Changes in iodine status among US adults, 2001-2012

Area of Science:

• Nutrition Science
• Public Health
• Epidemiology

Background:

• Urinary iodine concentrations (UICs) in the US have shown stability since 1988-1994.
• However, selected subgroups within the population have demonstrated persistently low iodine levels.

Purpose of the Study:

• To investigate iodine status among adults aged 20 years and older.
• To assess iodine deficiency using two distinct population criteria.
• To identify demographic and behavioral factors associated with low iodine levels.

Main Methods:

• Utilized data from the National Health and Nutrition Examination Surveys (NHANES) spanning 2001-2012.
• Employed linear logistic regression analyses, adjusting for relevant covariates.
• Analyzed urinary iodine concentrations (UICs) to determine prevalence and identify risk factors.

Main Results:

• The prevalence of UICs <50 μg/L increased nationally from 11.6% (2001-2004) to 13.2% (2009-2012).
• Higher prevalence was observed in women, young adults, non-Hispanic Blacks (NHBs), and non-users of iodine-containing supplements.
• Adjusted odds ratios indicated significantly higher risks for young adults (1.54) and NHBs (1.70) indicating borderline iodine status.

Conclusions:

• Median UICs suggest that women and NHBs are at the borderline of iodine deficiency.
• Iodine deficiency poses critical consequences, especially for pregnant women and NHBs.
• Regular monitoring of iodine status is crucial for public health initiatives in the US.