Factors affecting iron stores in infants 4-18 months of age

The Influence of Intensive Nutritional Education on the Iron Status in Infants

Iron is an essential nutrient for a child’s proper development at every growth stage. It is crucial for the production of red blood and muscle cells, DNA replication, and the development of the brain, nervous and immune systems. Iron deficiency is the most common micronutrient deficiency in children worldwide. Despite widespread access to nutritional information for children, parents continue to make many feeding mistakes. This study aimed to assess whether any nutritional intervention would affect the iron status in children. The parents of 203 children were randomly assigned to one of two groups: the study group received intensive mobile nutritional education for a year, while the control group received no intervention. Blood tests were performed on both groups at the beginning of the study and one year later. The educational intervention resulted in statistically significantly higher levels of RBC (red blood cells; p = 0.020), HGB (haemoglobin; p = 0.039), HCT (haematocrit; p = 0.036), MCV (mean cell volume; p = 0.018) parameters and iron dietary intake (p ≤ 0.001). Even a non-targeted dietary intervention improves the iron status in children. As iron management is insufficient in most children, an iron-targeted nutritional intervention appears necessary.

Individual, household and national factors associated with iron, vitamin A and zinc deficiencies among children aged 6-59 months in Nepal

Iron, vitamin A and zinc deficiencies are the top three micronutrients contributing to disability-adjusted life years globally. The study assessed the factors associated with iron, vitamin A, and Zinc deficiencies among Nepalese children (n = 1709) aged 6-59 months using data from the 2016 Nepal National Micronutrient Status Survey. The following cut-off points were applied: iron deficiency [ferritin < 12 μg/L or soluble transferrin receptor (sTfR) > 8.3 mg/L], vitamin A deficiency (retinol-binding protein < 0.69 μmol/L) and zinc deficiency (serum zinc < 65 μg/dl for morning sample and <57 μg/dl for afternoon sample). We used multiple logistic regression adjusted for sampling weights and clustering to examine the predictors of micronutrient deficiencies. The prevalence of iron depletion (ferritin), tissue iron (sTfR), vitamin A and zinc deficiencies were 36.7%, 27.6%, 8.5% and 20.4%, respectively. Children were more likely to be iron deficient (ferritin) if aged 6-23 months, stunted, and in a middle-wealth quintile household. Vitamin A deficiency was associated with development region and was higher among children living in severe food-insecure households and those who did not consume fruits. Zinc deficiency was higher among children in rural areas and the poorest wealth quintile. The Government of Nepal should focus on addressing micronutrient deficiencies in the early years, with emphasis on improving food systems, promote healthy diets, among younger and stunted children and provide social cash transfer targeting high-risk development regions, poorest and food insecure households.

Role of Breastfeeding and Complementary Food on Hemoglobin and Ferritin Levels in a Cambodian Cross-Sectional Sample of Children Aged 3 to 24 Months

BACKGROUND

Iron deficiency derives from a low intake of dietary iron, poor absorption of iron, and high requirements due to growth as well as blood loss. An estimated number of about 50% of all anemia may be attributed to iron deficiency among young children in Cambodia.

METHODS

A cross-sectional survey was conducted in rural Cambodia in September 2012. Villages in pre-selected communes were randomly chosen using stunting as a primary indicator of nutritional status. In total, 928 randomly selected households with children aged 3-23 months were included. Hemoglobin, ferritin, soluble transferrin receptor (sTfR), and retinol binding protein (RBP) were assessed from capillary blood samples. In addition, length/height and weight of mothers and children were taken and data on dietary diversity was collected. A child feeding index (CFI) was created. Associations between biomarkers of iron and vitamin A status and nutritional status or food intake were explored.

RESULTS

Anemia prevalence was highest among 6- to 12-months-olds (71%). Ferritin and sTfR inversely correlated and were significantly associated with hemoglobin concentrations. The consumption of animal source foods (ASF) significantly impacts on the interaction between ferritin, sTfR and hemoglobin. Concentrations of RBP were significantly higher in children who had received a vitamin A supplement. The CFI was associated with sTfR and hemoglobin. Lower length and weight were associated with lower ferritin levels and showed an indirect effect on hemoglobin through ferritin.

CONCLUSION

Nutrition programs targeting children under 2 years of age need to focus on the preparation of complementary foods with high nutrient density to sustainably prevent micronutrient deficiency and generally improve nutritional status. Future assessments of the micronutrient status should include identification of hemoglobinopathies and parasitic infections to better understand all causes of anemia in Cambodian infants and young children.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00004379.

Prevalence of anaemia and its associated factors in African children at one and three years residing in the Capricorn District of Limpopo Province, South Africa

Objective: The present study evaluated the prevalence of anaemia and its determinants in one- and three-year-old children from the Capricorn District of Limpopo Province, South Africa. Methods: A prospective cohort study conducted in rural villages in the Capricorn District of Limpopo Province, South Africa. At birth, a cohort of 219 children was followed until they were one and three years of age. Data collected included the children’s anthropometric measurements, blood for biochemical analysis (full blood count, ferritin, folate and vitamin B12) and socio-demographic status.Results: At one year, anaemia (Hb < 11 g/dL) was present in 52% of the children, decreasing to 22% by the third year. Iron deficiency (ferritin < 12 µg/mL) was common in these children (39% and 33% at one year and three years, respectively) particularly in the presence of anaemia. Folate and vitamin B12 deficiencies (< 5 ng/mL and < 145 pg/mL, respectively) were common at one year, with the children accumulating enough vitamin B12 by three years; however, folate deficiency levels remained fairly constant between the two time points.Conclusion: There was a high prevalence of anaemia in the study participants at one year and three years of age. Factors that increased the risk of anaemia at three years were: a mother with only a primary school education, anaemia at one year, male gender, overweight, and combined overweight and stunting. Protective factors against anaemia were having a younger mother who served as the main caregiver.

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.

Timing of the introduction of complementary foods in infancy: a randomized controlled trial

OBJECTIVE

To increase knowledge on iron status and growth during the first 6 months of life. We hypothesized that iron status would be better in infants who received complementary foods in addition to breast milk compared with those exclusively breastfed.

METHODS

One hundred nineteen healthy term (≥37 weeks) singleton infants were randomly assigned to receive either complementary foods in addition to breast milk from age 4 months (CF) or to exclusive breastfeeding for 6 months (EBF). Dietary data were collected by 3-day weighed food records, and data on iron status and growth were also collected.

RESULTS

One hundred infants (84%) completed the trial. Infants in the CF group had higher mean serum ferritin levels at 6 months (P = .02), which remained significant when adjusted for baseline characteristics. No difference was seen between groups in iron deficiency anemia, iron deficiency, or iron depletion. The average daily energy intake from complementary foods of 5-month-olds in the CF group was 36.8 kJ per kg body weight. Infants in both groups grew at the same rate between 4 and 6 months of age.

CONCLUSIONS

In a high-income country, adding a small amount of complementary food in addition to breast milk to infants' diets from 4 months of age does not affect growth rate between 4 and 6 months, but has a small and positive effect on iron status at 6 months. The biological importance of this finding remains to be determined.

Consumption of cow's milk as a cause of iron deficiency in infants and toddlers

Consumption of cow's milk (CM) by infants and toddlers has adverse effects on their iron stores, a finding that has been well documented in many localities. Several mechanisms have been identified that may contribute to iron deficiency in this young population group. The most important of these is probably the low iron content of CM, which makes it difficult for infants to obtain the amounts of iron needed for growth. A second mechanism is the occult intestinal blood loss associated with CM consumption during infancy, a condition that affects about 40% of otherwise healthy infants. Loss of iron in the form of blood diminishes with age and ceases after the age of 1 year. A third mechanism is the inhibition of non-heme iron absorption by calcium and casein, both of which are present in high amounts in CM. Fortification of CM with iron, as practiced in some countries, can protect infants and toddlers against CM's negative effects on iron status. Consumption of CM produces a high renal solute load, which leads to a higher urine solute concentration than consumption of breast milk or formula, thereby narrowing the margin of safety during dehydrating events, such as diarrhea. The high protein intake from CM may also place infants at increased risk of obesity in later childhood. It is thus recommended that unmodified, unfortified CM not be fed to infants and that it be fed to toddlers in modest amounts only.

Alimentação complementar e estado nutricional de crianças menores de dois anos atendidas no Programa Saúde da Família em Acrelândia, Acre, Amazônia Ocidental Brasileira

Com objetivo de investigar o estado nutricional e alimentação complementar em crianças de 6 a 24 meses, residentes na Amazônia Ocidental Brasileira, um estudo transversal foi realizado na área urbana do Município de Acrelândia, Estado do Acre, com 164 crianças. As prevalências de déficit de estatura/idade e anemia foram de 12% e 40%, respectivamente, e de deficiência de ferro isolada, de 85%. Os níveis séricos das vitaminas A e B12 estavam baixos em 15% e 12% das crianças, respectivamente. Houve baixo consumo alimentar dos seguintes nutrientes (% de crianças abaixo das recomendações): ácido fólico (33%), vitamina C (40%), vitamina A (42%), zinco (46%) e ferro (71%). A biodisponibilidade de ferro da dieta foi de 8%. Observou-se baixo consumo de frutas, hortaliças e carnes, com consumo excessivo de leite de vaca e mingau.

Anemia e deficiência de ferro em pré-escolares da Amazônia Ocidental brasileira: prevalência e fatores associados

Estudo transversal de base populacional que investigou prevalênciasde anemia e fatores associados à anemia, anemia ferropriva e deficiência de ferro entre crianças de 6 a 60 meses da área urbana de dois municípios do Acre, Brasil (N = 624). Dosagens de hemoglobina sanguínea, ferritina e receptor solúvel de transferrina plasmáticas foram realizadas mediante sangue venoso. Condições sócio-econômicas, demográficas e de morbidade foram obtidas por questionário. Razões de prevalências foram calculadas por regressão de Poisson em modelo hierárquico. As prevalências de anemia, anemia ferropriva e deficiência de ferro foram de 30,6%, 20,9% e 43,5%, respectivamente. Menores de 24 meses apresentaram maior risco para anemia, anemia ferropriva e deficiência de ferro. Pertencer ao maior tercil do índice de riqueza conferiu proteção contra anemia ferropriva (RP = 0,62; IC95%: 0,40-0,98). Pertencer ao maior quartil do índice estatura/idade foi protetor contra anemia (0,62; 0,44-0,86) e anemia ferropriva (0,51; 0,33-0,79), e ocorrência recente de diarréia representou risco (anemia: 1,47; 1,12-1,92 e anemia ferropriva: 1,44; 1,03-2,01). A infestação por geohelmintos conferiu risco para anemia, anemia ferropriva e deficiência de ferro.

Linear and ponderal growth trajectories in well-nourished, iron-sufficient infants are unimpaired by iron supplementation

Iron deficiency remains the most common nutritional deficiency worldwide and supplementation is recommended during periods of high risk, including infancy. However, questions have been raised about possible adverse effects of iron on growth in iron-sufficient (IS) infants and the advisability of across-the-board iron supplementation. This study examined whether short- or long-term growth was impaired in IS infants who received iron supplementation. From a longitudinal study of healthy, breast-fed, low- to middle-income Chilean infants randomly assigned to iron supplementation or usual nutrition at 6 or 12 mo, we retrospectively identified infants meeting criteria for iron sufficiency at the time of random assignment (n = 273). Using multilevel analysis, ponderal and linear growth were modeled before, during, and after iron supplementation up to 10 y in 3 comparisons: 1) iron supplementation compared with usual nutrition from 6 to 12 mo; 2) iron supplementation compared with usual nutrition from 12 to 18 mo; and 3) 15 mg/d of iron as drops compared with iron-fortified formula (12 mg/L). Growth trajectories did not differ during or after supplementation indicating no adverse effect of iron in any comparison. These results suggest that, at least in some environments, iron does not impair growth in IS infants.

Prevalence and predictors of iron deficiency in fully breastfed infants at 6 mo of age: comparison of data from 6 studies

BACKGROUND

Iron deficiency (ID) can occur among exclusively breastfed infants before 6 mo of age.

OBJECTIVE

The objective was to determine which subgroups of fully breastfed infants are at highest risk of ID.

DESIGN

We assessed the prevalence of ID (ferritin < 12 mug/L) and iron deficiency anemia (IDA; ferritin < 12 mug/L and hemoglobin < 105 g/L) and risk factors associated with ID and IDA at 6 mo among 404 fully breastfed infants with a birth weight >2500 g from 6 studies in Ghana, Honduras, Mexico, and Sweden. Infants with an elevated C-reactive protein concentration (8%) were excluded.

RESULTS

The percentages of infants with ID were 6% in Sweden, 17% in Mexico, 13-25% in Honduras, and 12-37% in Ghana. The percentages with IDA were 2% in Sweden, 4% in Mexico, 5-11% in Honduras, and 8-16% in Ghana. With data pooled, the key predictors of ID (20%) were male sex [adjusted odds ratio (AOR): 4.6; 95% CI: 2.5, 8.5] and birth weight 2500-2999 g (AOR: 2.4; 95% CI: 1.4, 4.3). The predictors of IDA (8%) were male sex (AOR: 7.6; 95% CI: 2.5, 23.0), birth weight of 2500-2999 g (AOR: 3.4; 1.5, 7.5), and weight gain above the median since birth (AOR: 3.4; 95% CI: 1.3, 8.6). The combination of birth weight 2500-2999 g or male sex had a sensitivity of 91% for identifying ID and of 97% for identifying IDA.

CONCLUSIONS

Among fully breastfed infants with a birth weight >2500 g, IDA is uncommon before 6 mo, but male infants and those with a birth weight of 2500-2999 g are at higher risk of ID and IDA.

Dietary practices and nutritional status of 0–24-month-old children from Brazilian Amazonia

Objective

To assess the nutritional status and dietary practices of 0–24-month-old children living in Brazilian Amazonia.

Design

Cross-sectional study. Information on children’s dietary intakes was obtained from diet history data. Weight and length were measured for anthropometric evaluation. Fe status was assessed using fasting venous blood samples; Hb, serum ferritin and soluble transferrin receptor concentrations were measured.

Setting

The towns of Assis Brasil and Acrelândia in the state of Acre, north-west Brazil.

Subjects

A total of sixty-nine randomly selected 0–24-month-old children.

Results

Of these children, 40·3 % were anaemic, 63·1 % were Fe-deficient, 28·1 % had Fe-deficiency anaemia and 11·6 % were stunted. Breast-feeding was initiated by 97·1 % of mothers, followed by early feeding with complementary foods. The dietary pattern reflected a high intake of carbohydrate-rich foods and cow’s milk, with irregular intakes of fruit, vegetables and meat. All infants and 92·3 % of toddlers were at risk of inadequate Fe intakes. Fe from animal foods contributed on average 0·5 % and 14·3 % to total dietary Fe intake among infants and toddlers, respectively.

Conclusions

Poor nutritional status and inadequate feeding practices in this study population reinforce the importance of exclusive breast-feeding during the first 6 months of life. Greater emphasis is required to improve the bioavailability of dietary Fe during complementary feeding practices.

Setting the stage for child health and development: prevention of iron deficiency in early infancy

Iron deficiency is estimated to be the most common nutritional deficiency worldwide and is particularly persistent among infants and children. The high prevalence of anemia in 6- to 9-mo-old children raises the concern that birth iron stores in some infants are inadequate to sustain growth and development through the first 6 mo of life, and postnatal factors are contributing to early depletion of iron stores and development of anemia. At the same time, there are concerns about negative effects of excess iron in infants. Maternal iron status, infant birth weight and gestational age, as well as the timing of umbilical cord clamping at birth all contribute to the establishment of adequate total body iron at birth. Postnatally, feeding practices and growth rate are factors that will affect how quickly birth iron is depleted during the first 6 mo of life. Under conditions in which maternal iron status, birth weight, gestational age, and umbilical cord clamping time are optimal, and exclusive breast-feeding is practiced, infants should have adequate iron stores for the first 6-8 mo of life. Under suboptimal conditions, infants may not reach this goal and may need to be targeted for iron supplementation before 6 mo of age.

Extrinsic iron staining in infant teeth from iron-fortified formula and rice cereal

Extrinsic staining of teeth due to excessive iron intake has been reported previously in the literature. We describe a 7-month-old infant who presented with extrinsic teeth staining due to inadvertent over consumption of dietary iron. The infant was fed iron-fortified formula and rice cereal. Rice cereal, fortified with iron, was being used as part of a normal infant diet and as a thickening agent when added to the formula for treatment of gastroesophageal reflux. After several months of administration, "blackening" of the infant's teeth was noted by the mother. The stain was removed by the pediatric dentist who simply scraped the affected teeth. No further staining occurred after the amount of dietary iron was reduced.

Infant feeding in the second 6 months of life related to iron status: an observational study

OBJECTIVE

To investigate the relationship between iron status in infancy and type of milk and weaning solids consumed.

DESIGN

An observational cohort study.

SETTING

928 term infants from the Avon Longitudinal Study of Parents and Children in 1993-94.

METHODS

Haemoglobin and ferritin concentrations at 8 and 12 months were assessed in relation to type and quantity of milk intake at 8 months.

RESULTS

By WHO criteria, 22.7% of the infants were anaemic at 8 months and 18.1% at 12 months. More breast--than formula-fed infants were anaemic at 8 and 12 months. Cows' milk as the main drink was associated with increased anaemia at 12 months and low ferritin at 8 and 12 months. No association was found between any nutrients and haemoglobin concentrations. Protein and non-haem iron intakes were positively associated with ferritin concentrations and calcium intake negatively. This effect was more marked in infants being fed cows' milk. More than 25% of infants in the breast milk and cows' milk groups and 41% of infants having >6 breast feeds per day had iron intakes below the lower reference nutrient intake. Feeding cows' milk or formula above 600 ml or >6 breast feeds per day was associated with lower intakes of solids.

CONCLUSIONS

Both breast and cows' milk feeding were associated with higher levels of anaemia. Satisfactory iron intake from solids in later infancy is more likely if formula intake is <600 ml per day and breast feeds are limited to <6 feeds per day. Cows' milk should be strongly discouraged as a main drink before 12 months.

Fetal alcohol exposure, iron-deficiency anemia, and infant growth

OBJECTIVES

Our goals were to determine whether prenatal alcohol exposure is associated with an increased incidence of iron-deficiency anemia in infancy and to compare effects of fetal alcohol exposure and iron-deficiency anemia on infant growth. We also tested whether effects of fetal alcohol exposure on growth are mediated or moderated by iron-deficiency anemia.

METHODS

A total of 96 infants born to mothers from the Coloured (mixed ancestry) community in Cape Town, South Africa, were recruited prenatally; 42 mothers drank heavily during pregnancy, and 54 abstained or drank small amounts of alcohol. Growth was assessed at birth and 6.5 and 12 months, and iron-deficiency anemia was assessed at 6.5 or 12 months.

RESULTS

Infants whose mothers binge drank during pregnancy (> or = 4 drinks per occasion) were 3.6 times more likely to be diagnosed with iron-deficiency anemia at 12 months than were infants whose mothers did not binge drink. Prenatal alcohol exposure was associated with reduced weight at birth, 6.5 months, and 12 months and with shorter length at 6.5 and 12 months. Iron-deficiency anemia was related to reduced 12-month weight and head circumference and to slower growth velocity between 6 and 12 months. The effects of prenatal alcohol on weight were not mediated by iron-deficiency anemia; however, they were seen primarily in infants with iron-deficiency anemia.

CONCLUSIONS

The association of maternal binge drinking with an increased incidence of iron-deficiency anemia may reflect disruption of accumulation of fetal iron stores or postnatal deficiencies in iron uptake, absorption, or intake. Moreover, iron deficiency seems to exacerbate the prenatal alcohol effects on growth.

Session 4: Mineral metabolism and body composition Iron status of breast-fed infants

Fe deficiency is a common nutritional disorder during infancy, particularly in low-income countries. The Fe status of a breast-fed infant is strongly influenced by the body Fe content at birth, which is determined by factors that operate before birth (maternal Fe status before and during pregnancy; infant gestational age and birth weight) and at the time of delivery (the timing of umbilical cord clamping). Delaying the clamping of the umbilical cord for 2 min can increase body Fe content by approximately 33% (75 mg), and results in greater Fe stores at 6 months of age. After birth, male gender and a rapid rate of weight gain are associated with lower Fe status. During the first half of infancy dietary Fe requirements depend on Fe stores at birth. For an exclusively-breast-fed full-term normal-birth-weight infant with delayed umbilical cord clamping, whose mother had adequate Fe status during pregnancy, the Fe provided from stores and breast milk is sufficient for ≥6 months, but before this time higher-risk infants may become Fe deficient. Fe supplementation can be beneficial for high-risk infants, but can have adverse effects on growth and morbidity of Fe-replete infants. After 6 months most breast-fed infants will require complementary foods that are rich in Fe.

Iron intake and iron status of preschool children: associations with breakfast cereals, vitamin C and meat

Objective:

To examine associations between breakfast cereal consumption and iron status and identify dietary patterns that might improve iron status in this vulnerable group.

Design:

Analysis of data from the UK National Diet and Nutrition Survey (NDNS) of children aged 1.5–4.5 years, including dietary intakes calculated from 4-day weighed records.

Subjects:

Data were used from 904 children with haematological measurements, excluding those taking iron supplements; 20% had low iron stores (ferritin < 10 μg l−1) while 8% were anaemic (Hb < 11 g dl−1).

Results:

High cereal consumers had significantly higher iron intakes than low cereal consumers (classified by tertiles) but the 10% difference in mean ferritin levels was not significant (P = 0.067). Lower intakes of vitamin C and meat among high consumers of cereal may have diluted the impact of cereal iron on iron status. When children were reclassified according to their intakes of vitamin C and iron from meat and breakfast cereals, the group with high (above median) intakes of two or more factors had a higher mean haemoglobin (Hb) level and a lower prevalence of anaemia compared with the group with low (below median) intakes of all three dietary constituents.

Conclusions:

Nutritional advice that aims to improve iron status should emphasize not only rich sources of iron but also factors that may enhance or inhibit absorption. Strategies to optimize iron status in this vulnerable age group include consuming an iron-fortified breakfast cereal, vitamin C-rich fruit or drink at breakfast, and avoiding tea with (or after) meals.

Epidemiology of anemia among 4- to 17-month-old children living in south central Nepal

OBJECTIVE

To describe the distribution of hemoglobin and prevalence of anemia in Nepali children living in the Terai region by potential risk factors for deficiency.

DESIGN

This was a cross-sectional, community-based study of baseline characteristics of children enrolled in a randomized, placebo-controlled clinical trial between January and March 2002. Participants were weighed and measured and had their blood drawn. Their mothers contributed demographic, morbidity, and feeding data.

SUBJECTS

There were 569 4- to 17-month-old children. Statistical models were based on 490 children.

RESULTS

Anemia was prevalent: 58% of the children had a hemoglobin <105 g/l. Iron-deficiency anemia (anemia with erythrocyte protoporphyrin (EP) > or =90 micromol/mol heme) was present in 43% of the children. Severe anemia was rare: less than 2% of the children had a hemoglobin <70 g/l. The mean (s.d.) hemoglobin concentration was 101 (12.5) g/l. Stunting and wasting were prevalent: 30.8% were stunted (length-for-age Z-score <-2) and 18.1% were wasted (weight-for-length Z-score <-2). Bivariate analyses revealed that age, caste, socioeconomic status, dietary diversity, stunting, and underweight were associated with hemoglobin concentration and/or anemia. In multivariate models with and without EP, age and caste were found to be strong predictors of both hemoglobin concentration and anemia.

CONCLUSIONS

Anemia and iron deficiency increased strongly with age and low-caste status among the study children. The data reveal the importance of targeting interventions to children in the first year of life before they become anemic and iron deficient.

Iron status in 6-y-old children: associations with growth and earlier iron status

OBJECTIVE

To investigate the iron status of 6-y-old children and its association with growth and earlier iron status.

DESIGN

In a cross-sectional study, children's body size measurements were recorded and blood samples taken near their sixth birthday.

SUBJECTS

A sample of 188 children, randomly selected in two previous studies, was contacted, and 139(74%) agreed to participate.

RESULTS

No children had iron deficiency anaemia, one was iron-deficient (serum ferritin (SF) <15 microg/l and mean corpuscular volume (MCV) <76 fl but 16% had depleted iron stores (SF<15 microg/l). Iron status indices were generally higher than at 1 and 2 y, but correlation was seen between iron status indices at 6 y and earlier values. Haemoglobin concentration at 6 y was negatively associated with length gain from birth to 1 y (B+/-s.e.=-1.269+/-0.452; P=0.007; adj. R2=0.119) (n=52), and proportional weight gain from birth to 1 y was higher among children with SF<15 microg/l at 6 y (295+/-33%; n=10) than those with SF> or =15 microg/l (258+/-31%; n=49) (P=0.001). MCV at 2 y predicted weight gain from 2 to 6 y (B+/-s.e.=1.721+/-0.581; P=0.005; adj. R2=0.153) (n=44); also, children with SF<15 microg/l at 6 y (n=9) gained 7.8+/-1.2 kg from 2 to 6 y, while children with SF> or =15 microg/l (n=35) gained 9.6+/-2.8 kg (P=0.007), furthermore a difference was seen in proportional weight gain from 2 to 6 y between children with depleted iron stores at 2 y and not, or 156+/-13 vs 169+/-18% (P=0.038).

CONCLUSION

The results suggest that low iron status at 1 and 2 y might lead to slower growth up to 6 y of age. Low iron status at 1 and 2 y and/or slower growth from 1 and 2 y up to 6 y might contribute to worse iron status at 6 y, while faster growth in early childhood is related to lower iron status.

Iron bioavailability from powdered and in-bottle-sterilized infant formulas in suckling and weanling rats

OBJECTIVE

The Maillard reaction and lactose isomerization may be induced during the manufacture of infant formulas. We studied the effects of dehydration and sterilization on iron bioavailability from an infant formula in suckling and weanling rats.

METHODS

In experiment 1, a previously reconstituted powdered infant formula and an in-bottle-sterilized liquid infant formula from the same manufacturer were fed from drinking bottles to 2-wk-old suckling rat pups for 7 d. In experiment 2, the same formulas were complemented with AIN-76 and fed to weanling rats for 7 d after a 4-d adaptation period. In both experiments, intake, body weight, and fecal and urinary excretions were monitored, and the following iron indexes were calculated: apparent absorption and retention and the coefficients percentage of absorption versus intake, percentage of retention versus absorption, and percentage of retention versus intake.

RESULTS

The liquid infant formula resulted in lower body weights on day 4, particularly among the younger rats that had significantly lower food intakes (P = 0.045). In weanling rats fed powdered and liquid infant formulas, food intake and body weight were not significantly different. The pups showed significantly higher absorption (percentage of absorption versus intake) and retention (percentages of retention versus absorption and retention versus intake) efficiencies than did the weanling rats (P < 0.001 for the three indexes). Hemoglobin values (P = 0.001) and liver iron concentrations (P = 0.009) were significantly higher in the weanling rats than in the pups. In contrast, erythrocyte iron concentrations and hematocrit were higher in the pups (P = 0.016 and 0.053, respectively).

CONCLUSIONS

In rat pups, iron bioavailability is negatively affected by the consumption of in-bottle-sterilized infant formula, possibly as the result of the content of Maillard reaction products, altered proteins, and lactulose. However, when this formula is included in a mixed diet and given to weanling rats, this detrimental effect no longer occurs.

Iron status in 2-year-old Icelandic children and associations with dietary intake and growth

OBJECTIVE

To investigate the effects of food and nutrient intake at 2 y and growth from birth on iron status at 2 y in a population with high birth weight.

DESIGN

In a cross-sectional study, children's food consumption and body size measurements were recorded and blood samples taken. Weighed 3-day food records were used to analyse food and nutrient intake.

SETTING

Children were recruited from across Iceland from the Icelandic National Registry by the University of Iceland, Computing Services. The children in the sample were born over a 1-y period.

SUBJECTS

Parents of randomly selected 2-year-old children (n=130) were contacted, and 72% (n=94) participated. Blood samples were analysed in 76% (n=71) of participating children.

RESULTS

In total, 9% of the children were iron-deficient (serum ferritin (SF)<12 microg/l and mean corpuscular volume (MCV) <74 fl) and 1.4% were also anaemic (Hb<105 g/l), while 27% of children were iron-depleted (SF<12 microg/l). Iron status indices were negatively associated with cow's milk consumption. Half of children consuming>500 g cow's milk/day (n=10) were iron-deficient, while one child in 58 consuming<500 g cow's milk/day had iron deficiency (P<0.001). In multiple regression analyses, also biscuits and crackers consumption was positively associated with MCV. Weight gain from birth to 2 y was negatively associated with SF (adjusted R(2)=0.15; P=0.002; n=58). Iron-depleted children were heavier than children not iron-depleted (14.7+/-1.3 vs 13.8+/-1.7 kg; P=0.043), had higher BMI (17.7+/-1.5 vs 16.7+/-1.4 kg/m(2); P=0.028) and gained more weight from birth (11.2+/-1.3 vs. 10.0+/-1.6 kg; P=0.011).

CONCLUSIONS

The results suggest that cow's milk consumption above 500 g/day should be avoided at the age of 2 y for better iron status. Iron depletion at 2 y is associated with faster growth from birth.

Dietary iron intake is positively associated with hemoglobin concentration during infancy but not during the second year of life

Iron status during infancy and early childhood reflects highly dynamic processes, which are affected by both internal and external factors. The regulation of iron metabolism seems to be subjected to developmental changes during infancy, although the exact nature of these changes and their implications are not fully understood. We wanted to explore the association between dietary iron intake and indicators of iron status, and to assess temporal changes in these variables. This was done by secondary analysis of data from a recently conducted dietary intervention trial in which healthy, term, well-nourished infants were randomly assigned to consume iron-fortified infant cereals with regular or low phytate content, or iron-fortified infant formula. Dietary iron intake from 6 to 8 mo and from 9 to 11 mo was associated with hemoglobin (Hb) concentration at 9 mo (r = 0.27, P < 0.001) and 12 mo (r = 0.21, P = 0.001), respectively, but iron intake from 12 to 18 mo was not associated with Hb at 18 mo. In contrast, iron intake from 6 to 11 mo was not associated with serum ferritin (S-Ft) at 9 or 12 mo, whereas iron intake from 12 to 17 mo was positively associated with S-Ft at 18 mo (r = 0.14, P = 0.032). These shifts in associations between dietary iron intake, and Hb and S-Ft, respectively, may be due to developmental changes in the channeling of dietary iron to erythropoiesis relative to storage, in the absence of iron deficiency anemia. These observations should be taken into consideration when evaluating iron nutritional status during infancy and early childhood.

Iron deficiency and risk factors for lower iron stores in 6–24-month-old New Zealanders

OBJECTIVES

To determine the prevalence of biochemical iron deficiency and identify factors associated with ferritin levels among 6-24-month-old urban South Island New Zealand children.

DESIGN

Cross-sectional survey conducted from May 1998 to March 1999.

SETTING

The cities of Christchurch, Dunedin and Invercargill.

SUBJECTS

A total of 323 randomly selected 6-24-month-old children participated (response rate 61%) of which 263 provided a blood sample.

METHODS

A complete blood cell count, zinc protoporphyrin, serum ferritin and C-reactive protein were measured on nonfasting venipuncture blood samples, 3-day weighed food records and general questionnaire data were collected.

RESULTS

Among children with C-reactive protein<10 mg/l (n=231), 4.3% had iron deficiency anaemia, 5.6% had iron deficiency without anaemia, and 18.6% had depleted iron stores, when a ferritin cutoff of < or =12 g/l was used. Age (negative), sex (girls>boys), ethnicity (Caucasian>non-Caucasian), weight-for-age percentiles (negative) and birth weight (positive) were associated with ferritin after adjusting for infection and socioeconomic status. When current consumption of iron fortified formula and >500 ml of cows' milk per day were included, these were associated with a 22% increase and 25% decrease in ferritin, respectively (R2=0.28).

CONCLUSIONS

The presence of suboptimal iron status (29%) among young New Zealand children is cause for concern, even though severe iron deficiency is rare, because children with marginal iron status are at risk of developing severe iron deficiency if exposed to a physiological challenge.

Iron status at 12 months of age -- effects of body size, growth and diet in a population with high birth weight

OBJECTIVE

To investigate effects of growth and food intake in infancy on iron status at the age of 12 months in a population with high birth weight and high frequency of breast-feeding.

DESIGN

In a longitudinal observational study infants' consumption and growth were recorded. Weighed 2 day food records at the ages of 6, 9 and 12 months were used to analyse food and nutrient intake.

SETTING

Healthy-born participants were recruited from four maternity wards. Blood samples and growth data were collected from healthcare centres and food consumption data at home.

SUBJECTS

Newborn infants (n=180) were selected randomly according to the mother's domicile and 77% (n=138) participated, of them, 83% (n=114), or 63% of original sample, came in for blood sampling.

RESULTS

Every fifth child was iron-deficient (serum ferritin <12 microg/l and mean corpuscular volume<74 fl) and 2.7% were also anaemic (Hb<105 g/l). Higher weight gain from 0 to 12 months was seen in infants who were iron-deficient at 12 months (6.7+/-0.9 kg) than in non-iron-deficient infants (6.2+/-0.9 kg) (P=0.050). Serum transferrin receptors at 12 months were positively associated with length gain from 0 to 12 months (adjusted r(2)=0.14; P=0.045) and mean corpuscular volume negatively to ponderal index at birth (adjusted r(2)=0.14; P=0.019) and 12 months (adjusted r(2)=0.17; P=0.006). Iron-deficient infants had shorter breast-feeding duration (5.3+/-2.2 months) than non-iron-deficient (7.9+/-3.2 months; P=0.001). Iron status indices were negatively associated with cow's milk consumption at 9-12 months, significant above 460 g/day, but were positively associated with iron-fortified breakfast cereals, fish and meat consumption.

CONCLUSIONS

: In a population of high birth weight, iron deficiency at 12 months is associated with faster growth and shorter breast-feeding duration from 0 to 12 months of age. The results suggest that a diet of 9-12-month-olds should avoid cow's milk above 500 g/day and include fish, meat and iron-fortified breakfast cereals to improve iron status.

The high prevalence of low hemoglobin concentration among Indonesian infants aged 3-5 months is related to maternal anemia

Iron deficiency anemia among young children is a large health problem. However, there is little information about the prevalence of anemia among young infants because it has been assumed that normal, breast-fed infants have adequate iron stores until 4-6 mo of age. We analyzed cross-sectional data from the HKI/GOI Nutrition and Health Surveillance System in rural Java, Indonesia from Sept. 1999 to Feb. 2001 for hemoglobin (Hb) of 3- to 5-mo-old breast-fed infants (n = 990) and related factors. The prevalence of Hb < 90 g/L was 13.4%, < 100 g/L, 37%, and < 110 g/L, 71%. Multiple logistic regression analysis revealed that normal birth weight infants (>2500 g) of anemic mothers (Hb < 120 g/L) had an odds ratio (OR) [95% confidence interval (CI)] of 1.81 [1.34-2.43] to have a low Hb (< 100 g/L) compared with infants of nonanemic mothers with a normal birth weight. Infants of nonanemic mothers but with low birth weight had an OR of 1.15 [0.61-2.16], and those with low birth weight and anemic mothers of 3.68 [1.69-8.02]. Other risk factors included stunting (OR 1.70 [0.97-2.95]), a young mother (<20 y, OR 1.54 [0.95-2.49]), lower maternal education and living in West Java or East Java. Considering that maternal postpartum Hb reflects Hb during pregnancy, that anemia among mothers in this population is due mainly to iron deficiency, and that children born to anemic mothers are at higher risk of a low Hb, we hypothesize that low infant Hb in this population is due to iron deficiency. Intervention studies in iron deficient populations should test this hypothesis.

Vitamin A and iron supplementation of Indonesian pregnant women benefits vitamin A status of their infants

Many Indonesian infants have an inadequate nutritional status, which may be due in part to inadequate maternal nutrition during pregnancy. This study was designed to investigate whether infant nutritional status could be improved by maternal vitamin A and Fe supplementation during gestation. Mothers of these infants from five villages had been randomly assigned on an individual basis, supervised and double-blind, to receive supplementation once weekly from approximately 18 weeks of pregnancy until delivery. Supplementation comprised 120 mg Fe and 500 microg folic acid with or without 4800 retinol equivalent vitamin A. Mothers of infants from four other villages who participated in the national Fe and folic acid supplementation programme were also recruited; intake of tablets was not supervised. Anthropometric and biochemical parameters of infants and their mothers were assessed approximately 4 months after delivery. Infants of mothers supplemented with vitamin A plus Fe had higher serum retinol concentrations than infants of mothers supplemented with Fe alone. However, the proportion of infants with serum retinol concentrations <0.70 micromol/l was >70 % in all groups. Maternal and infant serum retinol concentrations were correlated. Fe status, weight and length of infants were similar in all groups. Fe status of girls was better than that of boys, but boys were heavier and longer. We conclude that supplementation with vitamin A in conjunction with Fe supplementation of women during pregnancy benefits vitamin A status of their infants. However, considering the large proportion of infants with marginal serum retinol concentrations, it may still be necessary to increase their vitamin A intake.

Zinc and iron bioavailability in a powder or in-bottle-sterilized infant formula estimated by in vitro and in suckling rats

Maillard reaction and lactose isomerization may be induced during the processing involved in the manufacture of infant formulas. The effects of dehydratation and sterilization in an infant formula on iron and zinc bioavailability were studied. A powder (PIF), previously reconstituted, and an in-bottle-sterilized liquid infant formula (LIF), from the same manufacturer, were evaluated using an in vitro method and in suckling rats. After in vitro digestion the dialyzed and non-dialyzed soluble, and insoluble fractions of iron and zinc were separated. Two-week-old rat pups were fed PIF or LIF in a drinking bottle for 7 days. Infant formula intake (I), body weight and the fecal and urinary excretions were monitored and the following parameters calculated: apparent absorption (A), retention (R), and the coefficients %A/I, %R/A and %R/I. Soluble iron (dialyzed) and zinc (non-dialyzed) were higher (p < 0.001) in LIF than PIF after in vitro digestion. Insoluble iron was similar in both infant formulas but insoluble zinc was lower (p < 0.05) in LIF than PIF. Food intake (p = 0.045) and body weight on day 4 (p < 0.05) and on day 7 (p < 0.001) were lower in LIF compared to PIF. A, R (p < 0.05 for both minerals), %A/I, and %R/I (p < 0.001 and p < 0.05 for iron and zinc, respectively) were significantly lower in rats fed LIF. Similarly, the %R/A of iron was lower (p < 0.001) in this group. Hematocrit and hemoglobin did not show significant differences. Iron and zinc levels in liver, spleen and erythrocytes were similar in both groups, but skin iron concentration was higher in LIF. Therefore, in contrast with the in vitro results, consumption of the in-bottle-sterilized formula determines lower iron and zinc bioavailability compared to the reconstituted powder infant formula.

Iron bioavailability in infants from an infant cereal fortified with ferric pyrophosphate or ferrous fumarate

BACKGROUND

Infant cereals are commonly fortified with insoluble iron compounds with low relative bioavailability, such as ferric pyrophosphate, because of organoleptic changes that occur after addition of water-soluble iron sources.

OBJECTIVE

Our objective was to compare iron bioavailability from ferric pyrophosphate with an alternative iron source that is soluble in dilute acid, ferrous fumarate, and to evaluate the influence of ascorbic acid on iron bioavailability from ferrous fumarate in infants.

DESIGN

Iron bioavailability was measured as the incorporation of stable iron isotopes into erythrocytes 14 d after administration of labeled test meals (25 g dry wheat and soy infant cereal, 100 g water, and 2.5 mg Fe as [57Fe]ferric pyrophosphate or [57Fe]ferrous fumarate). Ascorbic acid was added to all test meals (25 mg in study 1 or 25 or 50 mg in study 2). Infants were fed each test meal on 4 consecutive days under standardized conditions. The 2 different test meals within each study were administered 2 wk apart in a crossover design.

RESULTS

Geometric mean iron bioavailability was significantly higher from [57Fe]ferrous fumarate than from [57Fe]ferric pyrophosphate [4.1% (range: 1.7-14.7%) compared with 1.3% (range: 0. 7-2.7%); n = 8, P = 0.008]. In this study, doubling the ascorbic acid content did not further enhance iron bioavailability; the geometric means (range) were 3.4% (1.9-6.6%) and 4.2% (1.2-18.7%) for the test meals with 25 and 50 mg ascorbic acid added, respectively (n = 9).

CONCLUSION

Iron bioavailability from iron-fortified infant cereals can be improved by using an iron compound with high relative bioavailability and by ensuring adequate ascorbic acid content of the product.

Predictors of micronutrient status among six- to twelve-month-old breast-fed Ghanaian infants

This study describes the factors associated with hemoglobin and plasma ferritin, zinc and retinol concentrations and erythrocyte riboflavin status among 208 Ghanaian infants who participated in a complementary feeding intervention trial from 6 to 12 mo of age. Anthropometric, morbidity and dietary data were collected regularly from 1 to 12 mo; blood samples were collected at 6 and 12 mo. The prevalence of low micronutrient status at 6 and 12 mo, respectively, was as follows: hemoglobin <100 g/L, 30 and 34%; plasma ferritin <12 microg/L, 17 and 43%; plasma zinc <10.7 micromol/L, 4 and 6%; plasma retinol <0.7 micromol/L, 26 and 26%; erythrocyte riboflavin <200 umol/L of packed red cells, 14 and 10%. Multiple regression was used to identify factors significantly associated with micronutrient status. From 6 to 12 mo, fever prevalence was associated with a decrease in hemoglobin, but an increase in erythrocyte riboflavin concentrations, and diarrhea prevalence was related to a decrease in plasma retinol. Seasonal differences were evident for most of the indicators of micronutrient status, and elevated C-reactive protein levels (indicative of recent infection) were related to lower hemoglobin, retinol and zinc concentrations but higher ferritin and erythrocyte riboflavin concentrations. Weight at birth or at 1 mo of age was positively related to iron, zinc and vitamin A status, but a more rapid weight gain was associated with depletion of iron stores. Socioeconomic status was related to higher hemoglobin, riboflavin and zinc concentrations. The feeding of a micronutrient-fortified food was positively associated with plasma ferritin and retinol concentrations at 12 mo. These results suggest that prenatal factors, socioeconomic status, dietary intake and morbidity all influence infant micronutrient status, and that fortification of complementary foods is one potential avenue for preventing deficiencies.