Urinary iodine concentrations (UICs) in the US have been reported to be stable since 1988-1994, although those in selected subgroups remained low. We aimed to investigate iodine status among adults (≥20 years) by two different criteria of assessing iodine deficiency in population. Utilizing National Health and Nutrition Examination Surveys 2001-2012, we conducted linear logistic regressions adjusting for covariates. The prevalence of <50 μg/L UIC was higher in women than in men; increased from 11.6% (2001-2004) to 13.2% (2009-2012) at the national level and in young adults, non-Hispanic blacks (NHBs) and non-users of iodine-containing supplements (all, p <0.05); the adjusted odds ratios (95%CI) in young adults (1.54 [1.11-2.15], p = 0.0007) and NHBs (1.70 [1.15-2.52], p = 0.0078). Median UICs confirm women and NHBs being in borderline iodine status. Recognizing the critical consequence of iodine deficiency particularly in women and NHBs, regular monitoring of iodine status is important for public health in the US.
Keywords: Iodine deficiency; NHANES; iodine status; prevalence; urinary iodine.