Table 1.
Baseline characteristics of colorectal cancer patients stratified by vitamin D status.
| Total
population n = 798 |
Vitamin D insufficient
(<50 nmol/L) n = 333 |
Vitamin D
sufficient (⩾50 nmol/L) n = 448 |
|
|---|---|---|---|
| Age (years) | 66.9 (62.2–73.0) | 66.9 (61.8–73.8) | 67.0 (62.8–72.5) |
| Gender (female) | 252 (32) | 91 (27) | 155 (35) |
| Education levela | |||
| Low | 313 (41) | 123 (38) | 183 (42) |
| Medium | 243 (32) | 103 (32) | 136 (32) |
| High | 210 (27) | 95 (30) | 112 (26) |
| Unknown | 32 | 12 | 17 |
| Season of blood collectionb | |||
| Spring | 223 (29) | 129 (39) | 94 (21) |
| Summer | 227 (29) | 46 (14) | 181 (41) |
| Autumn | 140 (18) | 50 (15) | 90 (20) |
| Winter | 185 (24) | 106 (32) | 79 (18) |
| Unknown | 23 | 2 | 4 |
| Serum 25(OH)D3 (nmol/l) | 53.9 (40.8–70.2) | 38.5 (28.9–44.5) | 67.2 (58.1–79.8) |
| Unknown | 17 | ||
| Interleukin 10 (pg/ml) | 0.3 (0.2–0.4) | 0.3 (0.2–0.4) | 0.2 (0.2–0.4) |
| Unknown | 67 | 24 | 28 |
| Interleukin 8 (pg/ml) | 5.8 (4.3–8.2) | 5.9 (4.4–8.5) | 5.7 (4.2–8.1) |
| Unknown | 29 | 5 | 9 |
| Interleukin 6 (pg/ml) | 1.0 (0.7–1.7) | 1.1 (0.8–1.8) | 1.0 (0.7–1.6) |
| Unknown | 31 | 5 | 11 |
| Tumour necrosis factor α (pg/ml) | 2.1 (1.7–2.6) | 2.1 (1.7–2.6) | 2.0 (1.6–2.6) |
| Unknown | 29 | 6 | 8 |
| C-reactive protein (μg/ml) | 2.5 (1.1–6.0) | 2.9 (1.2–6.9) | 2.4 (1.1–5.3) |
| Unknown | 112 | 40 | 56 |
| Type of cancer | |||
| Colon | 512 (64) | 204 (61) | 298 (67) |
| Rectal | 286 (36) | 129 (39) | 150 (33) |
| Tumour stage | |||
| I | 209 (28) | 77 (24) | 132 (31) |
| II | 200 (26) | 84 (26) | 116 (27) |
| III | 293 (39) | 139 (43) | 153 (36) |
| IV | 52 (7) | 21 (7) | 30 (7) |
| Unknown | 44 | 12 | 17 |
| Type of treatment | |||
| Surgery only | 419 (54) | 167 (52) | 247 (58) |
| Surgery + chemotherapy | 171 (22) | 68 (21) | 97 (23) |
| Surgery + radiotherapy | 97 (13) | 53 (17) | 41 (10) |
| surgery + chemo radiation | 69 (9) | 30 (10) | 37 (9) |
| unknown | 34 | 11 | 19 |
| Comorbidities (yes) | 592 (74) | 248 (74) | 331 (74) |
| Daily use of NSAIDs (yes) | 157 (20) | 58 (17) | 98 (22) |
| BMI (kg/m2) | 26.5 (24.4–29.5) | 26.9 (24.5–30.6) | 26.2 (24.3–29.1) |
| Unknown | 5 | 2 | 3 |
| Smoking | |||
| Current | 98 (13) | 39 (12) | 57 (13) |
| Former | 463 (59) | 193 (59) | 263 (60) |
| Never | 221 (28) | 97 (29) | 117 (27) |
| Unknown | 16 | 4 | 11 |
| Moderate to vigorous physical activity (hours/week)c | 11.5 (5.0–20.0) | 10.0 (4.3–19.0) | 12.8 (6.0–21.2) |
| Unknown | 18 | 4 | 12 |
| Dietary intake | |||
| Dietary vitamin D (µg/day) | 3.2 (2.2–4.2) | 3.1 (2.2–4.2) | 3.2 (2.2–4.3) |
| Total vitamin D (µg/day)d | 3.8 (2.6–6.2) | 3.4 (2.4–4.6) | 4.3 (2.9–8.5) |
| Calcium (mg/day) | 873 (655–1101) | 880 (651–1116) | 871 (656–1089) |
| Fibre (g/day) | 21.4 (16.8–26.5) | 20.9 (16.6–26.5) | 21.6 (17.2–26.3) |
| Total fat (g/day) | 71.3 (55.1–91.9) | 71.6 (54.3–92.1) | 70.8 (55.4–90.2) |
| EPA (g/day) | 0.06 (0.03–0.10) | 0.05 (0.03–0.10) | 0.07 (0.04–0.12) |
| DHA (g/day) | 0.08 (0.04–0.15) | 0.07 (0.03–0.13) | 0.08 (0.04–0.16) |
| Unknown | 22 | 7 | 14 |
| Use of vitamin D supplements (yes) | 210 (26) | 50 (15) | 160 (36) |
| Unknown | 12 | 3 | 9 |
Values presented are median (quartile 1 – quartile 3) or number (percentage).
BMI, body mass index; EPA, eicosapentaenoic acid; DHA, docosahexaenoic acid; NSAIDs, non-steroidal anti-inflammatory drugs.
Low education was defined as primary school and lower general secondary education; medium as lower vocational training and higher general secondary education; high as high vocational training and university.
Spring: March–May; summer: June–August; autumn: September–November; winter: December–February.
Activities with a Metabolic Equivalent score (MET score) ⩾ 3 were defined as moderate to vigorous physical activity.
Total vitamin D intake from diet and supplements.