Table 1.

Selected baseline characteristics of the study participants (N = 92)

CharacteristicsTreatment groupP*
Placebo (n = 23)Calcium (n = 23)Vitamin D (n = 23)Calcium + vitamin D (n = 23)
Demographics, medical history, habits, and anthropometrics
    Age, y58.5 (8.2)61.9 (8.2)60.2 (8.1)62.1 (7.5)0.39
    Men (%)707070701.00
    White (%)748365610.39
    College graduate (%)656157440.53
    History of colorectal cancer in first-degree relative (%)173017130.60
    Take NSAID regularly (%)22139220.60
    Take aspirin regularly (%)225230560.05
    If woman (n = 28), taking estrogens (%)49441.00
    Current smoker (%)94000.61
    Take multivitamin (%)303026390.86
    Body mass index, kg/m230.6 (7.2)29.4 (5.5)28.9 (5.6)31.6 (6.0)0.44
Mean dietary intakes
    Total energy intake, kcal/d1,596 (528)1,788 (691)1,848 (821)1,845 (752)0.59
    Total calcium, mg/d618 (308)746 (335)843 (526)824 (714)0.41
    Total vitamin D, IU/d277 (230)336 (202)360 (317)415 (316)0.40
    Total fat, g/d67 (32)72 (35)70 (32)74 (28)0.59
    Dietary fiber, g/d15 (7)17 (9)18 (9)17 (11)0.97
    Alcohol, g/d9 (14)11 (15)14 (18)10 (20)0.84
    OBS§6 (2)7 (2)7 (2)7 (2)0.46
Adenoma characteristic
    Multiple adenomas (%)172239260.45
    Large adenoma ≥1 cm (%)19321790.32
    Villous/tubulovillous adenoma** (%)49941.00
    Mild dysplasia (%)100961001001.00

NOTE: Data are given as mean (SD) unless otherwise specified.

  • *By Fisher's exact χ2 test for categorical variables and ANOVA for continuous variables.

  • At least once a week.

  • Diet plus supplements.

  • §See Statistical Analysis for details.

  • At least two adenomas.

  • At least one large adenoma.

  • **At least one villous or tubulovillous adenoma.