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Table 2 Relative risks (95% CI) of breast cancer according to quartile of plasma 25(OH)D, NHSII.

From: Plasma 25-hydroxyvitamin D and risk of breast cancer in the Nurses' Health Study II

  

Quartile 1

Quartile 2

Quartile 3

Quartile 4

P-value, test for trend

 

Cut points (ng/mL)§

< 18.4

18.4 to < 24.6

24.6 to < 30.6

≥ 30.6

 
 

Cases/controls

141/300

151/305

145/307

176/306

 
 

Simple

1.00 (ref)

1.06 (0.80 to 1.40)

1.02 (0.77 to 1.36)

1.26 (0.94 to 1.69)

0.14

 

Multivariate*

1.00 (ref)

1.05 (0.79 to 1.39)

0.95 (0.71 to 1.29)

1.20 (0.88 to 1.63)

0.32

Invasive

Cases/controls

95/300

98/305

97/307

125/306

 
 

Multivariate*

1.00 (ref)

1.03 (0.74 to 1.44)

1.01 (0.72 to 1.42)

1.29 (0.92 to 1.81)

0.14

ER+†

Cases/controls

79/300

72/305

70/307

100/306

 
 

Multivariate*

1.00 (ref)

0.89 (0.62 to 1.29)

0.84 (0.57 to 1.23)

1.21 (0.84 to 1.75)

0.29

ER-†

Cases/controls

16/300

20/305

21/307

20/306

 
 

Multivariate*

1.00 (ref)

1.26 (0.63 to 2.54)

1.37 (0.67 to 2.79)

1.31 (0.63 to 2.74)

0.47

ER+/PR+†

Cases/controls

71/300

60/305

58/307

86/306

 
 

Multivariate*

1.00 (ref)

0.82 (0.56 to 1.22)

0.76 (0.51 to 1.15)

1.16 (0.79 to 1.71)

0.43

ER-/PR-†

Cases/controls

14/300

18/305

21/307

17/306

 
 

Multivariate*

1.00 (ref)

1.27 (0.61 to 2.65)

1.52 (0.73 to 3.19)

1.18 (0.54 to 2.60)

0.64

  1. *Multivariate conditional logistic regression models adjusted for: age at menarche (< 12, 12, 13, ≥ 14 y), BMI at age 18 (< 21, 21 to < 23, ≥ 23 kg/m2), parity and age at first birth (nulliparous, one to two children and < 25 y, one to two children and 25 to 29 y, one to two children and ≥ 30 y, three or more children and < 25 y, three or more children and ≥ 25 y), BMI at blood collection (continuous), family history of breast cancer (yes/no), history of benign breast disease (yes/no).
  2. Multivariate unconditional logistic regression models adjusted for above covariates and matching factors: age at blood collection (continuous), date of blood collection (February to April, May to July, August to October, November to January), fasting status at blood collection (> 8 h/≤8 h), time of blood collection (1 to 4 am, 5 to 6 am, 7 am to 12 pm, continuous), luteal day (< 8, ≥ 8, untimed collection), race (Caucasian/other), menopausal status at blood collection (premenopausal, postmenopausal, unknown menopausal status).
  3. † P-value, test for heterogeneity from polytomous logistic regression: 0.41 for ER+ vs. ER-; 0.51 for ER+/PR+ vs. ER-/PR-
  4. §Cut points in nmol/L are: < 45.9, 45.9 to < 61.4, 61.4 to < 76.4, ≥ 76.4
  5. Abbreviations: 25(OH)D, 25-hydroxyvitamin D; ref, referent; ER, estrogen receptor; PR, progesterone receptor