From: The establishment of serum 25-hydroxyvitamin D reference intervals in children aged 0–14 years in Zigong area, China
Season
Number of cases
25(OH)D (ng/ml)
Spring
598
48.10 (26.58 ~ 73.65)
Summer
526
57.25 (33.50 ~ 80.03)
Autumn
347
63.40 (35.90 ~ 85.00)
Winter
288
43.35 (26.43 ~ 71.68)
Z value
43.082
P value
0.000