A survey of iodine nutritional status in the populations of Guizhou Province after implementation of a new standard of salt iodine / 中华地方病学杂志

ABSTRACT

Objective To investigate the iodine nutritional status in the populations of Guizhou Province after implementation of a new standard of salt iodine and to provide a basis in formulating strategy for control of iodine deficiency disorders.Methods In 2011 and 2014,30 units were sampled in Guizhou Province using the sampling method of Probability Proportional to Size.One primary school was chosen in each unit,by the randomized sampling method,40 or 50 students in each school were sampled for examining their urinary iodine level and for testing their household salt iodine level;12 and 50 children were chosen before and after the adjustment,respectively,for testing their urinary iodine level;near the location of the primary school,1 township was chosen,15-20 pregnant women in each township were sampled to test their urinary iodine level.Results Totally 1215 salt samples were collected before adjustment,the median of salt iodine was 32.2 mg/kg;consumption rate of qualified salt was 96.63％;totally 364 urine samples of 8-10 children were collected,the median of urinary iodine (MUI)of children was 308.9 μg/L;450 urine samples of pregnant women were sampled,and their MUI was 216.5 μg/L,among these,121 below 150 μg/L,the proportion was 26.9％.Totally 1 538 salt samples were collected after the adjustment,the median of salt iodine was 26.6 mg/kg;consumption rate of qualified salt was 96.40％;totally 1538urinary samples of 8-10 children were collected,the MUI of children was 218.3 μg/L;and 601 urinary samples of pregnant women were collected,the MUI was 175.1μg/L,among these,241 below 150 μg/L,the proportion was 40.1％.As can be seen from the results,the percentage of sample below 150 μg/L after the adjustment was increased to 13.2％ compared to that before the adjustment,the difference was statistically significant (x2 =19.89,P ＜0.01).Conclusion After implementation of a new standard of salt iodine in Guizhou Province,the iodine nutrition is suitable in residents,but the iodine nutrition of pregnant women is in a trend of declining,which should be noticed.