三种维生素A干预方法对小儿抗感染免疫的作用

Effects of Vitamin A Supplementation on Anti-infection Immunity of Infants

目的通过3种形式维生素A干预试验,观察小儿血清维生素A水平的变化及感染性疾病发生的情况。方法149名观察对象被随机分为4组:孕后期干预组:孕7、8个月分别给予孕母10万IU的维生素A;哺乳期干预组:产后1周内给予母亲20万IU的维生素A;小儿干预组:出生后4、5个月分别给予小儿10万IU的维生素A;对照组:未给予母亲或小儿任何干预。所有对象均随访至出生后1年,观察呼吸道与消化道感染性疾病发病情况。结果孕妇膳食维生素A摄入不足(总平均<80%RDA),所生小儿中有46%3个月时血清维生素A浓度低于正常范围(<1.05μmol/L)。小儿干预组小儿血清维生素A水平明显增高,生后3个月～1岁增长1.0倍;孕后期干预组与哺乳期干预组小儿血清维生素A无显著变化。尽管维生素A干预对腹泻、总呼吸道感染无明显保护作用,但小儿干预组小儿出生后1年内下呼吸道感染的年人均发病率(2%)明显低于对照组。结论维生素A干预,尤其是对小儿直接干预的方法可以直接改善小儿血清维生素A水平,并能降低其下呼吸道感染的发病率。

Objective To explore the effects of three different ways of vitamin A supp lementation on young infant' s serum vitamin A level and morbidity of infectious disease.Methods 149pregnant women were enrolled at their third trimester a nd divided into four groups randomly:pregnancy intervention,33pregnant wom en received100,000IU vitamin A at their7 th and8 th month of pregnancy;postpartum supplementation,32mothers received200, 000IU vitamin A within a week after delivery;infant supplementation,46yo ung infants received100,000IU vitamin A at4 th and5 th month;controls,38healthy neonates without any vitamin A supplementation .Morbidity of diarrhea and respiratory infection disease of every child was rec orded every3months to1year.Results The dietary intake of vitamin A in pregnan t women is entirely lower than80%RDA.There are46%infants whose serum vit amin A level is below the margin of subclinical deficiency(<1.05ìmol/L) .Vitamin A level of cord blood(1.06±0.42ìmol/L)is apparently lower than that of the serum of their mothers(2.60±1.1ìmol/L).The results of assessing the three ways of intervention showed that comparing with controls ,only the serum vitamin A level of group3infants significantly raised from the 3 th month to12 th month after birth.It is quite interesting that the morbidity of lower respi ratory infection in infant intervention group(2%)is significantly lower tha n that of the control group(20%;P<0.05).Conclusion The results of pr esent study confirmed vitamin A intervention,especially through vitamin A supplementation directly to infants,could reform serum vitamin A level and decrease the morbidity of lower respiratory infection.