Table 2.
Risk of colorectal cancer, total colon cancer, proximal colon cancer, distal colon and rectal cancer according to vitamin D intake using repeated measurements analyses. The Norwegian Women and Cancer Cohort Study (n 95 416)
| Vitamin D intake repeated measurements analyses | Age-adjusted analyses | Multivariable analyses* | ||||||
|---|---|---|---|---|---|---|---|---|
| Number of cases | HR | 95 % CI | P | Number of cases | HR | 95 % CI | P | |
| Colorectal cancer | ||||||||
| Continuous (5 µg increase) | 1774 | 0·96 | 0·93, 0·99 | 0·01 | 1198 | 0·97 | 0·93, 1·01 | 0·13 |
| Grouped | ||||||||
| Reference value (< 10 µg) | 349 | 1·00 | 227 | 1·00 | ||||
| 10–19 µg | 1260 | 0·95 | 0·84, 1·07 | 0·36 | 859 | 0·96 | 0·83, 1·12 | 0·60 |
| ≥ 20 µg | 165 | 0·77 | 0·65, 0·90 | 0·00 | 112 | 0·83 | 0·68, 1·02 | 0·07 |
| Total colon cancer | ||||||||
| Continuous (5 µg increase) | 1228 | 0·96 | 0·93, 1·00 | 0·04 | 828 | 0·96 | 0·91, 1·01 | 0·08 |
| Grouped | ||||||||
| Reference value (< 10 µg) | 237 | 1·00 | 146 | 1·00 | ||||
| 10–19 µg | 870 | 0·91 | 0·79, 1·05 | 0·22 | 604 | 0·86 | 0·72, 1·04 | 0·12 |
| ≥ 20 µg | 121 | 0·80 | 0·66, 0·96 | 0·02 | 78 | 0·81 | 0·64, 1·04 | 0·10 |
| Proximal colon cancer | ||||||||
| Continuous (5 µg increase) | 726 | 0·98 | 0·94, 1·03 | 0·36 | 483 | 0·95 | 0·89, 1·01 | 0·12 |
| Grouped | ||||||||
| Reference value (< 10 µg) | 134 | 1·00 | 77 | 1·00 | ||||
| 10–19 µg | 513 | 0·85 | 0·70, 1·03 | 0·10 | 358 | 0·73 | 0·57, 0·94 | 0·02 |
| ≥ 20 µg | 79 | 0·86 | 0·68, 1·09 | 0·21 | 48 | 0·81 | 0·59, 1·11 | 0·18 |
| Distal colon cancer | ||||||||
| Continuous (5 µg increase) | 467 | 0·94 | 0·89, 1·00 | 0·06 | 320 | 0·98 | 0·91, 1·06 | 0·62 |
| Grouped | ||||||||
| Reference value (< 10 µg) | 94 | 1·00 | 62 | 1·00 | ||||
| 10–19 µg | 332 | 0·99 | 0·79, 1·25 | 0·94 | 229 | 1·06 | 0·79, 1·42 | 0·70 |
| ≥ 20 µg | 41 | 0·74 | 0·53, 1·02 | 0·07 | 29 | 0·87 | 0·58, 1·29 | 0·48 |
| Rectal cancer | ||||||||
| Continuous (5 µg increase) | 465 | 0·95 | 0·89, 1·01 | 0·10 | 310 | 1·00 | 0·93, 1·08 | 0·97 |
| Grouped | ||||||||
| Reference value (< 10 µg) | 95 | 1·00 | 68 | 1·00 | ||||
| 10–19 µg | 333 | 1·01 | 0·80, 1·27 | 0·93 | 213 | 1·20 | 0·91, 1·60 | 0·21 |
| ≥ 20 µg | 37 | 0·67 | 0·48, 0·94 | 0·02 | 29 | 0·88 | 0·59, 1·32 | 0·54 |
*
Multivariable analyses are adjusted for: smoking status, read meat, processed meat, dairy products, alcohol, fibre, BMI, physical activity, education and energy.