Table 3.

Variables predicting serum 25(OH)D in obese subjects

Variable	n	Simple linear regression			Multiple stepwise regression
		β	r2	P	β	r2	P
Age	411	−2.18	0.094	<0.001	−1.89	0.098	<0.001
Soda intake	395	−3.49	0.041	<0.001	−3.14	0.132
Skip breakfast	411	−8.66	0.053	<0.001	−5.62	0.158
Juice intake	395	−2.40	0.022	<0.001	−2.00	0.172
Milk intake	395	3.28	0.023	0.002
Fruit/vegetable intake	405	3.82	0.021	0.003
BMI Z score	411	−3.00	0.003	0.273

Skip breakfast, Yes/no; soda/juice/milk intake, number of 8-ounce glasses/day; fruit/vegetable intake, less than one, one or two, or at least three servings per day; β, regression coefficient.

The simple linear regressions are for the individual independent variables indicated. For the multiple stepwise regression analysis, only the four independent variables incorporated into the model are listed, and the r² values displayed are cumulative [i.e. the four variables together account for ∼17% of the total variance in 25(OH)D levels]. The r² for the three dietary variables (with age ignored) is 0.106.