More than 40 years ago, human growth retardation from deficiency of zinc was first reported. Recently, the marginal zinc deficiency was revealed to occur mostly during pregnancy and infancy, and is predominant in children throughout the world. Also, zinc with or without macronutrients along with other micronutrient deficits can occur in patients with gastrointestinal disease. Specific attention should be given to the suboptimal intake of zinc that is resulting in growth retardation.

The only most important cause of nutritional growth retardation (NGR) throughout the world is poverty related malnutrition that involves multiple macro-and-micro nutrient deficits. NGR is an underappreciated issue in paediatric endocrine clinics as these patients do not show any clinical evidence of malnutrition or obvious nutrient deficits. A slowing in body weight progression and reduced growth rates are the only clinical manifestations of the changed nutrient status seen in children. The slowing of growth happens due to an adaptive response to suboptimal nutrition for maintaining the equilibrium between the potential of genetic growth and nutritional intake. The potential effects of suboptimal intake of zinc in patients with NGR are difficult to evaluate because there are no good clinical markers relating to this mineral.

Zinc is identified to be an important micronutrient that is involved in growth, even though the mechanisms by which zinc deficiency impairs the growth has not been explained. Numerous zinc-containing nucleoproteins are involved in the gene expression of numerous proteins and many of them are essential for growth. Deficiency of zinc reduces IGF-I production and might decrease the cellular IGF-responsiveness. In experimental models, small restriction of energy has shown to have more significant growth retardation than suboptimal zinc intake. The concurrent restriction of energy and zinc did not increase the growth deterioration of chronic suboptimal nutrition. The USDA food guide is a simple guideline serving the needs of paediatric endocrinologists while evaluating the quality of the dietary intake of a short child and also providing guidelines for food intake to the patients.

Source: Cole CR, Lifshitz F. Zinc nutrition and growth retardation. Pediatr Endocrinol Rev. 2008 Jun;5(4):889-96. PMID: 18552751.