Ekhard E. Ziegler

Enteral nutrient supply for preterm infants: commentary from the European Society of Paediatric Gastroenterology, Hepatology and Nutrition Committee on Nutrition.

The number of surviving children born prematurely has increased substantially during the last 2 decades. The major goal of enteral nutrient supply to these infants is to achieve growth similar to foetal growth coupled with satisfactory functional development. The accumulation of knowledge since the previous guideline on nutrition of preterm infants from the Committee on Nutrition of the European Society of Paediatric Gastroenterology and Nutrition in 1987 has made a new guideline necessary. Thus, an ad hoc expert panel was convened by the Committee on Nutrition of the European Society of Paediatric Gastroenterology, Hepatology, and Nutrition in 2007 to make appropriate recommendations. The present guideline, of which the major recommendations are summarised here (for the full report, see http://links.lww.com/A1480), is consistent with, but not identical to, recent guidelines from the Life Sciences Research Office of the American Society for Nutritional Sciences published in 2002 and recommendations from the handbook Nutrition of the Preterm Infant. Scientific Basis and Practical Guidelines, 2nd ed, edited by Tsang et al, and published in 2005. The preferred food for premature infants is fortified human milk from the infants own mother, or, alternatively, formula designed for premature infants. This guideline aims to provide proposed advisable ranges for nutrient intakes for stable-growing preterm infants up to a weight of approximately 1800 g, because most data are available for these infants. These recommendations are based on a considered review of available scientific reports on the subject, and on expert consensus for which the available scientific data are considered inadequate.

Weight Gain in the First Week of Life and Overweight in Adulthood A Cohort Study of European American Subjects Fed Infant Formula

Background—Successful prevention of obesity and related cardiovascular risk factors requires a clear understanding of its determinants over the life course. Rapid infancy weight gain is associated with childhood obesity, whereas low infancy weight is associated with coronary heart disease. Our aim was to identify during which periods in infancy weight gain is associated with adult obesity. Methods and Results—A cohort of European American formula-fed subjects, measured on 7 occasions during infancy as part of several infant formula studies, were contacted at age 20 to 32 years, when they reported usual adult weight and height. A life-course plot was used to identify critical periods of weight gain associated with adulthood overweight (body mass index ≥25 kg/m2). These associations were tested with logistic regressions. Data were available for 653 subjects (72% of eligible subjects). Approximately 32% of them were overweight adults. The period between birth and age 8 days was identified as potentially critical. After adjustment for important confounding factors, weight gain during the first week of life was associated with adulthood overweight status (OR for each 100-g increase 1.28, 95% CI 1.08 to 1.52), as was weight gain during the first 112 days of life (OR 1.04, 95% CI 1.01 to 1.08). Similar results were obtained after standardization with z scores from a reference population. Conclusions—In formula-fed infants, weight gain during the first week of life may be a critical determinant for the development of obesity several decades later. These results contribute to the understanding of chronic disease programming and suggest new approaches to obesity prevention.

Aggressive nutrition of the very low birthweight infant

We propose an approach to nutrition of the VLBW infant that aims at minimizing the interruption of nutrient uptake engendered by premature birth. Our approach is aggressive in that it goes beyond current practice in several key aspects. The gap in nutrient intakes between the proposed aggressive approach and current practice will most likely disappear over the next few years as todays aggressive practice becomes tomorrows standard practice. As the gap diminishes, so will the threat that nutritional deprivation poses to growth and development of VLBW infants.

Lactose Enhances Mineral Absorption in Infancy

Summary To determine if lactose promotes the intestinal absorption of calcium and other minerals by infants, metabolic balance studies were performed with infants fed two formulas nearly identical in composition except for carbohydrate. One contained only lactose and the other contained sucrose and corn starch hydrolysate. Each of six normal infants had two balance studies performed with each formula in alternating sequence. When lactose was the carbohydrate, net absorption and net retention of calcium were significantly greater than when lactose was not present in the formula. Absorptions of magnesium and manganese were also significantly enhanced by lactose. Absorptions of copper and zinc were somewhat greater (not statistically significant) when lactose was present, whereas absorption of iron was not affected. Absorption of phosphorus was not different, but urinary excretion was less when the lactose-containing formula was fed and, hence, net retention of phosphorus was significantly enhanced. These results confirm findings from animal studies and previous human studies and show that, in infants, lactose has a significant and sustained promoting effect on absorption of calcium and other minerals.

Meeting the Nutritional Needs of the Low-Birth-Weight Infant

Delivering adequate amounts of nutrients to premature infants at all times is challenging because the infant’s immature gastrointestinal tract is initially unable to accept feedings, necessitating the use of parenteral nutrition. In the past, inadequate amounts of nutrients have commonly been given to premature infants because the administration of nutrients was thought to be hazardous. Inadequate nutrient intakes have resulted in widespread postnatal growth restriction. Now that it is known that postnatal growth restriction is associated with poor neurocognitive development, efforts are made to increase nutrient intakes. In this review, nutrient requirements of premature infants that have been determined by the factorial and empirical methods are reviewed. Current good practices regarding parenteral nutrition are discussed, as are guidelines for the introduction and advancement of enteral feedings. Because of its trophic effects on the gastrointestinal tract and its anti-infectious effects, human milk is strongly preferred as the early feeding of choice for premature infants. Human milk also protects infants against necrotizing enterocolitis. Once full feeding is achieved, the challenge is to provide nutrients in amounts that support the infant’s growth like that of the fetus. In the case of the infant fed his/her mother’s milk or banked donor milk, nutrient fortification is necessary and is generally practiced. However, adequate intakes of protein are seldom achieved with routine fortification and methods of providing additional fortification are discussed.

Vitamin D deficiency in breastfed infants in Iowa.

OBJECTIVE. The purpose of this work was to assess the vitamin D status of breastfed infants living in Iowa (latitude: 41°N). METHODS. Blood samples and dietary records from 84 breastfed infants participating in another study were used for a survey of vitamin D status at 280 days of age. The vitamin D status of those (35 infants) who did not receive preformed vitamin D at 280 days of age (unsupplemented infants) was assessed longitudinally between 112 days and 15 months of age. Plasma 25-hydroxyvitamin D and, in most cases, parathyroid hormone and alkaline phosphatase were determined. RESULTS. At 280 days of age, 10% of breastfed infants were vitamin D deficient (25-hydroxyvitamin D <11 ng/mL). Deficiency was significantly more prevalent among dark-skinned infants and during winter and occurred exclusively in unsupplemented infants. During winter, 78% of unsupplemented infants were vitamin D deficient. During summer, only 1 infant who had dark skin pigmentation was vitamin D deficient. Longitudinal assessment of unsupplemented infants similarly showed that the majority of breastfed infants were vitamin D deficient during winter. Severe deficiency (25-hydroxyvitamin D <5 ng/mL) was common and was accompanied by elevation of parathyroid hormone and alkaline phosphatase. The prevalence of vitamin D deficiency decreased with age but was still 12% at 15 months of age if no preformed vitamin D was received. CONCLUSIONS.Vitamin D deficiency, including severe deficiency, was common among breastfed infants in Iowa who did not receive preformed vitamin D. Deficiency occurred mostly during winter but was not completely absent during summer. It affected infants with light as well as dark skin pigmentation. Consumption of preformed vitamin D from vitamin supplements or formula is effective in preventing vitamin D deficiency. Vitamin D supplementation should be provided to all breastfed infants.

Cow milk feeding in infancy: Further observations on blood loss from the gastrointestinal tract

Because feeding of cow milk causes normal infants to lose increased amounts of occult blood from the gastrointestinal tract, we conducted a prospective trial to measure intestinal blood loss quantitatively and to monitor iron nutritional status. Fifty-two infants entered the trial at 168 days of age and were assigned at random to receive either cow milk or a milk-based formula. Initially, 31 infants had been breast-fed and 21 had been fed formulas. With the feeding of cow milk, the proportion of guaiac-positive stools increased from 3.0% at baseline to 30.3% during the first 28 days of the trial (p less than 0.01), whereas the proportion of positive stools remained low (5.0%) with the feeding of formula. The proportion of guaiac-positive stools among cow milk-fed infants declined later, but for the entire trial it remained significantly (p less than 0.01) elevated. Stool hemoglobin concentration increased markedly with the introduction of cow milk, rising from a mean (+/- SD) of 622 +/- 527 micrograms/gm dry stool at baseline to 3598 +/- 10,479 micrograms/gm dry stool during the first 28 days of ingestion of cow milk. Among infants fed formula, stool hemoglobin did not increase and was significantly (p less than 0.01) less than in the cow milk group. Among infants fed cow milk, the increase in hemoglobin concentration tended to be greater for those who had initially been fed human milk than for those who had initially been fed formulas. Iron nutritional status was not significantly different between the two feeding groups. However, one infant became iron deficient after 4 weeks of ingesting cow milk. We conclude that cow milk feeding leads to increased intestinal tract blood loss in a large proportion of normal infants and that the amount of iron lost is nutritionally important.

Reference data on gains in weight and length during the first two years of life

Serial data from studies of infants at the University of Iowa and from the Fels Longitudinal Study were used to develop sex-specific percentiles for increments in weight and recumbent length for selected intervals during the first 24 months of life. Weight increments are presented for 1-month intervals from birth to 6 months, 2-month intervals from birth to 12 months, and 3-month intervals from birth to 24 months. Length increments are presented for 2-month intervals from birth to 6 months, and for 3-month intervals from birth to 24 months of age. Weights and lengths at the target ages were obtained for the Iowa data by simple interpolation, and for the Fels data by fitting families of three-parameter mathematical functions to the serial data from ages 1 to 24 months. The tabular presentations are based on the Iowa data from birth to 3 months of age, on the combined Iowa and Fels data from 3 to 6 months of age, and on the Fels data from 6 to 24 months of age. We believe that these reference data will be useful in screening for deviations from normal growth and may aid in early detection of failure to thrive or excessive weight gain during early life.

Effect of iron fortification of infant formula on trace mineral absorption

This study was designed to examine whether iron fortification of infant formulas has an effect on utilization of other nutrients, particularly the trace elements zinc and copper. Metabolic balance studies were performed with seven normal infants who were between 43 and 420 days of age. Two formulas of nearly identical composition except for iron concentration (10.2 and 2.5 mg/L) were fed. Each infant had four balance studies performed, two while being fed formula 10.2 and two while being fed formula 2.5, in an alternating sequence. No effect of formula iron concentration was evident on absorption and/or retention of nitrogen, fat, calcium, and magnesium. Although absorption of phosphorus was significantly (p less than 0.05) less with formula 10.2 than formula 2.5, the difference was trivial. No effect on absorption of zinc was seen. However, absorption of copper was only 13.4% (SD 13.0) of intake when formula 10.2 was fed, compared with 27.5% (SD 15.3) of intake when formula 2.5 was fed. The difference was statistically significant (p less than 0.01). We conclude that iron in amounts present in iron-fortified formulas has a measurable effect on copper utilization. Because the magnitude of the effect is relatively small, we doubt that the finding is clinically relevant.

Fluid intake, renal solute load, and water balance in infancy.

A simple, largely empiric method for estimating renal solute load is proposed. Utilizing this method, examples of urine concentration and water balance are described in hypothetic infants receiving various feedings at differing volumes of intake and with normal or increased extrarenal losses of fluid. Circumstances in which water balance must be a primary consideration in infant feeding are discussed.