Table 3.

RRs and 95% CIs for breast cancer by quintile of 25(OH)D and 1,25(OH)2D, stratified by participant's age at blood collection

<60 y
≥60 y
Case/controlsMultivariable RR* (95% CI)Cases/controlsMultivariable RR* (95% CI)
25(OH)D
    Quintile
        197/941.0062/471.00
        284/860.96 (0.62-1.49)65/491.07 (0.60-1.92)
        377/870.80 (0.51-1.26)48/570.64 (0.35-1.16)
        490/1020.85 (0.55-1.32)54/550.68 (0.38-1.24)
        570/760.92 (0.57-1.48)54/710.57 (0.31-1.04)
        Ptrend0.880.03
        Pinteraction0.20
1,25(OH)2D
    Quintile
        187/811.0060/491.00
        258/710.76 (0.47-1.25)55/530.76 (0.42-1.38)
        370/870.72 (0.46-1.15)50/381.00 (0.53-1.88)
        489/781.17 (0.75-1.84)39/470.61 (0.32-1.15)
        579/790.88 (0.56-1.40)53/510.72 (0.40-1.32)
        Ptrend0.910.23
        Pinteraction0.41
  • * RR from unconditional logistic regression adjusted for age, fasting status at blood draw, month of blood collection, time of day of blood collection, BMI at age 18, parity/age at first birth, family history of breast cancer, benign breast disease, age at menarche, plasma α-carotene level, and intake of alcohol. See footnotes to Table 2 for variable categories. Results for postmenopausal women also adjusted for quartile of plasma estradiol (in nonusers of postmenopausal hormones), age at menopause, and total duration of postmenopausal hormone use.

  • Two-sided Ptrend over quintiles, calculated by using the median value of each quintile as a continuous variable in the multivariable model.