European Journal of Pediatrics

, Volume 173, Issue 7, pp 929–934 | Cite as

An assessment of iodine nutritional status and thyroid hormone levels in children aged 8–10 years living in Zhejiang Province, China: a cross-sectional study

  • Yan Zou
  • Xiaoming Lou
  • Gangqiang DingEmail author
  • Zhe Mo
  • Wenming Zhu
  • Guangming Mao
  • Jinshui Zhou
Original Article


Iodine is an essential nutrient for the synthesis of thyroid hormones that are critical for brain development. Iodine deficiencies were prevalent in China until the introduction of universal salt iodization (USI) in 1995. USI has been considered as the world’s best achievements. This study aims to assess children’s iodine nutrition and goiter status in Zhejiang Province in order to provide reasonable suggestions to the government for policy-making under the USI period. A cross-sectional survey in Zhejiang Province was conducted to children aged 8–10 years by stage cluster random sampling method. Spot urine samples were collected and analyzed. Thyroid ultrasonography examination was performed by special trained technicians using a 7.5-MHz transducer. Fasting venous blood samples were collected and analyzed for thyroid functional status. The median urinary iodine concentration was found to be 173.3 μg/L. The percentage of urine samples with iodine concentration <100 μg/L, 100–300 μg/L, and >300 μg/L was 15.5, 42.0, and 13.3 %, respectively. Goiter prevalence rate with iodine concentration <100 μg/L, 100–300 μg/L, and >300 μg/L was 6.8, 10.0, and 14.9 %, respectively, with no significant difference. Children with goiter have lower serum FT3 and T3 concentrations compared to those without goiter (p < 0.05). Conclusions: The median urinary iodine concentration of children aged 8–10 years falls in optimal iodine status as recommended by WHO/UNICEF/ICCIDD. Maintaining USI at an appropriate level is an important part of preventing iodine deficiency disorders and should always be based on routine monitoring urinary iodine concentration by the province.


Urinary iodine concentration Goiter Survey 



This study was financially supported by Zhejiang Province science and technology fund (2009C03010-1). We thank all the health care professionals from the centers for disease control and prevention for the sampling unit.

Author contributions

G.D. was responsible for the study design. Y.Z. was responsible for data collection and analysis, paper writing, and revision. X.L. and Z.M. took part in the field investigation and data collection. W.Z was in charge of laboratory detection. J.Z and G.M. did the thyroid measurements by ultrasound.

Conflict of interest

The authors declare no conflict of interest.


  1. 1.
    Zhejiang provincial center for disease control and prevention. Annals of Zhejiang provincial center for disease control and prevention. 2000Google Scholar
  2. 2.
    Boy E, Mannar V, Pandav C et al (2009) Achievements, challenges, and promising new approaches in vitamin and mineral deficiency control. Nutr Rev 67:S24–S30PubMedCrossRefGoogle Scholar
  3. 3.
    Ceviz N, Ozkan B, Olgun H et al (2004) Left ventricular systolic and diastolic functions in children living in a moderate-severe iodine deficiency area. J Pediatr Endocrinol Metab 17:197–201PubMedCrossRefGoogle Scholar
  4. 4.
    Delange F, de Benoist B, Alnwick D (1999) Risks of iodine-induced hyperthyroidism after correction of iodine deficiency by iodized salt. Thyroid 9:545–556PubMedCrossRefGoogle Scholar
  5. 5.
    Filipsson Nyström H, Andersson M et al (2010) Thyroid volume in Swedish school children: a national, stratified, population-based survey. Eur J Clin Nutr 64:1289–1295PubMedCrossRefGoogle Scholar
  6. 6.
    Gordon RC, Rose MC, Skeaff SA et al (2009) Iodine supplementation improves cognition in mildly iodine-deficient children. Am J Clin Nutr 90:1264–1271PubMedCrossRefGoogle Scholar
  7. 7.
    Kapelari K, Kirchlechner C, Högler W et al (2008) Pediatric reference intervals for thyroid hormone levels from birth to adulthood: a retrospective study. BMC Endocr Disord 8:15PubMedCentralPubMedCrossRefGoogle Scholar
  8. 8.
    König F, Andersson M, Hotz K et al (2011) Ten repeat collections for urinary iodine from spot samples or 24-hour samples are needed to reliably estimate individual iodine status in women. J Nutr 141:2049–2054PubMedCrossRefGoogle Scholar
  9. 9.
    Ministry of Health. Announcement on food safety national standard “iodine content in edible salt;” 2011[cited 2012 Mar 15]. Available from:
  10. 10.
    Ministry of Health (2007) Diagnostic criterion for endemic goiter. MOH, Beijing, in ChineseGoogle Scholar
  11. 11.
    Pineda-Lucatero A, Avila-Jiménez L, Ramos-Hernández RI et al (2008) Iodine deficiency and its association with intelligence quotient in schoolchildren from Colima, Mexico. Public Health Nutr 11:690–698PubMedCrossRefGoogle Scholar
  12. 12.
    Simsek E, Safak A, Yavuz O et al (2003) Sensitivity of iodine deficiency indicators and iodine status in Turkey. J Pediatr Endocrinol Metab 16:197–202PubMedCrossRefGoogle Scholar
  13. 13.
    Stanbury JB, Ermans AE, Bourdoux P et al (1998) Iodine-induced hyperthyroidism: occurrence and epidemiology. Thyroid 8:83–100PubMedCrossRefGoogle Scholar
  14. 14.
    World Health Organization/UNICEF/International Council for Control of Iodine Deficiency Disorders (2008) Elimination of iodine deficiency disorders: a manual for health workers. WHO Regional Office for Eastern Mediterranean, CairoGoogle Scholar
  15. 15.
    World Health Organization: WHO/UNICEF/ICCIDD (2007) Assessment of iodine deficiency disorders and monitoring their elimination, 3rd edn. Geneva: a guide for programme managersGoogle Scholar
  16. 16.
    Zimmermann MB, Hess SY, Adou P et al (2003) Thyroid size and goiter prevalence after introduction of iodized salt: a 5-y prospective study in schoolchildren in Côte d’Ivoire. Am J Clin Nutr 77:663–667PubMedGoogle Scholar
  17. 17.
    Zimmermann MB, Jooste PL, Pandav CS (2008) Iodine-deficiency disorders. Lancet 372:1251–1262PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Yan Zou
    • 1
  • Xiaoming Lou
    • 1
  • Gangqiang Ding
    • 1
    Email author
  • Zhe Mo
    • 1
  • Wenming Zhu
    • 1
  • Guangming Mao
    • 1
  • Jinshui Zhou
    • 1
  1. 1.Zhejiang Provincial Center for Disease Control and PreventionHangzhouPeople’s Republic of China

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