Journal of Nutrition and Health

The Korean Nutrition Society (한국영양학회)
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A study to evaluate the safety of iodine intake levels in women of childbearing age: 2013-2015 Korea National Health and Nutrition Examination Survey

가임기 여성의 요오드 섭취 수준의 안전성 평가 연구: 2013-2015 국민건강영양조사 자료 활용

  • Lee, Jung-Sug (Department of Food and Nutrition, Kookmin University)
  • Received : 2021.11.11
  • Accepted : 2021.12.10
  • Published : 2021.12.31
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Abstract

Purpose: This study was conducted to evaluate the safety of iodine intake based on ingestion levels and urinary iodine excretion of women of childbearing age (15-45 years old) using data from the 2013-2015 Korea National Health and Nutrition Examination Survey. Methods: Iodine intake was calculated using the 24 hours dietary recall method and urinary iodine excretion. The iodine nutrition database for the analysis of dietary iodine intake was constructed using the food composition database of the Rural Development Administration (RDA), the Korean Nutrition Society (KNS), the Ministries of Food and Drug Safety, China and, Japan. The World Health Organization (WHO) evaluation criteria and hazard quotient (HQ) calculated using biomonitoring equivalents (BE) were applied to evaluate the safety of the iodine intake. Results: Of the study subjects, 15.22% had a urinary iodine concentration level of less than 100 ㎍/L, which was diagnosed as deficient, and 48.16% had an excessive iodine concentration of over 300 ㎍/L. Urinary iodine concentration was 878.71 ㎍/L, iodine/creatinine was 589.00 ㎍/g, and iodine/creatinine was significantly higher at the age of 30-45 years. The dietary iodine intake was 273.47 ㎍/day, and the iodine intake calculated from the urinary iodine excretion was 1,198.10 ㎍/day. Foods with a high contribution to iodine intake were vegetables, seafood, seaweed and processed foods. The HQ was 1.665 when the urinary iodine content was > 1,000 ㎍/L. Conclusion: The results of this study implicate that the urinary iodine concentration, rather than the dietary iodine intake, is more appropriate to evaluate the iodine status under the current situation that a comprehensive iodine database for Koreans has not been established.

본 연구는 제6기 (2013-2015년) 국민건강영양조사 자료를 활용하여 만 15-45세의 가임기 여성 1,559명을 대상으로 요오드 섭취 및 소변 중 요오드 함량을 기준으로 요오드 섭취의 안전성을 평가하였다. 요오드 섭취량 분석을 위해 요오드 영양성분 DB를 구축한 후 24시간 식사조사자료와 매칭하여 식이를 통한 요오드 섭취량을 분석하였고, 소변 중 요오드 함량을 적용하여 하루 단위의 요오드 섭취량을 산출하였다. 또한 요오드 섭취의 안전성 평가를 위해 WHO의 평가기준을 적용하였고, 요오드의 영양소 섭취기준 중 상한섭취량을 기준으로 하여 BE를 산출한 후 소변 중 요오드 함량을 적용하여 HQ를 계산하였다. 그 결과 소변 중 요오드 함량이 100 ㎍/L 미만이어서 요오드 결핍으로 진단되는 비율은 15.22%이었고, 요오드 섭취 과잉으로 진단되는 300 ㎍/L 이상인 대상자는 48.16%이었다. 소변 중 요오드 함량은 평균 878.71 ㎍/L이었고, 요오드/크레아티닌은 589.00 ㎍/g이었으며, 요오드/크레아티닌은 30-45세 연령군이 15-18세, 19-29세 연령군에 비해 유의적으로 높았다. 식이를 통한 요오드 섭취량은 273.47 ㎍/day, 소변 중 요오드 함량을 통해 산출된 요오드 섭취량은 1,198.10 ㎍/day로, 두 조사방법에 의한 차이는 924.63 ㎍/day로 식이를 통한 요오드 섭취량보다 소변을 통해 산출된 요오드 섭취량이 더 높았다. 요오드 섭취량에 기여도가 높은 식품은 채소류, 어패류, 해조류 및 가공식품이었고, 요오드 섭취의 위험도를 평가하는 HQ는 한국인 영양소섭취기준 적용 시 0.228이었고, 소변 중 요오드 함량이 1,000 ㎍/L 이상 시 평균 1.665로 1 이상의 높은 수준이었다. 혈중 TSH는 2.14 mIU/L, free T4는 1.10 ng/L이었으며, 소변 중 요오드 수준과 HQ는 혈중 TSH 농도에 유의적인 차이를 보이지 않았으나, 혈중 free T4 농도는 연령과 소변 중 요오드 수준이 증가할수록 유의적으로 감소하였다. 본 연구결과 국내 가임기 여성의 과반수는 요오드를 과잉 섭취하였고, 특히 상위 10% 정도는 HQ 1 이상으로 건강에 위험할 정도의 극단적인 섭취량을 보였다, 또한, 식이와 소변을 통해 산출된 요오드 섭취량 사이에 차이가 상당히 큰 것으로 보아 충분한 요오드 DB가 구축되지 않은 현 상황에서 식이를 통한 요오드 영양상태를 평가하기보다는 소변으로 배출된 요오드 함량을 적용하여 요오드 영양상태를 평가하는 것이 더 적절할 것으로 사료되며, 과잉의 요오드 섭취가 갑상샘질환 뿐만이 아니라 관련 질환의 유병율에 미치는 다양한 연구가 수행될 필요가 있을 것으로 판단된다.

Keywords

Acknowledgement

This research was supported by grants from the 2021 Amorepacific Foundation.

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