Ulla M. Saarinen

Iron absorption in infants: High bioavailability ofbreast milk iron as indicated by the extrinsic tag method of iron absorption and by the concentration of serum ferritin†

Breast feeding is thought to result in a lower incidence of iron deficiency than does the use of unfortified cow milk forumalas, but there is scant documentation for this belief. The relationship of breast and cow milk feeding to absorption of iron and to iron status was investigated in a total of 45 term infants at about six months of age. Iron absorption was measured by total body counting. Laboratory assessment of iron status was based on the serum ferritin, hemoglobin, mean corpuscular volume, and transferrin saturation. The results indicated that infants fed breast milk during the entire first six to seven months of life attained greater iron stores than did those fed a cow milk formula. Breast-fed infants absorbed an average of 49% of a trace dose of extrinsic iron administered during a breast feeding in contrast to about 10% reported to be absorbed from cow milk under similar conditions. The data indicate that term infants who are breast fed may not require routine administration of supplemental iron.

PROLONGED BREAST FEEDING AS PROPHYLAXIS FOR RECURRENT OTITIS MEDIA

ABSTRACT. The incidence of otitis media was studied in 237 healthy children in reference to the duration of breast‐feeding, with a follow‐up from birth to three years of age. Recurrent otitis media was strongly associated with early bottle‐feeding, in contrast to prolonged breast‐feeding which had a long‐term protecting effect up to three years of age. It is uncertain whether the prophylactic effect of prolonged breast‐feeding on recurrent otitis is due to protection by human milk from infections or allergy, or to avoidance of harmful effects caused by cows milk.

Iron absorption from breast milk, cow's milk, and iron-supplemented formula: an opportunistic use of changes in total body iron determined by hemoglobin, ferritin, and body weight in 132 infants.

Summary: Iron absorption was measured by using changes in the calculated total body iron (TBI) in infants on three different milk regimens: breast milk (n = 86), home-prepared cows milk formula (n = 15), and proprietary iron-supplemented infant formula (n = 31) during the first 4 months of life. The TBI was determined as the sum of the hemoglobin iron (HbI) and the body storage iron (BSI). In the latter assessment, we found a close to linear correlation between the concentration of serum ferritin (SF) expressed as the logarithm and the BSI expressed as milligrams per unit of body weight. Accordingly, the BSI could be calculated from SF and body weight. Iron absorption from milk was estimated from the increment of TBI and from the estimated iron intake at different time intervals. From 2-4 months of age the monthly increment of TBI was 33.5 mg in the iron-supplemented formula group, 20 mg in the breast milk group, and 6.5 mg in the cows milk group. The differences were statistically highly significant (P < 0.001). The calculated percentage intake was about 70% for breast milk iron, about 30% for cows milk iron, and about 10% for the supplemental iron in infant formula. Our data emphasize the exceptionally high bioavailability of breast milk iron which markedly dropped after the introduction of solid foods at 4 months of age. These data suggest an inhibitory effect of the solid vegetable foods on iron absorption, especially from breast milk. Our findings indicate that exclusive breast feeding is an effective means in preventing iron deficiency in early infancy as an alternative to the use of iron-supplemented infant formulas.Speculation: Quantitative estimation of body iron stores by serum ferritin and body weight provides a way to calculate the amount of total body iron. This method provides a new way to study iron absorption without the use of radioactive isotopes, and indicates unusually high bioavailability of breast milk iron if the solid foods are introduced late.

Recombinant human granulocyte-macrophage colony-stimulating factor in the treatment of febrile neutropenia: a double blind placebo-controlled study in children.

In a double blind study of 58 episodes of fever and profound neutropenia, children with cancer received either recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) or placebo, combined with identical antimicrobial therapy, i.e. imipenem, on admission. The criteria for discontinuation of therapy were identical. A difference was demonstrated both in the number of hospital days, totaling 252 days in the rhGM-CSF group and 354 in the placebo group, days receiving antibiotics (220 vs. 322), and in the resolution of neutropenia (4.5 days vs. 6.0 days; P < 0.05). The number of episodes requiring antimicrobial therapy for longer than 10 days was 5 of 28 (12%) in the rhGM-CSF group as opposed to 15 of 30 (50%) in the placebo group (P = 0.01). rhGM-CSF was well-tolerated. We conclude that rhGM-CSF was efficacious in accelerating myeloid recovery and reducing the length of hospitalization in febrile neutropenia.

Developmental changes in red blood cell counts and indices of infants after exclusion of iron deficiency by laboratory criteria and continuous iron supplementation.

The developmental changes in red blood cell counts and indices were determined in infants after mild iron deficiency was excluded. The normal values were obtained from a selected group of healthy, term infants who were receiving continuous iron supplementation during a period of one year while normal values for transferrin saturation and serum ferritin were being maintained. The data indicated marked developmental changes in red blood cell counts and indices during the first year of life that are independent of iron intake. Serial analysis of individual infants values indicated that the red cell measurement at 4 months of age are, to some extent, predictive of the level of subsequent values within the normal range.

Need for iron supplementation in infants on prolonged breast feeding

Iron status, as measured by blood counts and indices, serum iron, transferrin saturation, and serum ferritin values, was studied longitudinally in 56 infants on prolonged breast feeding, and compared to that of 29 infants receiving cow milk formula prepared at home and of 47 infants receiving a proprietary infant formula. The first two groups received no iron supplementation, whereas the proprietary formula was supplemented with iron. Although breast feeding was found to be sufficient to meet iron needs during the first 6 months of life, supplemental iron would be necessary during the second half of infancy in order to guarantee the optimal iron status.

Myocardial function in children and adolescents after therapy with anthracyclines and chest irradiation

Cardiotoxicity is a potential adverse effect of anthracycline (A) therapy. Radiotherapy (XRT) may also cause a variety of cardiac complications. The purpose of the present study was to evaluate these cardiac side-effects in children and adolescents treated for cancer. We assessed the cardiac status of 91 patients, divided into three groups: Group A (n = 53) had anthracyclines at a mean cumulative dose of 410 mg/m2, group A+XRT (n = 26) had both chest irradiation (XRT) and A (mean 360 mg/m2), and group XRT (n = 12) had XRT alone. The patients differed from the controls in both systolic and diastolic indices of myocardial function. In echocardiography, the left ventricular (LV) contractility was abnormal in 32% in group A, in 50% in group A+XRT, and in 8% in group XRT. In radionuclide cineangiography, the LV ejection fraction was subnormal in 19% in group A, in 24% in group A+XRT, and in 1 patient in group XRT. A higher cumulative dose of A predicted decreased contractility. Treatment with A and/or XRT often leads to cardiotoxicity. Although in most cases this cardiotoxicity seems to be mild and subclinical, the long-term clinical sequelae merit further evaluation.

Developmental changes in serum iron, total iron-binding capacity, and transferrin saturation in infancy.

THE LEVELS of serum iron and total iron-binding capacity have established roles as diagnostic measures of iron deficiency. Transferrin saturation of less than 16% is a widely used criterion of iron-deficient erythropoiesis leading to iron deficiency anemia? Distinct changes in serum iron and transferrin saturation during infancy have been indicated by three earlier studies. 2-4 We investigated the developmental changes in serum iron, total iron-binding capacity, and transferrin saturation in infancy to establish the lower limits of normal values under conditions in which iron deficiency was prevented by dietary supplementation, and its absence confirmed by laboratory tests.

Serum ferritin in assessment of iron nutrition in healthy infants.

ABSTRACT. We followed up 238 infants on 7 occasions during their first year of life. The diets of the infants were systematically either supplemented or not supplemented with iron. Developmental changes in serum ferritin were determined from a group with adequate intake of iron and without evidence of iron deficiency by three laboratory criteria: hemoglobin, mean corpuscular volume and transferrin saturation. The data indicate that the average level of serum ferritin correlates well with iron nutrition within groups of infants since the developmental changes are in accordance with the known changes in storage iron, the level of serum ferritin correlates with iron intake, and low ferritin levels are associated with lower transferrin saturation. The usefulness of serum ferritin as the sole criterion of iron deficiency in individual infants is limited, suggesting the use of more than one indicator to refine the diagnosis of iron deficiency without anemia.

IRON ABSORPTION FROM INFANT MILK FORMULA AND THE OPTIMAL LEVEL OF IRON SUPPLEMENTATION

Abstract. Thirty healthy infants, aged 11–13 months, were studied with regard to the iron absorption from proprietary milk formula. The infants were divided into three groups (I‐III) depending on the concentration of iron in the formula: 0.8 (I), 6.8 (II), and 12.8 (III) mg/1, respectively. The calculated amount of iron absorbed per test dose of SO ml of milk averaged 5 μg (I), 32 μg (II), and 43 μg (III). Group I differed significantly from groups II and III. No correlation was found between iron absorption and hemoglobin, MCV, serum transferrin saturation or serum ferritin within the range of normal values. Our findings suggest that at least 7 mg of iron as ferrous sulphate per litre of formula is required to prevent iron deficiency.