|
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
|