Iron and the exclusively breast-fed infant from birth to six months

This study was designed to determine whether normal, full-term, exclusively breast-fed infants develop iron deficiency anemia, as defined by hemoglobin or red blood cell indices more than two standard deviations below the age-specific mean, or depletion of iron stores, as defined by an abnormally low serum ferritin level. Thirty-three breast-fed infants were followed from birth to 6 months. Maternal blood and cord blood at delivery, and venous blood from the infants at 2, 4, and 6 months were analyzed for anemia as defined above. At 6 months of age, the mean hemoglobin concentration of these infants was slightly higher than the normal mean; four of 33 infants (12%) had a mean corpuscular volume greater than 2 SD below the reported normal mean; and two of 33 infants (6%) had a serum ferritin level less than 12 ng protein/ml. These data suggest that the infant who is exclusively breast-fed for the first 6 months of life is not at high risk for the development of iron deficiency anemia or the depletion of iron stores during that time.     

Iron status in exclusively breast-fed infants.

The aim of this study is to evaluate the iron nutritional status of infants breast-fed exclusively and for a prolonged period in relation to their growth rate and dietary changes. Forty subjects (25 breast-fed; 15 formula-fed) were studied from 0 to 9 months of age. Milk (human or formula) was the only source of food during the first 6 months. From the sixth month onward mothers were instructed to use iron- and ascorbic acid-rich foods to supplement breast-feeding. At the ninth month, prevalence of anemia was 27.8% in the breast-fed group and 7.1% in the formula-fed group. Storage iron was absent in 27.8% of the breast-fed infants vs none of the formula-fed infants. These findings reinforce the recommendation that breast-fed infants be given supplemental iron from the fourth month of life.     

Does maternal iron supplementation during the lactation period affect iron status of exclusively breast-fed infants?

Iron deficiency anemia (IDA) causes growth and developmental retardation in infants. Iron supplementation from the 4th month of age may prevent IDA, but side effects of oral iron supplementation limit its usage. The aim of this study was to investigate the effect of maternal iron supplementation on the iron status of mothers and their exclusively breast-fed infants. In a prospective, placebo-controlled, double-blinded randomized study, healthy mothers (Hb > or = 11 g/dl) and their 10-20-day-old healthy term infants who were admitted to Hacettepe University for neonatal screening were enrolled. The mothers who were intending to exclusively breast-feed at least up to four months were included. Iron supplementation (n = 82, 80 mg elementary iron) and placebo (n = 86) were given to the mothers randomly for four months. The anthropometrical measurements of infants were recorded monthly. Of all, 69 mothers and their infants in the iron group and 63 in the placebo group completed the study. At the end of the study period, blood samples (complete blood count, serum iron, iron binding capacity and serum ferritin) were drawn from the mothers and their infants. After adjustment for baseline hemoglobin value, the mean levels of hemoglobin, serum iron and ferritin were similar in the two groups at the end of the study; however, serum iron binding capacity was significantly lower in the iron group than in the placebo group. Giving maternal iron supplementation during the first four months of the lactation period had no effect on the serum iron and ferritin levels of mothers and infants. This could be due to the relatively short duration of the follow-up period. A longer follow-up period is recommended to detect the effect of the maternal iron supplementation during lactation.     

Iron supplementation of breast-fed Honduran and Swedish infants from 4 to 9 months of age

OBJECTIVE: The objective was to study the effects of iron supplementation on hemoglobin and iron status in 2 different populations. Study design: In a randomized, placebo-controlled, masked clinical trial, we assigned term Swedish (n = 101) and Honduran (n = 131) infants to 3 groups at 4 months of age: (1) iron supplements, 1 mg/kg/d, from 4 to 9 months, (2) placebo, 4 to 6 months and iron, 6 to 9 months, and (3) placebo, 4 to 9 months. All infants were breast-fed exclusively to 6 months and partially to 9 months. RESULTS: From 4 to 6 months, the effect of iron (group 1 vs 2 + 3) was significant and similar in both populations for hemoglobin, ferritin, and zinc protoporphyrin. From 6 to 9 months, the effect (group 2 vs group 3) was significant and similar at both sites for all iron status variables except hemoglobin, for which there was a significant effect only in Honduras. In Honduras, the prevalence of iron deficiency anemia at 9 months was 29% in the placebo group and 9% in the supplemented groups. In Sweden, iron supplements caused no reduction in the already low prevalence of iron deficiency anemia at 9 months (<3%). CONCLUSION: Iron supplementation from 4 to 9 months or 6 to 9 months significantly reduced iron deficiency anemia in Honduran breast-fed infants. The unexpected hemoglobin response at 4 to 6 months in both populations suggests that regulation of hemoglobin synthesis is immature at this age.     

Efficacy of daily and weekly iron supplementation on iron status in exclusively breast-fed infants

Iron deficiency anemia (IDA) remains the most prevalent nutritional deficiency in infants worldwide. The purpose of this study was to determine the efficacy of daily and weekly iron supplementation for 3 months to improve the iron status in 4-month-old, exclusively breast-fed healthy infants. Infants 4 months of age were eligible for the open, randomized controlled trial if their mothers intended to continue exclusive breast-feeding until the infants were 6 months of age. Infants or mothers with iron deficiency (ID) or IDA on admission were excluded. The infants (n = 79) were randomly assigned to three groups, the first group receiving daily (1 mg/kg daily), the second group weekly (7 mg/kg weekly), and the third group no iron supplementation. Anthropometric measurements were taken on admission and at 6 and 7 months of age. Iron status was analyzed on admission and monthly for 3 months. Both hematologic parameters and anthropometric measurements were found to be similar among the three groups during the study period. Seven infants (31.8%) in the control group, six (26.0%) in the daily group, and three (13.6%) in the weekly group developed ID or IDA (P > 0.05). Infants whose mothers had ID or IDA during the study period were more likely to develop ID or IDA independently from iron supplementation. Serum ferritin levels decreased between 4 and 6 months of age in the control and daily groups; the weekly group showed no such decrease. In all groups, the mean levels of serum ferritin were significantly increased from 6 months to 7 months of age during the weaning period. In this study, which had a limited number of cases, weekly or daily iron supplementation was not found to decrease the likelihood of IDA. In conclusion, exclusively breast-fed infants with maternal IDA appeared to be at increased risk of developing IDA.     

Iron status in low birth weight infants on breast and formula feeding

Iron status in 15 low birth weight infants, 1000–2499 g, on breast feeding was studied longitudinally for the first 6 months of age, and the findings compared to those of 30 low birth weight infants receiving a proprietary iron-fortified formula. The two groups received no iron supplement until they developed iron deficiency. The incidence of iron deficiency at 6 months was significantly greater in the breast-fed group than in the formula-fed group (86% v 33%). The breast-fed group had significantly lower serum ferritin and hemoglobin values after 4 months of age. The findings indicate that breast-fed low birth weight infants have a higher risk of developing iron deficiency and should receive iron supplementation from 2 months of age.Abbreviations TIBC total iron-binding capacity - MCV mean corpuscular volume     

Folate nutrition is optimal in exclusively breast-fed infants but inadequate in some of their mothers and in formula-fed infants

Plasma concentrations of folate were studied in a group of exclusively breast-fed infants and their mothers (their numbers gradually decreased from 200 at birth to 7 at 12 months) and in infants completely weaned to a cow's milk formula (containing 35 micrograms of folate/L) and solid foods. The exclusively breast-fed infants were in no danger of folate deficiency; their plasma levels were elevated after the age of 2 months and, on average, were 2.0-3.3-fold higher than maternal levels throughout the study. None of these infants had an inadequate plasma concentration, whereas up to 5% of the mothers had values less than or equal to 3 micrograms/L, despite supplementation during lactation with 0.1 mg folate/day. In the formula-fed infants, 69-94% of the plasma folate concentrations lay below the lowest concentration for the breast-fed infants. Although no infant had signs of anemia or macrocytosis in red cell indices, the infants weaned earliest had the lowest hemoglobin concentrations (p = 0.09) and the highest mean corpuscular volume (MCV) values (p = 0.06) at 9 months of age. Thus, an infant fed a formula containing the recommended amount of folate runs a risk of folate deficiency.     

Controversies in neonatal nutrition

The assessment of growth parameters remains one of the most practical and valuable tools to estimate nutritional status in neonates. Growth assessment in full-term infants is performed by using charts developed by the National Center for Health and Statistics. The assessment of post-natal growth in premature infants is controversial and can be performed by using either intrauterine or extrauterine standards. The selection of appropriate growth charts should be based on clinical, demographic, ethnic, and socioeconomic similarities of the population used for reference. Daily energy intakes ranging from 100 to 120 kcal/kg/day have been recommended for full-term infants, while higher intakes ranging from 114 to 181 kcal/kg/day have been recommended for premature neonates. Full-term infants should be nursed or nipple fed on demand; however, premature infants should ideally be tube fed by intermittent gastric feeding (gavage). Continuous gastric and transpyloric feedings are indicated in selected infants. Human milk is a preferred food for full-term infants during the first six months of life; however, this precept does not suggest that all infants who are exclusively breast-fed will grow adequately. Preterm human milk is also a preferred food for the low birthweight infant, provided nutritional supplements are used. It is unclear whether the supplementation of vitamin D, iron, and fluoride in full-term breast-fed infants should be started at birth, at the time of initiation of solid foods, or at the age of six months. The routine supplementation of multivitamins, folic acid, and vitamin E to all low birthweight infants is controversial. Most investigators suggest vitamin supplementation be given until the intake of formula or breast milk is sufficient to meet daily requirements. Vitamin E appears to exert a protective effect in premature infants against the development of severe retinopathy. The supplementation of vitamin E should be dependent upon the serum vitamin E concentration. It is controversial whether iron supplementation for premature infants should be initiated soon after birth or at two months of age, or whether higher doses of iron should be given to very low birthweight infants. If iron supplementation is started at birth, vitamin E status should be closely monitored. Although the optimal intakes of calcium and phosphorus in infant feedings have not been firmly established, the levels of calcium and phosphorus in human milk appear to be inadequate for the growing low birthweight infant.(ABSTRACT TRUNCATED AT 400 WORDS)     

Iron status in low-birth-weight infants, small and appropriate for gestational age. A follow-up study

Iron nutrition was measured in 84 low-birth-weight infants. At birth, they were assigned to three groups: preterm infants appropriate for gestational age (n = 29); preterm infants small for gestational age (n = 17); and full-term infants small for gestational age (n = 38). A sub-sample of infants was supplemented with iron 3 mg/kg from two to four months of age. At birth, preterm appropriate-for-gestational-age infants had a lower hemoglobin concentration than full-term small-for-gestational-age infants (p < 0.01) and a higher serum ferritin than preterm small-for-gestational-age infants (p < 0.05). In the non-supplemented group, full-term small-for-gestational-age infants had significantly higher hemoglobin concentrations at four months of age. At this age, iron-supplemented preterm infants appropriate or small for gestational age had significantly higher hemoglobin levels than non-supplemented subjects, while iron supplementation did not have an effect on final hemoglobin concentration in full-term small-for-gestational-age infants. We conclude that preterm infants, irrespective of their adequacy for gestational age, show evidence of iron deficiency before four months of age. Full-term infants do not develop iron deficiency up to this age.     

Iron status at 9 months of infants with low iron stores at birth

OBJECTIVE: To determine the 9-month follow-up iron status of infants born with abnormally low serum ferritin concentrations.Study design: Ten infants of >34 weeks' gestation with cord serum ferritin concentrations <5th percentile at birth (<70 microg/L) and 12 control infants with cord serum ferritin concentrations >80 microg/L had follow-up serum ferritin concentrations measured at 9 +/- 1 month of age. The mean follow-up ferritins, incidences of iron deficiency and iron-deficiency anemia, and growth rates from 0 to 12 months were compared between the two groups. RESULTS: At follow-up, the low birth ferritin group had a lower mean ferritin than the control group (30 +/- 17 vs 57 +/- 33 microg/L; P =.03), but no infant in either group had iron deficiency (serum ferritin <10 microg/L) or iron-deficiency anemia. Both groups grew equally well, but more rapid growth rates were associated with lower follow-up ferritin concentrations only in the low birth ferritin group (r = -0.52; P =.05). Both groups were predominantly breast-fed without iron supplementation before 6 months. CONCLUSIONS: Infants born with serum ferritin concentrations <5th percentile continue to have significantly lower ferritin concentrations at 9 months of age compared with infants born with normal iron status, potentially conferring a greater risk of later onset iron deficiency in the second postnatal year.     

Duration of exclusive breastfeeding is a positive predictor of iron status in 6‐ to 10‐month‐old infants in rural Kenya

The prevalence of iron‐deficiency anemia (IDA) is high in infants in Sub‐Saharan Africa. Exclusive breastfeeding of infants to 6 months of age is recommended by the World Health Organization, but breast milk is low in iron. Some studies suggest exclusive breastfeeding, although beneficial for the infant, may increase risk for IDA in resource‐limited settings. The objective of this study was to determine if duration of exclusive breastfeeding is associated with anemia and iron deficiency in rural Kenyan infants. This was a cross‐sectional study of 6–10‐month‐old infants (n = 134) in southern coastal Kenya. Anthropometrics, hemoglobin (Hb), plasma ferritin (PF), soluble transferrin receptor (sTfR), and C‐reactive protein were measured. Body iron stores were calculated from the sTfR/PF ratio. Socioeconomic factors, duration of exclusive breastfeeding, nature of complementary diet, and demographic characteristics were determined using a questionnaire. Mean ± SD age of the infants was 7.7 ± 0.8 months. Prevalence of anemia, ID, and IDA were 74.6%, 82.1%, and 64.9%, respectively. Months of exclusive breastfeeding correlated positively with Hb (r = 0.187; p < .05) and negatively with sTfR (r = ?0.246; p < .05). sTfR concentrations were lower in infants exclusively breastfed at least 6 months compared with those exclusively breastfed for less than 6 months (7.6 (6.3, 9) vs. 8.9 (6.7, 13.4); p < .05). Controlling for gender, birth weight, and inflammation, months spent exclusively breastfeeding was a significant negative predictor of sTfR and a positive predictor of Hb (p < .05). The IDA prevalence in rural Kenyan infants is high, and greater duration of exclusive breastfeeding predicts better iron status and higher Hb in this age group.     

Iron status and infant feeding practices in an urban ambulatory center

The relationship of infant feeding practices to iron status was examined in a group of 280 infants, 9 to 12 months of age, attending a "well-baby" clinic. Of this group, 7.6% were found to be iron depleted, 19.7% were iron deficient without anemia, and 8.2% were iron deficient with anemia. The incidence of iron-deficiency anemia was significantly greater in the black infants than the white infants (14.3% v 2.7%). The introduction of whole cow's milk into the diet had occurred prior to 6 months of age in 29.2% of the infants, and 62.1% of these infants had laboratory evidence of nutritional iron inadequacy, as contrasted with only 21.8% of those with iron deficiencies fed cow's milk after 6 months of age. Of the 21 infants with iron-deficiency anemia, 19 (90.5%) had been fed whole cow's milk prior to 6 months of age. Iron deficiency remains a nutritional problem for infants in an urban setting and is largely a result of the early introduction of whole cow's milk into the diet.     

Daily multivitamins with iron to prevent anemia in infancy: a randomized clinical trial.

This study assessed the effectiveness of multivitamins (MV) with iron as prophylaxis against iron deficiency (ID) and anemia in infancy. The study was a double-blind, randomized trial at 2 urban primary care clinics. Subjects included healthy, full-term infants enrolled at their 6-month well-child visit. Parents administered MV, either with iron or without iron, by mouth daily for 3 months. At 9 months of age, 28.3% of 310 had either anemia or ID without anemia. Among infants with any adherence, anemia was found in 11.1% of the iron group and 21.7% in the noniron group (RR=0.5, 95% CI=0.3-1.0). Iron deficiency without anemia was found in 18.5% of the iron group; 14.4% of the noniron group (p=0.46). When administered daily starting at age 6 months, standard-dose multivitamins with iron appear to reduce anemia prevalence at 9 months of age.     

When to start supplementary iron to prevent iron deficiency in early childhood in sub-Saharan Africa setting

BACKGROUND: To study the efficacy of oral ferrous fumarate, an inexpensive, readily available preparation on iron deficiency in infants in Africa. PROCEDURE: Four months old (group 1, n = 252) and 6-18 months old (group 2, n = 360) healthy infants attending four primary health care centers (PHC) for vaccination/well-child visits in Benin were studied. Ninety-six pregnant women (PW) over 36 weeks gestational age attending the same PHC during the study period were also studied. Infants were offered 2 months supplementation with oral powdered generic ferrous fumarate (GFF), that is, 5 mg/kg/day of elemental iron, given twice and were reevaluated 2 months later for hematological indices. The prevalence of anemia and iron deficiency among pregnant women was assessed using hematological indices and transferrin saturation. RESULTS: The prevalence of anemia was 42.0%, 61.9%, and 37.5% in groups 1, 2, and PW, respectively. All anemic PW were iron deficient. Hemoglobin level shifted towards high values after supplementation. In addition, 24 infants from group 1 whose mothers interrupted the treatment, showed a significant decrease in hemoglobin level values, and similar improvement after two additional months of supplementation. CONCLUSION: Programs to prevent iron deficiency in Africa should utilize inexpensive preparations, start during pregnancy, continue in infants at 3 months of age and address problems of noncompliance.     

Predicting iron status in low birthweight infants

OBJECTIVE: To determine the iron status of a selected group of low birthweight infants at approximately 9 months of age, and examine the feasibility of predicting iron status by examining the history of supplementary iron intake. METHODS: All live low birthweight infants recorded in the Dunedin Hospital Queen Mary Maternity Unit birth register who reached 9 months of age between November 1995 and September 1996 were eligible to participate. Infants were categorized into 'high' or 'low' iron intake groups depending on their consumption of infant formula or medicinal iron for one month prior to the study, and their iron status compared. RESULTS: Eighty-one infants of 73 mothers, with an average age of 10 months (range 8-13 months), participated. Thirty-three per cent (n = 27) were iron deficient: 19% (n = 15) had latent iron deficiency and 15% (n = 12) had iron deficiency anaemia. Those with a 'low' iron intake were 13-fold more likely to be iron deficient than infants with a 'high' iron intake (95% confidence interval: 4.4-41.5). Screening for iron deficiency using categories based on supplementary iron intake had a positive predictive value of 66% and a negative predictive value of 88%. CONCLUSIONS: The risk of iron deficiency was considerably greater for infants who had not received supplementary iron daily over the course of the previous month. Current preventative methods for avoiding poor iron status in this group of high risk infants are not effective. Screening for iron deficiency in low birthweight infants on the basis of iron intake from infant formula or medicinal iron provides a useful method for identifying infants whose iron status should be investigated.     

Red blood cell indices and iron status according to feeding practices in infants and young children

With the electronic counters routinely used, it has become practical to determine the concentration of hemoglobin, red cell indices, and RDW concurrently in association with transferrin saturation and ferritin in accordance with feeding practices. The 1028 infants and children aged 6 to 24 months, who had been mainly admitted with acute infectious or inflammatory diseases, were divided into three groups, i.e., children who were exclusively breast-fed more than 6 months (group A), those who had been given iron-fortified formula milk since birth (group B), and those who had been given breast milk for 5–6 months and then switched to the iron-fortified formula (group C). Children with anemia comprised 34.8% (104/299) of group A, significantly more than 5.6% (34/608) of group B and 6.6% (8,/121) of group C ( p < 0.001, respectively). Children with MCV < 70 fl comprised 39.5% (118/299) of group A, significantly more than 7.1% (43/608) of group B and 13.2% (16/121) of group C. Out of the total 146 patients with anemia, 82.2% ( n = 120) had laboratory evidence of iron deficiency, which was mostly suggested by a dietery history. The sensitivity of MCV values < 70 fl in IDA patients was 90.0%; specificity was 53.8%. The sensitivity of RDW values ≥ 15% was 83.3%; specificity was 57.7%. The positive predictive value could be increased to 97.8% by combining MCV < 70 fl and RDW ≥ 15%. The sensitivity of serum ferritin concentrations < 10ng/ml was 62.4% and specificity was 100%. The sensitivity of transferrin saturation < 12% was 72.3% and specificity was 81.3%. By combining the hemoglobin with MCV and RDW in screening for iron deficiency, the diagnostic accuracy of IDA can be increased. We support the use of appropriately iron-fortified weaning foods or the routine iron supplement starting at 6 months of age in exclusively breast-fed infants.     

Incidence of high erythrocyte count in infants and young children with iron deficiency anemia: re-evaluation of an old parameter

PURPOSE: To investigate the frequency of high erythrocyte count (red blood cell count >or=5.0 x 106/microL) in infants and young children with iron deficiency anemia and to document the differences in hematologic parameters at diagnosis and during iron therapy in IDA patients with and without a high erythrocyte count. PATIENTS AND METHODS: A total of 140 infants and young children aged 6 to 48 months with nutritional IDA without a history of any bleeding disorder were the subjects of this study. The patients were divided into three groups according to the severity of anemia. Group A1 children had Hb values 8.0 g/dL or less (severe anemia); group A2, 8.1 to 10.0 g/dL (moderate anemia); and group A3, 10.1-11.0 g/dL (mild anemia). All children received oral iron (3-5 mg/kg per day) for 12 weeks. Complete blood counts were done weekly during treatment. RESULTS: A total of 36 of the 140 patients (26%) had a high erythrocyte count. Of the 140 patients, 37 were in group A1, 80 in A2, and 23 in A3. The frequency of high erythrocyte count was 11%, 23%, and 61% in groups A1, A2, and A3, respectively. The patients with a high erythrocyte count had significantly higher Hb and Hct but significantly lower mean corpuscular volume and mean corpuscular hemoglobin (MCH) values than those with a low erythrocyte count (n = 104). A continuous elevation in the erythrocyte count has been observed in patients with a high red cell count, as in those with a low red cell count, after the institution of iron therapy. CONCLUSIONS: A high erythrocyte count is a common feature of iron deficiency anemia in infants and young children, with an increasing frequency from severe to moderate to mild anemia. High erythrocyte count cannot be regarded as a reliable preliminary parameter in differentiating iron deficiency from thalassemias in infants and children aged up to 48 months.     

Iron deficiency anemia and iron therapy effects on infant developmental test performance

The behavioral effects of iron deficiency and its treatment were evaluated in a double-blind randomized controlled community-based study of 191 Costa Rican infants, 12 to 23 months of age, with various degrees of iron deficiency. The Bayley Scales of Infant Development were administered before and both 1 week and 3 months after IM or oral administration of iron. Appropriate placebo-treated control infants were also tested. Infants with iron deficiency anemia showed significantly lower mental and motor test scores, even after considering factors relating to birth, nutrition, family background, parental IQ, and the home environment. After 1 week, neither IM nor oral iron treatments differed from placebo treatment in effects on scores. After 3 months, lower mental and motor test scores were no longer observed among iron-deficient anemic infants whose anemia and iron deficiency were both corrected (36%). However, significantly lower mental and motor test scores persisted among the majority of initially anemic infants (64%) who had more severe or chronic iron deficiency. Although no longer anemic, they still showed biochemical evidence of iron deficiency after 3 months of treatment. These persistent lower scores suggest either that iron therapy adequate for correcting anemia is insufficient to reverse behavioral and developmental disturbances in many infants or that certain ill effects are long-lasting, depending on the timing, severity, or chronicity of iron deficiency anemia in infancy.     

Hypocalcemic Rickets and Dilated Cardiomyopathy: Case Reports and Review of Literature

Internationally, there have been isolated case reports published of children presenting with dilated cardiomyopathy (DCM) in the setting of undiagnosed rickets. Although there has been an increased prevalence of rickets in the United States, there has been only one documented case of associated DCM. At our institution, a hospital database search was conducted from year 1997 to year 2007 to identify patients with confirmed vitamin D deficiency in addition to DCM. Through this search, four exclusively breast-fed African American infants were identified. These infants presented with congestive heart failure secondary to DCM and, at their admission, were found to have laboratory evidence consistent with hypocalcemic rickets. These patients responded dramatically to treatment with vitamin D and calcium, and cardiac function returned to normal within months. Early recognition of vitamin D deficiency was an important factor in these patients’ clinical course. These case reviews present a rare, serious complication of vitamin D-deficient rickets and support evidence for prevention of this nutritional deficiency with vitamin D supplementation in exclusively breast-fed infants.     

Prolonged exclusive breast-feeding results in low serum concentrations of immunoglobulin G, A and M

Serum levels of IgG, IgA and IgM were measured in 198 infants at ages 2, 4, 6, 9 and 12 months. By age 9 months 30 infants were still exclusively breast-fed; their IgG and IgM levels were significantly lower than those of infants weaned early to formula (before age 3.5 months). By 12 months 6 infants were still exclusively breast-fed; their IgA levels were by then also similarly lower. There was no significant difference in the number of infections experienced by these groups of infants. After 2 months on formula feeding, the IgG and IgM levels of the infants who were exclusively breast-fed for 9 months had caught up with the levels of the infants weaned early to formula. Only at 12 months of age prealbumin levels of the exclusively breast-fed infants showed a positive correlation to IgG and IgA levels; no correlation was found between immunoglobulin levels and levels of serum iron and zinc.