Association of serum 25-Hydroxyvitamin D with Vitamin D intervention and outdoor activity among children in North China: an observational study

Table 2 Characteristics of children with varying serum levels of 25(OH)D

	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
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

⁻x ± s and percentage (%) were used to describe the continuous and categorical variables, respectively; P < 0.05 was regarded as statistically significant

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