A survey of iodine nutritional status in the key populations before and after the adjustment of salt iodine content in Yantai of Shandong

Objective To investigate the iodine nutritional status in the key populations before and after the adjustment of salt iodine content in Yantai of Shandong. Methods In 2010 (the pre-adjustment period) and 2014, 2015 (the post-adjustment period), the changes in the residents' iodized salt, the goiter prevalence and urinary iodine of children aged 8-10, the urinary iodine of pregnant women, and the iodine content of drinking water before and after the adjustment were analyzed. Results The coverage rate of iodized salt and the edible rate of qualified iodized salt were 98.27% and 97.28%, respectively before the adjustment of salt iodine content, and 97.44% and 96.14% after the adjustment. The mean of salt iodine after the adjustment (21.96 mg/kg) was significantly lower than that of 2010 (31.45 mg/kg, t= 66.29, P < 0.05). The goiter prevalence of children aged 8-10 by thyroid palpation was 0.92% in 2010, while it was 1.89% by ultrasonic in 2014, 2015. There was significant difference in the iodine nutritional status of children in 2010 (191.0 μg/L) and in 2014, 2015 (173.0 μg/L, Z= 3.56, P < 0.05). The difference of iodine nutritional status in pregnant women between pre-adjustment (154.0 μg/L) and post-adjustment (130.4 μg/L) was also significant (Z= 5.54, P < 0.05). The median of water iodine was 5.4 μg/L after the adjustment. There were 52 towns with medians of water iodine below 10 μg/L. Conclusions The coverage rate of iodized salt and the edible rate of qualified iodized salt have all met the national standard before and after the adjustment of salt iodine content. The mean of salt iodine during 2014, 2015 is significantly lower than that of 2010. Before and after the adjustment, the goiter rates of children aged 8-10 are all below 5%. The adjustment of salt iodine content is more suitable to children aged 8-10 than to pregnant women currently. It is suggested that pregnant women eat more foods rich in iodine. Key words: Iodine; Salts; Urine; Nutrition Assessment