| Severe deficient | Deficient | Insufficient | Sufficient | P value |
---|---|---|---|---|---|
Vitamin D (ng/mL,−x ± s) | 7.45 ± 2.19 | 15.35 ± 2.87 | 25.04 ± 2.81 | 38.74 ± 10.57 | < 0.001 |
Percentage (%) | 6.57 | 25.51 | 33.52 | 34.40 | Â |
Male (%) | 51.20 | 53.07 | 55.42 | 56.34 | < 0.001 |
Age (years,−x ± s) | 7.54 ± 4.99 | 6.65 ± 3.94 | 4.18 ± 3.38 | 2.09 ± 2.39 | < 0.001 |
Ethnic (Han, %) | 98.31 | 98.49 | 98.28 | 98.14 | 0.063 |
Overweight and obesity (%) | 18.11 | 11.34 | 8.17 | 4.21 | < 0.001 |
Season (%) |  |  |  |  | < 0.001 |
 Spring | 30.50 | 29.82 | 31.12 | 32.29 |  |
 Summer | 26.53 | 29.33 | 28.19 | 27.83 |  |
 Autumn | 16.31 | 17.35 | 18.69 | 18.85 |  |
 Winter | 26.66 | 23.50 | 22.00 | 21.03 |  |
Outdoor activity time (%) |  |  |  |  | < 0.001 |
  < 30 min/d | 58.69 | 56.23 | 25.63 | 25.72 |  |
 30–60 min/d | 23.56 | 22.14 | 38.63 | 34.31 |  |
  > 60 min/d | 17.75 | 21.63 | 35.74 | 39.97 |  |
Intervention methods (%) |  |  |  |  | < 0.001 |
 No intervention | 90.31 | 74.10 | 50.16 | 26.18 |  |
 Supplementation intervention | 7.27 | 17.94 | 35.06 | 46.70 |  |
 Therapeutic intervention | 2.43 | 7.96 | 14.79 | 27.12 |  |