Table 1.

Selected baseline characteristics of the study participants (n = 193)a

Treatment group
CharacteristicsPlacebo (n = 66)Calcium 1 g (n = 64)Calcium 2 g (n = 63)Pb
Age, y60 (9)60 (9)58 (10)0.37
Men, %6463620.98
White, %98100100> 0.99
College graduate, %3519330.08
Employed, %5245560.48
Family history, %2625300.78
Take aspirinc, %2127160.34
Take non-aspirin NSAIDc, %911100.92
Currently smoke, %2016240.53
Alcohol intake, g/d11 (19)13 (20)8 (13)0.20
Body mass index, kg/m2
 Men28.0 (3.8)29.0 (3.1)28.8 (4.5)0.47
 Women30.1 (5.2)28.1 (8.4)26.3 (4.4)0.12
Vigorous/moderate physical activity, MET-hours/day33 (21)30 (22)28 (21)0.47
Dietary intakes
 Total energy, kcal/day2,097 (753)2,000 (627)2,102 (633)0.63
 Total fat, g/day64 (27)62 (24)70 (24)0.19
 Dietary fiber, g/day24 (10)22 (7)22 (9)0.33
 Total vitamin D, IU/day345 (251)294 (268)314 (207)0.48
 Total calcium, mg/day884 (339)787 (364)855 (416)0.33
 Phosphorous, mg/day1,359 (435)1,248 (441)1,327 (418)0.34
 Omega-3 fatty acids, g/day0.2 (0.2)0.2 (0.2)0.2 (0.2)0.41
 Take any vitamin supplement(s), %3838330.82

Abbreviation: MET, metabolic equivalents of task.

  • aUnless otherwise specified, values presented are mean (standard deviation).

  • bP values calculated from analysis of covariance for continuous variables, and χ2 or Fisher's exact test for categorical variables. Sex was included as a covariate when appropriate.

  • cRegularly take once or more a week.