Study on Dietary Intake Levels of Iodine for 3-6 Years Old Pre-school Children

Overview

Iodine as an essential trace element for human, both excessive and insufficient intake would be harmful for human health. As susceptible population, children will be more sensitive to adverse effects caused by inadequate intake of iodine since they are at the peak of growth and development. Meanwhile, there are few direct evidence to establish dietary intakes levels of iodine for 3-6 years old pre-school children.

Detailed description

This study plan to conduct iodine balance experiment by providing devised diet consist of different iodine contents, in order to simulate iodine equilibrium of iodine deficiency to iodine excess in children and find the lowest iodine requirement of iodine for pre-school children, then aim to provide data to establish recommend nutrient intake of iodine for 3-6-year-old pre-school children. On the other hand, this study will make use of natural geographic environment with high water iodine in China. The investigators will conduct big-scale epidemiologic study in areas with high water iodine levels in Shandong and areas with adequate iodine in Tianjin, to enroll pre-school children with various iodine intake levels. The investigators will collect 24-hour urine samples as well as dietary records to evaluate iodine intake levels, and detect thyroid volume and thyroglobulin to evaluate the effects of various iodine intake on pre-school children, aiming to find the lowest safe intake level of iodine and then establish the tolerable upper intake level (UL) of iodine for 3-6-year-old pre-school children. This study aims to define the RNI and UL of iodine for 3-6-year-old pre-school children, to provide data for revision of Chinese dietary intake levels of iodine, and to guide children safe and scientifical iodine fortification.

Interventions

• Other no intervention
  Natural exposure of iodine

Primary outcome measures

• urinary iodine concentration [Time frame: 2 weeks]
• diet iodine intake [Time frame: 2 weeks]
• urinary iodine excretion [Time frame: 2 weeks]
• thyroglobulin antibody [Time frame: 2 weeks]
• salt iodine concentration [Time frame: 2 weeks]
• water iodine intake [Time frame: 2 weeks]
• thyroid volume [Time frame: 2 weeks]

Eligibility criteria

Inclusion criteria

• for children with mild malnutrition: hemoglobin <110g / L, or weight for age <P50 according to the Chinese 2009 child growth and development reference standard, or BMI z score <-1 according to the WHO Child Growth Assessment Software (version 3.2.2 ) ; have not been treated for thyroid disease; have not used amiodarone and other drugs (including iodine supplements) during the investigation; have no major diseases ,chronic diseases and family history.
• for children with good nutritional status: healthy,-1 <BMI z score <1; have not been treated for thyroid disease; have not used amiodarone and other drugs (including iodine supplements) during the investigation; have no major diseases ,chronic diseases and family history;

Exclusion criteria

long-term low-protein; long-term low-heat energy malnutrition

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Observational model

Other

Study locations

China · 1 center

• Shandong Institute for Endemic Disease Control and Research — Yuncheng

Publications

• Laurberg P, Cerqueira C, Ovesen L, Rasmussen LB, Perrild H, Andersen S, Pedersen IB, Carle A. Iodine intake as a determinant of thyroid disorders in populations. Best Pract Res Clin Endocrinol Metab. 2010 Feb;24(1):13-27. doi: 10.1016/j.beem.2009.08.013. PMID 20172467
• Zimmermann MB, Boelaert K. Iodine deficiency and thyroid disorders. Lancet Diabetes Endocrinol. 2015 Apr;3(4):286-95. doi: 10.1016/S2213-8587(14)70225-6. Epub 2015 Jan 13. PMID 25591468
• Li Y, Teng D, Ba J, Chen B, Du J, He L, Lai X, Teng X, Shi X, Li Y, Chi H, Liao E, Liu C, Liu L, Qin G, Qin Y, Quan H, Shi B, Sun H, Tang X, Tong N, Wang G, Zhang JA, Wang Y, Xue Y, Yan L, Yang J, Yang L, Yao Y, Ye Z, Zhang Q, Zhang L, Zhu J, Zhu M, Ning G, Mu Y, Zhao J, Shan Z, Teng W. Efficacy and Safety of Long-Term Universal Salt Iodization on Thyroid Disorders: Epidemiological Evidence from 3 PMID 32075540
• Sang Z, Chen W, Shen J, Tan L, Zhao N, Liu H, Wen S, Wei W, Zhang G, Zhang W. Long-term exposure to excessive iodine from water is associated with thyroid dysfunction in children. J Nutr. 2013 Dec;143(12):2038-43. doi: 10.3945/jn.113.179135. Epub 2013 Oct 9. PMID 24108132
• Lee SY, Pearce EN. Reproductive endocrinology: Iodine intake in pregnancy--even a little excess is too much. Nat Rev Endocrinol. 2015 May;11(5):260-1. doi: 10.1038/nrendo.2015.28. Epub 2015 Feb 24. PMID 25707780
• Bougma K, Aboud FE, Harding KB, Marquis GS. Iodine and mental development of children 5 years old and under: a systematic review and meta-analysis. Nutrients. 2013 Apr 22;5(4):1384-416. doi: 10.3390/nu5041384. PMID 23609774
• Pearce EN, Lazarus JH, Moreno-Reyes R, Zimmermann MB. Consequences of iodine deficiency and excess in pregnant women: an overview of current knowns and unknowns. Am J Clin Nutr. 2016 Sep;104 Suppl 3(Suppl 3):918S-23S. doi: 10.3945/ajcn.115.110429. Epub 2016 Aug 17. PMID 27534632
• Zimmermann MB, Jooste PL, Mabapa NS, Mbhenyane X, Schoeman S, Biebinger R, Chaouki N, Bozo M, Grimci L, Bridson J. Treatment of iodine deficiency in school-age children increases insulin-like growth factor (IGF)-I and IGF binding protein-3 concentrations and improves somatic growth. J Clin Endocrinol Metab. 2007 Feb;92(2):437-42. doi: 10.1210/jc.2006-1901. Epub 2006 Nov 21. PMID 17118996

Identifiers

NCT: NCT06074770 · NSFC-8227121511

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗