Calcium intake may explain the reduction of colorectal cancer odds by dietary selenium - a case-control study in Poland

Table 2 Selenium dietary intake and odds ratios for colorectal cancer (overall, and by strata of dietary calcium intake)

	Model 1			Model 2			Model 3
	OR	95% CI	p-value	OR	95% CI	p-value	OR	95% CI	p-value
Dietary selenium intake (continuous)
for and each increase by 10 μg/day	0.934	0.889–0.980	.006	0.892	0.839–0.948	<.001	0.918	0.843–0.999	0.048
Dietary selenium intake (categorized, reference group < 60 μg/day)
60 to < 80 μg/day	0.814	0.619–1.070	.140	0.699	0.516–0.947	.021	0.717	0.513–1.002	.051
≥ 80 μg/day	0.462	0.318–0.672	<.001	0.396	0.258–0.608	<.001	0.419	0.247–0.712	.001
	p-value for trend = .005			p-value for trend < .001			p-value for trend = .001
Dietary calcium < 1000 mg/day
Dietary selenium intake (continuous)
for and each increase by 10 μg/day	0.997	0.930–1.069	.935	0.927	0.852–1.010	.082	0.874	0.779–0.980	.021
Dietary selenium intake (categorized, reference group < 60 μg/day)
60 to < 80 μg/day	0.809	0.585–1.121	.203	0.655	0.455–0.941	.022	0.562	0.378–0.835	.004
≥ 80 μg/day	0.574	0.326–1.011	.055	0.457	0.241–0.868	.017	0.332	0.162–0.680	.003
	p-value for trend = .066			p-value for trend = .002			p-value for trend < .001
Dietary calcium ≥1000 mg/day
Dietary selenium intake (continuous)
for and each increase by 10 μg/day	0.894	0.806–0.992	.034	0.864	0.764–0.977	.020	0.955	0.851–1.072	.437
Dietary selenium intake (categorized, reference group < 60 μg/day)
60 to < 80 μg/day	1.039	0.555–1.944	.905	0.844	0.424–1.679	.629	1.008	0.479–2.119	.984
≥ 80 μg/day	0.521	0.271–1.000	.050	0.475	0.230–0.980	.044	0.921	0.364–2.327	.862
	p-value for trend = .598			p-value for trend = .045			p-value for trend = .875

Model 1 –univariable logistic regression
Model 2 –adjusted for age [years], sex, BMI [kg/m²], pure alcohol consumption [g/week], average adult lifetime leisure-time physical activity [METs-h/week], smoking (non-smoker, past smoker, current smoker)
Model 3 –adjusted for covariates used in Model 2 and additionally fish consumption [yes/no], total dietary fibre [g/day], vitamin C [mg/day] and vitamin E [mg/day], taking mineral supplements [yes/no], and dietary calcium [mg/day]

ISSN: 2055-0928