Letters to the Editor

Indian Pediatrics 2000;37: 1282-1284.

Status of Urinary Iodine Excretion in Post Salt Iodization Phase in Selected Districts of India

Iodine deficiency is one of the world’s major cause of preventable mental retardation(1). In India, the surveys carried out by Central and State Health Directorates, Indian Council of Medical Research and Medical Colleges have documented that not even a single state and union territory is free from the problem of iodine deficiency disorders. Out of 275 districts surveyed, 235 have been found to be endemic for iodine deficiency(2).

In 1983, the country’s production of iodized salt was only 3 lakh tonnes. However, after adoption of Universal Salt Iodization Policy in 1984, under which the production of iodized salt was opened to the private manufacturers, the quantity of iodized salt produced increased significantly. In the year 1997, 42 lakh tonnes of iodized salt was produced, against the total requirement of 52 lakh tonnes for the country(3). Urinary iodine excretion (UIE) levels provide the true picture of current iodine nutriture in a population(1). Hence, the present study was conducted to assess iodine nutriture in the post salt iodization phase.

Pilot surveys were conducted during 1996-99, to assess the UIE levels in the population, in 28 districts of 8 states and 1 Union territory of the country, namely: (i) Andaman and Nicobar, (ii) Bihar, (iii) Delhi, (iv) Himachal Pradesh, (v) Kerela, (vi) Rajasthan, (vii) Tripura, (viii) Uttar Pradesh. The children in the 6-12 years age group were studied as they are representative of community’s iodine nutriture.

In the each selected district, one rural block which was at least 30 km away from the district headquarter was identified. In the block, all the primary schools were enlisted and three to four primary schools were selected randomly. "On the spot" casual urine samples were collected from one hundred fifty children in the age group of 6-12 years in all the districts except Hamirpur, Solan, Kangra, Meerut and Delhi from where a larger sample of children were included by utilizing the 30 cluster methodology. The urine samples were analyzed using the standard laboratory procedures(4).

A total of 9,286 urine samples were collected from 28 districts. The UIE levels in different districts is depicted in Table I. The median UIE level was 10 or more mcg/dl in all the districts except for District Lakhimpur, Uttar Pradesh. Thus, the UIE levels were in the acceptable range (between 100 to 300 mcg/dl)(1). Also, the current salt iodization level recommended in the country is appropriate to maintain the iodine nutriture of the population (15 ppm of iodine at the household level). Similar findings have been reported from other countries which have successfully imple-mented the salt iodization program(5,6).

Funding: Research grants from All India Institute of Medical Sciences, United Nations Children Fund and Indian Council of Medical Research.
Competing interests: None stated.

Table I__Status of Iodine Deficiency in Selected Districts of India

* UIE : Urinary iodine excretion.

** Figures in parentheses indicate percentages.

Umesh Kapil,
Additional Professor,
Department of Human Nutrition,
All India Institute of Medical Sciences,
New Delhi 110 029,
India.
E-mail: [email protected]

1. Indicators for Assessing Iodine Deficiency Disorders and their Control Through Salt Iodization. WHO-UNICEF-ICCIDD. World Health Organization, Geneva, 1994; pp 12- 16.

2. Policy Guidelines on National Iodine Defi-ciency Disorders Control Program. Nutrition and IDD Cell. Directorate of Health Services, Ministry of Health and Family Welfare, Government of India, New Delhi, 1997; pp 2-5.

3. Sundaresan S. Progress achieved in universal salt iodization program in India. In: Proceedings of Symposium on Elimination of IDD through Universal Access to Iodized Salt. Eds. Prakash R, Sunderesan S, Kapil U, New Delhi, Shivansh Computers and Publications, 1998; pp 28-42.

4. Dunn JT, Crutchfield HE, Gutekunst R, Dunn D. Methods for Measuring Iodine in Urine. A Joint Publication of WHO/UNICEF/ICCIDD, Geneva, 1993; pp 18-23.

5. Gomo ZAR, Allain TJ, Mantenga JA, Ndemere B, Wilson A, Urdal P. Urinary iodine concen-trations and thyroid function in adult Zimbab-weans during a period of transition in iodine status. Am J Clin Nutr 1999; 70: 888-891.

6. Jooste PL, Weight MJ, Lombard CJ. Short-term effectiveness of mandatory iodization of table salt, at an elevated iodine concentration, on the iodine and goiter status of school children with endemic goiter. Am J Clin Nutr 2000; 71: 75-80.