Table 1.
Characteristics of the study group (according to the quartiles of total vitamin D intake from food).
| Variable | Number (%) of Participants | p Value * | ||||
|---|---|---|---|---|---|---|
| Total | Quartiles of Vitamin D Intake from Food (µg/day) | |||||
| Q1 (0.01–1.32) |
Q2 (1.33–2.32) |
Q3 (2.33–4.03) |
Q4 (4.04–29.34) |
|||
| Total | 4469 (100.00) | 1117 (24.99) | 1116 (24.97) | 1118 (25.02) | 1118 (25.02) | |
| Region of Poland: | ||||||
| Central | 567 (12.67) | 149 (13.34) | 132 (11.83) | 144 (12.88) | 142 (12.70) | 0.00042 |
| Eastern | 914 (20.45) | 283 (25.34) | 197 (17.65) | 220 (19.68) | 214 (19.14) | |
| Northern | 1350 (30.21) | 299 (26.77) | 342 (30.64) | 325 (29.07) | 384 (34.35) | |
| North-Western | 396 (8.86) | 99 (8.86) | 110 (9.86) | 99 (8.86) | 88 (7.87) | |
| Southern | 993 (22.22) | 228 (20.41) | 266 (23.83) | 268 (23.97) | 231 (20.66) | |
| South-Western | 249 (5.57) | 59 (5.18) | 69 (6.18) | 62 (5.54) | 59 (5.28) | |
| Age: | 0.14204 | |||||
| 14–17 | 3131 (70.06) | 812 (72.69) | 764 (68.46) | 768 (68.69) | 787 (70.39) | |
| 18–20 | 1338 (29.94) | 305 (27.31) | 352 (31.54) | 350 (31.31) | 331 (29.61) | |
| Body Mass Index (BMI) classification: | ||||||
| Underweight | 445 (9.96) | 122 (10.92) | 108 (9.768) | 110 (9.84) | 105 (9.39) | 0.90188 |
| Normal weight | 3234 (72.36) | 796 (71.26) | 816 (73.12) | 805 (72.00) | 817 (73.08) | |
| Overweight | 927 (10.78) | 119 (10.65) | 125 (11.20) | 119 (10.64) | 119 (10.64) | |
| Obesity | 308 (6.89) | 80 (7.16) | 67 (6.00) | 84 (7.51) | 77 (6.88) | |
| Vitamin D supplementation: | ||||||
| No | 2222 (49.72) | 630 (56.40) | 555 (49.73) | 508 (45.44) | 529 (47.32) | <0.00001 |
| Yes | 2247 (50.28) | 487 (43.60) | 561 (50.27) | 610 (54.56) | 589 (52.68) | |
| Vegetarian or vegan diet: | ||||||
| No | 4113 (92.03) | 964 (86.30) | 1051 (94.18) | 1046 (93.56) | 1052 (94.10) | <0.00001 |
| Yes | 356 (7.97) | 153 (3.70) | 65 (5.82) | 72 (6.44) | 66 (5.90) | |
* Chi-squared test for comparisons of proportions, p ≤ 0.05.