Table 2.

Follow-up data on participants with posttreatment observational follow-up phase adenoma outcome data (N = 1,121)

Full factorial randomizationTwo-group randomization
Placebo (N = 210)Calcium (N = 215)Vitamin D (N = 213)Vitamin D + calcium (N = 224)Calcium + placebo (N = 132)Calcium + vitamin D (N = 127)
CharacteristicN (%)N (%)N (%)N (%)PN (%)N (%)P
Total months in observational phase, mean ± SD55.3 ± 15.853.7 ± 15.754.9 ± 15.454.2 ± 14.80.7255.5 ± 15.054.9 ± 13.70.74
Dietary calcium during observational follow-up phasea0.920.72
 0–699 mg/day15 (7.2)17 (7.9)20 (9.4)20 (9.0)69 (52.3)61 (48.0)
 700–799 mg/day68 (32.5)67 (31.2)69 (32.4)71 (32.0)33 (25.0)40 (31.5)
 800–899 mg/day67 (32.1)72 (33.5)77 (36.2)69 (31.1)22 (16.7)19 (15.0)
 900+ mg/day59 (28.2)59 (27.4)47 (22.1)62 (27.9)8 (6.1)7 (5.5)
 Missing100200
Calcium supplemental use during observational follow-up phase0.580.67
 0 mg/day146 (71.9)155 (75.2)158 (76.3)163 (74.4)40 (33.3)35 (28.5)
 1–399 mg/day40 (19.7)32 (15.5)26 (12.6)33 (15.1)26 (21.7)33 (26.8)
 400–1,199 mg/day15 (7.4)17 (8.3)23 (11.1)21 (9.6)50 (41.7)49 (39.8)
 1,200+ mg/day2 (1.0)2 (1.0)0 (0.0)2 (0.9)4 (3.3)6 (4.9)
 Missing7965124
Dietary vitamin D during observational follow-up phasea0.170.52
 0–19.9 IU/day30 (14.4)39 (18.1)53 (24.9)51 (23.0)44 (33.3)37 (29.1)
 20–49.9 IU/day62 (29.7)55 (25.6)55 (25.8)47 (21.2)25 (18.9)34 (26.8)
 50–99.9 IU/day56 (26.8)50 (23.3)49 (23.0)56 (25.2)28 (21.2)25 (19.7)
 100+ IU/day61 (29.2)71 (33.0)56 (26.3)68 (30.6)35 (26.5)31 (24.4)
 Missing100200
Vitamin D supplement use during observational follow-up phase0.990.36
 0–399 IU/day139 (68.8)144 (69.6)137 (68.8)144 (67.0)54 (44.6)48 (40.7)
 400–999 IU/day36 (17.8)32 (15.5)33 (16.6)37 (17.2)28 (23.1)37 (31.4)
 1000+ IU/day27 (13.4)31 (15.0)29 (14.6)34 (15.8)39 (32.2)33 (28.0)
 Missing88149119
  • aAssessed as the average of the annual dietary screener estimate.