Predicted 25(OH)D (quartiles) | Breast cancer cases | Person-years | MVa IRR | 95 % CI | P trend |
---|---|---|---|---|---|
Age <45 years | |||||
4 (highest) | 86 | 89,683 | 1.00 | Ref | 0.20 |
3 | 100 | 89,686 | 1.20 | 0.89, 1.62 | |
2 | 98 | 89,675 | 1.19 | 0.87, 1.63 | |
1 (lowest) | 107 | 89,651 | 1.28 | 0.90, 1.82 | |
Age ≥45 years | |||||
4 (highest) | 262 | 93,921 | 1.00 | Ref | 0.045 |
3 | 275 | 93,922 | 1.13 | 0.95, 1.35 | |
2 | 254 | 93,949 | 1.09 | 0.91, 1.31 | |
1 (lowest) | 272 | 93,924 | 1.25 | 1.03, 1.51 | |
BMIb <25 kg/m2 | |||||
4 (highest) | 126 | 72,829 | 1.00 | Ref | 0.99 |
3 | 112 | 72,853 | 0.98 | 0.75, 1.27 | |
2 | 130 | 72,830 | 1.13 | 0.87, 1.46 | |
1 (lowest) | 133 | 72,824 | 1.09 | 0.83, 1.42 | |
BMIb 25 to <30 kg/m2 | |||||
4 (highest) | 133 | 57,686 | 1.00 | Ref | 0.89 |
3 | 126 | 57,701 | 1.03 | 0.80, 1.32 | |
2 | 114 | 57,708 | 0.96 | 0.75, 1.25 | |
1 (lowest) | 121 | 57,708 | 1.04 | 0.80, 1.35 | |
BMIb ≥30 kg/m2 | |||||
4 (highest) | 108 | 53,074 | 1.00 | Ref | 0.0003 |
3 | 109 | 53,078 | 1.19 | 0.91, 1.56 | |
2 | 115 | 53,065 | 1.36 | 1.04, 1.79 | |
1 (lowest) | 127 | 53,054 | 1.66 | 1.25, 2.19 | |
No vitamin D supplementation | |||||
4 (highest) | 270 | 156,422 | 1.00 | Ref | 0.048 |
3 | 302 | 156,416 | 1.10 | 0.93, 1.30 | |
2 | 297 | 156,415 | 1.06 | 0.89, 1.27 | |
1 (lowest) | 338 | 156,372 | 1.23 | 1.02, 1.49 | |
Vitamin D supplementation, yes | |||||
4 (highest) | 53 | 27,203 | 1.00 | Ref | 0.31 |
3 | 60 | 27,206 | 1.13 | 0.77, 1.65 | |
2 | 64 | 27,201 | 1.14 | 0.77, 1.70 | |
1 (lowest) | 70 | 27,176 | 1.25 | 0.82, 1.90 |