Fig. 2
From: Vitamin D status in healthy Italian school-age children: a single-center cross-sectional study
Seasonal fluctuation in the median serum 25-hydroxyvitamin D [25(OH)D] distribution. Data are expressed as ng/mL. Median values are 21.7 ng/mL in winter, 22.9 ng/mL in spring, 25.7 ng/mL in autumn and 44.9 ng/mL in summer. The lowest levels of 25(OH)D were registered in winter and spring with 3.9 ng/mL each. Summertime is the period with the highest median serum 25(OH)D level and interquartile range (IQR of 17.35); none of the participants presented a state of deficiency (25(OH)D < 20 ng/mL) during summer. Significance p values (p < 0.005) are marked as (*)