Selected baseline characteristics of the study participants (N = 92)
| Characteristics | Treatment group | P* | |||
|---|---|---|---|---|---|
| Placebo (n = 23) | Calcium (n = 23) | Vitamin D (n = 23) | Calcium + vitamin D (n = 23) | ||
| Demographics, medical history, habits, and anthropometrics | |||||
| Age, y | 58.5 (8.2) | 61.9 (8.2) | 60.2 (8.1) | 62.1 (7.5) | 0.39 |
| Men (%) | 70 | 70 | 70 | 70 | 1.00 |
| White (%) | 74 | 83 | 65 | 61 | 0.39 |
| College graduate (%) | 65 | 61 | 57 | 44 | 0.53 |
| History of colorectal cancer in first-degree relative (%) | 17 | 30 | 17 | 13 | 0.60 |
| Take NSAID regularly† (%) | 22 | 13 | 9 | 22 | 0.60 |
| Take aspirin regularly† (%) | 22 | 52 | 30 | 56 | 0.05 |
| If woman (n = 28), taking estrogens (%) | 4 | 9 | 4 | 4 | 1.00 |
| Current smoker (%) | 9 | 4 | 0 | 0 | 0.61 |
| Take multivitamin (%) | 30 | 30 | 26 | 39 | 0.86 |
| Body mass index, kg/m2 | 30.6 (7.2) | 29.4 (5.5) | 28.9 (5.6) | 31.6 (6.0) | 0.44 |
| Mean dietary intakes | |||||
| Total energy intake, kcal/d | 1,596 (528) | 1,788 (691) | 1,848 (821) | 1,845 (752) | 0.59 |
| Total‡ calcium, mg/d | 618 (308) | 746 (335) | 843 (526) | 824 (714) | 0.41 |
| Total‡ vitamin D, IU/d | 277 (230) | 336 (202) | 360 (317) | 415 (316) | 0.40 |
| Total fat, g/d | 67 (32) | 72 (35) | 70 (32) | 74 (28) | 0.59 |
| Dietary fiber, g/d | 15 (7) | 17 (9) | 18 (9) | 17 (11) | 0.97 |
| Alcohol, g/d | 9 (14) | 11 (15) | 14 (18) | 10 (20) | 0.84 |
| OBS§ | 6 (2) | 7 (2) | 7 (2) | 7 (2) | 0.46 |
| Adenoma characteristic | |||||
| Multiple adenomas∥ (%) | 17 | 22 | 39 | 26 | 0.45 |
| Large adenoma ≥1 cm¶ (%) | 19 | 32 | 17 | 9 | 0.32 |
| Villous/tubulovillous adenoma** (%) | 4 | 9 | 9 | 4 | 1.00 |
| Mild dysplasia (%) | 100 | 96 | 100 | 100 | 1.00 |
NOTE: Data are given as mean (SD) unless otherwise specified.