Table 2. Association between plasma 25-hydroxyvitamin D and covariates among controls at baseline.

	Quartiles of plasma 25-hydroxyvitamin D
	Men					Women
Variables	Lowest	Second	Third	Highest	P for trend	Lowest	Second	Third	Highest	P for trend
Range, ng ml−1	(<22.9)	(22.9–27.5)	(27.6–32.0)	(32.1+)		(<18.7)	(18.7–22.2)	(22.3–26.9)	(27.0+)
Median, ng ml−1	19.9	25.0	29.6	35.6		16.6	20.6	24.1	31.4
Age, mean	57.6	55.1	56.9	58.0	0.45	55.3	57.9	56.8	55.6	0.92
Smoking, meana	25.9	23.9	21.4	23.9	0.44	0.8	1.3	0.4	0.2	0.22
Alcohol consumption, meana	172	172	183	174	0.40	11.2	3.6	4.6	3.5	0.062
Body mass index, meana	23.5	23.1	23.3	23.1	0.53	23.5	23.4	23.7	23.8	0.34
Physical exercise, n	18	21	16	20	0.70	11	16	12	15	0.83
Vitamin supplement use, n	15	9	21	8	0.30	14	15	12	13	0.74
Family history of colorectal cancer, n	0	1	1	2	0.15	0	2	1	1	0.47
Dietary fibre intake, meanb	7.53	8.56	8.39	7.64	0.84	7.13	7.60	7.62	7.80	0.96
Folate intake, meanb	338	340	331	312	0.091	279	288	292	300	0.48
Calcium intake, meanb	451	463	497	443	0.57	429	419	437	399	0.24
Vitamin D intake, meanb	6.30	6.84	7.14	6.47	0.92	5.00	5.19	4.84	5.54	0.067
n-3 fatty-acid intake, meanb	1.30	1.44	1.47	1.31	0.81	1.07	1.13	1.08	1.20	0.026
Red meat intake, meanb	17.8	17.8	16.2	17.0	0.50	10.6	13.8	13.4	12.9	0.49
Fish intake, meanb	59.5	63.9	66.2	58.9	0.70	42.2	44.0	39.1	48.4	0.087

^aAdjusted for age.

^bAdjusted for age, cohort, and energy intake.