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
 Age (y)58.5 (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
Medical history
 History of colorectal cancer in 1° relative (%)173017130.60
 Take NSAID regularly (%)22139220.60
 Take aspirin regularly (%)225230560.05
 If woman (n = 28), taking estrogens (%)49441.00
Habits
 Current smoker (%)94000.61
 Take multivitamin (%)303026390.86
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
Anthropometrics
 Body mass index (kg/m2)30.6 (7.2)29.4 (5.5)28.9 (5.56)31.6 (6.0)0.44
 Waist-to-hip ratio0.9 (0.1)0.9 (0.1)0.9 (0.1)1.0 (0.1)0.17
VDR BsmI genotype (%)
 bb353948300.25
 Bb35574352
 BB304917
Serum vitamin D
 25-OH-vitamin D (ng/mL)20.4 (7.6)25.7 (7.6)21.0 (8.3)20.9 (9.7)0.12
 1,25-(OH)2-vitamin D (pg/mL)39.2 (12.2)45.4 (35.3)44.5 (22.6)37.9 (12.5)0.60

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

Abbreviations: NSAID, nonsteroidal anti-inflammatory drug; VDR, vitamin D receptor.

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

  • At least once a week.

  • Diet plus supplements.