目的 探讨血清维生素D水平与过敏性紫癜（HSP）患儿病情及治疗的关系。方法 选取2015年1~12月第1次诊断为HSP的患儿50例为HSP组，以49例健康儿童作为健康对照组。空腹采集两组儿童血清，采用ELISA法检测血清25羟基维生素D₃[25-（OH） D₃]水平。根据25-（OH） D₃检测结果将HSP患儿进一步分为维生素D正常组（> 20 ng/mL）（n=9）、不足组（> 15 ng/mL~20 ng/mL）（n=15）、缺乏组（≤ 15 ng/mL）（n=25）、严重缺乏组（≤ 5 ng/mL）（n=1）。收集HSP患儿的一般资料、临床表现、激素治疗情况、入院前病程及住院天数进行分析比较。结果 HSP组患儿血清25-（OH） D₃水平（16±6 ng/mL）低于健康对照组（29±5 ng/mL）（P < 0.01）。与正常组+不足组患儿[25-（OH） D₃ > 15 ng/mL]相比，缺乏组+严重缺乏组患儿[25-（OH） D₃ ≤ 15 ng/mL]肾脏受累发生率、激素使用率均增高（P  < 0.05），中位住院天数延长（P  < 0.05），但入院前病程差异无统计学意义（P  > 0.05）。结论 HSP患儿血清25-（OH） D₃水平低，低血清25-（OH） D₃水平HSP患儿肾脏受累风险及激素使用率增高，住院时间延长。但补充维生素D对HSP有无治疗作用，能否缩短HSP患儿病程，改善远期预后，仍有待进一步研究。

Objective To investigate the association of serum vitamin D[25-(OH)D₃] level with the severity and treatment in children with Henoch-Schönlein purpura (HSP). Methods A total of 50 children with newly-diagnosed HSP between January and December, 2015 were enrolled as HSP group, and 49 healthy children were enrolled as control group. Fasting serum samples were collected, and ELISA was used to measure serum 25-(OH)D₃ level. According to the serum 25-(OH)D₃ level, the HSP group were further divided into normal group (> 20 ng/mL) (n=9), insuffciency group (15-20 ng/mL) (n=15), defciency group (≤ 15 ng/mL) (n=25), and severe defciency group (≤ 5 ng/mL) (n=1). The general data, clinical manifestations, hormone therapy, course of disease before admission, and length of hospital stay were compared between groups. Results The HSP group had a signifcantly lower serum 25-(OH)D₃ level than the control group (16±6 ng/mL vs 29±5 ng/mL; P  < 0.01). Compared with the normal and insuffciency groups, the defciency and severe deficiency groups had significant increases in the incidence rate of renal involvement, rate of hormone application, and median length of hospital stay (P  < 0.05), while there was no signifcant difference in course of disease before admission (P  > 0.05). Conclusions Children with HSP have a low serum 25-(OH)D₃ level, and such children may have a high risk of renal involvement, a high rate of hormone application, and a prolonged length of hospital stay. However, further studies are needed to investigate whether vitamin D supplementation is helpful to the treatment of HSP and can shorten the course of disease in children with HSP.