Assessment of Iodine Status and Associated Factors in Vulnerable Populations in Henan Province, China, in 2012

Background: Iodine content in table salt was adjusted from 30-50 mg/kg to 21-39 mg/kg from March of 2012 in Henan Province, China. The vulnerable population may be at risk of iodine deficiency. Objectives: To determine whether the iodine intake was sufficient in vulnerable populations and to investigate what factors may be associated with iodine status in these vulnerable populations in Henan Province, China. Methods: A cross-sectional survey was conducted in 17 cites in Henan Province, China, from April 2012 to December 2012 to assess the iodine status in vulnerable populations, including women of reproductive-age (n = 2648), pregnant women (n = 39684), lactating women (n = 6859), infants ＜2 years of age (n = 16481), and children aged 8-10 years (n = 3198). Questionnaires (n = 4865) related to demographic and dietary factors were collected from the investigated women to identify factors that were related to iodine intake and iodine status. Results: The median urinary iodine concentrations (mUICs) were 205 μg/L, 198 μg/L, 167 μg/L, 205 μg/L, 200 μg/L, respectively, in reproductive-age, pregnant and lactating women, infants ＜2 years of age, children aged 8-10 years. Higher income, and consuming more poultry and fish in the diet had positive impact on UIC levels. Low salt intake, consuming more rice and vegetables in the diet were negative factors for UIC. Conclusions: Iodine status of the vulnerable populations was generally adequate in Henan Province, China, according to WHO criteria. But the mUICs were slightly above the adequate level in reproductive-age women and children aged 8-10 years. It's important to monitor the iodine status in vulnerable populations after the adjustment on iodine content in table salt.