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Randomized clinical trial comparing different iodine interventions in school children

Published online by Cambridge University Press:  02 January 2007

Jinkou Zhao*
Jiangsu Provincial Center for Public Health and Diseases Control, Nanjing, China
Fujie Xu
Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, USA
Qinlan Zhang
Jiangsu Provincial Center for Public Health and Diseases Control, Nanjing, China
Li Shang
Jiangsu Provincial Center for Public Health and Diseases Control, Nanjing, China
Aixiang Xu
Nanjing Institute of Schistosomiasis Control, Nanjing, China
Yuan Gao
Nanjing Institute of Schistosomiasis Control, Nanjing, China
Zhigao Chen
Jiangsu Provincial Center for Public Health and Diseases Control, Nanjing, China
Kevin M Sullivan
Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, USA
Glen F Maberly
Department of International Health, Rollins School of Public health, Emory University, Atlanta, USA
*Corresponding author: Email
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The purpose of this trial was to compare three different iodine interventions.


School children aged 8–10 years were randomized into one of three groups: group A was provided with iodized salt by researchers with an iodine concentration of 25 ppm; group B purchased iodized salt from the market; and group C was similar to group B with the exception that they were given iodized oil capsules containing 400 mg iodine at the beginning of the study. Salt iodine content was measured bimonthly for 18 months and indicators of iodine deficiency were measured at baseline and 6, 9, 12 and 18 months after randomization.


The prevalence of abnormal thyroid volumes, based on the World Health Organization (WHO) body surface area reference > 97th percentile, was 18% at baseline and declined to less than 5% by 12 months in groups A and C, and to 9% after 18 months in group B. Results for goitre by palpation were similar. The median urinary iodine was 94 μgl−1 at baseline and increased in all groups to > 200 μgl−1 at the 6-month follow-up.


In this population of school children with initially a low to moderate level of iodine deficiency, the group receiving salt with 25 ppm (group A) was not iodine deficient on all indicators after 18 months of study. When the iodine content of the salt varied, such as in group B, by 18 months thyroid sizes had not yet achieved normal status.

Research Article
Copyright © CABI Publishing 1999


1WHO/UNICEF/ICCIDD. Global Prevalence of Iodine Deficiency Disorders. Micronutrient Deficiency Information System Working Paper No. 1. Geneva: WHO, 1991.Google Scholar
2Delange, F. The disorders induced by iodine deficiency. Thyroid 1994; 4(1): 107–28.Google Scholar
3UNICEF. First Call for Children: World Declaration and Plan of Action from the World Summit for Children. New York: UNICEF, 1990.Google Scholar
4 Comprehensive Evaluation and Planning Mission. Report of the Mission's Observations and Recommendations, Program of International Cooperation for the Elimination of IDD in China by the Year 2000. Program Against Micronutrient Malnutrition, Atlanta, USA, 1–15 07 1996.Google Scholar
5Zhao, JK, Gu, SD, Yang, XX. Current status of IDD in Jiangsu Province. Chin. J. Endem. Dis. Control 1997; 12(4a): 129–32.Google Scholar
6Van der Haar, F. Salt iodization in the control of iodine deficiency: increasing the cooperation among government, industry and science. Seventh Symposium on Salt 1993; 2: 421–6.Google Scholar
7WHO/UNICEF/ICCIDD Joint Consultation. Review of Findings from a Seven-Country Study in Africa on Levels of Salt Iodization in Relation to Iodine Deficiency Disorders, Including Iodine-induced Hyperthyroidism. WHO/NUT/97.2. Geneva: WHO, 1997.Google Scholar
8UNICEF. The State of the World's Children 1998. New York: Oxford University Press, 1998: 54–5, 64.Google Scholar
9Benmiloud, M, Chaouki, ML, Gutekunst, R, Teichert, HM, Wood, WG, Dunn, JT. Oral iodized oil for correcting iodine deficiency: optimal dosing and outcome indicator selection. J. Clin. Endocrinol. Metab. 1994; 79: 20–4.Google Scholar
10Bautista, A, Barker, PA, Dunn, JT, Sanchez, M, Kaiser, DL. The effects of oral iodized oil on the intelligence, thyroid status, and somatic growth in school-age children from an area of endemic goiter. Am. J. Clin. Nutr. 1982; 35: 127–34.Google Scholar
11 Anon. The effect of oral administration of iodized oil for prevention and treatment of endemic goiter. Chin. Med. J. 1981; 61(9): 533–4.Google Scholar
12Sullivan, KM, Houston, R, Gorstein, J, Cervinskas, J. Monitoring Universal Salt Iodization Programmes. Atlanta: PAMM/MI/ICCIDD, 1995: 86–7.Google Scholar
13Delange, F, Benker, G, Caron, P, et al. Thyroid volume and urinary iodine in European schoolchildren: standardization of values for assessment of iodine deficiency. Eur. J. Endocrinol. 1997; 136: 180–7.Google Scholar
14Dubois, D, Dubois, EF. Clinical calorimetry: a formula to estimate the approximate surface area if height and weight be known. Arch. Intern. Med. 1916; 17: 863.Google Scholar
15Dunn, JT, Crutchfield, HE, Gutekunst, R, Dunn, AD. Two simple methods for measuring iodine inurine. Thyroid 1993; 3: 119–23.Google Scholar
16WHO/UNICEF/ICCIDD Joint Consultation. Indicators for Assessing Iodine Deficiency Disorders and their Control through Salt Iodization. WHO/NUT/94.6. Geneva: WHO, 1994.Google Scholar
17Campbell, MJ, Gardner, MJ. Calculating confidence intervals for some non-parametric analyses. In: Gardner, MJ, Altman, GD, eds. Statistics with Confidence: Confidence Intervals and Statistical Guidelines. London: British Medical Journal, 1995: 72–4.Google Scholar
18Stanbury, JB, Ermans, AE, Bourdoux, P, et al. Iodine-induced hyperthyroidism: occurrence and epidemiology. Thyroid 1998; 8(1): 83100.Google Scholar
19Tonglet, R, Bourdoux, P, Minga, T, Ermans, AM. Efficacy of low doses of iodized oil in the control of iodine deficiency in Zaire. N. Engl. J. Med. 1992; 326(4): 236–41.Google Scholar
20Elnagar, B, Eltom, M, Karlsson, FA, Ermans, AM, Gebre-Medhin, M, Bourdoux, PP. The effects of different doses of oral iodized oil on goiter size, urinary iodine, and thyroid-related hormones. J. Clin. Endocrinol. Metab. 1995; 80(3): 891–7.Google Scholar
21Abuye, C, Hailemariam, B, Tibeb, HN, Urga, K, Gebru, H. The effect of varying doses of oral iodized oil in the prophylaxis of endemic goiter in elementary schools children. Ethiop. Med. J. 1995; 33(2): 115–23.Google Scholar
22Ingenbleek, Y, Jung, L, Ferard, G, Bordet, F, Goncalves, AM, Dechoux, L. Iodized rapeseed oil for eradication of severe endemic goiter. Lancet 1997; 350: 1542–5.Google Scholar
23Furnee, CA, Pfann, GA, West, CE, van der Haar, F, van der Heide, D, Hautvast, JG. New model for describing urinary iodine excretion: its use for comparing different oral preparations of iodized oil. Am. J. Clin. Nutr. 1995; 61(6): 1257–62.Google Scholar