Lancet. 1993 Jul 3;342(8862):7-12.
Although most studies on the effect of vitamin A supplementation have reported reductions in childhood mortality, the effects on morbidity are less clear. We have carried out two double-blind, randomised, placebo-controlled trials of vitamin A supplementation in adjacent populations in northern Ghana to assess the impact on childhood morbidity and mortality. The Survival Study included 21,906 children aged 6-90 months in 185 geographical clusters, who were followed for up to 26 months. The Health Study included 1455 children aged 6-59 months, who were monitored weekly for a year. Children were randomly assigned either 200,000 IU retinol equivalent (100,000 IU under 12 months) or placebo every 4 months; randomisation was by individual in the Health Study and by cluster in the Survival Study. There were no significant differences in the Health Study between the vitamin A and placebo groups in the prevalence of diarrhoea or acute respiratory infections; of the symptoms and conditions specifically asked about, only vomiting and anorexia were significantly less frequent in the supplemented children. Vitamin-A-supplemented children had significantly fewer attendances at clinics (rate ratio 0.88 [95% CI 0.81-0.95], p = 0.001), hospital admissions (0.62 [0.42-0.93], p = 0.02), and deaths (0.81 [0.68-0.98], p = 0.03) than children who received placebo. The extent of the effect on morbidity and mortality did not vary significantly with age or sex. However, the mortality rate due to acute gastroenteritis was lower in vitamin-A-supplemented than in placebo clusters (0.66 [0.47-0.92], p = 0.02); mortality rates for all other causes except acute lower respiratory infections and malaria were also lower in vitamin A clusters, but not significantly so. Improving the vitamin A intake of young children in populations where xerophthalmia exists, even at relatively low prevalence, should be a high priority for health and agricultural services in Africa and elsewhere.
尽管大多数关于补充维生素A效果的研究报告称儿童死亡率有所降低，但对发病率的影响尚不清楚。我们在加纳北部相邻人群中开展了两项双盲、随机、安慰剂对照的维生素A补充试验，以评估其对儿童发病率和死亡率的影响。生存研究纳入了185个地理区域的21906名6至90个月大的儿童，随访长达26个月。健康研究纳入了1455名6至59个月大的儿童，对其进行了为期一年的每周监测。儿童每4个月随机分配20万国际单位视黄醇当量（12个月以下为10万国际单位）或安慰剂；在健康研究中按个体随机分组，在生存研究中按群组随机分组。在健康研究中，维生素A组和安慰剂组在腹泻或急性呼吸道感染患病率方面没有显著差异；在专门询问的症状和疾病中，只有补充维生素A的儿童呕吐和食欲不振的发生率显著较低。补充维生素A的儿童去诊所就诊的次数（率比0.88[95%可信区间0.81 - 0.95]，p = 0.001）、住院次数（0.62[0.42 - 0.93]，p = 0.02）和死亡次数（0.81[0.68 - 0.98]，p = 0.03）均显著少于接受安慰剂的儿童。对发病率和死亡率的影响程度在年龄或性别上没有显著差异。然而，补充维生素A的群组中急性肠胃炎导致的死亡率低于安慰剂群组（0.66[0.47 - 0.92]，p = 0.02）；除急性下呼吸道感染和疟疾外，维生素A群组中所有其他原因导致的死亡率也较低，但差异不显著。在存在干眼症的人群中，即使患病率相对较低，提高幼儿的维生素A摄入量也应是非洲和其他地区卫生及农业服务的高度优先事项。
