3Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
4Department of Food and Nutrition, Seoul National University, Seoul, Korea.

Correspondence: YoonJu Song, PhD, Major of Food & Nutrition, School of Human Ecology, The Catholic University of Korea, 43 Jibong-ro, Wonmi-gu, Bucheon 420-743, Korea. Tel: 82-2-2164-4681, Fax: 82-2-2164-6583, Email: yjsong@catholic.ac.kr
Received April 12, 2015; Revised May 25, 2015; Accepted June 08, 2015.

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


Abstract

Background and Objectives

Iodine is essential for thyroid hormone production and the iodine intake of Koreans is high. Few studies have examined the association between iodine intake and thyroid disease in the Korean population due to the lack of an iodine database. Therefore, this study established an iodine database, evaluated iodine intake levels, and explored the association between iodine intake and thyroid disease.

Materials and Methods

We obtained data for 9998 subjects who had both biochemical and dietary data from the 2007-2009 Korea National Health and Nutrition Examination Survey.

Results

An iodine database was established for 667 food items. The median iodine intake in the population was 375.4 µg per day. The iodine contribution by food group was 65.6% from seaweed, 18.0% from salted vegetables, and 4.8% from fish. When subjects were divided into five groups across quintiles of iodine intake per 1000 kcal, excluding extreme subjects who consumed above the upper limit, age, sex, income, education, drinking, and smoking differed across the groups. While the energy and fat intakes decreased, other nutrients increased across the quintile groups. The consumption of seaweeds, fish, eggs, and salted vegetables increased across the quintile groups. After adjusting for all potential confounding variables, the odds ratio for thyroid disease in the highest quintile was 1.63 compared to that in the lowest quintile (p for trend=0.0352).

Conclusion

The iodine intake of the Korean population is high, with high consumption of seaweeds, salted vegetables, and fish positively associated with thyroid disease.

Keywords: Iodine; Intake; Database; Thyroid disease; Korean

Figures


Fig. 1
The distribution of iodine intake in the Korean adults population aged 20 or more using the data from 2007-2009 Korea National Health and Nutrition Examination Survey. Box: Q3-Q1 (Interquartile range), Q1: 25th percentile, Q3: 75th percentile
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Fig. 2
The average and range of iodine intake across quintile and extreme group. Quintile group was classified based on the iodine intake per 1000 kcal.
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Tables


Table 1
Composition of the table of iodine values for common Korean foods
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Table 2
The contribution of iodine intake according to food groups in total population
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Table 3
Socio-demographic characteristics of study subjects
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Table 4
Nutrient intake of study subjects
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Table 5
Food group intakes across quintile of iodine intake including extreme group
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Table 6
The odds ratio for thyroid disease across the quintile of iodine intakes
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Notes

This study was supported by the Research Fund, 2014 of The Catholic University of Korea.

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