Table 1 Major characteristics of the included participants

Age (year)

8.0 (6.0, 10.0)

8.0 (6.0, 11.0)

0.379

Gender

Male

33 (80.5%)

36 (85.7%)

0.366

Female

8 (19.5%)

6 (14.3%)

Daily outdoor activity M (SD)

48.06 ± 34.72

44.93 ± 26.51

0.674

BMI

BMI < 85th

31(75.6%)

27(64.3)

BMI 85–95

9(22)

12(28.6)

0.42

BMI > 95

1(2.4)

3(7.1)

Vitamin D status

Optimal

4 (9.8%)

3 (7.1%)

0.842

Insufficient

35 (85.3%)

36 (85.8%)

Deficient

2 (4.9%)

3 (5.8%)