Herrera M G, Nestel P, el Amin A, Fawzi W W, Mohamed K A, Weld L
Harvard Institute for International Development, Cambridge, Massachusetts 02138.
Lancet. 1992 Aug 1;340(8814):267-71. doi: 10.1016/0140-6736(92)92357-l.
Previous studies of the effect of 6-monthly vitamin A supplementation on child mortality have given conflicting results. In other trials, more frequent doses of vitamin A have significantly reduced mortality among children at risk of vitamin A deficiency. We have done a double-blind, placebo-controlled trial of vitamin A supplementation in the Sudan among 28,753 children aged 9-72 months at risk of vitamin A deficiency. Children were assigned to receive either 200,000 IU vitamin A and 40 IU vitamin E every 6 months (vitamin A group) or 40 IU vitamin E alone (placebo group). During the 18 months of follow-up, there were 120 deaths (8.4/1000) in the vitamin A group and 112 (7.9/1000) in the placebo group (relative risk 1.06, 95% confidence interval 0.82-1.37). Controlling for geographic site, round of observation, anthropometry, morbidity, dietary intake of vitamin A, sex, and all baseline differences between the two groups did not change the results. Children living in poor and unsanitary environments, younger children, and those sick, stunted, wasted, or consuming diets low in vitamin A were at a significantly higher risk of dying. The lack of an effect of large-dose vitamin A supplementation on mortality, despite a clear association between dietary vitamin A and mortality, underscores the need to identify factors that modify the efficacy of vitamin A supplements as a public-health measure. Reducing poverty, improvements in sanitation, and access to adequate diets should remain the main goals to improve child survival.
以往关于每6个月补充维生素A对儿童死亡率影响的研究结果相互矛盾。在其他试验中,更频繁剂量的维生素A显著降低了有维生素A缺乏风险儿童的死亡率。我们在苏丹对28753名9至72个月有维生素A缺乏风险的儿童进行了一项双盲、安慰剂对照的维生素A补充试验。儿童被分配接受每6个月200000国际单位维生素A和40国际单位维生素E(维生素A组)或仅40国际单位维生素E(安慰剂组)。在18个月的随访期间,维生素A组有120例死亡(8.4/1000),安慰剂组有112例(7.9/1000)(相对风险1.06,95%置信区间0.82 - 1.37)。控制地理地点、观察轮次、人体测量、发病率、维生素A的饮食摄入量、性别以及两组之间所有基线差异后,结果未改变。生活在贫困和不卫生环境中的儿童、年幼儿童以及患病、发育迟缓、消瘦或维生素A饮食摄入量低的儿童死亡风险显著更高。尽管饮食中的维生素A与死亡率之间存在明显关联,但大剂量补充维生素A对死亡率缺乏影响,这突出表明需要确定作为一项公共卫生措施可改变维生素A补充剂疗效的因素。减少贫困、改善卫生条件以及获得充足饮食仍应是改善儿童生存的主要目标。