Table 2.
Characteristics of subjects with adequate and insufficient circulating 25-hydroxy-vitamin D. All variables were non-normally distributed. Data are given as absolute frequency (and percentage) or median (and interquartile range). The Kruskal-Wallis test was used for continuous variables. Chi-squared test was used for categorical variables. The Bonferroni test adjustment was applied to account for multiple comparisons.
| Subjects Characteristics | 25-hydroxy-vitamin D | ||
|---|---|---|---|
| Adequate (≥50 nmol/L) |
Insufficient (<50 nmol/L) |
p-value | |
| N | 866 (83) | 179 (17) | |
| Main activity | |||
| Student | 356 (41) | 77 (43) | 0.7 |
| Worker | 510 (59) | 102 (67) | |
| Anthropometric characteristics | |||
| Body height, cm | 178.0 (173.0–182.0) | 176.0 (171.5–180.0) | 0.003 ** |
| Body weight, kg | 72.5 (65.9–80.0) | 71.3 (64.9–82.0) | 0.9 |
| Body mass index, kg/m2 | 22.9 (21.0–25.0) | 23.0 (20.7–26.3) | 0.3 |
| Body fat percentage, % | 17.4 (13.4–22.7) | 20.1 (14.6–25.2) | <0.0001 *** |
| Mid-upper arm circumference, cm | 27.0 (25.0–29.5) | 27.0 (24.0–30.1) | 0.4 |
| Waist circumference, cm | 80 (75–86) | 80 (75–91) | 0.1 |
| Frequency of recreational physical activity | |||
| Never | 177 (20) | 42 (24) | 0.03 * |
| 1 per week | 134 (16) | 40 (22) | |
| 2–4 per week | 396 (46) | 76 (43) | |
| 5–6 per week | 81 (9.4) | 7 (3.9) | |
| Every day | 78 (9.0) | 14 (7.8) | |
| Duration of recreational physical activity session | |||
| ≤1 h | 50 (7.3) | 16 (12) | 0.3 |
| >1–≤2 h | 509 (74) | 93 (68) | |
| >2–≤3 h | 118 (17) | 25 (18) | |
| >3 h | 12 (1.7) | 3 (2.2) | |
| Site of recreational physical activity | |||
| Indoor (only) | 117 (17) | 31 (23) | 0.1 |
| Outdoor (only) | 281 (41) | 59 (43) | |
| Both indoor and outdoor | 289 (42) | 47 (34) | |
| Frequency of alcohol consumption | |||
| Never | 161 (19) | 40 (22) | 0.1 |
| 1 per week | 338 (39) | 55 (31) | |
| 2 per week | 224 (26) | 61 (34) | |
| 3–4 per week | 97 (11) | 15 (8.4) | |
| 5–6 per week | 35 (4.0) | 7 (3.9) | |
| Every day | 11 (1.3) | 1 (0.6) | |
| Smoking | |||
| Never | 483 (56) | 119 (67) | 0.018 * |
| 1–10 cigarettes per day | 253 (29) | 46 (26) | |
| 11–20 cigarettes per day | 118 (14) | 12 (6.7) | |
| >20 cigarettes per day | 12 (1.4) | 2 (1.1) | |
| Season of measurement | |||
| Winter | 106 (12) | 64 (36) | <0.0001 *** |
| Spring | 313 (36) | 70 (39) | |
| Summer | 313 (36) | 18 (10) | |
| Autumn | 134 (16) | 27 (15) | |
| Biochemical indices | |||
| Cholesterol, mmol/L | 3.9 (3.5–4.3) | 4.0 (3.6–4.4) | 0.049 * |
| Ferritin, µmol/L | 76.0 (52.0–109.0) | 76.5 (51.0–103.5) | 0.9 |
* p < 0.05, ** p < 0.01, *** p < 0.0001.