许多发展中国家婴幼儿死亡率很高,大部分足由于感染及营养不良。预防及控制感染的技术进展能够阻断此种营养不良—感染综合征的恶性循环。由于重点放在疫苗接种,使用抗生素及口服补液上,而在很大程度上忽视了营养的补充。自从发现维生素A以来,当证实缺乏维生素A动物的感染发病率很高时,亦证实贫困儿童的某些感染的危险性亦增加,然而某些因素已妨碍了对此种关系的认识。第一,维生素A缺乏时,眼部体征很明显,以致眼科医生着重于把维生素A缺乏看作为一种眼 Infant mortality is high in many developing countries, mostly due to infection and malnutrition. Technological advances in the prevention and control of infections can block such malnutrition - a vicious circle of infectious syndromes. Due to the focus on vaccination, the use of antibiotics and oral rehydration, but to a large extent ignored the nutritional supplement. Since the discovery of vitamin A, it has also been confirmed that there is an increased risk of some infections among impoverished children when it is confirmed that there is a high incidence of infection with vitamin A-deficient animals. However, some factors have prevented the understanding of this relationship. First, when vitamin A deficiency, the signs of the eye is obvious, so that ophthalmologists focus on the lack of vitamin A as an eye