0A-S2-3文本框: TRACE MINERALS AND INFANT GROWTH
Castillo-Duran C. 
Institute of Nutrition and Food Technology (INTA) and Department of Pediatrics, Faculty of Medicine, Universidad de Chile

The process of growth is determined by the interaction of genetics, and a complex hormonal interplay, including insulin, growth hormone, IGF-I, thyroid hormones and sex steroids. These hormones depend on optimal nutrition, including some trace minerals.
Zinc. The possible mechanisms of growth disorders produced by Zn deficiency in humans are: decreased food intake; decreased activity of Zn metalloenzymes; altered gene expression (Zn-fingers, clusters, twists); alterations in the hormonal regulation of growth. Zinc deficiency is observed during fetal life, infancy, school age or adolescence;  is associated with delay in weight gain (moderate or severe deficiency) and in height (mild through severe deficiency). In most underprivileged communities, Zn deficiency is related to low global or flesh food intake, high phytate intake, and also to increased losses due to intestinal infections. A recent meta-analysis showed a small but significant effect of Zn-supplementation on growth of children, both in weight (+ 0.26 SD) and in height (+ 0.22 SD). It is unclear if Zn supplementation can recover all the height deficiency; thus prevention is the most important way to achieve a normal Zn status and normal growth. Similar to the experience with other micronutrients, nutritional education and fortification of foods commonly used by a given population is more adequate than oral Zn supplementation to prevent Zn deficiency. Also important are prevention and treatment of diseases which affect Zn nutrition, mainly digestive diseases (diarrheal disease, malabsorption syndrome).   
Iron. The results of studies on the effects of iron deficiency in children upon growth have been inconclusive. It has been difficult to control for other variables, such as age, intercurrent illnesses, malnutrition, birth weight, and zinc deficiency, which may also influence iron status or growth. 
Copper. Copper deficiency in infants is associated with early weaning, cow milk feeding, low birth weight, malnutrition and diarrheal disease. Studies in infants recovering from malnutrition show an effect of copper supplementation on growth velocity, mainly in weight gain. 
There is insufficient information about other trace minerals such manganese, selenium, chromium, or iodine have insufficient information to show their participation in human growth.
Conclusions: there is wide evidence for the participation of zinc on growth in humans. Some partial evidence also shows the participation of copper. There is insufficient evidence for the role of iron or other trace minerals on growth.