Iodine nutrition status among schoolchildren after salt iodisation

Abstract

Earlier studies done in Sri Lanka have indicated the importance of iodine deficiency as a public health problem. The universal salt iodisation programme has been implemented since 1995. The goals of salt iodisation are reduction of the goitre rate to <5% in school-aged children, to maintain the median urinary iodine level in the population between 100-200 microg/L and >90% of households using iodised salt.

Objective: To estimate the goitre prevalence, the urinary iodine level, and measure the household iodised salt consumption pattern by Province.

Method: A school-based study of 6574 randomly selected children in the age group 8-10 years, from 263 schools was assessed for goitre by palpation. The concentration of urinary iodine levels was measured in 2630 of these children. Estimation of iodine in the 6181 samples of salt used in households of the schoolchildren was also assessed by test kits.

Results: The prevalence of goitre in the Provinces varied from 16.3% to 26.2%. The median urinary iodine levels were above the cut-off point of 100 microg/L in all Provinces except in Uva. The highest median urinary iodine level was reported in North Central Province (231.3 microg/L). Overall, 35.4% of the children had urine iodine levels in the 'ideal' range (100-199.9 microg/L); 30.6% with lower values (<100 microg/L) indicated iodine deficiency and 16.3% with higher values (< 300 microg/L) indicated excessive iodine intake. Only 49.5% of households had used adequately iodised salt.

Conclusions: This study showed that iodine deficiency still exists in Uva Province, and that more than adequate iodine levels were found in the North Central Province. The level of permitted salt iodine at household level needs to be revised.