Assessment of the iodine status among school-age children and pregnant women in an iodine-deficient area of China

Abstract

Abstract Iodized salt (IS) is the significant source of iodine for residents living in iodine-deficient areas. To prevent and eliminate iodine deficiency among residents living in these areas, it is a vital practice to monitor IS consumption and assess the iodine status of residents regularly. This study was carried out in Mengzi city, which is an iodine-deficient area in Yunnan Province of China, among school-age children (SAC) and pregnant women (PW). Iodine concentration in salt was measured and qualified IS usage rate was investigated. The iodine status of SAC was assessed based on urinary iodine concentration (UIC), goiter and thyroid nodules diagnosis. The iodine status of PW was evaluated based on the UIC. The usage rate of qualified IS was 91.51%. Among SAC, the median UIC was 197.3 µg/L, the percentage with UIC levels < 100 µg/L, 100–200 µg/L, > 200 µg/L was 13.5% (83/617), 37.9% (234/617) and 48.6% (300/617), respectively. 9 (1.46%, 9/617) and 27 SAC (13.50%, 27/200) were diagnosed to be goiter and have thyroid nodules. Among PW, The median UIC was 148.28 µg/L, the percentage with UIC levels < 150 µg/L, 150–250 µg/L, > 250 µg/L was 51.3% (155/302), 37.8% (114/302) and 10.9% (33/302), separately. Qualified IS was consumed universally by residents. Partial SAC was at the over-optimal iodine status. Therefore, it is necessary to reduce iodine intake among those SAC by the means of restricting IS consumption within the recommended amount. PW cannot receive enough iodine from recommended amount of IS alone. Taking iodine-rich foods is critical.