An assessment of progress toward universal salt iodization in Rajasthan, India, using iodine nutrition indicators in school-aged children and pregnant women from the same households

Abstract

Background: In Rajasthan, an Indian State with significant salt production, the sale of non-iodized salt for human consumption was banned in 1992. This study explored the relationships between the use of iodized salt in Rajasthan and the iodine status of children and pregnant women living in the area.

Methods: In a State-wide survey, 30 clusters were selected proportionate-to-population-size and 40 school children, 6-12 years old, were enrolled by random house-to-house visits in each cluster. Twelve pregnant women from the same households were also sampled. Salt used for cooking and a casual urine sample from each child and pregnant woman were collected. The salt iodine content was measured by titration and the urinary iodine concentration (UIC) by a quality-assured colorimetric method.

Results: Salt iodine content was >or=15 mg/kg in 41.9% of the households, and 23.0% used non-iodized salt. Median UIC was 139 microg/L in children and 127 microg/L in pregnant women. In households using non-iodized salt, the median UIC's were 96 microg/L and 100 microg/L in children and women, respectively. Dis-aggregating the UIC distributions by salt iodine levels revealed a consistent, step-wise pattern of UIC in children with increasing salt iodine content. A similar but less steep pattern was observed in pregnant women. The iodine status of both children and pregnant women attained the optimal range only when the salt iodine content was close to 30 mg/kg.

Conclusion: For optimum iodine status in the population of Rajasthan, the iodization of household salt should be mandated at a higher level than what is practiced at present.