This clinical report covers diagnosis and prevention of iron deficiency and iron-deficiency anemia in infants (both breastfed and formula fed) and toddlers from birth through 3 years of age. Results of recent basic research support the concerns that iron-deficiency anemia and iron deficiency without anemia during infancy and childhood can have long-lasting detrimental effects on neurodevelopment. Therefore, pediatricians and other health care providers should strive to eliminate iron deficiency and iron-deficiency anemia. Appropriate iron intakes for infants and toddlers as well as methods for screening for iron deficiency and iron-deficiency anemia are presented.
INTRODUCTION
Iron deficiency (ID) and iron-deficiency anemia (IDA) continue to be of worldwide concern. Among children in the developing world, iron is the most common single-nutrient deficiency.1 In industrialized nations, despite a demonstrable decline in prevalence,2 IDA remains a common cause of anemia in young children. However, even more important than anemia itself is the indication that the more common ID without anemia may also adversely affect long-term neurodevelopment and behavior and that some of these effects may be irreversible.3,4 Because of the implications for pediatric health care providers and their patients, this report reviews and summarizes this information.
This clinical report is a revision and extension of a previous policy statement published in 1999,5 which addressed iron fortification of formulas. This report covers diagnosis and prevention of ID and IDA in infants (both breastfed and formula fed) and toddlers aged 1 through 3 years.
DEFINITIONS
Anemia: A hemoglobin (Hb) concentration 2 SDs below the mean Hb concentration for a normal population of the same gender and age range, as defined by the World Health Organization, the United Nations Children's Fund, and United Nations University.6 On the basis of the 1999–2002 US National Health and Nutrition Examination Survey, anemia is defined as a Hb concentration of less than 11.0 g/dL for both male and female children aged 12 through 35 months.7,8 For certain populations (ie, people living at high altitudes), adjustment of these values may be necessary.
Iron sufficiency: A state in which there is sufficient iron to maintain normal physiologic functions.
Iron deficiency: A state in which there is insufficient iron to maintain normal physiologic functions. ID results from inadequate iron absorption to accommodate an increase in requirements attributable to growth or resulting from a long-term negative iron balance. Either of these situations leads to a decrease in iron stores as measured by serum ferritin (SF) concentrations or bone marrow iron content. ID may or may not be accompanied by IDA.
Iron-deficiency anemia: An anemia (as defined above) that results from ID.
Iron overload: The accumulation of excess iron in body tissues. Iron overload usually occurs as a result of a genetic predisposition to absorb and store iron in excess amounts, the most common form of which is hereditary hemochromatosis. Iron overload can also occur as a complication of other hematologic disorders that result in chronic transfusion therapy, repeated injections of parenteral iron, or excessive iron ingestion.
Recommended dietary allowance for iron: The average daily dietary intake that is sufficient to meet the nutrient requirements of nearly all individuals (97%–98%) of a given age and gender.
Adequate intake for iron: This term is used when there is not enough information to establish a recommended dietary allowance for a population (eg, term infants, 0–6 months of age). The adequate intake is based on the estimated average nutrient intake by a group (or groups) of healthy individuals.
IRON REQUIREMENTS FOR INFANTS (UP TO 12 COMPLETED MONTHS OF AGE)
Eighty percent of the iron present in a newborn term infant is accreted during the third trimester of pregnancy. Infants born prematurely miss this rapid accretion and are deficient in total body iron. A number of maternal conditions, such as anemia, maternal hypertension with intrauterine growth restriction, or diabetes during pregnancy, can also result in low fetal iron stores in both term and preterm infants.
Preterm Infants
The deficit of total body iron in preterm infants increases with decreasing gestational age. It is worsened by the rapid postnatal growth that many infants experience and by frequent phlebotomies without adequate blood replacement. On the other hand, sick preterm infants who receive multiple transfusions are at risk of iron overload. The use of recombinant human erythropoietin to prevent transfusion therapy in preterm infants will further deplete iron stores if additional supplemental iron is not provided. The highly variable iron status of preterm infants, along with their risks for ID as well as toxicity, precludes determining the exact requirement, but it can be estimated to be between 2 and 4 mg/kg per day when given orally.9
Term Infants (Birth Through 12 Completed Months of Age)
The Institute of Medicine (IOM)10 used the average iron content of human milk to determine the adequate intake of 0.27 mg/day for term infants from birth through 6 months' completed age. The average iron content of human milk was determined to be 0.35 mg/L, and the average milk intake of an exclusively breastfed infant was determined to be 0.78 L/day. Multiplying these 2 numbers determined the adequate intake of 0.27 mg/day for term infants from birth through 6 months of age in the IOM report. The IOM further reasoned that there should be a direct correlation between infant size and human milk ingestion; therefore, no correction need be made for infant weight. It should be pointed out, however, that although bigger infants may ingest more milk, there is a large variation in iron concentration of human milk, and there is no guarantee that the iron content of the maternal milk matches the needs of the infant for iron.
For infants from 7 to 12 months' completed age, the recommended dietary allowance for iron, according to the IOM, is 11 mg/day, which was determined by using a factorial approach. The amount of iron lost, primarily from sloughed epithelial cells from skin and the intestinal and urinary tracts, was added to the amounts of iron required for increased blood volume, increased tissue mass, and storage iron during this period of life. It was noted that the iron needs of infants do not suddenly jump from 0.27 to 11 mg/day at 6 months of age; this disjuncture is the result of the use of very different methods of determining these values. However, it is clear that healthy, term newborn infants require very little iron early in life compared with the significant amounts of iron required after 6 months of age.
IRON REQUIREMENTS FOR TODDLERS (1–3 YEARS OF AGE)
Using a similar factorial approach as described for infants 7 to 12 months' completed age, the IOM determined that the recommended dietary allowance for iron for children from 1 through 3 years of age is 7 mg/day.9
PREVALENCE OF ID AND IDA
There are currently no national statistics for the prevalence of ID and IDA in infants before 12 months' completed age. Hay et al11 reported on a cohort of 284 term Norwegian infants. Using the definitions provided by Dallman12 in an IOM report, the prevalence of ID at 6 months of age was 4% and increased to 12% at 12 months of age.
The prevalence of ID and IDA among toddlers (1–3 years of age) in the United States is listed in Table 1 and was derived from National Health and Nutrition Examination Survey data collected between 1999 and 2002.7,8 The overall prevalence of anemia and possibly ID and IDA in infants and toddlers has declined since the 1970s.2 Although there is no direct proof, this decline has been attributed to use of iron-fortified formulas and iron-fortified infant foods provided by the Special Supplemental Program for Women, Infants, and Children (WIC) in the early 1970s and the decrease in use of whole cow milk for infants.8 Still, ID remains relatively common and occurs in 6.6% to 15.2% of toddlers, depending on ethnicity and socioeconomic status. The prevalence of IDA is 0.9% to 4.4%, again depending on race/ethnicity and socioeconomic status,7,8 but only accounts for approximately 40% of the anemia in toddlers (Table 1). These numbers are comparable to data collected in other industrialized countries.13,14
Population Sampled (No.) . | Proportion of US Toddler Population, % (SE)a . | ID, % (SE) . | IDA, % (SE) . | All Anemia, % (SE) . |
---|---|---|---|---|
General US population (672) | 9.2 (1.3) | 2.1 (0.6) | 5.1 (0.8) | |
Above poverty line (355)b | 66.4 (2.9) | 8.9 (1.7) | 2.2 (0.8)c | 4.6 (1.1) |
Below poverty line (268)b | 33.6 (2.9) | 8.6 (1.6) | 2.3 (1.2)c | 6.2 (1.3) |
Enrolled in WIC (360)d | 44.4 (3.2) | 10.7 (2.1) | 3.1 (1.2)c | 6.6 (1.4) |
Non-Hispanic white (196) | 58.0 (3.8) | 7.3 (1.9) | 2.0 (0.8)c | 4.6 (1.2) |
Non-Hispanic black (173) | 14.1 (2.1) | 6.6 (1.8) | 1.6 (0.9)c | 8.3 (1.9) |
Mexican American (231) | 15.0 (2.2) | 13.9 (3.1) | 0.9 (0.7)c | 3.2 (1.2)c |
Other ethnicity (72) | 13.0 (2.7) | 15.2 (4.7)c | 4.4 (2.7)c | 5.5 (2.7)c |
Population Sampled (No.) . | Proportion of US Toddler Population, % (SE)a . | ID, % (SE) . | IDA, % (SE) . | All Anemia, % (SE) . |
---|---|---|---|---|
General US population (672) | 9.2 (1.3) | 2.1 (0.6) | 5.1 (0.8) | |
Above poverty line (355)b | 66.4 (2.9) | 8.9 (1.7) | 2.2 (0.8)c | 4.6 (1.1) |
Below poverty line (268)b | 33.6 (2.9) | 8.6 (1.6) | 2.3 (1.2)c | 6.2 (1.3) |
Enrolled in WIC (360)d | 44.4 (3.2) | 10.7 (2.1) | 3.1 (1.2)c | 6.6 (1.4) |
Non-Hispanic white (196) | 58.0 (3.8) | 7.3 (1.9) | 2.0 (0.8)c | 4.6 (1.2) |
Non-Hispanic black (173) | 14.1 (2.1) | 6.6 (1.8) | 1.6 (0.9)c | 8.3 (1.9) |
Mexican American (231) | 15.0 (2.2) | 13.9 (3.1) | 0.9 (0.7)c | 3.2 (1.2)c |
Other ethnicity (72) | 13.0 (2.7) | 15.2 (4.7)c | 4.4 (2.7)c | 5.5 (2.7)c |
Shown are the unweighted number and weighted percentage and SEs for all children with complete data for Hb, SF, transferrin saturation, and zinc protoporphyrin. Anemia was defined as a Hb concentration of <11.0 g/dL; ID7 was defined as an abnormal value for at least 2 of 3 indicators: SF (abnormal cutoff: <10 μg/dL), zinc protoporphyrin (>1.42 μmol/L red blood cells), and transferrin saturation (<10%); and IDA was defined as anemia plus ID.
Proportion of row descriptor of all children in analytic sample (N = 672).
Children with income data (N = 623).
Estimate is statistically unreliable. Relative SE (SE of estimate/estimate × 100) ≥ 30%.
Any member of household who received benefits from WIC in the previous 12 months: children with food-security data (N = 668).
Related to the problem of ID/IDA is the interaction of iron and lead. Results of both animal and human studies have confirmed that IDA increases intestinal lead absorption.15,–,17 A reasonably well-established epidemiologic association has been made between IDA and increased lead concentrations.18 Thus, primary prevention of IDA could also serve as primary prevention of lead poisoning. This possibility is all the more attractive, because lead has been reported to induce neurotoxicity at even very low blood concentrations.19,20 In addition, preexisting IDA decreases the efficiency of lead chelation therapy, and iron supplementation corrects this effect. In contrast, iron supplementation in a child with IDA who also has lead poisoning without chelation therapy seems to increase blood lead concentrations and decrease basal lead excretion.21,22 The effect of iron supplementation on blood lead concentrations in iron-replete children with or without lead poisoning is not known. Thus, in theory, selective rather than universal iron supplementation would be more likely to reduce lead poisoning and its potential harmful effects on these children.
ID AND NEURODEVELOPMENT
The possible relationship between ID/IDA and later neurobehavioral development in children is the subject of many reports.3,23,–,31 Results of a preponderance of studies have demonstrated an association between IDA in infancy and later cognitive deficits. Lozoff et al3,25 have reported detecting cognitive deficits 1 to 2 decades after the iron-deficient insult during infancy. However, it has been difficult to establish a causal relationship because of the many confounding variables and the difficulty in designing and executing the large, randomized controlled trials necessary to distinguish small potential differences. The authors of a Cochrane Database systematic review, in which the question of whether treatment of IDA improved psychomotor development was examined, stated that there was inconclusive but plausible evidence (only 2 randomized controlled trials) demonstrating improvement if the treatment extended for more than 30 days.27 McCann and Ames28 recently reviewed the evidence of a causal relationship between ID/IDA and deficits in cognitive and behavioral function. They concluded that for IDA, there is at least some support for causality, but because specificity for both cause and effect have not been established unequivocally, it is premature to conclude the existence of a causal relationship between IDA and cognitive and behavioral performance. For ID, some evidence of causality exists, but it is less than that for IDA.28
It is known that iron is essential for normal neurodevelopment in a number of animal models. ID affects neuronal energy metabolism, the metabolism of neurotransmitters, myelination, and memory function. These observations would explain the behavioral findings in human infants that have been associated with ID.29,–,31 Therefore, taking into account that iron is the world's most common single-nutrient deficiency, it is important to minimize IDA and ID among infants and toddlers, even if an unequivocal relationship between IDA and ID and neurodevelopmental outcomes has yet to be established.
DIAGNOSIS
Iron status is a continuum. At one end of the spectrum is IDA, and at the other end is iron overload. ID and IDA are attributable to an imbalance between iron needs and available iron that results in a deficiency of mobilizable iron stores and is accompanied by changes in laboratory measurements that include Hb concentration, mean corpuscular Hb concentration, mean corpuscular volume, reticulocyte Hb concentration (abbreviated in the literature as CHr) content, total iron-binding capacity, transferrin saturation, zinc protoporphyrin, SF concentration, and serum transferrin receptor 1 (TfR1) concentration. Measurements that are used to describe iron status are listed in Table 2.
Parameter . | ID Without Anemia . | IDA . | Iron Overload . |
---|---|---|---|
SFa | ↓ | ↓↓ | ↑ |
Transferrin saturation | ↓ | ↓ | ↑↑ |
TfR1 | ↑↑ | ↑↑↑ | ↓ |
CHr | ↓ | ↓ | Normal |
Hb | Normal | ↓ | Normal |
Mean corpuscular volume | Normal | ↓ | Normal |
Parameter . | ID Without Anemia . | IDA . | Iron Overload . |
---|---|---|---|
SFa | ↓ | ↓↓ | ↑ |
Transferrin saturation | ↓ | ↓ | ↑↑ |
TfR1 | ↑↑ | ↑↑↑ | ↓ |
CHr | ↓ | ↓ | Normal |
Hb | Normal | ↓ | Normal |
Mean corpuscular volume | Normal | ↓ | Normal |
Confounded by the presence of inflammation. If SF is normal or increased and the CRP level is normal, then there is no ID. If SF is decreased, then ID is present regardless of the measure of CRP. If SF is normal or increased and the CRP level is increased, then the presence of ID cannot be determined.
Modified from American Academy of Pediatrics, Committee on Nutrition. Iron deficiency. In: Kleinman RE, ed. Pediatric Nutrition Handbook. 5th ed. Elk Grove Village, IL: American Academy of Pediatrics; 2004:304.
In a child with ID, as the Hb concentration falls 2 SDs below the mean for age and gender, IDA is present, by definition; for infants at 12 months of age, this is 11.0 mg/dL.7,8 When IDA accounted for most cases of anemia in children, “anemia” and “IDA” were roughly synonymous, and a simple measurement of Hb concentration was sufficient to make a presumptive diagnosis of anemia attributable to ID. Particularly in industrialized nations, the prevalence of ID and IDA has decreased, and other causes of anemia, such as hemolytic anemias, anemia of chronic disease, and anemia attributable to other nutrient deficiencies, have become proportionately more common.32
No single measurement is currently available that will characterize the iron status of a child. The limitations of using Hb concentration as a measure of iron status are its lack of specificity and sensitivity. Factors that limit erythropoiesis or result in chronic hemolysis, such as genetic disorders and chronic infections, may result in low Hb concentrations. Vitamin B12 or folate deficiency, although uncommon in the pediatric population, also can result in a low Hb concentration. The lack of sensitivity is largely attributable to the marked overlap in Hb concentrations between populations with iron sufficiency and those with ID.33 Thus, to identify ID or IDA, Hb concentration must be combined with other measurements of iron status. Once the diagnosis of IDA has been established, however, following Hb concentration is a good measure of response to treatment.
In establishing the definitive iron status of an individual, it is desirable to use the fewest tests that will accurately reflect iron status. Any battery of tests must include Hb concentration, because it determines the adequacy of the circulating red cell mass and whether anemia is present. One or more tests must be added to the determination of Hb concentration if ID or IDA is to be diagnosed. The 3 parameters that provide discriminatory information about iron status are SF, CHr, and TfR1 concentrations.
SF is a sensitive parameter for the assessment of iron stores in healthy subjects34,–,36 ; 1 μg/L of SF corresponds to 8 to 10 mg of available storage iron.34,37,38 Measurement of SF concentration is widely used in clinical practice and readily available. Cook et al36 selected an SF concentration below 12 μg/L as diagnostic for ID after a comprehensive population survey in the United States. Thus, a cutoff value of 12 μg/L has been widely used for adults and denotes depletion of iron stores. In children, a cutoff value of 10 μg/L has been suggested.39 Because SF is an acute-phase reactant, concentrations of SF may be elevated in the presence of chronic inflammation, infection, malignancy, or liver disease, and a simultaneous measurement of C-reactive protein (CRP) is required to rule out inflammation. Although Brugnara et al40 found SF concentration to be less accurate than either the CHr or TfR1 concentration in establishing iron status of children, combining SF concentration with a determination of CRP is currently more readily available to assess iron stores and is a reliable screening test as long as the CRP level is not elevated41 (Table 2).
CHr and TfR1 concentrations are not affected by inflammation (infection), malignancy, or anemia of chronic disease and, thus, would be preferable as biomarkers for iron status. Only the CHr assay is currently available for use in children. The CHr content assay has been validated in children, and standard values have been determined.40,42 The CHr assay provides a measure of iron available to cells recently released from the bone marrow. CHr content can be measured by flow cytometry, and 2 of the 4 automated hematology analyzers commonly used in the United States have the capability to measure CHr.43 A low CHr concentration has been shown to be the strongest predictor of ID in children40,42,43 and shows much promise for the diagnosis of ID when the assay becomes more widely available.
TfR1 is a measure of iron status, detecting ID at the cellular level. TfR1 is found on cell membranes and facilitates transfer of iron into the cell. When the iron supply is inadequate, there is an upregulation of TfR1 to enable the cell to compete more effectively for iron, and subsequently, more circulating TfR1 is found in serum. An increase in serum TfR1 concentrations is seen in patients with ID or IDA, although it does not increase in serum until iron stores are completely exhausted in adults.44,–,46 However, the TfR1 assay is not widely available, and standard values for infants and children have yet to be established.
Thus, to establish a diagnosis of IDA, the following sets of tests can be used at the present time (when coupled with determination of a Hb concentration of <11 g/dL): (1) SF and CRP measurements or (2) CHr measurement. For diagnosing ID without anemia, measure either (1) SF and CRP or (2) CHr.
Another approach to making the diagnosis of IDA in a clinically stable child with mild anemia (Hb concentration between 10 and 11 g/dL) is to monitor the response to iron supplementation, especially if a dietary history indicates that the diet is likely to be iron deficient. An increase in Hb concentration of 1 g/dL after 1 month of therapeutic supplementation has been used to signify the presence of IDA. This approach requires that iron supplementation be adequate, iron be adequately absorbed, and patient compliance with adequate follow-up can be ensured. However, because only 40% of the cases of anemia identified at 12 months of age will be secondary to IDA (Table 1), strong consideration should be given to establishing a diagnosis of IDA by using the screening tests described previously.
PREVENTION OF ID AND IDA
Preterm Infants
The preterm infant (<37 weeks' gestation) who is fed human milk should receive a supplement of elemental iron at 2 mg/kg per day starting by 1 month of age and extending through 12 months of age.47 This can be provided as medicinal iron or in iron-fortified complementary foods. Preterm infants fed a standard preterm infant formula (14.6 mg of iron per L) or a standard term infant formula (12.0 mg of iron per L) will receive approximately 1.8 to 2.2 mg/kg per day of iron, assuming a formula intake of 150 mL/kg per day. Despite the use of iron-containing formulas, 14% of preterm infants develop ID between 4 and 8 months of age.48 Thus, some formula-fed preterm infants may need an additional iron supplement,47 although there is not enough evidence to make this a general recommendation at this time. Exceptions to this iron-supplementation practice in preterm infants would be infants who received multiple transfusions during hospitalization, who might not need any iron supplementation.
Term, Breastfed Infants
Infants who are born at term usually have sufficient iron stores until 4 to 6 months of age.49 Infants born at term have high Hb concentration and high blood volume in proportion to body weight. They experience a physiologic decline in both blood volume and Hb concentration during the first several months of life. These facts have led to the supposition that breastfed infants need very little iron. It is assumed that the small amount of iron in human milk is sufficient for the exclusively breastfed infant. The World Health Organization recommends exclusive breastfeeding for 6 months, and the American Academy of Pediatrics (AAP) has recommended exclusive breastfeeding for a minimum of 4 months but preferably for 6 months. Exclusive breastfeeding for more than 6 months has been associated with increased risk of IDA at 9 months of age.49,50 Recommendations for exclusive breastfeeding for 6 months do not take into account infants who are born with lower-than-usual iron stores (low birth weight infants, infants of diabetic mothers), a condition that also has been linked to lower SF concentrations at 9 months of age.51 In a double-blind study, Friel et al52 demonstrated that exclusively breastfed infants supplemented with iron between 1 and 6 months of age had higher Hb concentration and higher mean corpuscular volume at 6 months of age than did their unsupplemented peers. Supplementation also resulted in better visual acuity and higher Bayley Psychomotor Developmental Indices at 13 months. Thus, it is recommended that exclusively breastfed term infants receive an iron supplementation of 1 mg/kg per day, starting at 4 months of age and continued until appropriate iron-containing complementary foods have been introduced (Tables 3 and 4). For partially breastfed infants, the proportion of human milk versus formula is uncertain; therefore, beginning at 4 months of age, infants who receive more than one-half of their daily feedings as human milk and who are not receiving iron-containing complementary foods should also receive 1 mg/kg per day of supplemental iron.
. | Elemental Iron, mg . |
---|---|
Commercial baby food,a heme iron | |
Meat | |
Baby food, lamb, junior, 1 jar (2.5 oz) | 1.2 |
Baby food, chicken, strained, 1 jar (2.5 oz) | 1.0 |
Baby food, lamb, strained, 1 jar (2.5 oz) | 0.8 |
Baby food, beef, junior, 1 jar (2.5 oz) | 0.7 |
Baby food, beef, strained, 1 jar (2.5 oz) | 0.7 |
Baby food, chicken, junior, 1 jar (2.5 oz) | 0.7 |
Baby food, pork, strained, 1 jar (2.5 oz) | 0.7 |
Baby food, ham, strained, 1 jar (2.5 oz) | 0.7 |
Baby food, ham, junior, 1 jar (2.5 oz) | 0.7 |
Baby food, turkey, strained, 1 jar (2.5 oz) | 0.5 |
Baby food, veal, strained, 1 jar (2.5 oz) | 0.5 |
Commercial baby food,a nonheme iron | |
Vegetables | |
Baby food, green beans, junior, 1 jar (6 oz) | 1.8 |
Baby food, peas, strained, 1 jar (3.4 oz) | 0.9 |
Baby food, green beans, strained, 1 jar (4 oz) | 0.8 |
Baby food, spinach, creamed, strained, 1 jar (4 oz) | 0.7 |
Baby food, sweet potatoes, junior (6 oz) | 0.7 |
Cereals | |
Baby food, brown rice cereal, dry, instant, 1 tbsp | 1.8 |
Baby food, oatmeal cereal, dry, 1 tbsp | 1.6 |
Baby food, rice cereal, dry, 1 tbsp | 1.2 |
Baby food, barley cereal, dry, 1 tbsp | 1.1 |
Table food, heme iron | |
Clams, canned, drained solids, 3 oz | 23.8 |
Chicken liver, cooked, simmered, 3 oz | 9.9 |
Oysters, Eastern canned, 3 oz | 5.7 |
Beef liver, cooked, braised, 3 oz | 5.6 |
Shrimp, cooked moist heat, 3 oz | 2.6 |
Beef, composite of trimmed cuts, lean only, all grades, cooked, 3 oz | 2.5 |
Sardines, Atlantic, canned in oil, drained solids with bone, 3 oz | 2.5 |
Turkey, all classes, dark meat, roasted, 3 oz | 2.0 |
Lamb, domestic, composite of trimmed retail cuts, separable lean only, choice, cooked, 3 oz | 1.7 |
Fish, tuna, light, canned in water, drained solids, 3 oz | 1.3 |
Chicken, broiler or fryer, dark meat, roasted, 3 oz | 1.1 |
Turkey, all classes, light meat, roasted, 3 oz | 1.1 |
Veal, composite of trimmed cuts, lean only, cooked, 3 oz | 1.0 |
Chicken, broiler or fryer, breast, roasted, 3 oz | 0.9 |
Pork, composite of trimmed cuts (leg, loin, shoulder), lean only, cooked, 3 oz | 0.9 |
Fish, salmon, pink, cooked, 3 oz | 0.8 |
Table food, nonheme iron | |
Oatmeal, instant, fortified, cooked, 1 cup | 14.0 |
Blackstrap molasses,b 2 tbsp | 7.4 |
Tofu, raw, regular, ½ cup | 6.7 |
Wheat germ, toasted, ½ cup | 5.1 |
Ready-to-eat cereal, fortified at different levels, 1 cup | ∼4.5 to 18 |
Soybeans, mature seeds, cooked, boiled, ½ cup | 4.4 |
Apricots, dehydrated (low-moisture), uncooked, ½ cup | 3.8 |
Sunflower seeds, dried, ½ cup | 3.7 |
Lentils, mature seeds, cooked, ½ cup | 3.3 |
Spinach, cooked, boiled, drained, ½ cup | 3.2 |
Chickpeas, mature seeds, cooked, ½ cup | 2.4 |
Prunes, dehydrated (low-moisture), uncooked, ½ cup | 2.3 |
Lima beans, large, mature seeds, cooked, ½ cup | 2.2 |
Navy beans, mature seeds, cooked, ½ cup | 2.2 |
Kidney beans, all types, mature seeds, cooked, ½ cup | 2.0 |
Molasses, 2 tbsp | 1.9 |
Pinto beans, mature seeds, cooked, ½ cup | 1.8 |
Raisins, seedless, packed, ½ cup | 1.6 |
Prunes, dehydrated (low moisture), stewed, ½ cup | 1.6 |
Prune juice, canned, 4 fl oz | 1.5 |
Green peas, cooked, boiled, drain, ½ cup | 1.2 |
Enriched white rice, long-grain, regular, cooked, ½ cup | 1.0 |
Whole egg, cooked (fried or poached), 1 large egg | 0.9 |
Enriched spaghetti, cooked, ½ cup | 0.9 |
White bread, commercially prepared, 1 slice | 0.9 |
Whole-wheat bread, commercially prepared, 1 slice | 0.7 |
Spaghetti or macaroni, whole wheat, cooked, ½ cup | 0.7 |
Peanut butter, smooth style, 2 tbsp | 0.6 |
Brown rice, medium-grain, cooked, ½ cup | 0.5 |
. | Elemental Iron, mg . |
---|---|
Commercial baby food,a heme iron | |
Meat | |
Baby food, lamb, junior, 1 jar (2.5 oz) | 1.2 |
Baby food, chicken, strained, 1 jar (2.5 oz) | 1.0 |
Baby food, lamb, strained, 1 jar (2.5 oz) | 0.8 |
Baby food, beef, junior, 1 jar (2.5 oz) | 0.7 |
Baby food, beef, strained, 1 jar (2.5 oz) | 0.7 |
Baby food, chicken, junior, 1 jar (2.5 oz) | 0.7 |
Baby food, pork, strained, 1 jar (2.5 oz) | 0.7 |
Baby food, ham, strained, 1 jar (2.5 oz) | 0.7 |
Baby food, ham, junior, 1 jar (2.5 oz) | 0.7 |
Baby food, turkey, strained, 1 jar (2.5 oz) | 0.5 |
Baby food, veal, strained, 1 jar (2.5 oz) | 0.5 |
Commercial baby food,a nonheme iron | |
Vegetables | |
Baby food, green beans, junior, 1 jar (6 oz) | 1.8 |
Baby food, peas, strained, 1 jar (3.4 oz) | 0.9 |
Baby food, green beans, strained, 1 jar (4 oz) | 0.8 |
Baby food, spinach, creamed, strained, 1 jar (4 oz) | 0.7 |
Baby food, sweet potatoes, junior (6 oz) | 0.7 |
Cereals | |
Baby food, brown rice cereal, dry, instant, 1 tbsp | 1.8 |
Baby food, oatmeal cereal, dry, 1 tbsp | 1.6 |
Baby food, rice cereal, dry, 1 tbsp | 1.2 |
Baby food, barley cereal, dry, 1 tbsp | 1.1 |
Table food, heme iron | |
Clams, canned, drained solids, 3 oz | 23.8 |
Chicken liver, cooked, simmered, 3 oz | 9.9 |
Oysters, Eastern canned, 3 oz | 5.7 |
Beef liver, cooked, braised, 3 oz | 5.6 |
Shrimp, cooked moist heat, 3 oz | 2.6 |
Beef, composite of trimmed cuts, lean only, all grades, cooked, 3 oz | 2.5 |
Sardines, Atlantic, canned in oil, drained solids with bone, 3 oz | 2.5 |
Turkey, all classes, dark meat, roasted, 3 oz | 2.0 |
Lamb, domestic, composite of trimmed retail cuts, separable lean only, choice, cooked, 3 oz | 1.7 |
Fish, tuna, light, canned in water, drained solids, 3 oz | 1.3 |
Chicken, broiler or fryer, dark meat, roasted, 3 oz | 1.1 |
Turkey, all classes, light meat, roasted, 3 oz | 1.1 |
Veal, composite of trimmed cuts, lean only, cooked, 3 oz | 1.0 |
Chicken, broiler or fryer, breast, roasted, 3 oz | 0.9 |
Pork, composite of trimmed cuts (leg, loin, shoulder), lean only, cooked, 3 oz | 0.9 |
Fish, salmon, pink, cooked, 3 oz | 0.8 |
Table food, nonheme iron | |
Oatmeal, instant, fortified, cooked, 1 cup | 14.0 |
Blackstrap molasses,b 2 tbsp | 7.4 |
Tofu, raw, regular, ½ cup | 6.7 |
Wheat germ, toasted, ½ cup | 5.1 |
Ready-to-eat cereal, fortified at different levels, 1 cup | ∼4.5 to 18 |
Soybeans, mature seeds, cooked, boiled, ½ cup | 4.4 |
Apricots, dehydrated (low-moisture), uncooked, ½ cup | 3.8 |
Sunflower seeds, dried, ½ cup | 3.7 |
Lentils, mature seeds, cooked, ½ cup | 3.3 |
Spinach, cooked, boiled, drained, ½ cup | 3.2 |
Chickpeas, mature seeds, cooked, ½ cup | 2.4 |
Prunes, dehydrated (low-moisture), uncooked, ½ cup | 2.3 |
Lima beans, large, mature seeds, cooked, ½ cup | 2.2 |
Navy beans, mature seeds, cooked, ½ cup | 2.2 |
Kidney beans, all types, mature seeds, cooked, ½ cup | 2.0 |
Molasses, 2 tbsp | 1.9 |
Pinto beans, mature seeds, cooked, ½ cup | 1.8 |
Raisins, seedless, packed, ½ cup | 1.6 |
Prunes, dehydrated (low moisture), stewed, ½ cup | 1.6 |
Prune juice, canned, 4 fl oz | 1.5 |
Green peas, cooked, boiled, drain, ½ cup | 1.2 |
Enriched white rice, long-grain, regular, cooked, ½ cup | 1.0 |
Whole egg, cooked (fried or poached), 1 large egg | 0.9 |
Enriched spaghetti, cooked, ½ cup | 0.9 |
White bread, commercially prepared, 1 slice | 0.9 |
Whole-wheat bread, commercially prepared, 1 slice | 0.7 |
Spaghetti or macaroni, whole wheat, cooked, ½ cup | 0.7 |
Peanut butter, smooth style, 2 tbsp | 0.6 |
Brown rice, medium-grain, cooked, ½ cup | 0.5 |
Note that all figures are rounded.
Baby food values are generally based on generic jar, not branded jar; 3 oz of table-food meat = 85 g; a 2.5-oz jar of baby food = 71 g (an infant would not be expected to eat 3 oz [approximately the size of a deck of cards] of pureed table meat at a meal).
Source of iron value was obtained from a manufacturer of this type of molasses.
Source of iron values in foods: US Department of Agriculture, Agricultural Research Service. USDA National Nutrient Database for Standard Reference, Release 20: Nutrient Data Laboratory home page. Available at: www.ars.usda.gov/ba/bhnrc/ndl.
Fruits | Vegetables |
Citrus fruits (eg, orange, tangerine, grapefruit) | Green, red, and yellow peppers |
Pineapples | Broccoli |
Fruit juices enriched with vitamin C | Tomatoes |
Strawberries | Cabbages |
Cantaloupe | Potatoes |
Kiwifruit | Leafy green vegetables |
Raspberries | Cauliflower |
Fruits | Vegetables |
Citrus fruits (eg, orange, tangerine, grapefruit) | Green, red, and yellow peppers |
Pineapples | Broccoli |
Fruit juices enriched with vitamin C | Tomatoes |
Strawberries | Cabbages |
Cantaloupe | Potatoes |
Kiwifruit | Leafy green vegetables |
Raspberries | Cauliflower |
Term, Formula-Fed Infants
For the term, formula-fed infant, the level of iron fortification of formula to prevent ID remains controversial.53,54 For more than 25 years, 12 mg of iron per L has been the level of fortification in standard term infant formulas in the United States, consistent with guidelines of WIC for iron-fortified formula (at least 10 mg/L), thus creating a natural experiment. The level of 12 mg/L was determined by calculating the total iron needs of the child from 0 to 12 months of age, assuming average birth weight and average weight gain during the first year. The calculation also assumed that formula was the only source of iron during this period. Others have recommended lower amounts of iron in infant formula,55 and there have been studies to examine iron-fortification levels of less than 12 mg/L.56,–,61 However, it is the conclusion of the AAP that infant formula that contains 12 mg of elemental iron per L is safe for its intended use. Although there has been some concern about linear growth in iron-replete infants given medicinal iron,62 no published studies have convincingly documented decreased linear growth in iron-replete infants receiving formulas containing high amounts of iron. Evidence is also insufficient to associate formulas that contain 12 mg of iron per L with gastrointestinal symptoms. At least 4 studies have shown no adverse effects.63,–,66 Reports have conflicted on whether iron fortification is associated with increased risk of infection. Decreased incidence, increased incidence, and no change in number of infections have all been reported.67,68 The authors of a recent systematic review concluded that “iron supplementation has no apparent harmful effect on the overall incidence of infectious illnesses in children, though it slightly increases the risk of developing diarrhoea.”69 Finally, when examining specifically infants given formula with 12 mg of iron per L, Singhal et al70 were “unable to identify adverse health effects in older infants and toddlers consuming a high iron-containing formula.” They found no difference between controls and the treatment group in incidence of infection, gastrointestinal problems, or general morbidity.
Toddlers (1–3 Years of Age)
The iron requirement for toddlers is 7 mg/day. Ideally, the iron requirements of toddlers would be met and ID/IDA would be prevented with naturally iron-rich foods rather than iron supplementation. These foods include those with heme sources of iron (ie, red meat) and nonheme sources of iron (ie, legumes, iron-fortified cereals) (Table 3). Foods that contain vitamin C (ascorbic acid), such as orange juice, aid in iron absorption and are listed in Table 4. Foods that contain phytates (found in soy) reduce iron absorption. Through public education and altering feeding practices, the amount of iron available to older infants and toddlers via a normal diet could be maximized (Table 3).
In developing countries, iron requirements of older infants and toddlers have been met by iron fortification of various foods, including corn flour,71 soy sauce,72 fish sauce,73 and rice.74 However, there are many technical and practical barriers to a successful fortification program for toddlers. Not the least of these barriers is the determination of which foods to fortify with iron. In the United States, fortification of infant formula and infant cereal has been credited with the decline in IDA. However, toddlers in the United States typically do not eat enough of any other food to serve as a vehicle for iron fortification. Universal food fortification for all ages is problematic, given the possible adverse effects of iron in certain subsets of older children and adults.
As an alternative for toddlers who do not eat adequate amounts of iron-containing food (Table 3), iron supplements are available in the form of iron sulfate drops and chewable iron tablets or as a component of either liquid or chewable multivitamins. Iron sprinkles with or without additional zinc are available in Canada. Barriers to adequate iron supplementation are (1) lack of education for care providers and patients, (2) poor compliance made worse by the perception of adverse effects, including nausea, vomiting, constipation, stomach upset, and teeth staining, (3) cost, (4) current federal supplemental nutrition programs not providing iron supplements, and (5) risk of iron overload.
Screening for ID and IDA
The AAP has concluded that universal screening for anemia should be performed with determination of Hb concentration at approximately 1 year of age. Universal screening would also include an assessment of risk factors associated with ID/IDA: history of prematurity or low birth weight; exposure to lead; exclusive breastfeeding beyond 4 months of age without supplemental iron; and weaning to whole milk or complementary foods that do not include iron-fortified cereals or foods naturally rich in iron (Table 3). Additional risk factors include the feeding problems, poor growth, and inadequate nutrition typically seen in infants with special health care needs as well as low socioeconomic status, especially children of Mexican American descent, as identified in the recent National Health and Nutrition Examination Survey8,75 (Table 1). Selective screening can be performed at any age when these risk factors for ID and IDA have been identified, including risk of inadequate iron intake according to dietary history.
It has been acknowledged that screening for anemia with a Hb determination neither identifies children with ID nor specifically identifies those with IDA.76 In the United States, 60% of anemia is not attributable to ID, and most toddlers with ID do not have anemia (Table 2). It is also known that there is poor follow-up testing and poor documentation of improved Hb concentrations. In 1 study, 14% of the children had a positive screening result for anemia. However, only 18.3% of these children with a positive screening result had follow-up testing performed, and of that group, only 11.6% had documented correction of low Hb levels.77 Therefore, for infants identified with a Hb concentration of less than 11.0 mg/dL or identified with significant risk of ID or IDA as described previously, SF and CRP or CHr levels in addition to Hb concentration should be measured to increase the sensitivity and specificity of the diagnosis. In addition, the AAP, the World Health Organization, and the European Society for Pediatric Gastroenterology, Hepatology and Nutrition also support the use of the measurement of TfR1 as a screening test once the method has been validated and normal values for infants and toddlers have been established.
Another step to improve the current screening system is to use technology-based reminders for screening and follow-up of infants and toddlers with a diagnosis of ID/IDA. Reminders could be incorporated into electronic health records, and there should be documentation that Hb concentrations have returned to the normal range. The efficacy of any program for minimizing ID and IDA should be tracked scientifically and evaluated through well-planned surveillance programs.
SUMMARY
Given that iron is the world's most common single-nutrient deficiency and there is some evidence of adverse effects of both ID and IDA on cognitive and behavioral development, it is important to minimize ID and IDA in infants and toddlers without waiting for unequivocal evidence. Controversies remain regarding the timing and methods used for screening for ID/IDA as well as regarding the use of iron supplements to prevent ID/IDA. Although further study is required to generate higher levels of evidence to settle these controversies, the currently available evidence supports the following recommendations.
Term, healthy infants have sufficient iron for at least the first 4 months of life. Human milk contains very little iron. Exclusively breastfed infants are at increasing risk of ID after 4 completed months of age. Therefore, at 4 months of age, breastfed infants should be supplemented with 1 mg/kg per day of oral iron beginning at 4 months of age until appropriate iron-containing complementary foods (including iron-fortified cereals) are introduced in the diet (see Table 3). For partially breastfed infants, the proportion of human milk versus formula is uncertain; therefore, beginning at 4 months of age, partially breastfed infants (more than half of their daily feedings as human milk) who are not receiving iron-containing complementary foods should also receive 1 mg/kg per day of supplemental iron.
For formula-fed infants, the iron needs for the first 12 months of life can be met by a standard infant formula (iron content: 10–12 mg/L) and the introduction of iron-containing complementary foods after 4 to 6 months of age, including iron-fortified cereals (Table 3). Whole milk should not be used before 12 completed months of age.
The iron intake between 6 and 12 months of age should be 11 mg/day. When infants are given complementary foods, red meat and vegetables with higher iron content should be introduced early (Table 3). To augment the iron supply, liquid iron supplements are appropriate if iron needs are not being met by the intake of formula and complementary foods.
Toddlers 1 through 3 years of age should have an iron intake of 7 mg/day. This would be best delivered by eating red meats, cereals fortified with iron, vegetables that contain iron, and fruits with vitamin C, which augments the absorption of iron (T3,Tables 3 and 4). For toddlers not receiving this iron intake, liquid supplements are suitable for children 12 through 36 months of age, and chewable multivitamins can be used for children 3 years and older.
All preterm infants should have an iron intake of at least 2 mg/kg per day through 12 months of age, which is the amount of iron supplied by iron-fortified formulas. Preterm infants fed human milk should receive an iron supplement of 2 mg/kg per day by 1 month of age, and this should be continued until the infant is weaned to iron-fortified formula or begins eating complementary foods that supply the 2 mg/kg of iron. An exception to this practice would include infants who have received an iron load from multiple transfusions of packed red blood cells.
Universal screening for anemia should be performed at approximately 12 months of age with determination of Hb concentration and an assessment of risk factors associated with ID/IDA. These risk factors would include low socioeconomic status (especially children of Mexican American descent [Table 1]), a history of prematurity or low birth weight, exposure to lead, exclusive breastfeeding beyond 4 months of age without supplemental iron, and weaning to whole milk or complementary foods that do not include iron-fortified cereals or foods naturally rich in iron (Table 3). Additional risk factors are the feeding problems, poor growth, and inadequate nutrition typically seen in infants with special health care needs. For infants and toddlers (1–3 years of age), additional screening can be performed at any time if there is a risk of ID/IDA, including inadequate dietary iron intake.
If the Hb level is less than 11.0 mg/dL at 12 months of age, then further evaluation for IDA is required to establish it as a cause of anemia. If there is a high risk of dietary ID as described in point 6 above, then further testing for ID should be performed, given the potential adverse effects on neurodevelopmental outcomes. Additional screening tests for ID or IDA should include measurement of:
SF and CRP levels; or
CHr concentration.
If a child has mild anemia (Hb level of 10–11 mg/d) and can be closely monitored, an alternative method of diagnosis would be to document a 1 g/dL increase in plasma Hb concentration after 1 month of appropriate iron-replacement therapy, especially if the history indicates that the diet is likely to be iron deficient.
Use of the TfR1 assay as screening for ID is promising, and the AAP supports the development of TfR1 standards for use of this assay in infants and children.
If IDA (or any anemia) or ID has been confirmed by history and laboratory evidence, a means of carefully tracking and following infants and toddlers with a diagnosis of ID/IDA should be implemented. Electronic health records could be used not only to generate reminder messages to screen for IDA and ID at 12 months of age but also to document that IDA and ID have been adequately treated once diagnosed.
ADDENDUM
Development of This Report
This report was written by the primary authors after extensive review of the literature using PubMed, previous AAP reports, Cochrane reviews, and reports from other groups.1,6,7,48,77
The report was also submitted to the following sections and committees of the AAP that were asked to comment on the manuscript: Committee on Fetus and Newborn (COFN); Committee on Psychosocial Aspects of Child and Family Health (COPACFH); Section on Administration and Practice Management (SOAPM); Section on Developmental and Behavioral Pediatrics (SODBP); Section on Gastroenterology, Hepatology, and Nutrition (SOGHN); Section on Hematology and Oncology (SOHO); and Section on Breast Feeding (SOBr).
Additional comments were sought from the Centers for Disease Control and Prevention (CDC), the Department of Agriculture (WIC), the National Institutes of Health (NIH), and the Food and Drug Administration (FDA), because these governmental agencies were involved in the development of the statement and will necessarily deal with its impact. As it was developed it was extensively reviewed and revised by members of the AAP Committee on Nutrition, who unanimously approved this clinical report. It is openly acknowledged that where the highest levels of evidence are absent, the opinions and suggestions of members of the Committee on Nutrition as well as other groups consulted for this statement were taken into consideration in developing this clinical report.
Lead Authors
Robert D. Baker, MD, PhD, Former Committee Member
Frank R. Greer, MD, Immediate Past Chairperson
Committee on Nutrition, 2009–2010
Jatinder J. S. Bhatia, MD, Chairperson
Steven A. Abrams, MD
Stephen R. Daniels, MD, PhD
Marcie Beth Schneider, MD
Janet Silverstein, MD
Nicolas Stettler, MD, MSCE
Dan W. Thomas, MD
Liaisons
Laurence Grummer-Strawn, PhD
Centers for Disease Control and Prevention
Rear Admiral Van S. Hubbard, MD, PhD
National Institutes of Health
Valérie Marchand, MD
Canadian Paediatric Society
Benson M. Silverman, MD
Food and Drug Administration
Valery Soto, MS, RD, LD
US Department of Agriculture
Staff
Debra L. Burrowes, MHA
The guidance in this report does not indicate an exclusive course of treatment or serve as a standard of medical care. Variations, taking into account individual circumstances, may be appropriate.
All clinical reports from the American Academy of Pediatrics automatically expire 5 years after publication unless reaffirmed,revised, or retired at or before that time.
REFERENCES
Competing Interests
This document is copyrighted and is property of the American Academy of Pediatrics and its Board of Directors. All authors have filed conflict of interest statements with the American Academy of Pediatrics. Any conflicts have been resolved through a process approved by the Board of Directors. The American Academy of Pediatrics has neither solicited nor accepted any commercial involvement in the development of the content of this publication.
Comments
Re: screening for iron deficiency
To the Editors:
We are gratified that Drs Meyers, Lozoff and Georgieff agree with our stance of the importance of preventing irons deficiency (ID) and iron deficiency anemia (IDA) especially in infants and young children because of possible detrimental impact on neurodevelopment ( 1,2,3,4 ). Their letter highlights one of the many perplexing issues in deciding how to deal with the problem of ID and IDA, the lack of a single, straight- forward test that accurately reflects iron status across its spectrum. In our clinical report (5)we suggest three options for screening tests: 1) Hemoglobin (Hb), serum ferritin (SF) and C-reactive protein (CRP); 2) Hb and reticulocyte hemoglobin concentration (CHr); and 3) Hb and tranferrin receptor 1 (TfR1). The first set of tests is simple to interpret and readily available. The second set is straight-forward, has been validated in the pediatric age group, but is not available to all. The third is also straight-forward, but is the least widely available and has not been completely validated for the age groups considered in this report. Yet, this is the set of tests recommended by the World Health Organization (6). Drs Meyers, Lozoff and Georgieff mention erythrocyte protoporphyrin , zinc protoporphyrin, mean corpuscular volume, red cell distribution width and transferrin saturation as possible additions or alternatives to the tests suggested in our report. These, among other screening options were considered, but if anything, adding them to the screening process makes the interpretation of the results even more complicated for the practitioner. The bottom line is that there is no ideal screening test at the present time. For the reasons pointed out in our report we are pushing for further development of either CHr or TfR1. Either of these tests with the addition of an Hb determination would offer an accurate assessment of iron status.
Sincerely,
Robert D. Baker, MD, PhD Frank R. Greer, MD
1. McCann JC, Ames BN. An overview of evidence for a causal relation between iron deficiency during development and deficits in cognitive or behavioral function. Am J Clin Nutr. 2007;85(4):931-945 2. Logan S, Martins S, Gilbert R. Iron therapy for improving psychomotor development and cognitive function in children under the age of three with iron deficiency anaemia. Cochrane Database Syst Rev. 2001;(2):CD001444 3. Lozoff B, De Andraca I, Castillo M, Smith JB, Walter T, Pino P. Behavioral and developmental effects of preventing iron-deficiency anemia in healthy full-term infants. Pediatrics. 2003;112(4):846-854 4. Grantham-McGregor S. Does iron-deficiency anemia affect child development? Pediatrics. 2003;112(4):978 5. Baker RD, Greer FR. Clinical Report – Diagnosis and prevention of iron deficiency and iron deficiency anemia in infants and young children (0-3 years of age).Pediatrics. 2010;104: 119-123 6. World Health Organization. Assessing the Iron Status of Populations: Report of a Joint World Health Organization/Centers for Disease Control and Prevention Technical Consultation on the Assessment of Iron Status at the Population Level. Geneva, Switzerland; April 6-8, 2004. Available at: http://whqlibdoc.who.int/publications/2004/9241593156_eng.pdf. Accessed September 29, 2008
Conflict of Interest:
None declared
screening for iron deficiency
We applaud the AAP Committee on Nutrition’s new recommendations (1) for screening young children for iron deficiency (ID) and iron deficiency anemia (IDA) and the important emphasis placed on preventing, identifying, and treating ID without anemia, as evidence now suggests this condition may have adverse neurodevelopmental consequences. However, as noted by the report and numerous investigators in the field, the detection of pre- anemic ID is difficult since widely accessible sensitive and specific tests are not available. The report recommends the use of serum ferritin (SF) with C-reactive protein (CRP), reticulocyte hemoglobin (CHr), or soluble transferrin receptor 1 (TfR1) to screen children at risk for ID or those with low hemoglobin (Hb). But as noted in the report, CHr is measured only by a limited number of cell counters currently in use, while TfR1 is not yet commercially available. The report does not mention the use of erythrocyte protoporphyrin (EP)/zinc protoporphyrin (ZPP), mean corpuscular volume (MCV), red cell distribution width (RDW) or transferrin saturation (TS), which have been in wide use for ID screening for decades, and which are more readily available at relatively low cost. ZPP, in particular, has been demonstrated to be highly suited for ID screening in young children. (2-7) Furthermore, the Committee’s statement that “SF is a sensitive parameter for the assessment of iron stores in healthy subjects” cites 3 references, all of which are studies of adults. (8-10) Evidence suggests that SF is not sensitive for screening for ID in infants. For example, in a study of one-year-old infants with screening hemoglobin < 11.5 g/dl, Dallman et al reported that only 29% of those who responded to an iron challenge had had a low SF at the time of screening. (11) Until the problems with accessibility of CHr and Tfr1 are solved, we feel that, at a minimum, the new recommendations should include readily available tests such TS (with CRP), red cell measures included in a complete blood count, and/or ZPP as suggested screening tests for ID. For the child whose MCV and/or RDW is abnormal but other screening parameters are normal, the clinician might consider obtaining additional tests of iron sufficiency (SF, TS, ZPP) or a trial of iron therapy.
REFERENCES 1) Baker RD, Greer FR, the Committee on Nutrition. Clinical report - diagnosis and prevention of iron deficiency and iron-deficiency anemia in infants and young children (0-3 years of age). Pediatrics 2010;126:1040- 1050
2) Yip R, Schwartz S, Deinard A. Screening for iron deficiency with The erythrocyte protoporphyrin test. Pediatrics 1983;72:214-219
3) Siegel JM, LaGrone DH. The use of zinc protoporphyrin in screening young children for iron deficiency. Clin Pediatr 1994;33:473-479
4) Rettmer RL,m Carlson TH, Origenes ML Jr, et al. Zinc protoporphyrin/heme ratio for diagnosis of preanemic iron deficiency Pediatrics 1999;104:e37
5) Mei Z, Parvanta I, Cogswell ME et al. Erythrocyte protoporphyrin or hemoglobin: which is a better screening test for iron deficiency in children and women? Am J Clin Nutr 2003;77:1229-1233
6) Labbé RF, Dewanji A. Iron assessment tests: transferrin receptor vis-à-vis zinc protoporphyrin. Clin Biochem 2003;37:165-174
7) Crowell R, Ferris AM, Wood RJ, et al. Comparative effectiveness of zinc protoporphyrin and hemoglobin concentrations in identifying iron deficiency in a group of low-income, preschool-aged children: practical implications of recent illness. Pediatrics 2006;118:224-232
8) Jacobs A, Miller F, Worwood M, Beamish MR, Wardrop CA. Ferritin in the serum of normal subjects and patients with iron deficiency and iron overload. Br Med J. 1972;4(5834):206 –208
9) Walters GO, Miller FM, Worwood M. Serum ferritin concentration and iron stores in normal subjects. J Clin Pathol. 1973;26(10):770 –772
10) Cook JD, Lipschitz DA, Miles LE, Finch CA. Serum ferritin as a measure of iron stores in normal subjects. Am J Clin Nutr. 1974;27(7):681– 687
11) Dallman PR, Reeves JD, Driggers DA, Lo YET. Diagnosis of iron deficiency: the limitations of laboratory tests in predicting response to iron treatment in 1-year-old infants. J Pediatr 1981;99:376-381
Conflict of Interest:
None declared
Response to comments on iron recommendations
Re: CR120445, Diagnosis and prevention of iron deficiency and iron deficiency anemia in infants and young children (0-3 years)(1)
To the Editors:
Iron nutriture has always been a difficult, controversial, but important topic in pediatrics. It is not surprising that the AAP’s clinical report on iron has generated a number letters. We thank Dr Schanler, Dr Furman and Drs Hernell and Lönnerdahl for their comments on our report on iron.
Their comments focus on the recommendation that full-term exclusively breastfed babies receive iron supplementation starting at four months of age and continuing until a complementary dietary source of iron is established. In making this recommendation, we weighed the potential harm of not supplementing these infants with the potential harm of providing supplemental iron. We readily admit that the evidence on either side of this equation is not yet certain; however, we concluded that there was substantial and growing evidence of behavioral and developmental harm from iron deficiency (ID) and scant and yet to be established evidence of deleterious effects from iron supplementation. We also concluded that exclusively breastfed infants are at risk of becoming iron deficient. One objection voiced by each of these letters is that our report cites only one study that reports on exclusively breastfed, term babies who received iron or placebo in a blinded manner (Friel, et al)(2). While the authors of our report felt that Friel’s study was the best available, there are other studies that show that breastfed babies are at risk of ID and iron deficiency anemia (IDA) and/or that iron supplementation improves iron status of these infants (Pizzaro et al.(3) Calvo et al.(4) Arvas et al.(5) Innis et al.(6) Zeigler et al.(7) Hokama et al.(8)). The paper by Calvos et al. includes a calculation that concludes that the iron required by an infant in the first year exceeds, by several fold, the total amount of iron available in breastmilk. Despite the fact that the calculation is theoretical and open to question, it is provocative. Others have pointed out that by the time an exclusively breastfed infant doubles his birthweight, supplemental iron is necessary since breast milk alone will not supply the iron to support the infant’s needs.
In questioning the recommendation, Dr Furman challenges the validity of the study by Friel. In particular she points out the small sample size, the high drop out rate, and the questionable power of the study. Of course a larger study would be more reassuring that the correct conclusions were made. Large, powerful studies protect against type II errors. Since statistical differences in visual acuity psychomotor development were documented, the validity of the conclusion is not in question. It would, for instance, not be correct to use Friel’s data to try to demonstrate that iron supplementation caused no harm. For this a much larger study would be necessary. The drop out rate reflects the real life problems inherent in studies of this sort. We believe that one can draw conclusions regarding neurodevelopment from Dr. Friel’s data and that those conclusion are scientifically justified. It is important to note that we based our overall assessment of the relationship between iron status and neurodevelopment on many studies(9,10,11), including meta- analyses(12,13), not just on Dr. Friel’s work.
Dr Furman cites a recent study by Ziegler et al.7 We assert that this study actually supports our recommendations. The study examined iron status and not neurodevelopment. It demonstrated a statistically significant “moderate” improvement in iron status in supplemented infants. The difference did not last beyond the time of supplementation. Combining the conclusions of this study with those of Dr Lozoff (9,10,11) that tracked neurodevelopmental changes two decades after iron deficiency has been corrected, we would contend that it is important to prevent any period of iron deficiency in infants and young children.
Each of the critiques from Schanler, Furman and from Hernell and Lönnerdahl mention “harm” from iron supplementation. To substantiate harm they point to a study, co-authored by Hernell and Lönnerdahl,(14) which reported that a small number of exclusively breastfed Swedish babies (n =31) supplemented with iron beginning at 4 months had decreased length (one centimeter) despite responding with a rise in serum hemoglobin. The impact on length did not occur in the Honduran comparison group. We await further studies confirming this finding, but we could find no previous reports of such an effect. Several subsequent studies including Friel’s(2) and Zeigler’s (7) looked for an effect on linear growth, but found none, though these studies were not powered to exclude harm. The Swedish infants, supplemented or not, had a positive Z-score for length at all time points measured. An alternative explanation for the small effect on growth could be “catch down growth”. There is considerable “adjustment” in growth during the first year. In developed countries babies are larger and tend to catch down while smaller babies catch up. In Lönnerdahl’s study the supplemented Swedish infants were significantly larger than the unsupplemented babies at the outset. Thus the larger Swedish babies may have been exhibiting normal “catch down” growth rather than an adverse effect of iron supplementation. While proving no harm is statistically difficult, we would like to point out that for approximately the past 30 years standard formula in the United States has contained 12 mg/L iron which by most calculation is more than double the concentration needed to supply the iron requirements. No harmful effects have been documented. We realize that both human milk and formula are complex matrices, and iron absorption from human milk is different from formula and absorption from both is different from supplemental iron; however, once absorption has taken place, iron from all sources is treated similarly. By any criteria, the less than a centimeter difference in length while maintaining a positive z score for length could not be classified as harm.
Lönnerdahl et al. have used their finding of increased Hb in response to supplements in Swedish breastfed infants in their study to argue that the infants have disregulation of iron absorption (15). Dr. Furman also brings up the idea of disregulation in her criticism. We found this explanation intriguing, but unsubstantiated. At six months the iron absorption from human milk was reported as 11.9+7.4% in iron supplemented infants and 17.8+12.2% in unsupplemented infants. There were just 6 infants in the supplemented group and 19 in the unsupplemented group. While there was no statistical difference, these numbers are far too few to prove “no difference”. We await further studies to either confirm or refute the conclusion of Lönnerdahl et al. Since “no difference” was the basis for the disregulation hypothesis, we question disregulation of iron absorption during the first six months of life. Iron is a highly regulated metal. Regulation occurs at the level of intestinal lumen, the apical and basal lateral surfaces of the enterocyte as well as within the enterocyte. There is regulation by transport proteins as well as entrance and exit for storage sites. The utilization of iron at the level of the erythron is regulated as well as the salvage of iron via macrophages. For Lönnerdahl’s explanation to be valid there would necessarily be a breakdown at least two levels of regulation, not merely at the level of absorption but also at the erythron. We offer an alternative explanation for Lönnerdahl’s findings, that the increase in Hb in apparent response to iron supplementation suggests that the additional iron is needed by these breastfed infants to increase erythropoesis.
Hernell and Lönnerdahl argue that the prevalence of iron deficiency is very low. However, we would point out that the prevalence data is based solely on hematologic criteria which are set somewhat arbitrarily and may not be relevant to consideration of neurobehavioral development. In our deliberations we were persuaded that the potential negative and long-lasting influence of iron deficiency (iron deficiency taken to mean body iron content low enough to hinder optimal function) overpowered any possible negative effects. Dr Schanler suggests that instead of universal supplementation of exclusively breastfed infants, that we perform screening of “at risk” infants. We address, in the report, the difficulty in identifying “at risk” infants. We also highlight the problems inherent to a targeted screening program. In Dr. Betsy Lozoff’s editorial (16) that accompanied Dr Friel’s paper, she states “No simple accurate way of identifying breastfed infants at 1-2 months who will later become iron deficient is available now or in the foreseeable future.” The recommendation for universal supplementation avoids the issue of screening. It would be difficult to decide whom to screen, because risk factors in addition to exclusive breastfeeding may include infants of diabetic mothers, maternal iron deficiency, twins, late preterm infants, children of minority mothers, children not in daycare, lower SES, such that the population to be screened encompasses a large percentage of most physician practices in the United States..What tests to use for screening and what levels would be considered abnormal are also problematic.. Also, from a practical point of view, it would be difficult to persuade parents and pediatricians to agree to screening studies that would necessitate a venipuncture.
Dr. Schanler suggests that rather than recommending iron supplements other means of improving the iron deficit of breastfeeding infants be exploited. In particular Dr Schanler mentions early cord clamping. This clinical report is specifically directed toward the pediatrician and the authors of our report felt that recommendations for early versus late cord clamping is not under the direct control of pediatricians, but the American College of Obstetrics and Gynecology; thus while the AAP and/or the Section on Breastfeeding may want to advocate for late cord clamping in a joint statement with our obstetrical colleagues, this is beyond the purview of this report.
We stand by the conclusions of our report, specifically with regards to iron supplementation of breastfed infants. While the definitive studies have not been done, a mounting body of evidence supports that iron deficiency is associated with developmental and behavioral changes. Data from the present pediatrics population indicates that iron deficiency is common at 12 months of age. Iron deficiency occurs long before there is overt anemia and may have long lasting consequences. Because of the very low iron content of human milk, exclusively breastfed infants are a risk of iron deficiency. Supplementing breastfed infants would protect them. Why put these infants at any risk, when no appreciable harm of iron supplementation has been convincingly demonstrated?
Sincerely,
Robert D. Baker, MD, PhD, FAAP Frank R. Greer, MD, FAAP
1. Baker RD, Greer FR and the American Academy of Pediatrics Committee on Nutrition. Clinical report diagnosis and prevention of iron deficiency and iron-deficiency anemia in infants and young children (0-3 years of age). Pediatr, published on line Oct 5, 2010. DOI:10.1542/peds.2010-2576.
2. Friel JK, Aziz K, Andrews WL, Harding SV, Courage ML and Adams RJ. A double-masked randomized control trial of iron supplementation in early infancy in healthy term breast-fed infants. J Pediatr 2003; 143: 582-586.
3. Pizarro F, Yip R, Dallman PR, Olivares M, Hertrampf E, Walter T. Iron status with different feeding regimens: relevance to screening and prevention of iron deficiency. J Pediatr 1991; 118:687-692.
4. Calvo EB, Galindo AC, Aspres NB. Iron status of exclusively breast-fed infants. Pediatr 1992; 90:375-379.
5. Arvas A, Elgörmüs Y, Gür E, Alikaþifoðlu M, Çelebri A. Iron status in breast-fed full-term infants. Turkish J Pediatr 2000; 42:22-26.
6. Innes SM, Nelson CM, Wadsworth LD, MacLaren IA, Lwanga D. Incidence of iron deficiency anemia and depleted iron stores among nine- month old infants in Vancouver , Canada. Canada J Public Health 1997; 88:80-84.
7. Ziegler EE, Nelson SE, Jeter JM. Iron supplementation of breastfed infants from an early age. Am J Clin Nutr 2009; 89:525-532.
8. Hokama T. Levels of serum ferritin and total body iron among infants with different feeding regimens. Acta Pediatr Japn 1993; 35:298- 301.
9. Lozoff B, Jimenez E, Wolf AW. Long-term developmental outcome of infants with iron deficiency. New Engl J Med. 1991; 325:687-694.
10. Lozoff B, Jimenez E, Hagan J, Mollen E, Wolf AW. Poorer behavioral and developmental outcome more than 10 years after treatment for iron deficiency in infancy. Pediatr 2000; 105(4). Available at: www.pediatrics.org/cgi/content/full/105/4/e51
11. Lozoff B, De Andraca I, Castillo M, Smith JB, Walter T, Pino P. Behavioral and delvelopmental effects of preventing iron-deficiency anemia in healthy full-term infants [Published correction appears in Pediatr 2004; 113(6):1853]. Pediatr 2003; 112(4): 846-854.
12. Logan S, Martins S, Gilbert R. Iron therapy for improving psychomotor development and cognitive function in children under the age of three with iron deficiency anemia. Cochrane Database Syst Rev. 2001;(2):CD001444.
13. McCann JC, Ames BN. An overview of evidence for a causal relation between iron deficiency during development and deficits in cognitive or behavioral function. Am J Clin Nutr. 2007;85(4):931-945
14. Dewey KG, Domellöf M, Cohen RJ, Landa Rivera R, Hernell O, Lönnerdal B. Iron supplementation effects growth and morbidity of breast- fed infants: results of a randomized trial in Sweden and Honduras. J Nutr. 2002;132(11):3249-3255.
15. Domellöf M, Lönnerdahl B, Abrams SA, Hernell O. Iron absoption in breast-fed infants: effect of age, iron status, iron supplements, and complementary foods. Am J Clin Nutr 2002; 76: 198-204.
16. Lozoff B. Do breast-fed benefit from iron before 6 months? J Pediatr 2003; 143:554-556.
Conflict of Interest:
None declared
Recommendations on iron questioned
We read with interest the recently published Clinical Report – Diagnosis and Prevention of Iron Deficiency and Iron-Deficiency Anemia in Infants and Young Children (0-3 Years of Age) by RD Baker, FR Greer and the Committee on Nutrition of the American Academy of Pediatrics (1), but were astonished to find that the authors recommend changing the recommendation on provision of iron, now to include all breastfed infants, based on one (1) clinical study and at the same time ignoring clinical studies suggesting adverse effects of this practice. This is especially surprising as they in their introductory part emphasize the need for larger studies and systematic reviews for evaluating the potential correlation between iron deficiency anemia (IDA) and iron deficiency (ID) and neurodevelopment, and conclude that “an unequivocal relationship between IDA and ID and neurodevelopmental outcomes has yet to be established”. In the study by Friel et al (2), which is the basis for the new recommendations, term breastfed infants were randomly selected to receive either 7.5 mg/day of elemental iron as ferrous sulfate or placebo from one month (study entry) to 6 months of age and anthropometry and hematological indexes were evaluated at entry and at 3.5, 6 and 12 months of age. In addition, mental and psychomotor developmental indexes (MDI and PDI) were assessed by the Bayley scales and visual acuity assessed by Teller cards at 12 to 18 months of age. One problem, which the authors acknowledge, is that the study was underpowered, partially due to the low initial breastfeeding rate in the population studied, and partially due to the high dropout rate. In fact, the authors´ power calculation arrived to the conclusion that 100 infants would be needed in each group to detect a 5 percent difference in MDI and PDI, but at 12 months of age only 26 and 20 infants, respectively, were available for intention-to-treat analyses, and only 24 and 17 had received iron for more than 30 days of the intended 150 days. There was a trend toward improved visual acuity with iron supplementation, which became significant only when excluding non- compliers. It is questionable whether an effect on visual acuity as measured by Teller cards can be based on 17 and 23 infants at a mean age of 13 months (12-18 months) (3,4). Power calculations for anthropometry and hematological indexes were not reported, but it is generally agreed that for anthropometry considerably larger sample sizes are needed. From what we have learned during the last decades on the association of the intakes of docosahexaenoic acid (DHA) and neurodevelopment interpretations of the effect of single nutrients based on underpowered studies warrant caution (3-5). Friel et al found a difference of 7 points in PDI and mean values for both groups were within the normal range. The new recommendations is to give iron supplements, 1 mg/kg/day, to all breastfed infants (if breast milk constitute more than half of their daily feedings) from 4 months of age until appropriate iron-containing complementary foods are introduced into the diet. This is based on the observation by Friel et al that infants in the intervention group had significantly higher hemoglobin (Hb) concentration and mean corpuscular volume (MCV) value than the infants in the placebo group at 6 months of age, based on 28 and 21 infants, respectively (2). Iron supplements prevented the decrease in Hb concentration seen in breastfed infants not given supplementary iron and reduced the decrease in serum ferritin level. In our studies comparing various levels of iron content in infant formulas we found no difference in Hb concentration reflecting the difference in iron intake, and more iron in the formula did not prevent the decrease in Hb concentration between 1 and 6 months of age (6-7). In our study on the effects of giving exclusively breastfed infants iron supplements as iron drops we found that giving supplements between 4 and 6 months increased Hb (8). Thus, it seems that giving iron as supplements affects Hb differently from giving more iron as fortification in formulas (9). Our interpretation is that increased Hb does not necessarily reflect previous ID or IDA but the effect may rather reflect immature metabolism of surplus iron. When we compared Honduran infants (with initially lower iron status) with Swedish infants (with satisfactory iron status) the change in Hb between 4 and 6 months was very similar (+ 5g/L in both groups), emphasizing that Hb increases with iron supplementation regardless of initial iron status. Thus, the suggestion by the authors to use Hb response to iron supplementation as a diagnostic tool for IDA (1) is in our view highly questionable in that age group. It should be noted that in the study by Friel et al (2) there was a slower decrease in serum ferritin in the intervention group, but the values continued to decrease until 12 months of age, with no difference between the groups at that age, also reflecting that supplemental iron between 1 and 6 months did not affect iron stores at 12 months, supporting our observation that supplemental iron in contrast to fortification iron is not incorporated into ferritin during the first half of infancy (9). These shifts in associations between dietary iron intake, and Hb and serum ferritin, respectively may be due to developmental changes in the channeling of dietary iron to erythropoiesis relative to storage, in the absence of IDA (10). We find it notable that the authors do not clearly discriminate between iron fortification, i.e. iron content in infant formulas, and iron supplementation, i.e. medicinal iron given as iron drops, when discussing potential adverse effects of high iron intakes. We have shown that iron supplements to iron-replete Swedish breastfed infants at the same level as now recommended in the clinical report had significant negative effect on linear growth. In contrast, there was no obvious effect on growth in the Honduran cohort of the same study. However, when the latter infants were divided into iron deficient and iron-replete infants, a negative effect was seen in the iron-replete subgroup (11). This most likely explains why this adverse effect has not been noted in more studies as most populations studied include a significant proportion of iron deficient infants and/or children, thus obscuring a negative effect on iron- replete infants. In fact, when initial infant iron status has been measured and groups have been studied separately with regard to outcome an adverse effect has been noticed in several studies (12-14). While these studies were performed in developing countries, it is interesting that a recent study by Ziegler et al in which the effect of medicinal iron and iron fortified cereals between four and nine months of age was evaluated (i.e. a design similar to ours), a significant reduction in length gain and a trend towards reduced weight gain was noted (15). Our suggestion that iron in fortified foods is handled differently from medicinal iron and that this needs to be taken into account when recommendations are given (9) is thus in agreement with the study by Ziegler et al (15) who observed the adverse effect in the infants given medicinal iron, but not in the group given fortified cereals. While we agree with the authors that few adverse effects have been noted for “high” iron fortified infant formulas (12 mg/L), we still believe that this level is unnecessarily high and some caution is warranted. This is also the position taken by the ESPGHAN coordinated international expert group on a global standard for the composition of infant formulas (16). Although iron may be better absorbed from breast milk than from infant formula it seems unreasonable that infant formula should contain approximately 4,000 % more iron than the average concentration in breast milk! Several studies have shown similar iron status in infants receiving infant formulas containing 4 or 7-8 mg iron/L, and in fact, we have shown similar iron status in infants fed formula containing 1.8 mg iron/L up till 6 months of age (7). Iron is a known pro-oxidant and having a high luminal concentration of iron may not be beneficial, although the adverse consequences may not be immediately apparent. Infant formula containing high level of iron has been shown to be less protective against oxidative stress than breast milk in vitro (17), but clinical studies on this are scarce. Although we believe that the risk of adverse effects is lower with iron fortification than with medicinal iron, a recent study by Lozoff et al. suggests a long term negative effect of high iron formula on neurodevelopment (18). We also find it surprising that Baker and Greer do not discuss the problem of diagnosing ID and IDA during infancy when iron metabolism obviously is in dynamic change, i.e. if the same cut-offs for Hb and serum ferritin should be used to define ID and IDA throughout infancy. We have suggested that this may not be the case (19). Nor do they discuss particular risk groups for ID among the population of term breastfed infants, e.g. those with birth weight between 2,500 and 3,000 g (20). Friel and collaborators concluded from their study: “A larger study that focuses on the long-term developmental outcomes is needed before recommendations can be considered regarding the whole population of breast -fed infants”. We are surprised that Baker and Greer on behalf of the Committee on Nutrition of the American Academy of Pediatrics (1) reached a different conclusion. Neither do we believe that recommending iron supplements to the population of breastfed infants at large is appropriate, nor that an iron fortification level of infant formulas as high as 12 mg/L is necessary. In both cases we find the lack of an evidenced-based approach remarkable, particularly as these recommendations will be used for US infants in general.
Olle Hernell, MD, PhD Bo Lönnerdal PhD Department of Clinical Sciences/Pediatrics Department of Nutrition Umeå University University of California Sweden Davis, CA, USA
References 1. Baker RD, Greer FR, and the Committee of Nutrition of the American Academy of Pediatrics. Clinical Report – Diagnosis and prevention of iron deficiency and iron deficiency anemia in infants and young children (0-3 years of age). Pediatrics 2010;126(5):1-11 2. Friel JK, Aziz K, Andrews WL, Harding SV, Courage ML, Adams RJ. A double-masked, randomized controlled trial of iron supplementation in early infancy in healthy term breast-fed infants. J Pediatr 2003;143:582-6 3. SanGiovannia JP, Catherine S. Berkey CS, Dwyer JT, Colditz GA. Dietary essential fatty acids, long-chain polyunsaturated fatty acids, and visual resolution acuity in healthy fullterm infants: a systematic review. Early Hum Dev. 2000;57(3):165-88 4. Simmer K, Patole SK, Rao SC. Longchain polyunsaturated fatty acid supplementation in infants born at term. Cochrane Database Syst Rev. 2008 Jan 23;(1):CD000376 5. Beyerlein A, Hadders-Algra M, Kennedy K, Fewtrell M, Singhal A, Rosenfeld E, Lucas A, Bouwstra H, Koletzko B, von Kries R. Infant formula supplementation with long-chain polyunsaturated fatty acids has no effect on bayley developmental scores at 18 months of age—IPD meta-analysis of 4 large clinical trials. J Pediatr Gastroenterol Nutr 2010;50(1):79-84 6. Lönnerdal B, Hernell O. Iron, zinc, copper and selenium status of breast-fed infants and infants fed trace element fortified milk-based infant formula. Acta Paediatr 1994;83(4):367-73 7. Hernell O, Lönnerdal B. Iron status of infants fed low-iron formula: no effect of added bovine lactoferrin or nucleotides. Am J Clin Nutr 2002;76(4):858-64 8. Domellöf M, Cohen RJ, Dewey KG, Hernell O, Rivera LL, Lönnerdal B. Iron supplementation of breast-fed Honduran and Swedish infants from 4 to 9 months of age. J Pediatr 2001;138(5):679-87 9. Domellöf M, Lind T, Lönnerdal B, Persson LA, Dewey KG, Hernell O. Effects of mode of oral iron administration on serum ferritin and haemoglobin in infants. Acta Paediatr 2008;97(8):1055-60 10. Lind T, Hernell O, Lönnerdal B, Stenlund H, Domellöf M, Persson LA. Dietary iron intake is positively associated with hemoglobin concentration during infancy but not during the second year of life. J Nutr 2004;134(5):1064-70 11. Dewey KG, Domellöf M, Cohen RJ, Landa Rivera L, Hernell O, Lönnerdal B. Iron supplementation affects growth and morbidity of breast-fed infants: results of a randomized trial in Sweden and Honduras. J Nutr 2002;132(11):3249-55 12. Idjradinata P, Watkins WE, Pollitt E. Adverse effect of iron supplementation on weight gain of iron-replete young children. Lancet. 1994;343:1252-4 13. Majumdar I, Paul P, Talib VH, Ranga S. The effect of iron therapy on the growth of iron-replete and iron- deplete children. J Trop Pediatr. 2003;49:84-8 14. Lind T, Seswandhana R, Persson LA, Lönnerdal B. Iron supplementation of iron-replete Indonesian infants is associated with reduced weight-for- age. Acta Paediatr 2008;97:770-5 15. Ziegler EE, Nelson SE, Jeter JM. Iron status of breastfed infants is improved equally by medicinal iron and iron-fortified cereal. Am J Clin Nutr 2009;90(1):76-87 16. Koletzko B, Baker S, Cleghorn G, Neto UF, Gopalan S, Hernell O, Hock QS, Jirapinyo P, Lonnerdal B, Pencharz P, Pzyrembel H, Ramirez-Mayans J, Shamir R, Turck D, Yamashiro Y, Zong-Yi D. Global standard for the composition of infant formula: recommendations of an ESPGHAN coordinated international expert group. J Pediatr Gastroenterol Nutr 2005;41(5):584-99 17. Friel JK, Martin SM, Langdon M, Herzberg GR, Buettner GR. Milk from mothers of both premature and full-term infants provides better antioxidant protection than does infant formula. Pediatr Res 2002;51(5):612-8 18. Lozoff B, Castillo M, Smith JB. Poorer developmental outcome with 12 mg/L iron-fortified formula in infancy. Abstract 2225, Pediatric Academic Societies Annual meeting, Honolulu, HI, 2008, EPASS2008: 635340.2 19. Domellöf M, Dewey KG, Lönnerdal B, Cohen RJ, Hernell O. The diagnostic criteria for iron deficiency in infants should be reevaluated. J Nutr. 2002;132:3680-6 20. Yang Z, Lönnerdal B, Adu-Afarwuah S, Brown KH, Chaparro CM, Cohen RJ, Domellöf, M, Hernell O, Lartey A Dewey KG. Prevalence and predictors of iron deficiency in fully breastfed infants at 6 mo of age: comparison of data from 6 studies. Am J Clin Nutr 2009;89:1433–40
Conflict of Interest:
None declared
Red meats for dietary iron: a concerning AAP recommendation
As a family physician, nutrition enthusiast, public-health researcher, and parent of a toddler, I read with great interest the AAP clinical report on the diagnosis and prevention of iron deficiency and iron-deficiency anemia in infants and young children.1 The report addresses two important deficiency states and, in general, gives sound clinical advice based on the best available evidence.
Where the report raises concern is in its statements about red meat. For instance the authors talk about “heme sources of iron (ie, red meat) …”. Red meat is certainly a source of heme iron, and if one allows that “ie” is a typo for “eg”, than the reader has no cause for concern. However, later in the article, summary recommendations suggest reader concern is actually warranted (the authors seem unduly biased in favor of red meat over other heme—and over non-heme—sources of iron). For instance, recommendations state that for 1 to 3 year olds, sufficient iron would “best be delivered by eating red meats, cereals fortified with iron, vegetables that contain iron, and fruits with vitamin C”.
“Best be delivered by eating red meats”? (And red meats as the first and most prominently featured source of iron?) Data from the report’s own Table 3 (Foods to Increase Iron Intake and Iron Absorption) suggests why red meats should not be listed first, or considered best. In fact, the elemental iron available in red meats pales in comparison to that from shellfish. While there may be arguments to avoid excessive shellfish consumption in toddlers,2 the elemental iron in red meats also pales in comparison to that from legumes (eg, soybeans/tofu and lentils). It is, of course, possible that the authors lump “legumes” with other “vegetables that contain iron” in their recommendation, and further consider non-heme (ie, plant-derived) iron sources inferior to heme (ie, animal-derived) sources due to absorbability. Yet while non-heme iron itself may be less absorbable, heme sources of iron may be far less preferable for other reasons.
Particularly less-preferable is red meat. One need only consider direct implications for health (eg, food safety3, chronic-disease risk4, 5, and potential early mortality6) to understand why—although other implications for overall community and world wellness are also important (eg, human rights considerations7, environmental justice issues8, and the impact on climate change9). Given that dietary behaviors develop throughout childhood,10 why would AAP recommend starting children down a carnivorous path towards potentially poor personal, public, and planetary health?
It would appear that recommendations for red meat in the AAP iron- deficiency statement represent either a misreading of the facts, unsupported personal biases, or insidious industry influence. The report’s conflict-of-interest disclosure reassures against the third possibility, but neither of the two remaining options is comforting. When the health of children is at stake, only the soundest dietary guidance will do. In the case of iron, and diet in general, I would submit that AAP consider modifying its recommendations to be consistent with general advice for healthful eating: e.g. “For adequate iron and good nutrition, focus mostly on eating legumes and other vegetables, whole grains, and fruit. If you choose to consume animal products, choose fish and shellfish over other meats, particularly red meat”.
No conflicts of interest to disclose
Sean C. Lucan, MD, MPH, MS Department of Family and Social Medicine Montefiore Medical Center Albert Einstein College of Medicine 1300 Morris Park Ave Mazer Building, Room 410 Bronx, NY 10461 Tel: (718) 430-3667 Fax: (718) 430-8645
References:
1. Baker RD, Greer FR. Diagnosis and prevention of iron deficiency and iron-deficiency anemia in infants and young children (0-3 years of age). Pediatrics. 2010;126(5):1040-1050.
2. United States Food and Drug Administration. What You Need to Know About Mercury in Fish and Shellfish: 2004 EPA and FDA Advice For Women Who Might Become Pregnant, Women Who are Pregnant, Nursing Mothers, Young Children. http://www.fda.gov/food/foodsafety/product- specificinformation/seafood/foodbornepathogenscontaminants/methylmercury/ucm115662.htm. Published 2004. Accessed November 15, 2010.
3. Price L. Prevalence of high-priority antibiotic resistant bacteria in the US food supply. American Public Health Association 138th Annual Meeting and Expo. http://apha.confex.com/apha/138am/webprogram/Paper232107.html. Published 2010.
4. Bernstein AM, Sun Q, Hu FB, Stampfer MJ, Manson JE, Willett WC. Major Dietary Protein Sources and Risk of Coronary Heart Disease in Women. Circulation. 2010.
5. Key TJ, Schatzkin A, Willett WC, Allen NE, Spencer EA, Travis RC. Diet, nutrition and the prevention of cancer. Public Health Nutr. 2004;7(1A):187-200.
6. Fung TT, van Dam RM, Hankinson SE, Stampfer M, Willett WC, Hu FB. Low-carbohydrate diets and all-cause and cause-specific mortality: two cohort studies. Ann Intern Med. 2010;153(5):289-298.
7. Human Rights Watch. Blood, Sweat, and Fear: Workers’ Rights in U.S. Meat and Poultry Plants. http://www.hrw.org/en/reports/2005/01/24/blood-sweat-and-fear-0. Published 2004.
8. Wenz PS. Environmental justice. Albany: State University of New York Press; 1988.
9. Walsh B. Meat: Making Global Warming Worse. Time magazine Wednesday, September 10, 2008.
10. Birch LL, Fisher JO. Development of eating behaviors among children and adolescents. Pediatrics. 1998;101(3 Pt 2):539-549.
Conflict of Interest:
None declared
Exclusively breastfed infants: iron recommendations are premature
Dear Editor,
The new AAP recommendations for prevention of iron deficiency and iron deficiency anemia conclude that “exclusively breastfed term infants [should] receive an iron supplement of 1 mg/kg/day starting at 4 months of age.” (1) Prevention of iron deficiency and iron deficiency anemia are important public health goals. But while late preterm and low birth weight infants and other infants with risk for low iron stores may benefit from iron supplementation, this recommendation is controversial with respect to healthy full term infants with birth weight over 2500 grams, who represent the largest proportion of exclusively breastfeeding infants in the US.
The study referenced in the AAP recommendation included 77 full term infants randomized to 7.5 mg of iron daily or placebo from one to six months of age. (2) By 6 months of age, 26 infants (34%) had dropped out of the study, 15 (19%) were noncompliant with iron/placebo treatment, and most in both groups were receiving formula (i.e. not exclusively breastfeeding), with all but 3 infants also receiving cereal. Although the study initially was powered to evaluate development, enrollment stopped prior to the full number needed, and so the results regarding neurodevelopmental outcomes are interesting but not conclusive or scientifically defensible. This particular data set is not ideal for support of a significant AAP policy recommendation.
A more recent study enrolled 75 full term infants and supplemented 37 with 7 mg/day of iron and 38 with placebo from age 1 to 5.5 months; 63 infants completed the intervention (16% drop out rate).(3) Two infants (6%) in the placebo group were iron deficient by 5.5 months. The study was not powered to test the hypothesis that iron supplementation prevents iron deficiency, and the effect of treatment on iron stores was “modest” and did not extend beyond the period of supplementation.
Finally, among exclusively breastfed Swedish infants at 6 months of age, there was no statistically significant difference between those who had received iron from 4 months of age and those who had received placebo in measures of iron sufficiency including MCV, serum ferritin, zinc protoporphyrin or transferrin receptors.(4) Although iron supplementation increased hemoglobin levels, it did not decrease the already low prevalence of iron deficiency or iron deficiency anemia (2.9%) observed in these infants. In this study, infants over 6 months of age with lower body iron stores absorbed more iron than iron-replete peers, while iron absorption among infants 4-6 months of age was not apparently related to the sufficiency of iron stores, suggesting that self-regulatory mechanisms develop in later infancy. (4) Thus it appears that 4-6 month olds will absorb the additional iron they receive whether they need it or not.
There is very limited information about the effect of giving iron to iron-replete infants. A negative effect of iron supplementation on linear growth among iron-replete infants has been suggested though not confirmed. (5) Whether saturation of lactoferrin due to iron supplementation could diminish its immunomodulatory functions and increase the risk of infection among exclusively breastfed infants has not been studied. Finally, although biological plausibility certainly exists with regards to a hypothesized relationship between iron deficiency and neurodevelopmental outcome, evidence among infants below the age of 2 years is extremely limited, and studies are handicapped by small sample size and lack of randomization.(6 )
The great majority of healthy full term exclusively breastfed infants with birth weights over 2500 grams in the US do not have iron deficiency by 6 months of age. These infants do not need iron, and it is not known whether iron supplementation negatively affects growth (or risk of infection). There is also not yet evidence that iron supplementation as recommended improves developmental outcome among the minority of infants who are iron deficient and could theoretically benefit from iron.
The new recommendation will generate a great deal of prescribing. It may generate additional testing of iron status and hemoglobin as parents will appropriately ask if their infant is “OK”. And while infants in studies are treated to cherry flavored and palatable iron suspensions, insurance-covered iron drops are not as tasty, and parents and infants may object to the drops. Although none of these latter factors is a “deal breaker”, each should be considered.
The AAP has PROS (Pediatric Research in Office Settings), a large network of practices that collaborate in performing office-based research. Why not harness this resource to study the question of whether iron supplementation, as compared to non-supplementation, from 4-6 months of age among exclusively breastfed infants with birth weight >2500 grams (1) prevents iron deficiency, and (2) has a beneficial effect on developmental outcome, and (3) is at least neutral with respect to growth and risk of infection. This seems to be a golden opportunity to make sure that recommendations are based on evidence gathered in studies with an optimal sample size, powered to answer the question(s) at hand.
I recognize that a great deal of hard work and thought has gone into these current recommendations, and that they utilize the best available information well considered by experts. However, I believe it would be preferable to do the best study possible, and then make a recommendation based on that evidence.
Thank you for your consideration,
Lydia Furman, M.D.
1. Baker RD, Greer FR and the American Academy of Pediatrics Committee on Nutrition. Clinical report diagnosis and prevention of iron deficiency and iron-deficiency anemia in infants and young children (0-3 years of age). Pediatr, published on line Oct 5, 2010. DOI:10.1542/peds.2010-2576.
2. Freil JK, Aziz K, Andrews WL, Harding SV, Courage ML and Adams RJ. A double-masked randomized control trial of iron supplementation in early infancy in healthy term breast-fed infants. J Pediatr 2003; 143: 582-586.
3. Ziegler EE, Nelson SE, and Jeter JM. Iron supplementation of breastfed infants from an early age. Am J Clin Nutr 2009; 89: 525-532.
4. Domellöf M, Cohen RJ, Dewey KG, Hernell O, Rivera LL and Lönnerdal B. Iron supplementation of breast-fed Honduran and Swedish infants from 4 to 9 months of age. J Pediatr 2001;138: 679–687. 5. Dewey KG, Magnus Domellő M, Cohen RJ, Rivera LL, Hernell H and Lőnnerdal B. Iron Supplementation Affects Growth and Morbidity of Breast-Fed Infants: Results of a Randomized Trial in Sweden and Honduras J. Nutr. 132: 3249–3255, 2002.
6. McCann JC and Ames BN. An overview of evidence for a causal relation between iron deficiency during development and deficits in cognitive or behavioral function. Am J Clin Nutr 2007; 85: 931–945.
Conflict of Interest:
None declared
Concerns with early universal iron supplementation of breastfeeding infants
October 27, 2010
RE: Concerns with early universal iron supplementation of breastfeeding infants
To the Editors:
We have major concerns about universal iron supplementation at 4 months in breastfeeding infants, reported by Drs Baker and Greer, “Clinical Report-Diagnosis and Prevention of Iron Deficiency and Iron- Deficiency Anemia in Infants and Young Children (0-3 Years of Age).”
We point out that as a clinical recommendation for millions of infants, supplementary iron drops beginning at 4 months of age is inconsistent with previous recommendations of the American Academy of Pediatrics.1-3 The only supportive data for this recommendation comes from 1 study where 77 breastfed term newborns were supplemented with iron at some time between 1 and 6 months of age.4 Follow-up studies found ‘improved’ psychomotor but not cognitive development at 13 months. It has been pointed out that this outcome is unusual and the 13 month exam is not necessarily predictive of overall developmental outcome.5
We would like the authors to acknowledge other ways to ensure that breastfeeding infants have adequate iron status. We suggest that delayed cord clamping at birth be included in their recommendations and that screening of ‘at risk’ infants be used as a guide to determine iron supplementation before 6 months.1, 6
The Clinical Report does not address potential harms of supplementation nor does it discuss the difference in bioavailability of iron contained in human milk vs. iron-fortified fluids and foods. Given that research has shown potential harm in infant growth and morbidity when iron supplementation is provided to iron-sufficient infants one wonders if universal iron supplementation will be deleterious to the population of developing infants who are breastfeeding exclusively.7
Furthermore, in a relatively recent US study the prevalence of iron deficiency anemia is low (3%) among unsupplemented breastfed infants in the first 6 mo.8
Lastly, the authors acknowledge that this report was submitted for review to the Section on Breastfeeding of the American Academy of Pediatrics. It did not mention that we disagreed and provided our additional recommendations, 2 years ago. The manuscript infers that the Section, along with many other groups, endorsed this report. This is wrong and will mislead the medical community.
We would welcome a discussion of science and changes in recommendations that are evidence-based. We do not have issues with screening at risk populations. We further request that the section “Development of this Report,” be retracted and removed from publication.
Sincerely,
Richard J. Schanler, MD, FAAP Chairperson, AAP Section on Breastfeeding
Section Executive Committee:
Lori Feldman-Winter, MD, FAAP Camden, NJ Susan Landers, MD, FAAP Austin, TX Lawrence Noble, MD, FAAP Elmhurst, NY Kinga Szucs, MD, FAAP Carmel, IN Laura Viehmann, MD, FAAP Cumberland, RI
References
1. American Academy of Pediatrics, Section on Breastfeeding. Breastfeeding and the Use of Human Milk. Pediatrics 2005; 115:496-506.
2. American Academy of Pediatrics, American College of Obstetricians and Gynecologists. Breastfeeding Handbook for Physicians. Elk Grove Village, IL: American Academy of Pediatrics; 2006.
3. American Academy of Pediatrics. Pediatric Nutrition Handbook. Pediatric Nutrition Handbook 2009.
4. Friel JK, Aziz A, Andrews WL, Harding SV, Courage ML, Adams RJ. A double-masked, randomized control trial of iron supplementation in early infancy in healthy term breast-fed infants. J Pediatr 2003; 143:582-6.
5. Lozoff B. Do breast-fed babies benefit from iron before 6 months? J Pediatr 2003; 143:554-6.
6. Hutton EK, Hassan ES. Late vs early clamping of the umbilical cord in full term neonates: systemic review and meta-analysis. JAMA 2007; 297:1241-52.
7. Dewey KG, Domellöf M, Cohen RJ, Landa Rivera L, Hernell O, Lonnerdal B. Iron supplementation affects growth and morbidity of breast- fed infants: results of a randomized trial in Sweden and Honduras. J Nutr 2002; 132:3249-55.
8. Ziegler EE, Nelson SE, Jeter JM. Iron supplementation of breastfed infants from an early age. Am J Clin Nutr 2009; 89:525-32.
Conflict of Interest:
None declared