Objective  To analyze the iodine nutritional status of residents from 2005 to 2021 in Wujiang District of Suzhou City of Jiangsu Province.

Methods  Wujiang District of Suzhou City was divided into five areaseast, west, south, north and middle areas, and a certain number of households, pregnant women and children aged 8 to 10 in the areas were randomly selected every year. Salt samples of households and the random urine samples of pregnant women and children were collected, thyroid volume of children was monitored by B-ultrasound, and the median salt iodine and urine iodine were calculated.

Results  From 2005 to 2021, the average consumption rate of qualified iodized salt was 95.59%(4 795/5 016), the average qualified rate of iodized salt was 97.46%(4 795/4 920), the average non-iodized salt rate was 1.91%(96/5 016), and the median salt iodine was 27.91 mg/kg. After the implementation of the new standard for iodized salt, the median salt iodine was significantly decreased (P < 0.01). The rate of thyroid enlargement in children was 0.93%, and the median urinary iodine was 204.10 μg/L; after reducing iodine concentration in salt, the median urinary iodine in children was significantly decreased (P < 0.05), and the ratio of children with urinary iodine concentration≥300 μg/L was significantly decreased as well (P < 0.01). The median urinary iodine of pregnant women from 2005 to 2021 was 154.96 μg/L, and the ratio of those with urinary iodine concentration < 150 μg/L was 54.42%.

Conclusion  From 2005 to 2021, the popularity rate of iodized salt in Wujiang District of Suzhou City is high, and the iodine nutrition of pregnant women and children is at an appropriate level. After reducing iodine concentration in salt, the risk of iodine excess in children is reduced, but some pregnant women are still at iodine deficiency level, so we suggest accelerating the policy of classified iodized salt for pregnant women to ensure the physiological needs of iodized salt during pregnancy.