Table 2.

Intake of vitamins A, C, and E (from dietary and supplemental sources) and risk of ovarian cancer in the National Breast Screening Study

CasesIncident ovarian cancer risk
Person-yearsHazard ratio (95% confidence interval)
Vitamin A, diet only (IU/d)
    <6,58970201,0931.00 (reference)
    >6,589-8,64765201,0930.85 (0.59-1.22)
    >8,647-11,53469200,2630.96 (0.67-1.38)
    >11,53460198,7560.77 (0.52-1.14)
    Ptrend0.51
Vitamin A, diet and supplements (IU/d)
    <6,59564201,1131.00 (reference)
    >6,595-8,65970201,3570.83 (0.57-1.20)
    >8,659-11,56066200,2920.96 (0.57-1.38)
    >11,56064198,6510.79 (0.53-1.16)
    Ptrend0.37
Vitamin C, diet only (mg/d)
    <11559199,5351.00 (reference)
    >115-15974200,1061.27 (0.78-1.64)
    >159-20668201,0521.14 (0.63-1.91)
    >20663200,7200.90 (0.58-1.37)
    Ptrend0.54
Vitamin C, diet and supplements (mg/d)
    <12253199,3101.00 (reference)
    >122-17261199,9031.22 (0.82-1.81)
    >172-24777200,3311.31 (0.89-1.94)
    >24773201,8691.11 (0.75-1.66)
    Ptrend0.59
Vitamin E, diet only (mg/d)
    <1760201,3491.00 (reference)
    >17-2176201,0001.31 (0.91-1.89)
    >21-2577200,1911.27 (0.88-1.85)
    >2551198,8730.87 (0.57-1.31)
    Ptrend0.31
Vitamin E, diet and supplements (mg/d)
    0-1757200,8921.00 (reference)
    >17-2268200,4361.27 (0.87-1.86)
    >22-2864199,3041.01 (0.58-1.52)
    >2875200,7801.24 (0.85-1.82)
    Ptrend0.48
  • NOTE: Results are adjusted hazard ratio and 95% confidence interval and show association based on increasing quartiles of intake. Multivariate adjusted for age (time to event variable), pack-years of smoking (none plus three levels), menopausal status, use of oral contraceptives (ever versus never), body mass index (<25, 25 to 29, >30 kg/m2), education (≤12 versus >12 years), participation in vigorous physical activity (any, none, missing), energy intake at baseline (continuous), study center, and randomization group (intervention versus control).