Table 8.

Average level of 25(OH)D (ng/ml) in children and adolescents of the three study regions in different seasons.

Season	Level 25(OH)D, ng/ml M ± m, Me (Q1–Q3)
	Moscow, (M)	Krasnoyarsk, (K)	Stavropol, (S)	General group	p between regions
Winter (1)	31.71 ± 14.44 29.20 (22.90–39.20)	38.40 ± 29.41 29.45 (22.70– 39.95)	30.07 ± 12.56 31.70 (18.20–36.00)	33.38 ± 19.81 9.20 (22.90–39.10)	p > 0.05
Spring (2)	26.43 ± 26.42 15.05 (10.70–36.65)	23.17 ± 9.62 21.16 (15.47–28.54)	35.65 ± 19.62 32.00 (21.60–43.40)	28.66 ± 18.17 23.47 (16.40–34.10)	pM2-S2 = 0.031 pK2-S2 = 0.005
Summer (3)	39.02 ± 16.04 31.65 (26.80–48.54)	32.23 ± 14.56 29.16 (22.51–34.45)	35.16 ± 14.31 31.07 (24.57–44.56)	34.96 ± 14.93 30.70 (24.57–42.59)	p>0.05
Autumn (4)	34.68 ± 15.55 31.30 (24.00–40.80)	27.26 ± 22.11 21.24 (15.11–30.30)	34.29 ± 13.15 31.60 (24.10–43.91)	32.90 ± 16.28 30.30 (21.68–40.14)	pM4-K4 = 0.002 pS4-K4 = 0.000
Total	33.26 ± 16.35 30.10 (22.20–41.61)	30.50 ± 21.16 25.00 (19.47–35.30)	34.20 ± 14.65 31.60 (23.50–43.56)	32.74 ± 17.47 29.60 (21.68–39.70)	pM-K = 0.008 pK-S = 0.000
p between seasons	pM1-2 = 0.025 pM2-3 = 0.008 pM2-4 = 0.016	pK1-2 = 0.002 pK1-4 = 0.006 pK2-3 = 0.002 pK3-4 = 0.008	p > 0.05	p1-2 = 0.008 p2-3 = 0.000 p2-4 = 0.005

Mann–Whitney test was applied.