Association between dietary vitamin C (tertiles and UK RNI19) and IP. Lowest and middle tertiles of intake are compared with the highest tertile
| Cases No (%) | Controls No (%) | Crude OR (95% CI) | Adjusted OR* (95% CI) | p Value for trend | |
|---|---|---|---|---|---|
| n, number; OR, odds ratio; CI, confidence interval. | |||||
| *Adjusted for obesity, smoking and total energy intake; †cases and controls with vitamin C intake <40 mg/day. | |||||
| Tertiles of vitamin C (mg/day) | |||||
| 1, <55.7 | 33 (45) | 40 (27) | 2.6 (1.2 to 5.8) | 3.3 (1.4 to 7.9) | 0.01 |
| 2, 55.7–94.9 | 19 (26) | 54 (37) | 0.9 (0.4 to 1.8) | 0.8 (0.4 to 1.7) | |
| 3, >94.9 (referent) | 21 (29) | 52 (36) | 1.0 | 1.0 | |
| Vitamin C (mg) by RNI | |||||
| <40 mg v ⩾40 mg | 15 (21)† | 10 (7)† | 3.4 (1.4 to 8.2) | 3.9 (1.5 to 9.7) | |