Prevention of iron deficiency by milk fortification. II. A field trial with a full-fat acidified milk

In a longitudinal study from age 3 to 15 mo, 276 term, healthy, spontaneously weaned infants received a full-fat acidified milk fortified with 15 mg of elemental Fe as ferrous sulfate and 100 mg of ascorbic acid/100 g of powder and 278 control infants received milk without additives. At ages 9 and 15 mo significant differences were encountered in all measures of Fe nutriture in favor of the fortified group (p less than 0.001). Anemia (Hg less than 110 g/L) was present in 25.7% of unfortified infants compared with only 2.5% in those fortified at age 15 mo. Saturation of transferrin less than 9% was present in 33.8% and serum ferritin less than 10 micrograms/L in 39.1% of the nonfortified infants. The figures for the fortified group were 7 and 8.5% respectively. The efficiency of the fortified acidified milk in eradicating Fe deficiency in the infants while discouraging use by other family members make this milk a useful targeted product in programs of supplementary food distribution in the underdeveloped world.     

Time course of and effect of dietary iron level on iron incorporation into erythrocytes by infants

As a part of our effort to explore various aspects of ferrokinetics in infancy, the present study was designed to determine the timing of entry of an orally ingested iron isotope into circulating erythrocytes, and the effect of the level of dietary iron [0.3 mg/100 kcal (418.4 kJ) vs. 1.8 mg/100 kcal] after isotope administration on erythrocyte incorporation of the isotope. We administered the stable isotope, (58)Fe, orally to 56-d-old and 168-d-old infants. All infants were fed a low-iron formula (LF) before and until 5 h after isotope administration. Thereafter, half the infants were fed a formula high in iron (HF group) while the remaining infants continued to receive the LF (LF group) for an additional 28 d. The quantity of (58)Fe in circulating erythrocytes increased from 14 to 28 d after isotope administration was nearly constant from 28 through 84 d of age (plateau value) and decreased between 84 and 112 d. Erythrocyte incorporation of (58)Fe was greater by the 168-d-old infants than by the 56-d-old infants, presumably because of the lesser iron stores of the older infants. In the 56-d-old infants, erythrocyte incorporation of (58)Fe was greater by the LF than by the HF group, but this difference was not significant in the 168-d-old infants. Thus, at least in younger infants, the level of iron intake after administration of an iron isotope affects erythrocyte incorporation of the isotope. The fact that less isotope was present in erythrocytes 112 d than 84 d after administration indicates that the life span of erythrocytes of infants, even beyond the immediate newborn period, is less than the 120-d life span of erythrocytes in the adult.     

Iron deficiency and anemia in iron-fortified formula and human milk-fed preterm infants until 6 months post-term

Purpose

An iron intake of >2 mg/kg/d is recommended for preterm infants. We hypothesized that human milk (HM)-fed preterm infants require iron supplementation after discharge, whereas iron-fortified formulae (IFF; 0.8–1.0 mg iron/100 ml) may provide sufficient dietary iron until 6 months post-term.

Methods

At term age, 3 and 6 months post-term, ferritin (μg/l) was measured in 92 IFF-fed infants (gestational age (median (interquartile range)) 30.7 (1.4) weeks, birth weight 1,375 (338) gram) and 46 HM-fed infants (gestational age 30.0 (1.7) weeks, birth weight 1,400 (571) gram). Iron intake (mg/kg/d) between term age and 6 months post-term was calculated.

Results

Iron was supplemented to 71.7 % of HM-fed and 83.7 % of IFF-fed infants between term age and 3 months post-term and to 13 % of HM-fed and 0 % of IFF-fed infants between 3 and 6 months post-term. IFF-fed infants had an iron intake from supplements and formula of 2.66 (1.22) mg/kg/d between term age and 3 months post-term and 1.19 (0.32) mg/kg/d between 3 and 6 months post-term. At 3 and 6 months post-term, the incidence of ferritin <12 μg/l was higher in HM-fed compared to IFF-fed infants (23.8 vs. 7.8 % and 26.3 vs. 9.5 %, P < 0.02).

Conclusion

This observational study demonstrates that ferritin <12 μg/l is more prevalent in HM-fed infants until 6 months post-term. This may be due to early cessation of additional iron supplementation. We speculate that additional iron supplementation is not necessary in preterm infants fed IFF (0.8–1.0 mg iron/100 ml), as they achieve ferritin ≥12 μg/l without additional iron supplements between 3 and 6 months post-term.     

Determination of iron in stools as a method to monitor consumption of iron-fortified products in infants

We describe a quantitative method for determination of iron in stool to monitor consumption of iron-fortified milk in infants. The method is simple, fast, and inexpensive. Stool samples from infants consuming fortified milk or nonfortified milk were ashed, and ashes were diluted in hydrochloric acid and reacted with bathophenantroline disulphonate. Mean iron excretion per subject was obtained. Anemia was present in 25.7% of infants in the nonfortified group (upper level of 95% confidence limit for mean iron excretion was 14.9 mg iron/100 g stool) and in 22.2% of infants from the noncompliant fortified group (mean excretion less than 15 mg iron/100 g stool). In contrast, only 0.8% of infants who had properly consumed the fortified milk had anemia. We conclude that this method for determination of stool iron should be considered for estimating compliance in evaluation of results of field trials of iron-fortified products in infants.     

Nutrient intake in the United States during the first 12 months of life

Nutrient intakes of 463 infants ranging in age from 1 week to 12 months from the Nationwide Food Consumption Survey 1977-78 were evaluated according to different foods (milk and milk products, noniron-fortified formula, iron-fortified formula, infant cereal, commercial baby foods, and table foods). Breast-fed infants and infants fed a combination of cow's milk and formula were excluded. Results indicated that iron was the nutrient most often consumed in amounts less than the RDA. Infants fed a diet that included either cow's milk or noniron-fortified formula had a median iron intake less than the recommended allowance. In comparison, infants who were fed an iron-fortified formula had a median iron intake well above the RDA. The relative proportion of iron derived from different foods is discussed.     

Efficacy of a microencapsulated iron pyrophosphate-fortified fruit juice: a randomised, double-blind, placebo-controlled study in Spanish iron-deficient women

Fe-deficiency anaemia is a worldwide health problem. We studied the influence of consuming an Fe-fortified fruit juice on Fe status in menstruating women. A randomised, double-blind, placebo-controlled study of 16 weeks of duration was performed. Subjects were randomised into two groups: the P group (n 58) or the F group (n 64), and consumed, as a supplement to their usual diet, 500 ml/d of a placebo fruit juice or an Fe-fortified fruit juice, respectively. The Fe-fortified fruit juice, containing microencapsulated iron pyrophosphate, provided 18 mg Fe/d (100 % of the RDA). At baseline and monthly, dietary intake, body weight and Fe parameters were determined: total erythrocytes, haematocrit, mean corpuscular volume (MCV), red blood cell distribution width (RDW), Hb, serum Fe, serum ferritin, serum transferrin, transferrin saturation, soluble transferrin receptor (sTfR) and zinc protoporphyrin (ZnPP). The fruit juice consumption involved increased intake of carbohydrates and vitamin C, and increased BMI within normal limits. Ferritin was higher in the F group after week 4 (P < 0·05) and became 80 % higher than in the P group after week 16 (P < 0·001), and transferrin decreased in the F group compared with the P group after week 4 (P < 0·001). RDW was higher at weeks 4 and 8 in the F group compared with the P group (P < 0·05). Transferrin saturation increased after week 8, and haematocrit, MCV and Hb increased after week 12, in the F group compared with the P group. Serum Fe did not change. sTfR and ZnPP decreased in the F group at week 16 (P < 0·05). Iron pyrophosphate-fortified fruit juice improves Fe status and may be used to prevent Fe-deficiency anaemia.     

Iron status of infants fed low-iron formula: no effect of added bovine lactoferrin or nucleotides

BACKGROUND: The appropriate level of iron fortification in infant formula remains undetermined. OBJECTIVES: We compared hematologic indexes and iron-status indicators in infants who were either breast-fed or fed formula with concentrations of 2 or 4 mg Fe/L and evaluated the effects of providing part of the iron as bovine lactoferrin and of adding nucleotides. DESIGN: Healthy term infants were exclusively breast-fed (n = 16) or fed formula (n = 10-12) from age 4 +/- 2 wk to 6 mo. Anthropometric measures were taken monthly, and blood samples were taken at 1, 4, and 6 mo. Hematologic indexes; indicators of iron, zinc, and copper status; and erythrocyte fatty acids were assessed. RESULTS: No significant differences in hematology or iron status were observed between groups at 4 and 6 mo of age. Although 34% of all infants had a hemoglobin concentration <110 g/L at 6 mo, the absence of iron deficiency or defective erythropoiesis suggests that this hemoglobin cutoff is too high for this age group. Neither the source or the concentration of iron in formula nor fortification with nucleotides had any significant effect on serum zinc or copper, and nucleotide fortification did not affect erythrocyte fatty acids. CONCLUSIONS: A concentration of 1.6 mg Fe/L formula meets the iron requirement of healthy term infants aged 相似文献   

Extent of thermal processing of infant formula affects copper status in infant rhesus monkeys

BACKGROUND: Infant rhesus monkeys are excellent models in which to study the effect of infant formulas on trace element absorption and status. Infants fed powdered formula from birth exhibit normal growth and have blood variables similar to those of breast-fed infants. OBJECTIVES: The objectives were to evaluate the effects of feeding ready-to-feed (RTF) formulas exposed to different heat treatments to infant monkeys, and, for one of these formulas, to compare the effect of fortification with 2 iron concentrations. DESIGN: From birth to age 5 mo, infant monkeys (n = 6/group) were fed one of the following formulas exclusively: 1) 12 mg Fe/L processed in cans (RTF-12), 2) formula in glass bottles with 12 mg Fe/L and manufactured by an ultrahigh-temperature (UHT) process (UHT-12), or 3) formula manufactured by a standard thermal process (STP), containing either 8 (STP-8) or 12 (STP-12) mg Fe/L. All formulas had similar copper concentrations (0.6 mg Cu/L). Anthropometric measures and venous blood samples were taken monthly. RESULTS: Weight and length gain did not differ among groups; however, the STP-12 group weighed less than the UHT-12 group at ages 2, 4, and 5 mo. Hemoglobin values were significantly lower in the RTF-12 group than in all other groups at ages 4 and 5 mo and serum ferritin was lower in the RTF-12 group than in the STP-12 group at age 5 mo. Copper status was lower in STP-12 infants than in STP-8 infants. There was a progressive and significant decline in plasma copper, ceruloplasmin, and Cu/Zn superoxide dismutase activity in infants fed canned formula (RTF-12). Furthermore, coat color changed from normal brown to silver. These outcomes suggest that the canned formula induced copper deficiency in infant monkeys. CONCLUSIONS: Excessive heat treatment of formula can have a pronounced negative effect on copper status. High iron concentrations did not improve iron status but may adversely affect copper status.     

Nutrient intakes of older infants: effect of different milk feedings

Using 24-hour dietary and nutrient intake of 293 infants 7-12 months of age from NHANES II, 1976-80, we determined the hypothetical effects of different milk feedings on total intake of 12 nutrients. Infants were grouped by age at 7-8, 9-10, and 11-12 months. Human milk (HM), Fe-fortified infant formula (I-FM), whole cow's milk (WCM), and 2% lowfat milk (2%) were substituted to provide the same energy as that calculated from the difference between median energy intake provided by solid foods and the total diet. Nutrients from milk feedings were added to median nutrient intake from solid foods. Use of WCM or 2% resulted in low total intakes of Fe (6.3-11.1 mg) and linoleic acid (0.5-2.5 g) and high intakes of protein (32-47 g), Na (630-1,200 mg), K (1,400-1,900 mg), and Ca (920-1,170 mg) relative to the RDA. Feeding of HM provided total intakes that met the RDA for each nutrient except Fe (6.1-10.8 mg) and Ca (350-370 mg). When I-FM was fed, the RDA was met for each nutrient except Ca (370-490 mg) at all ages and Fe (13.1 mg) at 11-12 months. Estimated safe and adequate daily intake of Na was exceeded at 9-10 months by infants fed WCM/2% and at 11-12 months by all infants regardless of milk feeding, primarily because of the high Na content of solid foods. These data confirm that the milk feeding is still the major determinant of total nutrient intake in the second 6 months of life.     

α-Lactalbumin and casein-glycomacropeptide do not affect iron absorption from formula in healthy term infants

Iron absorption from infant formula is relatively low. α-Lactalbumin and casein-glycomacropeptide have been suggested to enhance mineral absorption. We therefore assessed the effect of α-lactalbumin and casein-glycomacropeptide on iron absorption from infant formula in healthy term infants. Thirty-one infants were randomly assigned to receive 1 of 3 formulas (4 mg iron/L, 13.1 g protein/L) from 4-8 wk to 6 mo of age: commercially available whey-predominant standard infant formula (standard formula), α-lactalbumin-enriched infant formula (α-LAC), or α-lactalbumin-enriched/casein-glycomacropeptide-reduced infant formula (α-LAC/RGMP). Nine breast-fed infants served as a reference. At 5.5 mo of age, (58)Fe was administered to all infants in a meal. Blood samples were collected 14 d later for iron absorption and iron status indices. Iron deficiency was defined as depleted iron stores, iron-deficient erythropoiesis, or iron deficiency anemia. Iron absorption (mean ± SD) was 10.3 ± 7.0% from standard formula, 8.6 ± 3.8% from α-LAC, 9.2 ± 6.5% from α-LAC/RGMP, and 12.9 ± 6.5% from breast milk, with no difference between the formula groups (P = 0.79) or all groups (P = 0.44). In the formula-fed infants only, iron absorption was negatively correlated with serum ferritin (r = -0.49; P = 0.005) and was higher (P = 0.023) in iron-deficient infants (16.4 ± 12.4%) compared with those with adequate iron status (8.6 ± 4.4%). Our findings indicate that α-lactalbumin and casein-glycomacropeptide do not affect iron absorption from infant formula in infants. Low serum ferritin concentrations are correlated with increased iron absorption from infant formula.     

Reducing Iron Content in Infant Formula from 8 to 2 mg/L Does Not Increase the Risk of Iron Deficiency at 4 or 6 Months of Age: A Randomized Controlled Trial

Many infant formulas are fortified with iron at 8–14 mg/L whereas breast milk contains about 0.3 mg/L. Another major difference between breast milk and infant formula is its high concentration of lactoferrin, a bioactive iron-binding protein. The aim of the present study was to investigate how reducing the iron content and adding bovine lactoferrin to infant formula affects iron status, health and development. Swedish healthy full-term formula-fed infants (n = 180) were randomized in a double-blind controlled trial. From 6 weeks to 6 months of age, 72 infants received low-iron formula (2 mg/L) fortified with bovine lactoferrin (1.0 g/L) (Lf+), 72 received low-iron formula un-fortified with lactoferrin (Lf−) and 36 received standard formula with 8 mg of iron/L and no lactoferrin fortification as controls (CF). Iron status and prevalence of iron deficiency (ID) were assessed at 4 and 6 months. All iron status indicators were unaffected by lactoferrin. At 4 and 6 months, the geometric means of ferritin for the combined low-iron groups compared to the CF-group were 67.7 vs. 88.7 and 39.5 vs. 50.9 µg/L, respectively (p = 0.054 and p = 0.056). No significant differences were found for other iron status indicators. In the low-iron group only one infant (0.7%) at 4 months and none at 6 months developed ID. Conclusion: Iron fortification of 2 mg/L is an adequate level during the first half of infancy for healthy term infants in a well-nourished population. Adding lactoferrin does not affect iron status.     

Effect of timing of introduction of complementary foods on iron and zinc status of formula fed infants at 12, 24, and 36 months of age

OBJECTIVE: The timing of introduction of complementary food to an infant's diet is variable throughout the world. Our objective was to determine whether early introduction of complementary foods affects iron and zinc status of formulated infants at 12, 24, and 36 months of age. DESIGN: A randomized, prospective trial was conducted. Infants were randomly assigned to receive either a) early introduction (at 3 to 4 months of age) of commercially prepared or parent's choice of complementary foods; or b) late introduction (at 6 months of age) of commercially prepared complementary foods or parent's choice of complementary foods. In addition to complementary foods, infants were fed commercial infant formula as recommended by their pediatrician. Hemoglobin, mean corpuscular volume, and serum ferritin and zinc concentrations were determined at 12, 24, and 36 months of age. Three-day diet diaries were completed at 3, 6, 12, 18, 24, 30, and 36 months of age. SUBJECTS/SETTING: One hundred seventy-five infants younger than 3 months were recruited by mailings to parents in the Cincinnati area. Of these, 172 were enrolled, 90 in the early-introduction group and 82 in the late-introduction group. One hundred thirty-three infants (n = 67 in the early, n = 66 in the late group) completed the study. STATISTICAL ANALYSES PERFORMED: Student t test and regression analyses were used to determine whether there were group differences and whether there was a relationship between serum parameters and dietary intake. RESULTS: Infants fed complementary foods early had significantly greater iron intakes until 6 months of age; however, there were no differences in the iron status parameters (ferritin, hemoglobin, and mean corpuscular volume) at 12, 24, or 36 months of age. The early introduction group consumed slightly less zinc than the late introduction group at 5 months (4.4 vs 4.8 mg/day, P < .01) and 6 months (4.4 vs 4.7 mg/day, P < .01). At all other times there were no differences between the early and late group in zinc intakes. The serum zinc concentration was not associated with dietary zinc. Both groups had normal serum zinc concentrations at 12, 24, and 36 months and there were no differences between groups. APPLICATIONS/CONCLUSIONS: The iron and zinc status of infants in this study was not influenced by the timing or type of complementary foods introduced. However, the infants were formula fed and the mean iron and zinc intakes that were equal or greater than the Recommended Dietary Allowances for the first 6 months of age.     

A community-based randomized controlled trial of iron and zinc supplementation in Indonesian infants: interactions between iron and zinc

BACKGROUND: Combined supplementation with iron and zinc during infancy may be effective in preventing deficiencies of these micronutrients, but knowledge of their potential interactions when given together is insufficient. OBJECTIVE: The goal was to compare the effect in infants of combined supplementation with iron and zinc and of supplementation with single micronutrients on iron and zinc status. DESIGN: Indonesian infants (n = 680) were randomly assigned to daily supplementation with 10 mg Fe (Fe group), 10 mg Zn (Zn group), 10 mg Fe + 10 mg Zn (Fe+Zn group), or placebo from 6 to 12 mo of age. Venous blood samples were collected at the start and end of the study. Five hundred forty-nine infants completed the supplementation and had both baseline and follow-up blood samples available for analysis. RESULTS: Baseline prevalences of anemia, iron deficiency anemia (anemia and low serum ferritin), and low serum zinc (< 10.7 micromol/L) were 41%, 8%, and 78%, respectively. After supplementation, the Fe group had higher hemoglobin (119.4 compared with 115.3 g/L; P < 0.05) and serum ferritin (46.5 compared with 32.3 microg/L; P < 0.05) values than did the Fe+Zn group, indicating an effect of zinc on iron absorption. The Zn group had higher serum zinc (11.58 compared with 9.06 micromol/L; P < 0.05) than did the placebo group. There was a dose effect on serum ferritin in the Fe and Fe+Zn groups, but at different levels. There was a significant dose effect on serum zinc in the Zn group, whereas no dose effect was found in the Fe+Zn group beyond 7 mg Zn/d. CONCLUSION: Supplementation with iron and zinc was less efficacious than were single supplements in improving iron and zinc status, with evidence of an interaction between iron and zinc when the combined supplement was given.     

Erythrocyte incorporation of iron by infants: iron bioavailability from a low-iron infant formula and an evaluation of the usefulness of correcting erythrocyte incorporation values, using a reference dose or plasma ferritin concentrations

Bioavailability of iron (Fe) from a low-Fe infant formula was determined by erythrocyte incorporation of 58Fe 14 d after administration in ten healthy, non-Fe-deficient infants. Two feeding protocols were compared, with each infant acting as his/her own control. At 140 and 154 d of age, infants were fed 1000 g of 58Fe-labelled formula (1.44 mg total Fe/1000 g) as six feeds over 24 h (Protocol A) or as two feeds/day on three consecutive days (Protocol B). A water solution with 57Fe and ascorbic acid was given separately as a reference dose in both study protocols. Erythrocyte incorporation of 58Fe and 57Fe was determined by thermal ionisation mass spectrometry. Geometric mean 58Fe incorporation was 7.6% (range 3.3-13.5%) with Protocol A as compared to 10.6% (range 6.7-18.6%) with Protocol B (P = 0.05); paired t test. Inter-individual variability of 58Fe was not reduced by correcting for the incorporation of 57Fe from the reference dose, or by correcting for plasma ferritin concentration. Fractional erythrocyte incorporation of Fe from low-Fe infant formula was in the same range as our earlier published data on erythrocyte incorporation of Fe from human milk extrinsically labelled with 58Fe (Davidsson et al. 1994a). The methodological evaluations included in this study clearly indicate the importance of using standardised study protocols when evaluating Fe bioavailability in infants. Corrections of erythrocyte incorporation data based on plasma ferritin or erythrocyte incorporation of Fe from a reference dose were not found to be useful.     

A follow-up study of nutrient intake, nutritional status, and growth in infants with cow milk allergy fed either a soy formula or an extensively hydrolyzed whey formula

BACKGROUND: Infants with cow milk allergy (CMA) are reported to have reduced growth and special nutritional needs. OBJECTIVE: The aim of the present study was to compare nutrient intake, nutritional status, and growth in infants with CMA who were fed either a soy formula or an extensively hydrolyzed whey formula. DESIGN: The study group comprised 168 double-blind challenge-proven infants with CMA. Eighty-four of the infants were fed a soy formula (mean starting age: 7.8 mo), and the other 84 infants were fed an extensively hydrolyzed whey formula (mean starting age: 7.5 mo). RESULTS: The length (SD score) of the infants was close to the mean Finnish reference growth by age 2 y in both groups. Weight-for-length measurements continued to reach the 50th percentile by age 4 y in both study groups. The mean nutrient intake followed the recommended intake in both groups, although most of the infants were supplemented with calcium and vitamin D. The observed serum transferrin receptor concentrations indicated a greater iron inadequacy in the tissue of infants in the soy formula group than in the hydrolyzed whey formula group (P = 0.08). However, there were no significant differences between the groups either in the percentages of abnormally low laboratory values (mean cell volume, hemoglobin, zinc, and ferritin) or in the percentages of high alkaline phosphatase activity, which indicates the comparable safety and effectiveness of the formulas studied. CONCLUSIONS: Both nutritional status and growth were well within reference values in the 2 groups, and the selection of a formula can largely be made on the basis of infant tolerance to the formulas.     

Iron absorption in breast-fed infants: effects of age,iron status,iron supplements,and complementary foods

BACKGROUND: Iron supplements are often recommended for older breast-fed infants, but little is known about factors affecting iron absorption from human milk or supplements. OBJECTIVE: We investigated the effects of age, iron status, and iron intake on iron absorption in healthy, term, breast-fed infants. DESIGN: Twenty-five infants were randomly assigned to receive either 1) iron supplements (1 mg x kg(-1) x d(-1)) from 4 to 9 mo of age, 2) placebo from 4 to 6 mo and iron supplements from 6 to 9 mo, or 3) placebo from 4 to 9 mo. Infants were exclusively breast-fed to 6 mo and partially breast-fed to 9 mo of age. Iron absorption was assessed by giving (58)Fe with mother's milk at 6 and 9 mo. Blood samples were obtained at 4, 6, and 9 mo, and complementary food intake was recorded at 9 mo. RESULTS: At 6 mo, mean (+/-SD) fractional iron absorption from human milk was relatively low (16.4 +/- 11.4%), with no significant difference between iron-supplemented and unsupplemented infants. At 9 mo, iron absorption from human milk remained low in iron-supplemented infants (16.9 +/- 9.3%) but was higher (P = 0.01) in unsupplemented infants (36.7 +/- 18.9%). Unexpectedly, iron absorption at 9 mo was not correlated with iron status but was significantly correlated with intake of dietary iron, including supplemental iron. CONCLUSIONS: Changes in the regulation of iron absorption between 6 and 9 mo enhance the infant's ability to adapt to a low-iron diet and provide a mechanism by which some, but not all, infants avoid iron deficiency despite low iron intakes in late infancy.     

Quantitative fecal carbohydrate excretion in premature infants

Despite relative lactase deficiency and pancreatic insufficiency, premature infants are fed formulas containing 50% lactose plus 50% glucose polymers. We measured total fecal carbohydrate excretion in six healthy 32-wk gestation premature infants who had been fed two 0.784-kcal/g formulas that were similar except for the carbohydrate source (100% lactose vs 50% lactose plus 50% glucose polymers). Using a cross-over design with the first formula randomly assigned, two 72-h balance studies were performed with carmine red, an intermittent external marker, and polyethylene glycol (PEG), a continuous internal marker. Formula and stools were analyzed for total carbohydrate (anthrone method) and PEG. There were no significant differences between the two formula periods for carbohydrate intake, mean daily stool output, or fecal carbohydrate excretion. Mean fecal carbohydrate excretion was less than 0.2 g/d, or less than 1% of carbohydrate intake. Thus, older (32-wk gestation) premature infants fed either 100% lactose or 50% lactose plus 50% glucose polymers have minimal fecal losses of intact carbohydrate.     

Concentrations of iron, copper and zinc in human milk and powdered infant formula

Concentrations of iron, copper and zinc were determined in 56 samples of mature human milk from Canarian women and 5 samples of powdered infant formula. According to the literature our data fall within the normal limits in each kind of milk. The mean concentration of Fe, Cu and Zn of powdered infant formula was significantly higher than those concentrations found in the human milks. Significant differences among the concentrations of the studied metals for the milks of considered mothers were observed. The Fe, Cu and Zn intakes of infants fed with human milk are lower than the requirements recommended by the Food and Nutrition Board (1989). However, the infants fed with powdered infant formula had consumed an adequate intake of Fe and Cu. A progressive decrease of the metal concentrations with the lactation stage was observed. The human milk obtained in spring presented Fe and Zn concentrations lower than in autumn, which could be due to changes in nutritional habits of the mothers. Age of mother and number of previous children seem to influence the Zn and Cu concentrations of human milk.     

Concentrations of iron,copper and zinc in human milk and powdered infant formula

Concentrations of iron, copper and zinc were determined in 56 samples of mature human milk from Canarian women and 5 samples of powdered infant formula. According to the literature our data fall within the normal limits in each kind of milk. The mean concentration of Fe, Cu and Zn of powdered infant formula was significantly higher than those concentrations found in the human milks. Significant differences among the concentrations of the studied metals for the milks of considered mothers were observed. The Fe, Cu and Zn intakes of infants fed with human milk are lower than the requirements recommended by the Food and Nutrition Board (1989). However, the infants fed with powdered infant formula had consumed an adequate intake of Fe and Cu. A progressive decrease of the metal concentrations with the lactation stage was observed. The human milk obtained in spring presented Fe and Zn concentrations lower than in autumn, which could be due to changes in nutritional habits of the mothers. Age of mother and number of previous children seem to influence the Zn and Cu concentrations of human milk.     

Lower calcium absorption in infants fed casein hydrolysate- and soy protein-based infant formulas containing palm olein versus formulas without palm olein

OBJECTIVE: Quantitative balance studies were performed to compare fat and calcium absorption in healthy, full term infants fed casein hydrolysate-based (CHF) and soy protein-based (SPF) infant formulas with or without palm olein (PO). Previous studies have reported that PO significantly reduced absorption of both fat and calcium in cow's milk-based formulas in which most of the calcium is inherent in the milk protein. In both SPF and CHF virtually all calcium is added as calcium salts. METHODS: Two randomized, blinded, crossover balance studies were conducted in normal term infants using a three-day home balance method. One study evaluated 10 infants fed commercially available CHF with or without PO, and the other study evaluated 12 infants fed commercially available SPF with or without PO. Fat and calcium absorption were determined based on the weight of formula intake, weight of stools, and measured calcium and fat in formula and stools. RESULTS: Fat and calcium intake did not differ between the groups fed CHF. However, infant's calcium and fat absorption was less, 41 +/- 6% (Mean +/- SEM) and 92.0 +/- 0.8%, respectively, when fed CHF with PO compared to 66 +/- 5% and 96.6 +/- 1.1%, respectively, when fed CHF without PO, (p < 0.01). For infants fed SPF, fat and calcium intake did not differ between the feeding groups. Mean calcium absorption was also significantly less when infants were fed SPF with PO, 22 +/- 3%, than when fed SPF with no PO, 37 +/- 4% (p < 0.05). Fat absorption did not differ between the two SPFs. CONCLUSION: This study demonstrates that PO, as the predominant fat, is associated with significantly lower absorption of calcium from infant formulas in which calcium salts are the source of calcium. These findings corroborate previous reports of this negative effect of PO in cow milk-based infant formulas in which most of the calcium is a component of the cow milk protein source.