Table 2. Comparison of vitamin D3 levels between IgA vasculitis and healthy children, and comparison of vitamin D3 levels within IgA vasculitis.

Grouping [N]	Levels of 25-hydroxyvitamin D3 [mean ± SD] [ng/mL]	P
IgA vasculitis patients [605]	15.47±6.58	0.00
Healthy children [400]	22.48±6.24
Renal involvement [110]	12.99±4.92	0.00
No renal involvement [495]	16.02±6.78
Streptococcal infection [165]	14.20±6.06	0.004
No streptococcal infection [440]	15.93±6.71
Gastrointestinal symptoms [231]	14.43±6.33	0.002
No gastrointestinal symptoms [374]	16.10±6.59
Joints involved [244]	15.27±6.88	0.565
No joints involved [361]	15.58±6.37