Table 2: Distribution of demographic characteristics.
| Total (n = 580) n (%) | Female (n = 276) n (%) | Male (n = 304) n (%) | p | ||
| Ca consumption | < 500 mg | 288 (49.6) | 122 (44.2) | 166 (54.6) | 0.021* |
| 500-1000 mg | 237 (40.9) | 129 (46.7) | 108 (35.5) | ||
| > 1000 mg | 55 (9.5) | 25 (9.1) | 30 (9.9) | ||
| Fish consumption | None | 118 (20.3) | 56 (20.3) | 62 (20.4) | 0.579 |
| 1-2 times a week | 190 (32.8) | 96 (34.8) | 94 (30.9) | ||
| 1-2 times a month | 272 (46.9) | 124 (44.9) | 148 (48.7) | ||
| Habit | Smoking | 22 (3.8) | 5 (1.8) | 17 (5.6) | 0.039* |
| Alcohol | 16 (2.8) | 6 (2.2) | 10 (3.3) | ||
| No | 542 (93.4) | 265 (96.0) | 277 (91.1) | ||
| Skin color | Dark | 228 (39.3) | 88 (31.9) | 140 (46.1) | 0.001** |
| Light | 352 (60.7) | 188 (68.1) | 164 (53.9) | ||
| Use of sunscreen | Using | 108 (18.6) | 81 (29.3) | 27 (8.9) | 0.001** |
| Not using | 472 (81.4) | 195 (70.7) | 277 (91.1) | ||
| Time spent in sunny areas during the day | < 15 min | 39 (6.7) | 31 (11.2) | 8 (2.6) | 0.001** |
| 15-60 min | 282 (48.6) | 152 (55.1) | 130 (42.8) | ||
| 60 > min | 259 (44.7) | 93 (33.7) | 166 (54.6) | ||
| Time spent in sunny areas during the day | < 60 min | 321 (55.3) | 183 (66.3) | 138 (45.4) | 0.001** |
| > 60 min | 259 (44.7) | 93 (33.7) | 166 (54.6) | ||
| Doing sports | Yes | 466 (80.3) | 195 (70.7) | 271 (89.1) | 0.001** |
| No | 114 (19.7) | 81 (29.3) | 33 (10.9) | ||
| Physical activity duration | < 15 min | 41 (8.8) | 24 (12.3) | 14 (6.3) | 0.001** |
| 15-60 min | 312 (67) | 144 (73.8) | 168 (62.0) | ||
| > 60 min | 113 (24.2) | 27 (13.8) | 86 (31.7) | ||
| Physical activity duration | < 60 min | 353 (75.8) | 168 (86.2) | 185 (68.3) | 0.001** |
| > 60 min | 113 (24.2) | 27 (13.8) | 86 (31.7) | ||
| Grade | Grade 1 | 300 (51.7) | 300 (51.7) | 163 (53.6) | 0.247 |
| Grade 2 | 192 (33.1) | 90 (32.6) | 102 (33.6) | ||
| Grade 3 | 88 (15.2) | 49 (17.8) | 39 (12.8) | ||
| Time spent in school | < 5 hours | 285 (49.1) | 117 (42.4) | 168 (55.3) | 0.002** |
| > 5 hours | 295 (50.9) | 159 (57.6) | 136 (44.7) | ||
Ca: Calcium; *p < 0.05; **p < 0.01.