Smith J C, Makdani D, Hegar A, Rao D, Douglass L W
U.S. Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Phytonutrients Laboratory, Maryland 20705-2350, USA.
J Am Coll Nutr. 1999 Jun;18(3):213-22. doi: 10.1080/07315724.1999.10718854.
To determine whether supplementation of vitamin A and/or zinc (Zn) improved serum levels of these nutrients and/or height and weight gains in preschool children, 22 to 66 months, living in Belize, Central America.
Subjects received either Zn, vitamin A, Zn and vitamin A or a placebo, (70 mg Zn and/or 3030 RE vitamin A, once per week) for 6 months in a 2x2 factorial design. Forty-three children, from a population of 104 prescreened, completed the study; they were selected, prior to treatment, for low/marginal serum concentrations of these micronutrients.
Serum Zn levels were greater (16%, p<0.001) for those who received Zn. In contrast, after vitamin A treatment there were no differences in serum vitamin A among groups. Although increases in height (+4.4 cm, p<0.001) and weight (+0.79 kg, p<0.001), compared with baseline values, were numerically greatest for children who received both supplements, only the vitamin A supplementation effect was significant, resulting in increased height (+1.4 cm, p<0.002) and greater weight gain (+0.15 kg, p<0.03) compared to those receiving no vitamin A. Vitamin A supplementation alone significantly increased (p<0.001) hemoglobin concentration.
The results suggest that the preschool children in this study, prescreened for low/marginal serum concentrations from a larger population prior to treatment, were enduring inadequate vitamin A and, to a lesser degree, Zn nutriture. Height and weight gain were significantly increased in the subjects who received a single weekly supplement 3030 RE of vitamin A.
确定补充维生素A和/或锌（Zn）是否能提高中美洲伯利兹22至66个月大的学龄前儿童的这些营养素血清水平和/或身高及体重增长。
受试者按照2×2析因设计，接受锌、维生素A、锌和维生素A或安慰剂（70毫克锌和/或3030视黄醇当量维生素A，每周一次）治疗6个月。从104名预先筛选的儿童中选取43名完成了研究；他们在治疗前因这些微量营养素的血清浓度低/处于边缘水平而被选中。
接受锌补充的儿童血清锌水平更高（16%，p<0.001）。相比之下，维生素A治疗后各组血清维生素A水平没有差异。虽然与基线值相比，接受两种补充剂的儿童身高增加最多（+4.4厘米）（p<0.001），体重增加最多（+0.79千克）（p<0.001），但只有维生素A补充剂的效果显著，与未接受维生素A的儿童相比，身高增加（+1.4厘米）（p<0.002），体重增加更多（+0.15千克）（p<0.03）。单独补充维生素A能显著提高血红蛋白浓度（p<0.001）。
结果表明，本研究中的学龄前儿童在治疗前从大量人群中预先筛选出血清浓度低/处于边缘水平，他们维生素A营养不足，锌营养不足的程度较轻。每周单次补充3030视黄醇当量维生素A的受试者身高和体重增长显著增加。
