Objective To evaluate the effectiveness of iodine deficiency disorders (IDD) prevention and control measures in Guangxi Zhuang Autonomous Region and provide reference for the development of local IDD prevention and control strategies.

Methods From 2021 to 2024, one township was randomly selected from the east, south, west, north, and central areas of each county/district in Nanning annually. In each township, at least 40 children aged 8-10 years and 20 pregnant women were selected. Urine and household salt samples of the children and the pregnant women were collected for testing. Thyroid volume examinations were conducted for some children.

Results A total of 15 941 household salt samples were tested from 2021 to 2024, with a median iodine concentration of 25.2 mg/kg. The differences in annual median salt iodine concentration in each year were significant (H=243.798, P<0.05). The qualified iodized salt coverage rate was 97.32%（15 513/15 941）and the differences in the annual coverage rate were significant (χ²=45.199, P＜0.05). A total of 10 649 urine samples from children aged 8-10 years were tested, with a median urinary iodine concentration (UIC) of 187 μg/L. Significant differences were observed in annual median UIC (H=118.013, P<0.05), in different age groups (H=27.073, P<0.05), and among boys and girls (H=35.414, P<0.05). Thyroid volume examinations were performed in 3 181 children, and 13 goiter cases were detected. A total of 5 276 urine samples from pregnant women were tested, with a median UIC of 142.0 μg/L. Significant differences were observed in annual median UIC (H=65.574 P<0.05). The iodine supplementation rate in the pregnant women was 97.92% (5 179/5 289).

Conclusion Since 2021, Nanning had maintained a high level of qualified iodized salt coverage and iodine supplementation rate in pregnant women. Children generally had adequate iodine nutrition status, the detection rate of goiter was low in children. The IDD prevention and control had got some achievement in Nanning, however, the median UIC in pregnant women was not high, indicating iodine insufficiency. It is necessary to strengthen iodine supplementation besides qualified iodized salt use. Additionally, the management of salt industry and market and health education about iodized salt use still need to be improved.