TABLE 1.
Age-adjusted characteristics of premenopausal women according to category of total vitamin D and calcium intakes (intakes from foods and supplements combined) at baseline: NHS2, 19911
| Total vitamin D, quintiles |
Total calcium, quintiles |
|||||||||
| Characteristic | 1 (n = 17,000) | 2 (n = 17,069) | 3 (n = 17,438) | 4 (n = 17,421) | 5 (n = 17,306) | 1 (n = 17,024) | 2 (n = 17,333) | 3 (n = 17,440) | 4 (n = 17,476) | 5 (n = 16,961) |
| Calcium intake,2 mg/d | 684 ± 2.7 | 842 ± 2.7 | 1024 ± 2.7 | 1156 ± 2.7 | 1364 ± 2.7 | 570 | 753 | 923 | 1163 | 1560 |
| Vitamin D intake,3 IU/d | 128 | 217 | 317 | 473 | 742 | 214 ± 1.7 | 289 ± 1.7 | 370 ± 1.7 | 459 ± 1.7 | 617 ± 1.7 |
| Age,4 y | 36.1 ± 4.6 | 36.1 ± 4.6 | 35.9 ± 4.6 | 35.5 ± 4.6 | 35.3 ± 4.5 | 36.2 ± 4.6 | 35.9 ± 4.6 | 35.7 ± 4.6 | 35.5 ± 4.6 | 35.6 ± 4.7 |
| BMI, kg/m2 | 24.8 ± 0.04 | 24.6 ± 0.04 | 24.5 ± 0.04 | 24.4 ± 0.04 | 24.3 ± 0.04 | 24.6 ± 0.04 | 24.6 ± 0.04 | 24.6 ± 0.04 | 24.4 ± 0.04 | 24.4 ± 0.04 |
| Age at menarche, y | 12.4 ± 0.01 | 12.4 ± 0.01 | 12.4 ± 0.01 | 12.4 ± 0.01 | 12.4 ± 0.01 | 12.4 ± 0.01 | 12.4 ± 0.01 | 12.4 ± 0.01 | 12.4 ± 0.01 | 12.4 ± 0.01 |
| Full-term pregnancies, n | 1.6 ± 0.01 | 1.6 ± 0.01 | 1.6 ± 0.01 | 1.6 ± 0.01 | 1.5 ± 0.01 | 1.5 ± 0.01 | 1.6 ± 0.01 | 1.5 ± 0.01 | 1.6 ± 0.01 | 1.5 ± 0.01 |
| Physical activity, MET-h/wk | 20.6 ± 0.5 | 23.1 ± 0.5 | 24.9 ± 0.5 | 25.0 ± 0.5 | 27.5 ± 0.5 | 21.3 ± 0.5 | 23.2 ± 0.5 | 24.8 ± 0.5 | 24.9 ± 0.5 | 26.9 ± 0.5 |
| Vegetable protein intake, % total kcal | 5.0 ± 0.01 | 5.1 ± 0.01 | 5.0 ± 0.01 | 5.0 ± 0.01 | 5.0 ± 0.01 | 4.8 ± 0.01 | 5.1 ± 0.01 | 5.2 ± 0.01 | 5.0 ± 0.01 | 4.9 ± 0.01 |
| Alcohol intake, g/d | 3.5 ± 0.05 | 3.3 ± 0.05 | 3.2 ± 0.05 | 3.1 ± 0.05 | 2.5 ± 0.05 | 3.5 ± 0.05 | 3.6 ± 0.05 | 3.3 ± 0.05 | 2.9 ± 0.05 | 2.5 ± 0.05 |
| Ever used OCs, % | 84.8 | 84.7 | 84.3 | 82.9 | 83.4 | 84.2 | 84.6 | 84.0 | 83.4 | 83.8 |
| Current smoker, % | 16.4 | 12.9 | 10.9 | 10.0 | 9.1 | 17.1 | 12.9 | 10.9 | 9.7 | 8.7 |
Values are means ± SEs unless otherwise indicated. All characteristics were calculated by using generalized linear models adjusted, unless otherwise specified, for the age of participants in 1991. MET-h, metabolic equivalent task hours; NHS2, Nurses’ Health Study II; OC, oral contraceptive.
Values are means ± SEs of total calcium intake per quintile of total vitamin D and quintile medians for total calcium.
Values are means ± SEs of total vitamin D intake per quintile of total calcium and quintile medians for total vitamin D.
All values are means ± SDs. Values are not age adjusted.