Table 3.

Association of urinary iodine concentrations with food group intakes and sociodemographic and lifestyle characteristics in US adults, NHANES 2007–2012 ¹.

	Total (n = 4017)				Men (n = 2151)				Women (n = 1866)
	Estimate	95% CI 2		p-Value 3	Estimate	95% CI		p-Value	Estimate	95% CI		p-Value
Intercept	5.20	5.05	5.36	<0.001 **	5.15	4.96	5.35	<0.001 **	5.03	4.85	5.22	<0.001 **
Dairy products 4, per 100 g/day	0.04	0.02	0.06	<0.001 **	0.03	0.01	0.06	0.006 **	0.05	0.02	0.07	0.002 **
Eggs, per 100 g/day	0.05	0.01	0.10	0.026 *	0.06	0.01	0.12	0.027 **	0.04	−0.05	0.12	0.384
Breads, per 100 g/day	0.03	0.00	0.06	0.045 *	0.01	−0.02	0.05	0.501	0.05	−0.01	0.12	0.119
Beverages, per 100 g/day	−0.01	−0.01	−0.01	<0.001 **	−0.01	−0.01	0.00	<0.001 **	−0.01	−0.02	−0.01	<0.001 **
Survey year
2007–2008	Reference				Reference				Reference
2009–2010	−0.13	−0.24	−0.03	0.014 **	−0.18	−0.30	−0.06	0.004 **	−0.08	−0.24	0.08	0.326
2011–2012	−0.11	−0.24	−0.02	0.086 *	−0.03	−0.17	0.12	0.722	−0.19	−0.35	−0.02	0.028 *
Sex
Men	−0.22	−0.29	−0.14	<0.001 **	‒	‒	‒	‒	‒	‒	‒	‒
Women	Reference				‒	‒	‒	‒	‒	‒	‒	‒
Age, years
20–39	Reference				Reference				Reference
40–59	−0.08	−0.17	0.01	0.061	0.05	−0.04	0.14	0.294	−0.22	−0.33	−0.10	0.001 **
60 and above	−0.02	−0.14	0.11	0.793	0.07	−0.06	0.20	0.302	−0.08	−0.25	0.10	0.383
Race/ethnicity 5
NHW	Reference				Reference				Reference
NHB	−0.09	−0.21	0.03	0.123	−0.17	−0.30	−0.04	0.012 *	−0.01	−0.15	0.13	0.873
All Hispanics	−0.02	−0.11	0.07	0.646	−0.09	−0.21	0.02	0.116	0.07	−0.06	0.20	0.276
Other	−0.01	−0.17	0.16	0.924	0.08	−0.29	0.12	0.422	0.07	−0.13	0.27	0.467
Iodine-containing supplement use 6
Yes	0.31	0.14	0.48	<0.001 **	0.19	0.01	0.36	0.041 *	0.41	0.19	0.62	<0.001 **
No	Reference				Reference				Reference
Table salt use 7
Rarely	0.02	−0.08	0.12	0.685	0.04	−0.09	0.17	0.550	−0.02	−0.13	0.10	0.786
Occasionally/very often	Reference				Reference				Reference
Salt use in preparation 7
Never/rarely	Reference				Reference				Reference
Occasionally/very often	0.04	−0.06	0.14	0.430	0.03	−0.09	0.15	0.631	0.04	−0.12	0.20	0.608

¹ Data are from the National Health and Nutrition Examination Surveys. All data except for sample size are weighted accounting for the complex study design according to the directions of the National Center for Health Statistics. Food groups (dairy products, eggs, breads, and beverages) correlated significantly with urinary iodine concentration (UIC) were included in multiple linear regressions; ² Estimates (95% Confidence Intervals) are from separate multiple linear regression analyses for total population, men, and women. The dependent variable is the natural log-transformed UIC; ³ The change in UIC associated with a 1 g/day change in food group intake is not very meaningful. We expressed intake per 100 g/day of these food groups; ⁴ p for trend obtained from multiple linear regression analysis (* p < 0.05, ** p < 0.01); ⁵ NHW, non-Hispanic white; NHB, non-Hispanic black; ⁶ Reported taking iodine-containing supplement yesterday; ⁷ The total n for salt use variables was 4017.