Characteristic | Cases (n = 516) | Controls (n = 516) | Pvalue‡‡ |
---|---|---|---|
Mean (SD) | |||
Age at serum collection (year) | 69.5 (5.9) | 69.6 (5.8) | 0.7 |
Plasma 25(OH)D (nmol/L) | 56.5 (22.0) | 56.2 (22.2) | 0.8 |
Latitude (degree) | 39.0 (4.7) | 39.3 (4.8) | 0.2 |
BMI at blood collection (kg/m2) | 25.9 (4.9) | 25.8 (4.8) | 0.9 |
Weight gain since age 18 (kg) | 14.1 (15.5) | 11.1 (18.3) | 0.006 |
Exercise METS† | 15.4 (13.8) | 15.6 (14.7) | 0.9 |
Age at menarche (years) | 12.7 (1.5) | 12.7 (1.4) | 0.6 |
Age at menopause (years) | 48.6 (6.1) | 47.8 (6.0) | 0.03 |
Percentage (%) | |||
Family history of breast cancer | 23.6 | 16.9 | 0.007 |
History of benign breast disease | 33.9 | 27.5 | 0.01 |
Race | |||
White | 96.7 | 97.1 | 0.7 |
Other (Black/Hispanic/Oriental) | 3.3 | 2.9 | |
College graduate | 24.2 | 23.4 | 0.5 |
Parity and age at first birth | |||
Nulliparous | 9.1 | 8.5 | 0.006 |
<25, 1 to 2 live births | 13.2 | 12.4 | |
25+, 1 to 2 live births | 22.5 | 14.7 | |
<25, 3+ live births | 35.3 | 45.0 | |
25+, 3+ live births | 20.0 | 19.4 | |
Postmenopausal hormone use | |||
Never | 22.1 | 25.4 | 0.4 |
Former | 58.1 | 53.1 | |
Current | 16.1 | 16.7 | |
Season of blood collection | |||
Dec to Feb | 15.1 | 18.2 | 0.1 |
Mar to May | 18.8 | 17.4 | |
Jun to Aug | 35.1 | 29.5 | |
Sep to Nov | 31.0 | 34.9 | |
Alcohol intake (≥ 1 drink/day) | 21.3 | 16.1 | 0.1 |
Multivitamin use containing vitamin D‡ | |||
Not current user | 30.8 | 34.9 | 0.6 |
Current user | 63.6 | 59.6 | |
Calcium supplement use | |||
Not current user | 32.4 | 32.9 | 0.5 |
Current user | 59.9 | 57.3 | |
Vitamin D supplement use§ | |||
Not current user | 54.1 | 53.7 | 0.9 |
Current user | 16.1 | 16.9 | |
Mean (SD) | |||
Dietary variables # | |||
Total calcium (mg/day) | 1358.0 (565.2) | 1293.7 (576.6) | 0.08 |
Dietary calcium (mg/day) | 777.0 (285.3) | 768.6 (283.0) | 0.6 |
Supplemental calcium (mg/day) | 581.0 (504.3) | 515.0 9493.4) | 0.08 |
Total vitamin D (IU/day) | 439.5 (243.6) | 415.0 (239.7) | 0.1 |
Dietary vitamin D (IU/day) | 192.0 (105.3) | 187.6 (96.1) | 0.5 |