Table 1.
Baseline Characteristics of Participants Included in Genetic Association Analysesa
| Characteristic | All (n = 1702) | No Vitamin Db (n = 848) | Vitamin Db (n = 854) | P Valuec | No Calciumd (n = 648) | Calciumd (n = 634) | P Valuec |
|---|---|---|---|---|---|---|---|
| Men, No. (%) | 1101 (64.7) | 548 (64.6) | 553 (64.8) | .96 | 560 (86.4) | 541 (85.3) | .58 |
| Age, mean (SD), y | 58.1 (6.8) | 58.2 (6.9) | 58.1 (6.7) | .63 | 58.3 (6.9) | 58.8 (6.9) | .22 |
| BMI, mean (SD) | 28.9 (5.1) | 28.9 (5.2) | 28.8 (5.1) | .80 | 29.0 (4.7) | 29.2 (5.2) | .45 |
| Current smoker, No. (%) | 148 (8.7) | 66 (7.8) | 82 (9.6) | .18 | 52 (8.0) | 56 (8.8) | .60 |
| Physical activity, MET-min/wk, mean (SD) | 3060 (2900) | 3076 (2851) | 3045 (2948) | .82 | 3200 (3081) | 3175 (2927) | .88 |
| Alcohol intake, mean (SD) drinks/d, No. | 0.82 (1.03) | 0.78 (1.00) | 0.87 (1.06) | .07 | 0.97 (1.1) | 0.91 (1.06) | .32 |
| Aspirin use ≥ 4 d/wk, No. (%) | 626 (36.8) | 305 (36.0) | 321 (37.6) | .49 | 271 (41.8) | 246 (38.8) | .27 |
| Dietary vitamin D intake, mean (SD), IU/d | 137 (99) | 141 (98) | 133 (100) | .08 | 138 (101) | 141 (98) | .66 |
| Dietary calcium intake, mean (SD), mg/d | 678 (311) | 694 (319) | 663 (302) | .04 | 681 (302) | 698 (320) | .35 |
| Multivitamin use, No. (%) | 971 (57.1) | 482 (57.0) | 489 (57.3) | .91 | 348 (53.7) | 331 (52.4) | .63 |
| Vitamin D supplement use, No. (%) | 231 (13.6) | 106 (12.5) | 125 (14.7) | .21 | 35 (5.4) | 36 (5.7) | .82 |
| Calcium supplement use, No. (%) | 337 (19.9) | 165 (19.5) | 172 (20.2) | .73 | 56 (8.7) | 52 (8.2) | .78 |
| Serum 25(OH)D, mean (SD), ng/mL | 25.4 (8.5) | 25.4 (8.7) | 25.5 (8.3) | .82 | 25.3 (8.2) | 25.5 (8.7) | .60 |
| One adenoma <1 cm, No. (%)e | 932 (56.5) | 472 (57.4) | 460 (55.7) | .50 | 344 (54.8) | 325 (53.2) | .58 |
| Advanced adenoma, No. (%)f | 312 (18.6) | 157 (18.8) | 155 (18.5) | .90 | 116 (18.3) | 119 (19.1) | .70 |
Abbreviations: 25(OH)D, 25-hydroxyvitamin D; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); MET, metabolic equivalent of task.
Data were missing for participants in the following categories: activity (n = 24), diet (n = 99), multivitamins (n = 2), vitamin D supplements (n = 4), calcium supplements (n = 3), adenomas (n = 53), advanced adenomas (n = 27).
All participants were included in these vitamin D groups.
P values for 2-sample t tests for continuous variables and Pearson χ2 tests for categorical variables.
Women who chose to take calcium supplements were excluded from these calcium groups.
Adenomas at qualifying colonoscopy within 120 days prior to enrollment; missing data due to missing pathology results.
Advanced adenomas defined as those with cancer, high-grade dysplasia, more than 25% villous features, or with an estimated diameter of 1 cm or larger.