Table 1.

Characteristics of the cases and controls, and association of these characteristics with plasma levels of 25(OH)D among controls

CharacteristicCasesControlsAssociation with 25(OH)D in controls
n (%)n (%)Mean*± SEMP
Sex
    Male146 (63.8)278 (64.1)26.6 ± 0.6
    Female83 (36.2)156 (35.9)23.4 ± 0.8<0.01
Ethnicity
    Japanese American89 (38.9)171 (39.4)27.0 ± 0.7
    Latino46 (20.1)88 (20.3)20.7 ± 0.9
    African-American45 (19.7)81 (18.7)16.8 ± 1.0
    White39 (17.0)74 (17.1)30.8 ± 1.0
    Native Hawaiian10 (4.4)20 (4.6)29.6 ± 1.9<0.01
Study area
    Hawaii127 (55.5)245 (56.5)28.6 ± 0.6
    Los Angeles102 (44.5)189 (43.5)19.5 ± 0.7<0.01
First-degree family history of colorectal cancer
    No200 (87.3)394 (90.8)25.2 ± 0.5
    Yes29 (12.7)40 (9.2)22.1 ± 1.40.03
Season of blood draw
    December to June127 (55.5)243 (56.0)23.4 ± 0.6
    July to November102 (44.5)191 (44.0)27.1 ± 0.7<0.01
Mean ± SDMean ± SDCorrelationP
Age at blood draw, y69.3 ± 8.069.2 ± 7.90.020.74
Time between blood draw and case diagnosis, y1.7 ± 1.41.7 ± 1.4−0.020.62
BMI, kg/m226.7 ± 5.025.8 ± 4.2−0.080.09
Physical activity, MET-h/d§6.3 ± 7.76.2 ± 7.10.070.13
Energy intake, kcal/d2,242 ± 9752,185 ± 1,031−0.100.03
Processed red meat intake, g/1,000 kcal/d8.0 ± 6.17.8 ± 6.6−0.010.82
Calcium intake, mg/1,000 kcal/d430.0 ± 229.2479.8 ± 283.30.110.02
Vitamin D intake, IU/1,000 kcal/d151.6 ± 167.9165.5 ± 204.70.090.06
Plasma 25(OH)D, ng/mL23.2 ± 10.125.0 ± 9.9

Abbreviation: MET-h, metabolic equivalent hours.

  • *Among controls, mean 25(OH)D (ng/mL) by level of the characteristic, adjusted for sex and ethnicity as appropriate (except for area). P value from analysis of covariance. To convert to nmol/L, multiply these values by 2.5.

  • Matching variables.

  • Among controls, partial correlation between 25(OH)D and the characteristic, adjusted for sex and ethnicity.

  • §Summary statistics based on slightly fewer than 229 cases and 434 controls due to missing values.