To understand the implementing situation of prevention measures for iodine deficiency disorders before (2011) and after (2013) the adjustment of salt iodine content in Guangxi, to evaluate the changes of iodine nutritional status, and to provide a basis for future prevention work.

Monitoring data of iodized salt, drinking water iodine and iodine nutritional status before and after the adjustment of iodine content of salt was collected. Changes in water iodine, salt iodine and urinary iodine before and after adjusting iodine content of salt were compared.

The monitoring work of iodized salt, drinking water iodine and iodine nutritional status was carried out in all the 109 counties (cities, districts) in 2011 and 2013. ①Drinking water iodine monitoring: a total of 4 968 water samples was tested in 2011, the median water iodine was 2.69 μg/L. Of which, 4 210 water samples below 10.00 μg/L, the proportion was 84.74%. A total of 7 554 water samples were tested in 2013, the median water iodine was 2.11 μg/L. Of which, 6 512 water samples below 10.00 μg/L, the proportion was 86.12%. ② Iodized salt monitoring: a total of 30 786 salt samples were tested in 2011; the salt median iodine was 32.30 mg/kg. The iodized salt coverage rate was 98.31%, iodized salt qualification rate was 97.36%, and qualified iodized salt consumption rate was 95.98% weighted by population. A total of 32 779 salt samples were tested in 2013; the salt median iodine was 24.94 mg/kg, the iodized salt coverage rate was 98.36%, iodized salt qualification rate was 95.97%, and qualified iodized salt consumption rate was 94.49% weighted by population. The difference of salt iodine was statistically significant between 2011 and 2013 (χ² = 17 830.03, P < 0.05). ③Urinary iodine monitoring: a total of 8 278 urinary samples were detected in 2011; the median urinary iodine was 241.10 μg/L. Among these, 889 urinary samples below 100.00 μg/L, the proportion was 10.74%; 2 174 urinary samples in 100.00-< 200.00 μg/L, the proportion was 26.26%; 2 451 urinary samples in 200.00-< 300.00 μg/L, the proportion was 29.61%; and 2 764 urinary samples ≥ 300.00 μg/L, the proportion was 33.39%. A total of 10 988 urinary samples were tested in 2013; the median urinary iodine was 200.35 μg/L. Among these, 1 716 urinary samples below 100.00 μg/L, the proportion was 15.62%; 3 745 urinary samples in 100.00-< 200.00 μg/L, the proportion was 34.08%; 2 970 urinary samples in 200.00-< 300.00 μg/L, the proportion was 27.03%; and 2 557 urinary samples ≥300.00 μg/L, the proportion was 23.27%. The difference of urinary iodine was statistically significant between 2011 and 2013 (χ² = 391.98, P < 0.05).

Guangxi belongs to an area with low iodine level. The situation of iodine deficiency disorders is in accordance with the national "Standard to Eliminate Iodine Deficiency Disorders". Scientific salt iodization and sustained elimination of iodine deficiency disorders should continue to ensure appropriate levels of iodine nutrition among residents in Guangxi.

Iodine; Salts; Drinking; Urine; Data collection