Table 1.

Selected baseline characteristics of the adjunct biomarker study participants (n = 105), by treatment group assignment

Randomization to vitamin D and to calcium (4-arm)Randomization to vitamin D only (2-arm)b
PlaceboCalciumVitamin DVit. D + calciumPlaceboVitamin D
Characteristicsa(n = 12)(n = 16)(n = 17)(n = 18)Pb(n = 23)(n = 19)Pc
Age, years59.9 (7.2)59.9 (6.5)59.2 (7.8)58.0 (7.1)0.8658.2 (5.3)59.2 (7.3)0.60
Men, %75.081.370.683.30.8300
White, %83.375.070.694.40.2969.684.20.30
College graduated, %66.737.564.755.60.3747.836.80.54
1° family history of CRC, %e012.520.05.60.374.411.10.57
Regularf NSAID users, %33.343.823.527.80.6326.131.60.70
Regularf aspirin users, %50.068.841.244.40.3930.431.60.94
If woman (n = 56), HRT users, %100.00.020.033.30.1121.731.60.50
Current smoker, %25.06.305.60.10015.80.08
Multivitamin users, %41.781.347.166.70.1069.5789.50.15
Physical activity, MET-min/wkg1,620 (1,195)2,128 (2,378)2,782 (2,764)4,042 (2,456)0.031,458 (1,235)3,021 (3,469)0.05
BMI, kg/m229.4 (4.9)32.3 (7.6)28.7 (5.5)30.2 (4.4)0.3129.7 (5.6)27.5 (4.7)0.18
No. adenomas1.6 (0.7)1.6 (1.0)1.4 (0.8)1.4 (0.7)0.701.2 (0.7)1.6 (1.0)0.11
Had advanced adenomah, %36.46.723.527.80.309.115.80.65
Had sessile serrated adenoma, %3.39.54.89.50.4514.37.10.42
Dietary intakes
 Total energy intake, kcal/d1,314 (381)1,737 (556)1,437 (527)1,569 (565)0.211,254 (549)1,429 (595)0.33
 Red/processed meat, svgs/d1.2 (0.9)1.0(0.7)0.9 (0.8)1.0 (0.7)0.740.6 (0.54)0.7 (0.6)0.59
 Fruits/vegetables, svgs/d3.0 (1.7)4.4 (2.0)4.5 (2.5)4.3 (1.7)0.284.7 (1.7)6.0 (2.4)0.04
 Alcohol intake, drinks/day0.7 (0.7)0.8 (1.0)0.9 (0.9)0.9 (0.9)0.950.5 (1.0)0.3 (0.5)0.42
 Total vitamin Di, IU/d354 (307)457 (189)313 (278)421 (296)0.48521 (354)634 (276)0.34
 Total calciumj, mg/d641 (284)863 (284)663 (272)656 (251)0.16938 (466)1,213 (553)0.09
Serum concentrations
 25-OH-vitamin D, ng/mL22.4 (8.2)24.5 (13.4)23.1 (8.7)22.7 (6.4)0.9324.8 (8.9)26.5 (9.6)0.54
 Ca++, mg/dL9.2 (0.2)9.3 (0.3)9.3 (0.3)9.4 (0.3)0.259.5 (0.3)9.4 (0.3)0.52
  • Abbreviations: CRC, colorectal cancer; d, day; HRT, hormone replacement therapy; IU, international unit; kcal, kilocalorie; min, minute; No., number; svgs, servings; Vit. D, vitamin D; wk, week.

  • aData presented as means (SD) unless otherwise specified.

  • bFrom χ2 tests for categorical variables, and general linear models for continuous variables.

  • cFrom χ2 test for categorical variables, and Student t tests for continuous variables.

  • dReceived a Bachelor's degree or higher.

  • eMissing data on 3 patients.

  • fAt least once a week; NSAIDs do not include aspirin.

  • gMissing data on 1 patient.

  • hDefined as those with high-grade dysplasia, more than 25% villous features, or an estimated diameter of at least 1 cm; missing data on 3 patients.

  • iDietary vitamin D plus supplemental vitamin D. Missing information for 3 placebo patients, 2 calcium, 2 vitamin D, one combined, 6 placebo (2-arm), and 5 vitamin D (2-arm) patients.

  • jDietary calcium plus supplemental calcium (extra calcium + multivitamin).