Randomized double-blind controlled trial on the effects on iron status in the first year between a no added iron and standard infant formula received for three months

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

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

Very low prevalence of iron deficiency among young French children: A national cross-sectional hospital-based survey

Although iron deficiency (ID) is considered the most frequent micronutrient deficiency in industrialized countries and is associated with impaired neurodevelopment when occurring in early years, accurate recent estimations of its prevalence are lacking. Our objective was to estimate ID prevalence and associated sociodemographic markers in young children in France. The Saturn-Inf national cross-sectional hospital-based survey recruited 3,831 French children <6 years old between 2008 and 2009 to assess lead poisoning prevalence and to establish a biobank. This secondary analysis measured serum ferritinemia (SF) in sera kept frozen at -80 °C for children with sufficient serum aliquots and C-reactive protein <10 mg/L. For the 657 participating children (17% of the Saturn-Inf study), the median age was 3.9 years (interquartile range: 2.2-5.1); 52% were boys. The median SF was 44 μg/L (interquartile range: 28-71). ID prevalence was 2.8% (95% confidence interval [1.7, 4.7]) and 3.2% (95% confidence interval [2.0, 5.1]) with an SF threshold of 10 and 12 μg/L, respectively. Low SF was significantly associated (p < .05) with mother being a migrant (32 vs. 45 μg/L for a mother born in France) or unemployed (37 vs. 50 μg/L for a mother employed). In this first national cross-sectional hospital-based study in France, ID prevalence was much lower than that in other French and European studies performed in underprivileged populations but close to the lowest values observed in other population-based studies in Europe.

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.

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.

Micronutrient fortification of food and its impact on woman and child health: a systematic review

BACKGROUND

Vitamins and minerals are essential for growth and metabolism. The World Health Organization estimates that more than 2 billion people are deficient in key vitamins and minerals. Groups most vulnerable to these micronutrient deficiencies are pregnant and lactating women and young children, given their increased demands. Food fortification is one of the strategies that has been used safely and effectively to prevent vitamin and mineral deficiencies.

METHODS

A comprehensive search was done to identify all available evidence for the impact of fortification interventions. Studies were included if food was fortified with a single, dual or multiple micronutrients and impact of fortification was analyzed on the health outcomes and relevant biochemical indicators of women and children. We performed a meta-analysis of outcomes using Review Manager Software version 5.1.

RESULTS

Our systematic review identified 201 studies that we reviewed for outcomes of relevance. Fortification for children showed significant impacts on increasing serum micronutrient concentrations. Hematologic markers also improved, including hemoglobin concentrations, which showed a significant rise when food was fortified with vitamin A, iron and multiple micronutrients. Fortification with zinc had no significant adverse impact on hemoglobin levels. Multiple micronutrient fortification showed non-significant impacts on height for age, weight for age and weight for height Z-scores, although they showed positive trends. The results for fortification in women showed that calcium and vitamin D fortification had significant impacts in the post-menopausal age group. Iron fortification led to a significant increase in serum ferritin and hemoglobin levels in women of reproductive age and pregnant women. Folate fortification significantly reduced the incidence of congenital abnormalities like neural tube defects without increasing the incidence of twinning. The number of studies pooled for zinc and multiple micronutrients for women were few, though the evidence suggested benefit. There was a dearth of evidence for the impact of fortification strategies on morbidity and mortality outcomes in women and children.

CONCLUSION

Fortification is potentially an effective strategy but evidence from the developing world is scarce. Programs need to assess the direct impact of fortification on morbidity and mortality.

Effect of iron-fortified foods on hematologic and biological outcomes: systematic review of randomized controlled trials

BACKGROUND

The utility of iron fortification of food to improve iron deficiency, anemia, and biological outcomes is not proven unequivocally.

OBJECTIVES

The objectives were to evaluate 1) the effect of iron fortification on hemoglobin and serum ferritin and the prevalence of iron deficiency and anemia, 2) the possible predictors of a positive hemoglobin response, 3) the effect of iron fortification on zinc and iron status, and 4) the effect of iron-fortified foods on mental and motor development, anthropometric measures, and infections.

DESIGN

Randomized and pseudorandomized controlled trials that included food fortification or biofortification with iron were included.

RESULTS

Data from 60 trials showed that iron fortification of foods resulted in a significant increase in hemoglobin (0.42 g/dL; 95% CI: 0.28, 0.56; P < 0.001) and serum ferritin (1.36 μg/L; 95% CI: 1.23, 1.52; P < 0.001), a reduced risk of anemia (RR: 0.59; 95% CI: 0.48, 0.71; P < 0.001) and iron deficiency (RR: 0.48; 95% CI: 0.38, 0.62; P < 0.001), improvement in other indicators of iron nutriture, and no effect on serum zinc concentrations, infections, physical growth, and mental and motor development. Significant heterogeneity was observed for most of the evaluated outcomes. Sensitivity analyses and meta-regression for hemoglobin suggested a higher response with lower trial quality (suboptimal allocation concealment and blinding), use of condiments, and sodium iron edetate and a lower response when adults were included.

CONCLUSION

Consumption of iron-fortified foods results in an improvement in hemoglobin, serum ferritin, and iron nutriture and a reduced risk of remaining anemic and iron deficient.

Effect of iron supplementation on haemoglobin response in children: systematic review of randomised controlled trials

OBJECTIVE

To evaluate the effect of iron supplementation on haemoglobin (Hb) in children through a systematic review of randomised controlled trials.

MATERIALS AND METHODS

Electronic databases, personal files, hand search of reviews, bibliographies of books, and abstracts and proceedings of international conferences were reviewed. Randomised controlled trials evaluating change in Hb levels with interventions that included oral or parenteral iron supplementation or iron-fortified formula milk or cereals were analysed.

RESULTS

A total of 55 trials (56 cohorts) provided relevant information. Publication bias was evident (P < 0.001). The pooled estimate (random-effects model) for change in Hb with iron supplementation (weighted mean difference) was 0.74 g/dL (95% CI, 0.61-0.87; P < 0.001; P < 0.001 for heterogeneity). Lower baseline Hb level, oral medicinal iron supplementation, and malarial nonhyperendemic region were significant predictors of greater Hb response and heterogeneity. Projections suggested that, on average, between 37.9% and 62.3% of baseline anaemia (Hb <11 g/dL) was responsive to iron supplementation among children under 6 years of age; the corresponding range for malarial hyperendemic regions was 5.8% to 31.8%.

CONCLUSIONS

This systematic review indicates that iron supplementation increases Hb levels in children significantly but modestly. The increase is greater in subjects who are anaemic at the start of the trial and lower in malarial hyperendemic areas and in those consuming iron-fortified food. The projected reductions in prevalence of anaemia with iron supplementation alone highlight the need for additional area-specific interventions, particularly in malaria-prone regions.

Behavioral consequences of developmental iron deficiency in infant rhesus monkeys

Human studies have shown that iron deficiency and iron deficiency anemia in infants are associated with behavioral impairment, but the periods of brain development most susceptible to iron deficiency have not been established. In the present study, rhesus monkeys were deprived of iron by dietary iron restriction during prenatal (n=14, 10 microg Fe/g diet) or early postnatal (n=12, 1.5 mg Fe/L formula) brain development and compared to controls (n=12, 100 microg Fe/g diet, 12 mg Fe/L formula) in behavioral evaluations conducted during the first four months of life in the nonhuman primate nursery. Iron deficiency anemia was detected in the pregnant dams in the third trimester and compromised iron status was seen in the prenatally iron-deprived infants at birth, but no iron deficiency was seen in either the prenatally or postnatally iron-deprived infants during the period of behavioral evaluation. Neither prenatal nor postnatal iron deprivation led to significant delays in growth, or gross or fine motor development. Prenatally deprived infants demonstrated a 20% reduced spontaneous activity level, lower inhibitory response to novel environments, and more changes from one behavior to another in weekly observation sessions. Postnatally deprived infants demonstrated poorer performance of an object concept task, and greater emotionality relative to controls. This study indicates that different syndromes of behavioral effects are associated with prenatal and postnatal iron deprivation in rhesus monkey infants and that these effects can occur in the absence of concurrent iron deficiency as reflected in hematological measures.

[Variations in serum ferritin and erythrocyte index in the first eight weeks of life in term newborn infants]

OBJECTIVE

To describe changes in erythrocyte index during the first 8 weeks of life in neonates in relation to their iron store.

MATERIAL AND METHODS

We performed a longitudinal study of a group of healthy term newborn infants, in whom we evaluated erythrocyte index and serum ferritin (SF) values at birth and at weeks 4 and 8 of age. Depending on the comparison made in SF values between birth and 2 months, the infants were divided into two groups: group I (without variation in SF) and group II (with a decrease in SF).

RESULTS

A total of 110 neonates were included, with 46 neonates in group I and 64 in group II. No differences in demographic or hematologic data were found, including neonates with anemia or a decrease in hemoglobin values (5.2 vs. 5.5 g/dL). SF decreased to lower values in group II than in group I (215 vs. 194 microg/L, p < 0.001), with a greater number of neonates with low iron stores at 2 months of age (0.15 vs. 0.37, p < 0.01; RR 2.464, 95 % CI: 1.162-5.227).

CONCLUSIONS

In healthy term newborn infants, erythrocyte index at birth showed no relation with iron store. SF values at 2 months of age depended on SF concentrations at birth. Decreased hemoglobin and SF values are part of physiological adaptation in the first few months of life.