Table 1. Baseline characteristics of participants in relation to 25(OH)D concentration and vitamin D status (<50 nmol/L and upper quartile [≥69.8 nmol/L]).
| Characteristic | Frequency n (%) | 25(OH)D level (nmol/L) mean (SD) | 25(OH)D <50 nmol/L n (%) | Upper quartile 25(OH)D (≥69.8 nmol/L) n (%) |
|---|---|---|---|---|
| Age | ||||
| <60 years | 40 (40) | 50.1 (17.8) | 14 (35) | 8 (20) |
| ≥60 years | 60 (60) | 59.6 (20.1) | 22 (37) | 17 (28) |
| p-value | 0.37 | 0.87 | 0.35 | |
| BMI | ||||
| <25.0 | 34 (35) | 60.0 (18.4) | 10 (29) | 9 (27) |
| 25–29.9 | 36 (37) | 59.3 (22.1) | 13 (36) | 11 (31) |
| 30+ | 27 (28) | 53.4 (16.3) | 13 (48) | 4 (15) |
| p for trend | 0.36 | 0.32 | 0.34 | |
| ITA skin type | ||||
| Intermediate/medium | 8 (8) | 67.5 (31.8) | 2 (25) | 3 (38) |
| Light/fair | 70 (72) | 58.0 (17.6) | 25 (36) | 17 (24) |
| Very light/very fair | 20 (20) | 53.4 (18.1) | 9 (45) | 4 (20) |
| p for trend | 0.22 | 0.58 | 0.62 | |
| Season at diagnosis | ||||
| Winter | 29 (29) | 52.0 (17.3) | 15 (52) | 4 (14) |
| Spring | 25 (25) | 58.3 (22.5) | 11 (44) | 4 (16) |
| Summer | 20 (20) | 62.3 (19.4) | 3 (15) | 7 (35) |
| Autumn | 26 (26) | 61.8 (16.8) | 7 (27) | 10 (39) |
| p for trend | 0.18 | 0.04 | 0.09 | |
| Sunscreen use 5 years ago | ||||
| Most of the time | 7 (7) | 60.0 (19.6) | 3 (43) | 2 (29) |
| Sometimes | 31 (31) | 61.0 (19.9) | 11 (36) | 8 (26) |
| Rarely/never | 61 (62) | 56.4 (19.1) | 22 (36) | 15 (25) |
| p for trend | 0.54 | 0.95 | 1.00 |
Values not summing to 100 indicate missing data.
SD: standard deviation; BMI: body mass index; ITA: Individual topography angle.