TABLE 2.

Pearson’s correlation coefficients between: (I) Log_e transformed serum antioxidant status variables and (II) Log_e transformed serum antioxidant status variables vs. selected dietary intake variables and continuous PHQ score; NHANES 2005–06 (n=1,798)

	I. Correlations between Loge transformed serum antioxidant status variables
	Retinol+retinyl esters	Vitamin E	Vitamin C	Total carotenoids	α-carotene	β-carotene	β-cryptoxanthin	Lutein +zeaxanthin	Lycopene
Loge transformed serum antioxidants, μmol/L
Retinol+retinyl esters	1
Vitamin E	0.38	1
Vitamin C	0.10	0.28	1
Total carotenoids	0.11	0.42	0.42	1
α-carotene	0.10	0.32	0.41	0.76	1
β-carotene	0.12	0.40	0.45	0.86	0.79	1
β-cryptoxanthin	0.02b	0.27	0.45	0.74	0.59	0.59	1
Lutein+zeaxathin	0.09	0.40	0.35	0.75	0.54	0.56	0.60	1
Lycopene	0.04 b	0.15	0.05	0.57	0.22	0.25	0.31	0.29	1
	II. Correlations of Loge transformed serum antioxidants with selected dietary intake variables and PHQ score
	Retinol+retinyl esters	Vitamin E	Vitamin C	Total carotenoids	α-carotene	β-carotene	β-cryptoxanthin	Lutein +zeaxanthin	Lycopene
Loge transformed dietary intake
Retinol, μg/d	0.14;0.12	0.10	0.08	−0.00*	0.05	0.05	−0.02*	−0.00*	−0.01*
vitamin E, mg/d	0.10	0.13;0.03*	0.13	0.17	0.16	0.14	0.09	0.17	0.14
vitamin C, mg/d	0.02*	0.11	0.36;0.26	0.27	0.26	0.21	0.35	0.24	0.03*
Total carotenoids, μg/d	0.08	0.10	0.18	0.29;0.16	0.27	0.26	0.18	0.25	0.16
α-carotene, μg/d	0.11	0.15	0.18	0.22	0.36;0.24	0.28	0.18	0.19	−0.05*
β-carotene, μg/d	0.12	0.16	0.21	0.30	0.37	0.34;0.22	0.18	0.28	−0.01*
β-Cryptoxanthin, μg/d	0.04*	0.12	0.31	0.27	0.22	0.21	0.39;0.28	0.23	0.03*
Lutein+zeaxanthin, μg/d	0.09	0.14	0.21	0.29	0.26	0.25	0.20	0.33;0.19	0.04*
Lycopene, μg/d	0.01	0.03*	0.05*	0.13	0.06	0.05	0.08	0.06	0.25;0.24
Fruits and vegetable intake, cup equivalent/d	0.08	0.14	0.28	0.30	0.31	0.26	0.29	0.26	0.09
Supplement use, past 30 days (0, 1, 2)	0.16	0.42	0.29	0.19	0.21	0.28	0.06	0.14	−0.00
Loge transformed (PHQ score)	−0.06	−0.10	−0.07	−0.07	−0.08	−0.09	−0.09	−0.09	−0.04*

Abbreviations: NHANES=National Health and Nutrition Examination Survey; PHQ=Patient Health Questionnaire; SEE=Standard error of the estimate.

^aValues are Pearson’s correlation coefficients. Italicized correlation coefficients are partial correlations between serum antioxidant and its corresponding dietary antioxidant (both Log_e transformed), controlling for Log_e transformed fruit and vegetable intake and supplement use (0, 1, 2 or more).

^*P>0.05 for null hypothesis that r=0; All other correlations were statistically significant.