Iron requirements, absorption and metabolism in infancy and childhood

Measurement of iron absorption and iron gains from birth to 6 months in breastfed and formula-fed infants using iron isotope dilution

Little is known about iron kinetics in early infancy. We administered stable iron isotopes to pregnant women and used maternal-fetal iron transfer to enrich newborn body iron. Dilution of enriched body iron by dietary iron with natural isotopic composition was used to assess iron kinetics from birth to 6 months. In breastfed (BF, n = 8), formula-fed (FF, n = 7), or mixed feeding (MF, n = 8) infants, median (interquartile range) iron intake was 0.27, 11.19 (10.46-15.55), and 4.13 (2.33-6.95) mg/day; iron absorbed was 0.128 (0.095-0.180), 0.457 (0.374-0.617), and 0.391 (0.283-0.473) mg/day (BF versus FF, P < 0.01); and total iron gains were 0.027 (-0.002-0.055), 0.349 (0.260-0.498), and 0.276 (0.175-0.368) mg/day (BF versus FF, P < 0.001; BF versus MF, P < 0.05). Isotope dilution can quantify long-term iron absorption and describe the trajectory of iron depletion during early infancy.

Iron deficiency during the first 1000 days of life: are we doing enough to protect the developing brain?

Iron is essential for the functioning of all cells and organs, most critically for the developing brain in the fundamental neuronal processes of myelination, energy and neurotransmitter metabolism. Iron deficiency, especially in the first 1000 days of life, can result in long-lasting, irreversible deficits in cognition, motor function and behaviour. Pregnant women, infants and young children are most vulnerable to iron deficiency, due to their high requirements to support growth and development, coupled with a frequently inadequate dietary supply. An unrecognised problem is that even if iron intake is adequate, common pregnancy-related and lifestyle factors can affect maternal-fetal iron supply in utero, resulting in an increased risk of deficiency for the mother and her fetus. Although preterm birth, gestational diabetes mellitus and intrauterine growth restriction are known risk factors, more recent evidence suggests that maternal obesity and delivery by caesarean section further increase the risk of iron deficiency in the newborn infant, which can persist into early childhood. Despite the considerable threat that early-life iron deficiency poses to long-term neurological development, life chances and a country's overall social and economic progress, strategies to tackle the issue are non-existent, too limited or totally inappropriate. Prevention strategies, focused on improving the health and nutritional status of women of reproductive age are required. Delayed cord clamping should be considered a priority. Better screening strategies to enable the early detection of iron deficiency during pregnancy and early-life should be prioritised, with intervention strategies to protect maternal health and the developing brain.

The critical roles of iron during the journey from fetus to adolescent: Developmental aspects of iron homeostasis

Iron is indispensable for human life. However, it is also potentially toxic, since it catalyzes the formation of harmful oxidative radicals in unbound form and may facilitate pathogen growth. Therefore, iron homeostasis needs to be tightly regulated. Rapid growth and development require large amounts of iron, while (especially young) children are vulnerable to infections with iron-dependent pathogens due to an immature immune system. Moreover, unbalanced iron status early in life may have effects on the nervous system, immune system and gut microbiota that persist into adulthood. In this narrative review, we assess the critical roles of iron for growth and development and elaborate how the body adapts to physiologically high iron demands during the journey from fetus to adolescent. As a first step towards the development of clinical guidelines for the management of iron disorders in children, we summarize the unmet needs regarding the developmental aspects of iron homeostasis.

Erythrocyte transfusions increased the risk of elevated serum ferritin in very low birthweight infants and were associated with altered longitudinal growth

Aim

There has been a lack of population‐based longitudinal data on serum ferritin in very low birthweight (VLBW) infants during hospitalisation. Our aim was to fill this gap in the knowledge and investigate risk factors for elevated serum ferritin and associations between erythrocyte transfusions and longitudinal growth.

Methods

We retrospectively reviewed longitudinal data on 126 VLBW infants treated at Umeå University Hospital, Sweden, between 2010 and 2013.

Results

The infants' mean gestational age and birthweight were 26.9 weeks and 899 g. Most (91%) received erythrocyte transfusions, and the majority had multiple erythrocyte transfusions. There was a significant correlation between serum ferritin and the volume of transfusions. Almost two‐thirds had at least one serum ferritin measurement of more than 350 µg/L, indicating iron overload. In those with complete anthropometric data (n = 78), there was no significant effect of serum ferritin concentrations in relation to longitudinal growth, but there was a positive association between the erythrocyte transfusion dose and longitudinal growth in VLBW infants born before 25 weeks.

Conclusion

This is the first population‐based study to investigate longitudinal data on serum ferritin in VLBW infants during hospitalisation. The unexpected positive finding in the subgroup born at less than 25 weeks needs further research with a larger cohort.

Association between Breast Milk Mineral Content and Maternal Adherence to Healthy Dietary Patterns in Spain: A Transversal Study

The composition of breast milk is influenced by many factors, some of which dependent on the mother and others on the child. Changes in lactation and other factors depending on the mother's physiology and anthropometric characteristics, as well as her nutritional status and diet, are of key importance. Breast milk minerals have been extensively studied with highly uneven results. In this work, a comparison will made with data across the world. To understand the factors that might explain the disparity, several minerals (Na, K, Ca, P, Mg, Fe, Se and I) have been analyzed using ICP-MS in a set of human milk samples (n = 75). The samples had an identical geographical origin (Galicia, in northwestern Spain) but different lactation circumstances, including maternal anthropometric data, lactating time, newborn sex and maternal adherence to healthy dietary patterns (Mediterranean Diet, MD, or Atlantic Diet, AD). The required concentrations of essential elements reported in the literature are similar to those found in these Spanish women. A univariate approach revealed that factors such as lactating time, body mass index (BMI) and newborn sex have a significant influence in breastmilk mineral content. According to multivariate linear regression analysis, minerals in milk are particularly associated with lactating time, but also with newborn sex, maternal BMI, age and diet pattern in some cases. More precisely, these results suggest that the iron and selenium concentrations in the milk of Galician donors may be positively influenced by maternal adherence to AD and MD, respectively.

Building a prediction model for iron deficiency anemia among infants in Shanghai, China

Iron deficiency anemia (IDA) is a common micronutrient deficiency worldwide in infants. Iron deficiency anemia, during infancy, can have long-lasting detrimental effects on the immune and neural systems; the damage is irreversible. This study aimed to build a prediction model to predict the potential risk of IDA among infants. To collect relevant information for model building, we recruited 528 infants from Fenglin Community Health Service Center in Shanghai, China, and collected the information of infants and their parents by using a structured questionnaire. We also got the blood routine examination results of the infants. Then, we used a multilayer perceptron model (MLP) of the neural network model in IBM SPSS Modeler 18.0 to construct the prediction model. Of the 528 included infants, 80 (15.2%) of them had lower hemoglobin values (<110 g/L) and were finally diagnosed with IDA. Based on the accuracy of different models, the model with the highest accuracy rate (97.3%) was chosen, and all the preselected 26 variables were included in the model. After the modeling, the results indicated that the number of months of exclusive breastfeeding was the most important predictive variable, followed by the mother having anemia during pregnancy, and then the number of months of feeding the infant with iron-fortified rice flour. The model has good sensitivity (100%) and specificity (100%). By using this model, we can predict the potential risk of an infant having IDA and can take the initiative to prevent iron deficiency through the improvement of feeding methods.

Iron Metabolism and Brain Development in Premature Infants

Iron is important for a remarkable array of essential functions during brain development, and it needs to be provided in adequate amounts, especially to preterm infants. In this review article, we provide an overview of iron metabolism and homeostasis at the cellular level, as well as its regulation at the mRNA translation level, and we emphasize the importance of iron for brain development in fetal and early life in preterm infants. We also review the risk factors for disrupted iron metabolism that lead to high risk of developing iron deficiency and subsequent adverse effects on neurodevelopment in preterm infants. At the other extreme, iron overload, which is usually caused by excess iron supplementation in iron-replete preterm infants, might negatively impact brain development or even induce brain injury. Maintaining the balance of iron during the fetal and neonatal periods is important, and thus iron status should be monitored routinely and evaluated thoroughly during the neonatal period or before discharge of preterm infants so that iron supplementation can be individualized.

Guts, Germs, and Iron: A Systematic Review on Iron Supplementation, Iron Fortification, and Diarrhea in Children Aged 4-59 Months

BACKGROUND

The impact of iron supplements and iron fortification on diarrhea in children is controversial, with some studies reporting an increase and others reporting no effect.

OBJECTIVE

The aim of the study was systematically assess the published literature on oral iron supplementation and fortification to evaluate its impact on diarrhea incidence among children aged 4-59 mo.

METHODS

Randomized controlled trials of oral iron supplementation or iron fortification that reported diarrheal outcomes in children aged 4-59 mo were identified from a systematic search of 5 databases.

RESULTS

Of the 906 records identified, 19 studies were found to fit the inclusion criteria for this systematic review. However, variable case definitions for diarrhea made meta-analysis impossible. Of the 19 studies, 7 (37%) studies showed a significant increase, either in overall diarrhea incidence or within a specific subgroup of the population, between iron-supplemented and control groups. Subgroups included children who were iron-replete and children undergoing their first month of iron intervention. Two studies reported an increase in bloody diarrhea. The remaining 12 (63%) studies showed no difference between iron-supplemented and control groups.

CONCLUSIONS

Studies on iron supplementation and fortification use divergent case definitions for diarrhea. A number of studies (37%) showed an increase in overall diarrhea incidence or within a specific subgroup of the population, between iron-supplemented and control groups, but the majority (63%) did not. In addition, there was no clear relation between diarrhea and type of intervention or amount of iron administered observed. In future studies, we recommend that diarrhea be clearly defined and consistently recorded as a secondary outcome. Antibiotic status of participants receiving iron should also be collected to help assess possible drug interactions resulting in a "red stool effect." Finally, further microbiome research is required to better understand the effects of oral iron on specific bacterial species in the colon.

Reference intervals for reticulocyte hemoglobin content in healthy infants

OBJECTIVES

Iron deficiency anemia in childhood is a serious public health problem worldwide. Reticulocyte hemoglobin content (Ret-He) is a novel biomarker of iron deficiency adopted for adults but there is a lack of reference intervals for Ret-He in infants. The aim of this study was to provide data from healthy infants.

METHODS

Swedish infants (n = 456), born at term after normal pregnancies were included. Ret-He was measured at birth (umbilical cord sample), 48-72 h, 4 months, and 12 months. Reference intervals were calculated as ±2 standard deviations from the mean of Ret-He.

RESULTS

Reference intervals for newborn Ret-He were 27.4 to 36.0 pg/L (N = 376) in the cord sample, 28.1-37.7 pg/L (N = 253) at 48-72 h, 25.6-33.4 pg/L (N = 341) at four months and 24.9-34.1 pg/L (N = 288) at 12 months. Ret-He was significantly lower among iron-deficient infants, at 4 months mean difference (95% CI) -4.2 pg/L (-6.1 to -2.4) and at 12 months mean difference (95% CI) -3.4 pg/L (-5.0 to -1.8).

CONCLUSIONS

This longitudinal study presents Ret-He reference intervals based on non-anemic and non-iron-deficient infants and constitutes a step towards standardizing Ret-He as a pre-anemia biomarker of iron deficiency in children.

Iron and the Breastfed Infant

The first 6 months of life is a crucial time in meeting iron needs. The purpose of this review is to examine iron in mother’s milk and whether or not it meets the physiological needs of the growing infant. Key issues include iron content and iron transport from the mammary gland as well as when and what foods should be added to the solely breastfed infant. We examine these topics in light of new molecular biology findings in the mammary gland.

Sex and Iron Modify Fibroblast Growth Factor 23 Concentration in 1-Year-Old Children

CONTEXT

Fibroblast growth factor 23 (FGF23) plays an important role in phosphate homeostasis, but its regulation is inadequately characterized.

OBJECTIVE

To examine FGF23 regulators, especially sex and iron status, in early childhood.

DESIGN

A cross-sectional study involving 1-year-old children.

SETTING AND PARTICIPANTS

Healthy term infants with a birth weight appropriate for gestational age were recruited to an ongoing vitamin D trial at Kätilöopisto Maternity Hospital, Helsinki, Finland. At 12-month follow-up visits, serum FGF23, 25-hydroxyvitamin D (25OHD), phosphate, ionized calcium, parathyroid hormone, and iron status were measured. All 721 children (51% girls) with complete data were included.

MAIN OUTCOME MEASURES

Intact and C-terminal FGF23 concentrations and iron status at 1 year of age.

RESULTS

Intact FGF23 was greater in girls than in boys [median, 44.4 pg/mL; interquartile range (IQR), 36.8 to 51.9; median, 40.9 pg/mL; IQR, 34.5 to 49.0, respectively; P < 0.001]. C-terminal FGF23 was similar in boys and girls (median, 2.8 pmol/L; IQR, 2.1 to 3.7; median, 2.9 pmol/L; IQR, 2.2 to 3.7, respectively; P = 0.393). The iron concentration was positively associated with intact FGF23 and was the strongest modifier of intact FGF23 (regression coefficient, 0.498; 95% confidence interval, 0.333 to 0.663; P < 0.001) with ferritin, season, ionized calcium, 25OHD, and sex as other covariates. The association between iron and C-terminal FGF23 was inversely related (regression coefficient, -0.072; 95% confidence interval, -0.092 to -0.051; P < 0.001).

CONCLUSIONS

At 1 year of age, FGF23 status was different in girls and boys, with intact FGF23 concentrations higher in girls. Iron modified FGF23 concentrations, with intact FGF23 higher and C-terminal lower, in those with greater iron concentrations.

Adjusting ferritin concentrations for inflammation: Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project

Background: The accurate estimation of iron deficiency is important in planning and implementing interventions. Ferritin is recommended as the primary measure of iron status, but interpretability is challenging in settings with infection and inflammation.Objective: We assessed the relation between ferritin concentrations and inflammation and malaria in preschool children (PSC) (age range: 6-59 mo) and women of reproductive age (WRA) (age range: 15-49 y) and investigated adjustment algorithms to account for these effects.Design: Cross-sectional data from 15 surveys for PSC (n = 27,865) and 8 surveys for WRA (24,844), from the Biomarkers Reflecting the Inflammation and Nutritional Determinants of Anemia (BRINDA) project were analyzed individually and combined with the use of a meta-analysis. Several approaches were explored to estimate depleted iron stores (ferritin concentration <12 μg/L in PSC and <15 μg/L in WRA) in inflammation and malaria settings as follows: 1) increase ferritin-concentration cutoff to <30 μg/L; 2) exclude individuals with C-reactive protein (CRP) concentrations >5 mg/L or α-1-acid glycoprotein (AGP) concentrations >1 g/L; 3) apply arithmetic correction factors; and 4) use a regression correction approach.Results: Depleted iron-store estimates incrementally increased as CRP and AGP deciles decreased (4% compared with 30%, and 6% compared with 29% from highest compared with lowest CRP deciles for pooled PSC and WRA, respectively, with similar results for AGP). Depending on the approach used to adjust for inflammation (CRP plus AGP), the estimated prevalence of depleted iron stores increased by 7-25 and 2-8 absolute median percentage points for PSC and WRA, respectively, compared with unadjusted values. Adjustment for malaria in addition to CRP and AGP did not substantially change the estimated prevalence of depleted iron stores.Conclusions: Our results lend support for the use of internal regression correction to estimate the prevalence of depleted iron stores in regions with inflammation. This approach appears to mathematically reflect the linear relation of ferritin concentrations with acute-phase proteins. More research is warranted to validate the proposed approaches, but this study contributes to the evidence base to guide decisions about how and when to adjust ferritin for inflammation.

Fibroblast Growth Factor 23 Concentrations Reflect Sex Differences in Mineral Metabolism and Growth in Early Infancy

BACKGROUND

The role of fibroblast growth factor 23 (FGF23) in the regulation of mineral homeostasis in early life is inadequately understood. We aimed to explore the effects of vitamin D supplementation on serum FGF23 and to elucidate longitudinal changes in FGF23, in addition to studying its association with mineral metabolism in early infancy.

METHODS

Altogether 113 healthy infants received vitamin D3 10, 30 or 40 µg/day from age 0.5 to 3.0 months. Cord blood at birth and capillary blood samples at 3 months were analyzed for serum 25-hydroxyvitamin D, parathyroid hormone, phosphate, calcium and intact and C-terminal FGF23.

RESULTS

In repeated-measures ANCOVA, intact FGF23 concentration increased with time (p < 0.001) and C-terminal FGF23 decreased (p < 0.001). At 3 months, girls had a higher concentration of intact FGF23 (51 vs. 26 pg/ml, p < 0.001) and a greater increase over time (x0394;FGF23 intact 45 vs. 16 pg/ml, p = 0.001) than boys. Vitamin D did not affect serum intact or C-terminal FGF23 concentrations. Girls showed a positive correlation between phosphate and intact FGF23 (p = 0.004), whereas in boys phosphate and C-terminal FGF23 correlated inversely (p = 0.006).

CONCLUSIONS

A substantial sex-related difference in intact FGF23 concentration exists during early infancy, possibly related to differences in skeletal growth between boys and girls.

Iron concentration in breast milk normalised within one week of a single high-dose infusion of iron isomaltoside in randomised controlled trial

AIM

We compared the iron concentration in breast milk after a single high dose of intravenous iron isomaltoside or daily oral iron for postpartum haemorrhage.

METHODS

In this randomised controlled trial, the women were allocated a single dose of intravenous 1200 mg iron isomaltoside or oral iron at a mean daily dose of 70.5 mg. We included 65 women with sufficient breast milk three days after inclusion - 30 from the intravenous iron group and 35 from the oral iron group - and collected breast milk and maternal blood samples three days and one week after allocation.

RESULTS

The mean (±SD) iron concentration in breast milk in the intravenous and oral groups was 0.72 ± 0.27 and 0.40 ± 0.18 mg/L at three days (p < 0.001) and 0.47 ± 0.17 and 0.44 ± 0.25 mg/L after one week (p = 0.64). Baseline samples were not available that soon after birth.

CONCLUSION

A single high dose of intravenous iron isomaltoside for postpartum haemorrhage led to a transient increase in the iron concentration in breast milk three days after treatment compared with oral iron. The difference disappeared one week after treatment, and mean iron concentrations were within the normal range in all samples.

Ferroportin Is Essential for Iron Absorption During Suckling, But Is Hyporesponsive to the Regulatory Hormone Hepcidin

BACKGROUND & AIMS

Previous studies have suggested that iron absorption in suckling mammals is refractory to stimuli that normally would decrease absorption in adults. To better understand the regulation of iron absorption during suckling, we have characterized the relationship between hepcidin, ferroportin, and iron absorption at this crucial stage of life.

METHODS

To determine whether ferroportin is involved in iron absorption during suckling, absorption was measured in intestine-specific ferroportin knockout mice. The effect of constitutive hepcidin overexpression on intestinal iron absorption also was investigated in suckling transmembrane serine protease 6 knockout mice. Finally, suckling mice were injected with lipopolysaccharide to induce hepcidin expression. Blood was collected for serum iron analysis, and liver tissue and duodenal enterocytes were collected for gene and protein expression profiles.

RESULTS

Iron absorption was very low in suckling ferroportin knockout mice, indicating that ferroportin is responsible for the majority of the iron absorbed at this time. However, increases in hepcidin during suckling, as seen in transmembrane serine protease 6 knockout mice and in mice injected with lipopolysaccharide, did not affect enterocyte ferroportin levels. Immunofluorescent localization of ferroportin showed that the protein localized to the basolateral membrane of duodenal enterocytes in both suckling and weaned mice.

CONCLUSIONS

These data show that the high iron absorption occurring during suckling is mediated by ferroportin. However, enterocyte ferroportin is hyporesponsive to hepcidin at this time, despite being expressed on the basolateral membrane. Alterations to ferroportin that prevent hepcidin binding during suckling may allow iron absorption to remain high regardless of hepcidin expression levels, reducing the likelihood of iron deficiency during development.

Association of Maternal Diet With Zinc, Copper, and Iron Concentrations in Transitional Human Milk Produced by Korean Mothers

The aims of this study were to evaluate zinc, copper, and iron concentrations in the transitory milk of Korean lactating mothers and to investigate the relationship between these concentrations and maternal diet. Human milk samples were collected between 5 and 15 days postpartum from 96 healthy, lactating mothers in postpartum care centers in Seoul, Korea. Dietary intake during lactation was determined based on a 3-day dietary record. The mean zinc, copper, and iron concentrations in the human milk samples collected were 3.88 ± 1.74 mg/L, 0.69 ± 0.25 mg/L, and 5.85 ± 8.53 mg/L, respectively. The mothers who consumed alcoholic beverages during pregnancy had tended to have lower concentrations of zinc and copper, as well as significantly lower concentrations of iron, in their milk (p < 0.047). In contrast, the mothers who took daily supplements had much higher iron concentrations in their milk (p = 0.002). Dietary intakes of zinc, copper, and iron during lactation did not affect the concentrations of zinc, copper, and iron in the milk samples analyzed. Intakes of vitamin C, selenium, and iodine were associated with the concentration of copper in the milk samples analyzed, and consumption of food categorized as 'meat and meat products' was positively associated with the concentration of zinc. Consumption of rice was the top contributor to the concentrations of all three minerals. In conclusion, associations between maternal diet and nutrient concentrations in transitory human milk can provide useful information, particularly in regard to infant growth.

Pilot Study of the Association of Anemia with the Levels of Zinc, Copper, Iron, Calcium, and Magnesium of Children Aged 6 Months to 3 Years in Beijing, China

This study sought to explore the relationship between anemia in children and levels of five minerals in blood. A sample consisted of 242 normal and 304 anemic children paired by sex and age. Hematological parameters were assessed using the Sysmex xs-800i hematology analyzer. Levels of zinc (Zn), copper (Cu), iron (Fe), magnesium (Mg), and calcium (Ca) were measured by polarographic analysis. Differences in these elements between the anemic and normal groups were compared by ANOVA. Relationships between Ca, Zn, Fe, Cu, Mg, and Hb levels were tested by Pearson's correlation analysis. The Mg level (1.51 ± 0.30 mmol/L) of the moderately anemic group (≤90 g/L) was significantly higher than that (1.36 ± 0.30 mmol/L) of the mildly anemic (90 g/L ≤Hb <110 g/L) and normal groups (1.31 ± 0.30 mmol/L) (p < 0.05). The rate of moderate anemia (13.7 %) in the higher Mg group (Mg >1.57 mmol/L) was higher than that (5.3 %) of the lower Mg group (Mg ≤1.57 mmol/L) (p < 0.01). The rate of moderate anemia (12.8 %) in the lower Fe group (≤78.4 umol/L) was higher than that (6.2 %) of the higher Fe group (>78.4 umol/L) (p < 0.05). Hemoglobin was inversely correlated with Mg levels in the anemic group (p < 0.05). These results indicate that blood levels of Mg and Fe were correlated with anemic children aged 6 months to 3 years. To prevent and treat anemia better, a combination of the levels of Hb, Mg, and Fe in whole blood is required.

An Overview of Iron in Term Breast-Fed Infants

BACKGROUND

Iron is an essential nutrient for normal growth and neurodevelopment of infants. Iron deficiency (ID) remains the most common micronutrient deficiency worldwide. There are convincing data that ID is associated with negative effects on neurological and psychomotor development.

OBJECTIVES

In this review, we provide an overview of current knowledge of the importance of iron in normal term breast-fed infants with a focus on recommendations, metabolism, and iron requirements.

CONCLUSIONS

Health organizations around the world recommend the introduction of iron-rich foods or iron supplements for growing infants to prevent ID. However, there is no routine screening for ID in infancy. Multicenter trials with long-term follow-up are needed to investigate the association between iron fortification/supplementation and various health outcomes.

Prevalence and determinants of anaemia among children aged 0–59 months in a rural region of Armenia: a case–control study

Objective

Despite the trend of increasing prevalence of childhood anaemia in Armenia, no studies exploring its risk factors have been conducted in the country. The present study aimed to investigate the prevalence and determinants of childhood anaemia in rural Armenia.

Design

Blood Hb level was measured among a representative sample of children using the HemoCue Hb201+ analyser. The revealed cases with anaemia were compared with randomly selected non-anaemic controls. Mothers of cases and controls were interviewed. Logistic and linear regression models were fitted to identify the risk factors of anaemia and low Hb level, respectively.

Setting

Talin communities, Aragatsotn Province, Armenia.

Subjects

Children under 5 years of age in Talin region.

Results

Of the 729 studied children, 32·4 % were anaemic with 14·7 % having moderate/severe anaemia. Infants were the most affected group with 51·1 % being anaemic before 6 months and 67·9 % at 6–12 months of age. Fitted regression models identified the following predictors of anaemia: younger age, male gender, shorter birth length, anaemia during pregnancy, lower meal frequency per day, lack of meat in the diet, using dung cakes for heating and living in a community that received an incomplete set of nutrition interventions.

Conclusions

The study identified several modifiable risk factors that could be targeted to reduce childhood anaemia in rural Armenia and, possibly, in rural areas in other low-/middle-income countries. The suggested interventions include prevention and treatment of anaemia during pregnancy, provision of adequate complementary feeding to children with inclusion of meat in their daily diet and reduction of their exposure to biomass fuel smoke.

Prevalence and risk factors of iron deficiency in healthy young children in the southwestern Netherlands

OBJECTIVES

Iron deficiency (ID) and iron deficiency anemia (IDA), during the first years of life, are associated with delayed motor and neurological development. Many studies evaluated iron status without an assessment of an acute-phase protein to identify infection. Because most indicators of iron status are influenced by infection, these data may underestimate the ID prevalence. A food consumption survey in the Netherlands showed that the mean iron intake of children ages 2 to 3 years was below the advised adequate intake of 7 mg/day. The aim of the study was to investigate iron status in a well-defined, healthy population of young children in the southwestern region of the Netherlands and to identify risk factors for ID.

METHODS

We conducted a multicenter, observational study in healthy children ages 0.5 to 3 years. We defined ID as ferritin <12 μg/L and IDA when, in addition, hemoglobin was <110 g/L. Children with elevated C-reactive protein levels (>5 mg/L) or underlying causes for anemia were excluded. Parents filled in a questionnaire to identify risk factors for ID.

RESULTS

We included 400 children in the study. ID and IDA were detected in 18.8% and 8.5% of the children, respectively. The present use of formula and the visit of preschool/day care were associated with a lower prevalence of ID, and a high intake of cow's milk was associated with a higher prevalence of ID, after adjustment for age.

CONCLUSIONS

ID is present in 18.8% of healthy children ages 0.5 to 3 years and living in the southwestern region of the Netherlands. The present visit of preschool/day care and the use of formula are associated with a reduced risk of ID, whereas a high intake of cow's milk is associated with an increased risk of ID.

Iron requirements of infants and toddlers

Iron deficiency (ID) is the most common micronutrient deficiency worldwide and young children are a special risk group because their rapid growth leads to high iron requirements. Risk factors associated with a higher prevalence of ID anemia (IDA) include low birth weight, high cow's-milk intake, low intake of iron-rich complementary foods, low socioeconomic status, and immigrant status. The aim of this position paper was to review the field and provide recommendations regarding iron requirements in infants and toddlers, including those of moderately or marginally low birth weight. There is no evidence that iron supplementation of pregnant women improves iron status in their offspring in a European setting. Delayed cord clamping reduces the risk of ID. There is insufficient evidence to support general iron supplementation of healthy European infants and toddlers of normal birth weight. Formula-fed infants up to 6 months of age should receive iron-fortified infant formula, with an iron content of 4 to 8 mg/L (0.6-1.2 mg(-1) · kg(-1) · day(-1)). Marginally low-birth-weight infants (2000-2500 g) should receive iron supplements of 1-2 mg(-1) · kg(-1) · day(-1). Follow-on formulas should be iron-fortified; however, there is not enough evidence to determine the optimal iron concentration in follow-on formula. From the age of 6 months, all infants and toddlers should receive iron-rich (complementary) foods, including meat products and/or iron-fortified foods. Unmodified cow's milk should not be fed as the main milk drink to infants before the age of 12 months and intake should be limited to <500 mL/day in toddlers. It is important to ensure that this dietary advice reaches high-risk groups such as socioeconomically disadvantaged families and immigrant families.

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.

Iron supplementation in pregnancy and breastfeeding and iron, copper and zinc status of lactating women from a human milk bank

This study evaluated the influence of iron supplementation in pregnancy and breastfeeding on iron status of lactating women from a Brazilian Human Milk Bank. Blood and mature breast milk samples were collected from 145 women for assessment of iron status, as well as copper and zinc status. Haemoglobin, serum iron and ferritin were determined, respectively, by electronic counting, colorimetry and chemiluminescence. Transferrin and ceruloplasmin were analysed by nephelometry. Serum copper and zinc were measured by atomic absorption spectrophotometry, and serum alkaline phosphatase was measured by a colorimetric method. Iron, zinc and copper in breast milk were determined by spectrometry. Mean values of iron, copper and zinc (blood and breast milk) were compared by ANOVA, followed by Tukey's test. Iron supplementation was beneficial to prevent anaemia in pregnancy but not effective to treat anaemia. During breastfeeding, iron supplementation had a negative effect on maternal copper status, confirming an interaction between these micronutrients.

Australasian neonatal intensive care enteral nutrition survey: implications for practice

AIM

This survey investigated standardised feeding guidelines and nutrition policy in Australasian neonatal intensive care units and compared these with previously published surveys and international consensus nutrition recommendations.

METHODS

An electronic survey on enteral nutrition comprising a wide range of questions about clinical practice was e-mailed to all 25 Australasian neonatal intensive care unit directors of tertiary perinatal centres.

RESULTS

Twenty-five surveys were distributed; 24 (96%) were completed. All respondents preferred breast milk as the first feed. For infants <1000 g, 58% started feeds at 1 mL every 4 hours and 83% started enteral feeds on day 0-2 in the absence of contraindications. The identification of bile-stained gastric aspirates significant enough to withhold feeds varied. Multicomponent breast milk fortifiers were added by 58% when enteral feeds reached 150 mL/kg day, while 21% added these earlier at 120 mL/kg day or less. Iron supplementation was started at 4 weeks by 63% and at 6 weeks by 27%. Only 42% of units had a neonatal dietitian. Of the 24 units who responded, 58% had no written enteral feeding guidelines.

CONCLUSION

Enteral nutrition was initiated earlier than in the past. Great variation remains in clinical practices. Nutritional implications are discussed. Standardisation of feeding guidelines and enteral nutrition policy based on current evidence and international consensus nutrition recommendations may be beneficial and should be encouraged.

Essential but toxic: controlling the flux of iron in the body

Iron is an essential nutrient, but, because it is toxic when present in excess, its levels in the body are tightly controlled. This regulation is affected by controlling the release of iron into the plasma. Most iron enters the plasma from macrophages, which recycle iron from senescent erythrocytes, but dietary iron absorption and the release of hepatocyte storage iron are other major sources. Cellular iron export is mediated by the membrane iron transporter ferroportin 1, in conjunction with an iron oxidase. Hephaestin provides this oxidase activity in the intestine, whereas ceruloplasmin is the oxidase used by most other tissues. The liver-derived peptide hepcidin binds to ferroportin 1 and removes it from the cell surface, thus reducing iron donation to the plasma. The levels of hepcidin, in turn, reflect body iron requirements. At the cellular level, ferroportin 1 can also be regulated independently of hepcidin by hypoxia-inducible factors and the iron regulatory proteins. The hepcidin-ferroportin axis plays a critical role in regulating body iron homeostasis.

Effect on haematological and anthropometric parameters of iron supplementation in the first 2 years of life. Risks and benefits

Effects of iron supplementation (IS) on haematological and anthropometric parameters in a cohort of 121 healthy children, followed from 6 to 24 months of life, in the Paediatric Department, Second University of Naples, were evaluated. Children were randomly segregated in four groups: (1) exclusively breast feeding (BF) weaned with non-iron fortified (NIF) foods, (2) BF and iron fortified formulas (IFF) and foods, (3) exclusively IFF and foods, (4) BF and oral iron supplementation (OIS). Haematological parameters (Hb, MCV, Serum ferritin and transferrin saturation) in addition to anthropometric measurements (length and weight) were obtained. Results from the study at 6, 12, 18 and 24 months showed significantly lower values of haematological parameters in BF infants than other groups and in IFF infants than in those with OIS. In contrast children with OIS showed significant lower length. It appears that IS may be of limited or no benefit for growth in non-iron deficient children.

Effect of delayed versus early umbilical cord clamping on neonatal outcomes and iron status at 4 months: a randomised controlled trial

OBJECTIVE

To investigate the effects of delayed umbilical cord clamping, compared with early clamping, on infant iron status at 4 months of age in a European setting.

DESIGN

Randomised controlled trial.

SETTING

Swedish county hospital.

PARTICIPANTS

400 full term infants born after a low risk pregnancy.

INTERVENTION

Infants were randomised to delayed umbilical cord clamping (≥ 180 seconds after delivery) or early clamping (≤ 10 seconds after delivery).

MAIN OUTCOME MEASURES

Haemoglobin and iron status at 4 months of age with the power estimate based on serum ferritin levels. Secondary outcomes included neonatal anaemia, early respiratory symptoms, polycythaemia, and need for phototherapy.

RESULTS

At 4 months of age, infants showed no significant differences in haemoglobin concentration between the groups, but infants subjected to delayed cord clamping had 45% (95% confidence interval 23% to 71%) higher mean ferritin concentration (117 μg/L v 81 μg/L, P < 0.001) and a lower prevalence of iron deficiency (1 (0.6%) v 10 (5.7%), P = 0.01, relative risk reduction 0.90; number needed to treat = 20 (17 to 67)). As for secondary outcomes, the delayed cord clamping group had lower prevalence of neonatal anaemia at 2 days of age (2 (1.2%) v 10 (6.3%), P = 0.02, relative risk reduction 0.80, number needed to treat 20 (15 to 111)). There were no significant differences between groups in postnatal respiratory symptoms, polycythaemia, or hyperbilirubinaemia requiring phototherapy.

CONCLUSIONS

Delayed cord clamping, compared with early clamping, resulted in improved iron status and reduced prevalence of iron deficiency at 4 months of age, and reduced prevalence of neonatal anaemia, without demonstrable adverse effects. As iron deficiency in infants even without anaemia has been associated with impaired development, delayed cord clamping seems to benefit full term infants even in regions with a relatively low prevalence of iron deficiency anaemia. Trial registration Clinical Trials NCT01245296.

Reduced expression of ferroportin-1 mediates hyporesponsiveness of suckling rats to stimuli that reduce iron absorption

BACKGROUND & AIMS

Suckling mammals absorb high levels of iron to support their rapid growth. In adults, iron absorption is controlled by systemic signals that alter expression of the iron-regulatory hormone hepcidin. We investigated whether hepcidin and absorption respond appropriately to systemic stimuli during suckling.

METHODS

In Sprague-Dawley rats, iron levels increased following administration of iron dextran, and inflammation was induced with lipopolysaccharide. Gene expression was measured by quantitative reverse-transcription polymerase chain reaction; protein levels were measured by immunoblot analyses. Iron absorption was determined based on retention of an oral dose of 59Fe.

RESULTS

Iron absorption was high during suckling and reduced to adult levels upon weaning. In response to iron dextran or lipopolysaccharide, iron absorption in adults decreased substantially, but, in suckling animals, the changes were minimal. Despite this, expression of hepcidin messenger RNA was strongly induced by each agent, before and after weaning. The hyporesponsiveness of iron absorption to increased levels of hepcidin during suckling correlated with reduced or absent duodenal expression of ferroportin 1 (Fpn1), normally a hepcidin target. Fpn1 expression was robust in adults. Predominance of the Fpn1A splice variant, which is under iron-dependent translational control, accounts for the low level of Fpn1 in the iron-deficient intestine of suckling rats.

CONCLUSIONS

Iron absorption during suckling is largely refractory to changes in expression of the systemic iron regulator hepcidin, and this in turn reflects limited expression of Fpn1 protein in the small intestine. Iron absorption is therefore not always controlled by hepcidin.

2008 Japanese Society for Dialysis Therapy: guidelines for renal anemia in chronic kidney disease

The Japanese Society for Dialysis Therapy (JSDT) guideline committee, chaired by Dr Y. Tsubakihara, presents the Japanese guidelines entitled "Guidelines for Renal Anemia in Chronic Kidney Disease." These guidelines replace the "2004 JSDT Guidelines for Renal Anemia in Chronic Hemodialysis Patients," and contain new, additional guidelines for peritoneal dialysis (PD), non-dialysis (ND), and pediatric chronic kidney disease (CKD) patients. Chapter 1 presents reference values for diagnosing anemia that are based on the most recent epidemiological data from the general Japanese population. In both men and women, hemoglobin (Hb) levels decrease along with an increase in age and the level for diagnosing anemia has been set at <13.5 g/dL in males and <11.5 g/dL in females. However, the guidelines explicitly state that the target Hb level in erythropoiesis stimulating agent (ESA) therapy is different to the anemia reference level. In addition, in defining renal anemia, the guidelines emphasize that the reduced production of erythropoietin (EPO) that is associated with renal disorders is the primary cause of renal anemia, and that renal anemia refers to a condition in which there is no increased production of EPO and serum EPO levels remain within the reference range for healthy individuals without anemia, irrespective of the glomerular filtration rate (GFR). In other words, renal anemia is clearly identified as an "endocrine disease." It is believed that defining renal anemia in this way will be extremely beneficial for ND patients exhibiting renal anemia despite having a high GFR. We have also emphasized that renal anemia may be treated not only with ESA therapy but also with appropriate iron supplementation and the improvement of anemia associated with chronic disease, which is associated with inflammation, and inadequate dialysis, another major cause of renal anemia. In Chapter 2, which discusses the target Hb levels in ESA therapy, the guidelines establish different target levels for hemodialysis (HD) patients than for PD and ND patients, for two reasons: (i) In Japanese HD patients, Hb levels following hemodialysis rise considerably above their previous levels because of ultrafiltration-induced hemoconcentration; and (ii) as noted in the 2004 guidelines, although 10 to 11 g/dL was optimal for long-term prognosis if the Hb level prior to the hemodialysis session in an HD patient had been established at the target level, it has been reported that, based on data accumulated on Japanese PD and ND patients, in patients without serious cardiovascular disease, higher levels have a cardiac or renal function protective effect, without any safety issues. Accordingly, the guidelines establish a target Hb level in PD and ND patients of 11 g/dL or more, and recommend 13 g/dL as the criterion for dose reduction/withdrawal. However, with the results of, for example, the CHOIR (Correction of Hemoglobin and Outcomes in Renal Insufficiency) study in mind, the guidelines establish an upper limit of 12 g/dL for patients with serious cardiovascular disease or patients for whom the attending physician determines high Hb levels would not be appropriate. Chapter 3 discusses the criteria for iron supplementation. The guidelines establish reference levels for iron supplementation in Japan that are lower than those established in the Western guidelines. This is because of concerns about long-term toxicity if the results of short-term studies conducted by Western manufacturers, in which an ESA cost-savings effect has been positioned as a primary endpoint, are too readily accepted. In other words, if the serum ferritin is <100 ng/mL and the transferrin saturation rate (TSAT) is <20%, then the criteria for iron supplementation will be met; if only one of these criteria is met, then iron supplementation should be considered unnecessary. Although there is a dearth of supporting evidence for these criteria, there are patients that have been surviving on hemodialysis in Japan for more than 40 years, and since there are approximately 20 000 patients who have been receiving hemodialysis for more than 20 years, which is a situation that is different from that in many other countries. As there are concerns about adverse reactions due to the overuse of iron preparations as well, we therefore adopted the expert opinion that evidence obtained from studies in which an ESA cost-savings effect had been positioned as the primary endpoint should not be accepted unquestioningly. In Chapter 4, which discusses ESA dosing regimens, and Chapter 5, which discusses poor response to ESAs, we gave priority to the usual doses that are listed in the package inserts of the ESAs that can be used in Japan. However, if the maximum dose of darbepoetin alfa that can currently be used in HD and PD patients were to be used, then the majority of poor responders would be rescued. Blood transfusions are discussed in Chapter 6. Blood transfusions are attributed to the difficulty of managing renal anemia not only in HD patients, but also in end-stage ND patients who respond poorly to ESAs. It is believed that the number of patients requiring transfusions could be reduced further if there were novel long-acting ESAs that could be used for ND patients. Chapter 7 discusses adverse reactions to ESA therapy. Of particular concern is the emergence and exacerbation of hypertension associated with rapid hematopoiesis due to ESA therapy. The treatment of renal anemia in pediatric CKD patients is discussed in Chapter 8; it is fundamentally the same as that in adults.

The nutritional requirements of infants. Towards EU alignment of reference values: the EURRECA network

This paper presents a review of the current knowledge regarding the macro- and micronutrient requirements of infants and discusses issues related to these requirements during the first year of life. The paper also reviews the current reference values used in European countries and the methodological approaches used to derive them by a sample of seven European and international authoritative committees from which background scientific reports are available. Throughout the paper, the main issues contributing to disparities in micronutrient reference values for infants are highlighted. The identification of these issues in relation to the specific physiological aspects of infants is important for informing future initiatives aimed at providing standardized approaches to overcome variability of micronutrient reference values across Europe for this age group.

Iron intake and iron status in breastfed infants during the first year of life

BACKGROUND & AIMS

Breastfed infants may be at particular risk for iron deficiency because breast milk is low in iron. In a secondary analysis of data from a complementary feeding trial, indicators of iron status were examined, with particular focus on the development of iron status in those infants who were fully breastfed during the first 4 months of life.

METHODS

In this retrospective analysis of data from a randomized controlled trial infants were stratified according to their predominant milk diet during the first 4 months of life, a subgroup of breastfed infants (group BM, n=53) were compared with a subgroup of infants fed (iron-fortified) formula (group F, n=23). Dietary iron intake and indicators of iron status were analysed at 4 months of age (during the full milk feeding period), and during the complementary feeding period at 7 and 10 months of age.

RESULTS

Iron intake was low in the BM group, ranging below the Dietary Reference Intakes throughout the complementary feeding period, with the (estimated) bioavailable iron intake only just achieving the reference requirements. At 4 months, iron deficiency (ID, Ferritin <12.0 ng/mL) was observed in 3 infants in the BM group and in 1 infant in the F group; no infant developed iron deficiency anaemia (IDA, ID and Hb <10.5 g/dl). At 7 and at 10 months of age, iron status was adequate in all infants of the F group. In the BM group, at 7 (10) months of age, ID was diagnosed in 10 (11) infants and IDA was found in 2 (1) infants.

CONCLUSIONS

Healthy infants, fully breastfed at 4 months of age, demonstrated ID in about 21% and IDA in up to 6% during the second half of infancy while fed according to the paediatric dietary guidelines. This finding supports the recommendation that supplementation with bioavailable iron via complementary foods should be started early (4-6 months of age) in order to prevent iron deficiency during infancy.

Care during the third stage of labour: obstetricians views and practice in an Albanian maternity hospital

BACKGROUND

Relatively little is known about current practice during the third stage of labour in low and middle income countries. We conducted a survey of attitudes and an audit of practice in a large maternity hospital in Albania.

METHODS

Survey of 35 obstetricians and audit of practice during the third stage was conducted in July 2008 at a tertiary referral hospital in Tirana. The survey questionnaire was self completed. Responses were anonymous. For the audit, information collected included time of administration of the uterotonic drug, gestation at birth, position of the baby before cord clamping, cord traction, and need for resuscitation.

RESULTS

77% (27/35) of obstetricians completed the questionnaire, of whom 78% (21/27) reported always or usually using active management, and 22% (6/27) always or usually using physiological care. When using active management: 56% (15/27) gave the uterotonic after cord clamping; intravenous oxytocin was almost always the drug used; and 71% (19/27) clamped the cord within one minute. For physiological care: 42% (8/19) clamped the cord within 20 seconds, and 96% (18/19) within one minute. 93% would randomise women to a trial of early versus late cord clamping.Practice was observed for 156 consecutive births, of which 26% (42/156) were by caesarean section. A prophylactic uterotonic was used for 87% (137/156): this was given after cord clamping for 55% (75/137), although timing of administration was not recorded for 21% (29/137). For 85% of births (132/156) cord clamping was within 20 seconds, and for all babies it was within 50 seconds. Controlled cord traction was used for 49% (76/156) of births.

CONCLUSIONS

Most obstetricians reported always or usually using active management for the third stage of labour. For timing and choice of the uterotonic drug, reported practice was similar to actual practice. Although some obstetricians reported they waited longer than one minute before clamping the cord, this was not observed in practice. Controlled cord traction was used for half the births.

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 infant's 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.

Treatment response to iron and folic acid alone is the same as with multivitamins and/or anthelminthics in severely anemic 6- to 24-month-old children

We assessed the effectiveness of iron+folic acid for the treatment of severe anemia [hemoglobin (Hb) <70 g/L] and the efficacy of added multivitamins and/or anthelminthics among children aged 6-24 mo in periurban Karachi, Pakistan. The study design was a double blind, placebo-controlled, randomized trial of currently recommended daily iron (25 mg) and folic acid (100 microg) for 90 d with daily multivitamins [vitamin A (300 microg, as retinol palmitate), vitamin E (6 mg tocopherol equivalents), vitamin B-12 (0.9 microg), vitamin C (15 mg), riboflavin (0.5 mg)] and/or anthelminthics (100 mg mebendazole twice daily for 3 d) compared with placebos. Treatment response was defined as reaching a Hb concentration > or =100 g/L at the end of 90 d. The prevalence of severe anemia in the 9518 children screened was 5.7% and a total of 462 severely anemic children were enrolled in the study. Adherence to treatment was approximately 70% for iron+folic acid, approximately 80% for multivitamins, and almost 100% for mebendazole. Children receiving iron+folic acid alone had a response rate of 38.7% at 90 d. The additional treatment with mebendazole or multivitamins did not significantly improve cure rates or change the Hb concentration over and above iron+folic acid treatment alone. Adherence to iron+folic acid of higher than the median resulted in a better treatment response rate of 50%. High-dose daily iron+folic acid performed as well as iron+folic acid with anthelminthics and multivitamins in the treatment of severe anemia in this setting. Higher adherence may be important in enhancing treatment impact.

Iron therapy for preterm infants

Preterm infants are at risk for both iron deficiency and iron overload. The role of iron in multiple organ functions suggests that iron supplementation is essential for the preterm infant. Conversely, the potential for iron overload and the poorly developed antioxidant measures in the preterm infant argue against indiscriminate iron supplementation in this population. This article reviews the predisposing factors and consequences of iron deficiency and iron overload in the preterm infant, discusses the current recommendation for iron supplementation and its appropriateness, and describes potential management strategies that strike a balance between iron deficiency and iron toxicity.

Iron supplementation does not affect copper and zinc absorption in breastfed infants

BACKGROUND

Iron supplements are commonly recommended for infants but were suggested to inhibit zinc and copper absorption.

OBJECTIVE

The objective of this study was to investigate potential effects of iron supplementation, infant age, and mineral status on zinc and copper absorption in infants at 6 and 9 mo of age.

DESIGN

Twenty-five healthy breastfed term infants were recruited from a larger randomized iron supplementation trial. Six of these infants received iron supplements (1 mg . kg(-1) . d(-1)) from 4 to 9 mo, 8 were supplemented from 6 to 9 mo, and 11 received placebo only. Zinc and copper absorption was measured at 6 and 9 mo of age, using orally administered (70)Zn and (65)Cu and fecal monitoring of recovered stable isotopes.

RESULTS

Mean (+/-SD) zinc absorption was 51.9 +/- 17.9%, and mean copper absorption was 79.0 +/- 13.5%. No significant difference was observed in zinc or copper absorption between 6 and 9 mo of age. When combining all measurements, no significant effect of prior iron supplementation was observed on zinc or copper absorption. No significant correlation was observed between plasma zinc and zinc absorption or between plasma copper and copper absorption. No significant correlation was observed between erythrocyte copper-zinc-dependent superoxide dismutase activity and copper absorption.

CONCLUSIONS

The study does not support the contention that iron supplements inhibit the absorption of zinc or copper in healthy breastfed infants at 6-9 mo of age. In addition, we did not find any age-related changes in zinc or copper absorption between 6 and 9 mo of age.