Table 2

Coefficient estimates and confidence intervals from logistic regression of the association between vitamin intake from diet and supplements and respiratory complaints

Model	Vitamin C (mg)			Vitamin D (mg)			Vitamin E (mg)			Vitamin A (μg)
Model	OR	95% CI	P value	OR	95% CI	P value	OR	95% CI	P value	OR	95% CI	P value
Crude
Constant	0.01	0.003 to 0.031	<0.001	0.003	0.001 to 0.009	<0.001	0.018	0.004 to 0.078	<0.001	0.007	0.003 to 0.017	<0.001
Vitamin intake	0.981	0.962 to 1.001	0.057	1.06	0.818 to 1.374	0.659	0.805	0.69 to 0.939	0.006	0.999	0.998 to 0.999	<0.001
Supplement intake (yes)	–	–	–	0.029	0.004 to 0.242	0.001	0.039	0.005 to 0.319	0.003	0.041	0.005 to 0.341	0.003
Fully adjusted
Constant	0.093	0.001 to 12.163	0.339	0.07	0 to 11.358	0.306	0.099	0.001 to 10.517	0.331	0.066	0.001 to 7.92	0.265
Vitamin	0.99	0.974 to 1.006	0.214	0.992	0.704 to 1.397	0.961	0.753	0.612 to 0.927	0.008	0.999	0.998 to 1	0.009
Supplement intake (yes)	–	–	–	0.039	0.004 to 0.346	0.004	0.058	0.006 to 0.516	0.011	0.046	0.005 to 0.425	0.007
BMI (kg/m²)	0.911	0.796 to 1.042	0.173	0.915	0.794 to 1.055	0.221	0.915	0.802 to 1.043	0.184	0.919	0.801 to 1.054	0.227
Sex (women)	0.337	0.047 to 2.415	0.279	0.3	0.044 to 2.029	0.217	0.325	0.05 to 2.105	0.238	0.309	0.049 to 1.939	0.21
Equivalised income ()	0.971	0.898 to 1.049	0.453	0.968	0.898 to 1.044	0.401	0.969	0.898 to 1.046	0.422	0.968	0.899 to 1.043	0.397
Age (years)	1.036	1.006 to 1.067	0.019	1.037	one to 1.075	0.048	1.03	0.989 to 1.072	0.156	1.043	1.01 to 1.077	0.011
Smoking status
Ex-regular smoker	1.512	0.254 to 8.994	0.649	1.43	0.232 to 8.819	0.7	1.931	0.349 to 10.675	0.45	1.542	0.271 to 8.779	0.625
Never regular smokers	0.025	0.002 to 0.307	0.004	0.023	0.002 to 0.271	0.003	0.029	0.002 to 0.343	0.005	0.025	0.002 to 0.281	0.003
Total energy (MJ)	0.929	0.494 to 1.748	0.818	0.892	0.533 to 1.493	0.665	1.164	0.575 to 2.353	0.673	0.944	0.533 to 1.672	0.844

BMI, body mass index.