Patients stratified by type of disease
| Characteristic | Crohn's disease (n=383) | Ulcerative colitis (n=434) | p Value |
| Age at diagnosis in years (median, range) | 26 (1–75) | 29 (10–78) | 0.0282-151 |
| Time since diagnosis in years, (median, range) | 8 (0–51) | 7 (0–46) | 0.312-151 |
| Use of corticosteroid enemas | 82 (21%) | 313 (72%) | <0.0012-152 |
| Use of systemic corticosteroids | 308 (80%) | 311 (72%) | 0.0042-152 |
| Current use of vitamin D supplements | 70 (18%) | 36 (8%) | <0.0012-152 |
| Current use of calcium supplements | 112 (29%) | 60 (14%) | <0.0012-152 |
| Current use of multivitamin supplements | 0.0012-152 | ||
| No | 89 (23%) | 139 (32%) | |
| Entire year | 203 (53%) | 176 (41%) | |
| Part of the year | 90 (24%) | 118 (27%) | |
| Sunbathing | 285 (75%) | 302 (70%) | 0.112-152 |
| Current use of systemic cytostatic agents2-153 | 72 (19%) | 65 (15%) | 0.142-152 |
| Current use of systemic 5-aminosalicylates2-154 | 186 (49%) | 267 (61%) | <0.0012-152 |
| Current use of B12 supplements | 42 (11%) | 5 (1%) | <0.0012-152 |
| Current use of folic acid supplements | 13 (3%) | 3 (1%) | 0.0052-152 |
| Current use of iron supplements | 20 (5%) | 4 (1%) | <0.0012-152 |
| Current use of cholestyramine therapy | 31 (8%) | 0 (0%) | <0.0012-152 |
| Undergone bowel surgery | 212 (60%) | 77 (18%) | <0.0012-152 |
| Age at first bowel surgery in years (median, range) | 29 (14–75) | 32 (10–59) | 0.162-151 |
| Number of surgical procedures (median, range) | 2 (1–20) | 2 (1–10) | 0.072-151 |
| Had a stoma | 71 (19%) | 65 (15%) | 0.192-152 |
2-150 Only female respondents.
↵2-151 Mann-Whitney test (2p).
↵2-152 χ2 for contingency tables (p).
↵2-153 Current systemic therapy with azathioprine or cyclosporin.
↵2-154 Current systemic therapy with mesalazine, olsalazine, or sulphasalazine.
Owing to missing values, sums may not add up.
HRT, hormone replacement therapy.