Objective: To probe into the changes and clinical significance of serum levels of 25-hydroxy vitamin D (25-(OH)D) and vitamin D antibody in children with Henoch-Schönlein purpura (HSP). Methods: Seventy-three children with HSP admitted to pediatrics of Nanyang the First People’s Hospital from Jul. 2017 to Jan. 2019 were extracted as the research objectives. According to whether the children were complicated with Henoch-Schönlein purpura nephritis (HSPN)

all children were divided into the HSPN group (n=32) and the HSP group (n=41). According to different clinical symptoms

all children were divided into the simple group (n=15)

the joint symptom group (n=17)

the gastrointestinal symptom group (n=4) and the mixed symptom group (n=27). Forty-one healthy children with normal physical examination in the same period were selected as the control group. Serum levels of 25-(OH)D and vitamin D antibody were detected by enzyme linked immunosorbent assay (ELISA). Changes of serum levels of 25-(OH)D and vitamin D antibody in each group were compared and analyzed. Results: The serum levels of 25-(OH)D in the HSP group were significantly lower than those in the control group (P<0.05)

and the serum levels of 25-(OH)D in the HSPN group were significantly lower than those in the HSP group and the control group (P<0.05). The serum levels of vitamin D antibody in the HSP group and HSPN group were higher than those in the control group (P<0.05). There was no significant difference in the levels of vitamin D antibody between the HSPN group and the HSP group (P>0.05). The levels of 25-(OH)D in the joint symptom group

the gastrointestinal symptom group and the mixed symptom group were lower than those in the simple group (P<0.05)

yet the differences in the levels of 25-(OH)D in the joint symptom group

the gastrointestinal symptom group and the mixed symptom group were not statistically significant (P>0.05). There was no significant difference in the levels of vitamin D antibody in children with HSP in different symptom groups (P>0.05). Conclusion: The levels of 25-(OH)D are relatively low in children with HSP

especially those with different symptoms. The levels of vitamin D antibody in children with HSP are significantly higher than those in normal healthy children. However

there is no statistical difference in the levels of vitamin D antibody in children with different symptoms. Therefore

the deficiency of 25-(OH)D in children with different symptoms of HSP may be related to the deficiency of vitamin D synthesis and malabsorption caused by impaired degree of skin

kidney and gastrointestinal tract.