Zinc balance in premature infants given the minimal dietary zinc requirement

doi:10.1016/S0022-3476(88)80067-2

The Journal of Pediatrics

Volume 112, Issue 2, February 1988, Pages 262-266

https://doi.org/10.1016/S0022-3476(88)80067-2 Get rights and content

A zinc balance study was conducted on low birth weight infants (670 to 2420 g) fed unsupplemented human milk (the mother's or pooled) (group 1, n=17) or human milk with zinc supplementation (group 2, n=17). The mean zinc concentrations of the diets in groups 1 and 2 were 2.2±1.1. mg/L and 8.4±0.8 mg/L, respectively, and the mean copper concentration of the diets in both groups was 0.45±0.12 mg/L. The studies were performed 7 to 128 days after birth, which corresponded to 29 to 43 weeks postconceptional age. The turning point of zinc balance from negative to positive appeared to be greatly influenced by the postconceptional age, being approximately 36 weeks in both group 1 and group 2, rather than other factors such as the zinc intake and the postnatal age. The calculated minimal requirement of dietary zinc during the period from 36 to 40 weeks postconceptional age, for an adequate amount of zinc retention in infants (250 μg/kg/d), was 0.8 mg/kg/d. Zinc supplementation did not appear to interfere with copper retention.

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Cited by (22)

Commentary on the “Normal supply of zinc to the newborn via milk”
2017, Journal of Trace Elements in Medicine and Biology
Zinc and copper requirements in preterm infants: An examination of the current literature
2013, Early Human Development
Citation Excerpt :
Data were considered significant at a P < 0.05. A total of fourteen studies on zinc retention were identified [11,17–19,21–30] with data on forty-five distinctly identifiable groups (Tables 1 and 2). All studies were identified in the primary PubMed search.
Zinc and copper are essential for preterm infants, but recommended requirements from different groups vary widely. Recommended zinc intakes have steadily increased over the years. Although this would be expected to impair copper absorption, recommended copper intakes have not risen in parallel.
To systematically review the literature on zinc and copper retention in preterm infants; to examine the effect on zinc intake on copper retention; and to estimate the zinc and copper intakes required to meet the levels of zinc and copper retention required for normal growth.
Studies reporting zinc and/or copper retention in preterm infants (< 36 weeks of gestation) during the first 120 days of life were identified using PubMed. Only studies reporting net retention were included.
Fourteen studies on zinc retention reporting data on 45 different groups were identified. Eleven studies (32 groups) were identified reporting copper retention. Zinc retention was significantly higher at higher zinc intakes, and higher in formula-based diets than in human milk based diets. Zinc intakes of between 1.8–2.4 mg/kg/d (from formula based diets) and 2.3–2.4 mg/kg/d (from human-milk based diets) were required to achieve adequate zinc retention. Copper retention was significantly positively correlated with copper intake and significantly negatively correlated with zinc intake. At the zinc intakes suggested previously (1.8–2.4, 2.3–2.4 mg/kg/d), copper intakes of between 200 and 250 mcg/kg/d are required to ensure adequate copper retention.
Our results support the higher zinc intakes recommended in recent guidelines. However, they suggest that recommended copper intakes have not kept pace with increasing zinc intakes, and that preterm infants may need higher copper intakes than currently recommended.
Selected macro/micronutrient needs of the routine preterm infant
2013, Journal of Pediatrics
Citation Excerpt :
The Institute of Medicine reviewed dietary reference intakes and identified the potential adverse effect of oral zinc on copper absorption as the most likely adverse effect of high zinc intake.44 Based on data from balance studies,35-43,45-49 we conclude that a zinc intake of 2.0-2.25 mg/kg/day is required to ensure an adequate zinc retention of 400 μg/kg/day. Preterm and LBW infants are at high risk for iron deficiency.
Requirements for optimal nutrition, especially for micronutrients, are not well defined for premature infants. The “reference fetus,” developed by Ziegler et al,¹ has served as a model to define nutritional needs and studies designed to determine nutrient requirements. Revision of nutrient requirements and provision of optimal nutrition may lead to improved outcomes in preterm infants. Appropriate provision of nutrients also may help prevent nutritional disorders, such as metabolic bone disease and anemia. In this review, we discuss calcium, phosphorus, magnesium, vitamin D, iron, and copper, and define optimal intakes based on the available published data.
Developmental Anatomy and Physiology of the Gastrointestinal Tract
2005, Avery's Diseases of the Newborn
Nutrition for preterm infants after hospital discharge
2005, Advances in Pediatrics
Intestinal zinc, iron, and copper during the perinatal period
2002, Nutrition

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^*: Supported by grants from Snow Brand Dairy Company and Morinaga Hoshikai, Japan.

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Zinc balance in premature infants given the minimal dietary zinc requirement*

J Pediatr

Am J Clin Nutr

The absorption and retention of magnesium, zinc and copper by low birth weight infants fed pasteurized human breast milk

Pediatr Res

Trace minerals

Trace mineral balances in preterm infants fed their own mother's milk

J Pediatr Gastroenterol Nutr

Serum zinc and copper concentration in low birth weight infants during first three months of life: correlation to birth weight and different feedings

Tohoku J Exp Med

Postnatal dependence of plasma copper and zinc levels on gestational age and maturity observed in infants fed a high zinc content formula

J Pediatr Gastroenterol Nutr

Effects of zinc and copper content of formulas on growth and on the concentration of zinc and copper in serum and hair

J Pediatr Gastroenterol Nutr

Intrauterine growth as estimated from live born birth weight data at 24 to 42 weeks of gestation

Pediatrics