反复呼吸道感染(Recurrent Respiratory TractInfection,RRTI)是小儿时期常见病,其机制较复杂,发病与多种因素有关,目前临床上治疗包括抗感染、对症、支持等综合治疗,但其效果仍不理想,因此,探求更多的治疗措施以减少其发生次数显得尤其重要。维生素A(V itam in A,VA)是机体必 Recurrent Respiratory Tract Infection (RRTI) is a common disease in infancy, the mechanism is complex, the incidence of multiple factors, the current clinical treatment including anti-infective, symptomatic, supportive and other comprehensive treatment, but its effect is still not ideal, Therefore, the search for more treatment to reduce the frequency of its occurrence is particularly important. Vitamin A (V itam in A, VA) is the body must