|Smith Jr, James|
Submitted to: The American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/19/1999
Publication Date: N/A
Interpretive Summary: The question of whether mild zinc and/or vitamin A deficiency contributes to poor growth in children remains largely unanswered. Therefore, the objective of this study was to increase zinc and/or vitamin A intake of children eating foods low in these two essential nutrients. Forty-four growth-stunted preschool(2-5 y)children living in Belize, Central America were studied. Vitamin A and/or zinc supplements were given for six months. The hypothesis was that the childrens' nutritional health, including growth, would be improved by increasing their vitamin A and/or zinc intake. Results: Zinc supplementation alone protected against developing anemia. The greatest improvement in growth (height and weight gain) were for children supplemented with a combination of both nutrients; however, the children given only vitamin A without extra zinc grew nearly as well. These data strongly indicate that the intakes of vitamin A, and to a lesser extent, zinc, were inadequate and caused growth to be limited. Thus, the data do not support the provocative hypothesis that stunted growth in young children is essentially irreversible and that they can not "catch up", even when a more nutritious diet is provided. These findings will benefit other nutritionists, dietitians, pediatricians ,and/or policy makers involved in improving the health of preschool children, both in the US and elsewhere.
Technical Abstract: The purpose of this study was to determine if the vitamin A and zinc status as well as anthropometric responses could be improved in 44 preschool children by supplementing these two nutrients (70 mg zinc and/or 3030 RE vitamin A, once per wk) for six months using a placebo-controlled double blind design. Results: Serum zinc concentrations were greater (16%, p<0.001) for those children who received zinc supplementation compared to the mean of those who were not treated with zinc. Serum vitamin A was not different among groups. Vitamin A or zinc supplementation alone resulted in significantly greater serum hemoglobin (7% greater, p<0.001) or (3% greater p<0.05), respectively. An age x zinc interaction affecting hemoglobin concentration was present. Increases in height (+4.4 cm, p<0.001) and weight (+0.8 kg, p<0.001) were greatest for children supplemented with both nutrients. However, only the vitamin A supplementation effect was significant, with greater weight gains (+0.15 kg, p<0.05) and increases in height (+1.4 cm, p<0.05) as compared to non-vitamin A supplemented children. In conclusion, after six months of vitamin A supplementation, alone or in combination with zinc, there were significantly greater increases in hemoglobin, height, and weight compared to those indices of the non-vitamin A treated; height-for-age Z (HAZ)score, and weight-for-age (WAZ) score changes were also greatest for those who received vitamin A, p<0.001 and p<0.05, respectively.