Breast Milk Iron Research Articles

Analysis of Iron (Fe) Content in Breast Milk of Breastfeeding Mothers with Level Anemia Normal, Mild and Moderate

Aims: The study aimed to determine the level of iron (Fe) in breast milk samples from breastfeeding mothers who were not anemic (normal), had mild anemia, and had moderate anemia. Methodology: This research is descriptive in nature with a cross-sectional research design. The research subjects were 30 breast milk samples from breastfeeding mothers who had babies aged 0-6 months in TTU Regency, East Nusa Tenggara. 10 samples each in the categories of no anemia (normal), mild anemia, and moderate anemia. Analysis of Fe levels in breast milk samples using Atomic Absorption Spectroscopy (SSA) at the Testing, Calibration, and Certification Services Laboratory Unit, Bogor Agricultural Institute. Results: The results of the analysis showed that the average Fe content in breast milk samples from breastfeeding mothers (normal category) was 4.17 mg/L; Fe levels in breast milk samples from breastfeeding mothers (mild anemia category) were 2.01 mg/L; while the Fe level in breast milk samples from breastfeeding mothers (moderate anemia category) was 1.05 mg/L. From the average figures, it can be seen that there is no significant difference in Fe levels between the three breast milk samples, which is confirmed by the distribution of Fe levels for the 30 samples which is not much different, even from the minimum number of Fe levels in breast milk samples from breastfeeding mothers (normal). still found at 1.03 mg/L (almost the same as the minimum Fe level for breast milk samples from breastfeeding mothers (mild anemia), namely 0.70 mg/L. Conclusion: there were no significant differences in Fe levels in breast milk samples from breastfeeding mothers in the categories of no anemia (normal), mild anemia, and moderate anemia. However, it is still recommended that it is very important to ensure sufficient iron in breast milk to help the baby's growth and development.

Trace elements status in human breast milk of mothers from Île-de-France region

Breastfeeding is the main source of nutrition during first months of life. Its composition varies according to parameters like mother’s diet and health, living area, number of pregnancies and lactation duration… Trace-elements concentration in breastmilk is then an important parameter that can affect infant’s health, growth or immune system and organ functions. Few data are available on this topic, and results are often very variable. The aim of this work is to determine reference values of Copper (Cu), Zinc (Zn), Selenium (Se), Cobalt (Co), Iron (Fe) and Iodine (I) in human breastmilk according to lactation duration and to study influencing parameters on its elementary composition. Regional Human Milk Bank of Necker Enfants Malades Hospital provided samples that came from breastfeeding woman involved in voluntary milk donation and epidemiologic data. Two hundred thirty-two breastmilk were analysed. After nitric acid mineralization of milk samples, Cu, Zn, Se, Co and I were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in a standard mode. Fe was measured by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Both assays were validated in terms of sensitivity, repeatability and accuracy.Studied breast milks came from mothers with an average age of 32 years and donation time ranged from one day after childbirth to 974 days (> 2.5 years); mean lactation duration is 59 days (> 8 weeks) while median duration is 29 days (around 4 weeks). In all studied samples, mean results and reference values are for Cu: 6.02 (1.71–13.23), Zn: 43.86 (7.3–107.0), Se: 0.12 (0.07–0.24), I: 0.29 (0.07–1.01) and Fe: 4.72 (1.25–11.49) µmol/L and for Co: 12.28 (5.27–25.82) nmol/L. Important number of studied milks allowed their distribution into seven classes of lactation durations. Samples were divided into four successive classes of fifteen days after childbirth, two other classes corresponding to the 3rd and 4th months and a last class for milks sampled after 4 months of lactation. Results were analysed in each class allowing study of evolution during lactation. That was particularly interesting for Zn, that presented an important variability in the total population (4–132 µmol/L) explained by variation along lactation evolution decreasing from 48 to 17 µmol/L in first and last duration classes respectively. In addition, Cu and Fe concentrations were also significantly correlated with lactation duration while Se and I were in a lesser extent (p = 0.002). In this study, we present reference values for studied trace elements at different lactation stages, allowing a fine interpretation of future breast milk samples results according to their sampling time. By continuing this study, we plan to increase number of samples in some of the classes and to study the influence of premature birth or twin pregnancy on breast milk elementary composition.

HUBUNGAN KADAR ZAT BESI SERUM DENGAN KONSENTRASI ZAT BESI ASI IBU MENYUSUI DI KABUPATEN SELUMA

<p><em>Background: Maternal iron status affects infant neurocognitive development. When the maternal iron intake and status are disturbed, it can lead to iron deficiency which can lead to anemia if not treated. Anemia in breastfeeding mothers has a negative impact on the quality and volume of breast milk, including the availability of iron in breast milk. This study aims to analyze the relationship between serum iron levels and breast milk iron concentration in breastfeeding mothers in Seluma Regency. Methods: This study was an analytic survey, cross-sectional design, conducted in Seluma Regency in 4 (four) public health center working areas, namely Rimbo Kedui Public Health Center, Talang Tinggi, Tais, and Masmambang. Respondents were 124 breastfeeding mothers of children aged 0-24 months who were taken by proportional consecutive sampling. Venous blood and breast milk samples were collected for iron level measurement. Iron measurement was done using the spectrophotometric method. Data on characteristics were obtained using a questionnaire. Furthermore, the data were analyzed univariately and bivariately. Results: The results of measuring iron levels showed that 38.7% of mothers had iron deficiency and 15.3% of mothers had low breast milk iron levels. The bivariate test results showed 25% of mothers who experienced iron deficiency had low breast milk iron levels. (p=0.034, OR= 3.28; CI= 1.190-9.071). Conclusion: There is a significant relationship between serum iron levels and breast milk iron levels in breastfeeding mothers. It is necessary to educate mothers regarding the prevention of iron deficiency during pregnancy and breastfeeding so that the quantity of breast milk iron can meet the needs of children during breastfeeding</em></p><p><strong><em>Keyword :</em></strong><em> Breast milk, Iron Deficiency, Breast milk Iron Level, Iron</em><em></em></p>

Metabolism of Iron in Breast Milk of Women during Different Stage of Lactation

Breast milk is the only source of nutrients that contains all the components of normal growth and development of children. That is why breastfeeding is so important for a healthy baby. In the dynamics of lactation, the analysis of iron, binding of iron, breastfeeding properties and quantitative indicators of lactoferrin have great scientific and practical importance.

Toxic metal and trace element status in the breast milk of Turkish new-born mothers

Background and aimThis study aims to evaluate the toxic metal and trace element concentrations in breast milk obtained from new-born nursing mothers in rural Giresun province, located on the coast of the Black Sea. MethodsMilk samples were randomly collected once from early lactation of 50 nursing mothers. Inductively coupled plasma mass spectrometry was used to analyse the concentrations of iron (Fe), nickel (Ni), manganese (Mn), cobalt (Co), chromium (Cr), copper (Cu), zinc (Zn), arsenic (As), molybdenum (Mo), cadmium (Cd) and lead (Pb) in the breast milk. Shapiro-Wilk test was used to evaluate the distribution of data. The Pearson-J correlation was used for normally distributed elements, and Spearman correlation analysis was used for others. ResultsThe mean amounts of elements were 3.36 µg kg−1 of Cr, 9.26 µg kg−1 of Mn, 797 µg kg−1 of Fe, 1.99 µg kg−1 of Ni, 5.92 µg kg−1 of Cu, 379 µg kg−1 of Zn and 2.23 µg kg−1 of Pb. Co, As, Mo and Cd concentrations were below the detection limit. A highly significant correlation was found between iron and Nickel in breast milk. ConclusionOur findings were evaluated in comparison with the WHO data, and whether they were in accordance with the recommended Dietary Reference Intake (DRI) values for 0–6-months-old infants was calculated. Pb levels were similar to those of WHO, while As and Cd were below the measurable limit. Fe, Mn, and Cr concentrations were higher than WHO data, while Co, Ni, Cu and Zn were lower. This research is the first study conducted in this region.

Immunological Effects of Adding Bovine Lactoferrin and Reducing Iron in Infant Formula: A Randomized Controlled Trial.

ABSTRACTObjectives:Compared to formula-fed infants, breastfed infants have a lower risk of infections. Two possible reasons for this are the presence of the anti-infective and anti-inflammatory protein lactoferrin and the lower level of iron in breast milk. We explored how adding bovine lactoferrin and reducing the iron concentration in infant formula affect immunology and risk of infections in healthy infants.Methods:In a double-blind controlled trial, term formula-fed (FF) Swedish infants (n = 180) were randomized to receive, from 6 weeks to 6 months of age, a low-iron formula (2 mg/L) with added bovine lactoferrin (1.0 g/L) (Lf+; n = 72); low-iron formula with no added lactoferrin (Lf−; n = 72); and standard formula at 8 mg/L iron and no added lactoferrin (control formula [CF]; n = 36). Cytokines, infections, and infection related treatments were assessed until 12 months of age.Results:No adverse effects were observed. There were no apparent effects on transforming growth factor beta (TGF-β)1, TGF-β2, tumor necrosis factor alfa (TNF-α) or interleukin2 (IL-2) at 4, 6, or 12 months, except of higher TGF-β2 at 6 months in the CF group in comparison to the low iron groups combined (P = 0.033). No significant differences in otitis, respiratory infections, gastroenteritis, or other monitored infections and treatments were detected for any of the study feeding groups during the first 6 months and only a few and diverging effects were observed between 6 and 12 months.Conclusions:Adding bovine lactoferrin and reducing iron from 8 to 2 mg/L in infant formula was safe. No clinically relevant effects on cytokines or infection related morbidity were observed in this well-nourished and healthy population.

Optimization of the micronutrients sufficiency of feeding women and children on exclusively breastfeeding by enriching of the woman diet

A significant part of pregnant and lactating women have a lack of several micronutrients at once (vitamin D, group B, iodine, iron, etc.). The secretion of vitamins A, E, D, C, B1, B2, B6, B12, iodine and selenium into breast milk decreases with their insufficient consumption and insufficient provision of the nursing mother. The content of folates, calcium, magnesium, phosphorus in breast milk is maintained even if they are insufficient in the mother, however, enriching the diet with them during breastfeeding, improving the status of the mother, prevents the depletion of reserves in her body. The iron and zinc content in breast milk is determined by the mothers status during pregnancy. The intake of vitamin-mineral supplements or food products enriched with micronutrients during the pregravid period, during pregnancy and lactation leads to an improvement in the provision of a woman and her child by increasing the content of vitamins, iodine and selenium in breast milk. The use of vitamin-mineral supplements is an effective way not only to eliminate multiple micronutrient deficiencies in the diet and improve the status of a lactating woman, but also to optimize the vitamin composition of breast milk and the provision of an exclusively breastfed baby.

Effect of maternal anemia on breast milk iron status

Objectives: Nutritional anemia is highly prevalent in lactating mothers. It is postulated that anemic pregnant women secrete less iron in their breast milk. This study was aimed to compare the iron levels in breast milk samples of anemic and non-anemic lactating pregnant women and to correlate breast milk iron levels with the hemoglobin (Hb) status of anemic and non-anemic mothers. Materials and Methods: A case–control study was conducted on 120 pregnant women aged 20–30 years having a normal antenatal history. They were classified into non-anemic and anemic groups based on their Hb status; Group 1: Hb ≥11 g/dl and Group 2: Hb 7–10.9 g/dl, respectively. Results: Maternal blood Hb was significantly different between the groups (11.8 ± 0.6 vs. 10.2 ± 0.5 g/dL, P > 0.05). Breast milk iron levels did not vary significantly between the groups (938.8 ± 465.6 vs. 1084.8 ± 440.8 μg/dl). No correlation was observed between maternal Hb levels of anemic lactating mothers and breast milk iron status (r = 0.054, P = 0.424). Conclusion: Our research study validates the finding that maternal anemia did not affect breast milk iron concentration during the early post-natal period by showing the optimum iron levels in it. Therefore, exclusive breastfeeding is the ideal nutrition for infants.

Determinants of Plasma Ferritin at 3 Months of Age Among Rural Bangladeshi Infants From the JiVitA-3 Trial

ObjectivesFerritin, a biomarker of iron stores, is rarely reported in infants despite a known role for iron in growth and development. Iron stores accumulated in utero decline in infancy, although breastmilk iron supports infant status. In rural northwest Bangladesh, an iron-replete area, infants are small and prone to common illnesses despite prevalent breastfeeding. We explored determinants of ferritin in 3 mo old infants in this setting. MethodsIn a double-blind, cluster-randomized trial (JiVitA-3) of multiple micronutrient or iron-folic acid supplementation from pregnancy ascertainment to 3 mo postpartum, maternal and infant hemoglobin (Hb), anthropometry, and plasma were obtained 3 mo after birth. Growth was assessed as weight gain since birth. In a preliminary analysis (n = 378), infant plasma ferritin, maternal ferritin, and infant α1-acid glycoprotein (AGP), a biomarker of inflammation, were assessed. Distributions are shown as mean ± SD or median (IQR) if skewed; associations of infant ferritin with biomarkers and anthropometry were assessed with Spearman correlation (rs) or linear regression with log10-transformed variables, if skewed. ResultsAmong infants, plasma ferritin was 118 (70,182) μg/L, Hb 111 ± 11 g/L; and AGP 0.91 (0.68, 1.17) g/L, with 40.5% of infants inflamed (AGP > 1.00 g/L). Among mothers, ferritin was 60 (38, 88) μg/L and Hb 121 ± 10 g/L. Ferritin was lower in boys (n = 200) than girls (n = 178) [102 (58,159) vs 142 (87,212) μg/L], but weight (5.4 ± 0.6 vs 4.9 ± 0.8 kg) and weight gain since birth (2.8 ± 0.5 vs 2.4 ± 0.7) were higher (all p < 0.0001). When adjusted for sex, infant ferritin was positively associated with AGP (p = 0.025). Adjusted for AGP and low birth weight status, each 1 kg gain in weight from birth to 3 months was associated with 32.0% lower ferritin (95%CI: –45.7, –14.9; p = 0.001) in boys, but not girls [8.4% lower ferritin (95%CI: –21.6, 7.1; p = 0.269)]. Ferritin was not associated with infant Hb (rs = 0.02), or maternal ferritin (rs = –0.003) or Hb (rs = –0.001) (all p > 0.05). ConclusionsInfant ferritin was unassociated with aspects of maternal or infant iron status. It was associated positively with AGP, which was commonly elevated, and negatively with growth in boys, whose size and rate of growth exceeded that of girls. Funding SourcesBill and Melinda Gates Foundation.

Formulation of Snack Bar from Torbangun Leaf as Food Source for Iron and Calcium

Indonesia has local unutilized food and it contains mineral, it is torbangun leaf. Consumption of torbangun leaf can increase level of several mineral such as iron, calcium, zink, and magnesium in breast milk. Torbangun leaf powder contains 70.77 mg iron; 1258.29 mg calcium; dan 97.42 mg Phosphor. Torbangun leaf also contains lactogogum which can stimulate breast milk gland on mother by proliferating secretion cell of mamari. Therefore the quality and quantity of breast milk could increase. Torbangun leaves can be developed into emergency food items such as snack bars. The aim of this study was to develop snack bar with substitution torbangun leaves. From trial error, torbangun leaf was substitution until 10 g, 15 g, and 20 g. The best formula was substituted 10 g torbangun leaf which 9.6% protein; 10.43% fat; 66.3% carbohydrate; 1006.54 mg calcium; and 44.76 mg iron, with total an energy was 397.47 kcal/100 g.

Total metal content and chemical speciation analysis of iron, copper, zinc and iodine in human breast milk using high-performance liquid chromatography separation and inductively coupled plasma mass spectrometry detection

The aim of this research was to quantify essential trace elements (iron, copper, zinc and iodine) and establish their speciation in human milk. Both the element and the species are important in new-born nutrition. Colostrum, and transitional and mature milks (25) were collected from 18 mothers of pre-term or full-term infants. Concentrations of the target elements were determined using ICP-MS. For speciation, HPLC coupled to ICP-MS was employed. Total contents of the micronutrients varied in mothers of pre-term (Fe = 0.997, Cu = 0.506, Zn = 4.15 and I = 0.458 mg L−1) and mothers of full-term (Fe = 0.733, Cu = 0.234, Zn = 2.91 and I = 0.255 mg L−1) infants. Fe, Cu and Zn were associated with biomolecules with high molecular mass compounds, such as immunoglobulins, albumin and lactoferrin whilst iodine was only found as iodide.

Dietary iron absorption during early postnatal life.

Inadequate iron levels during early life can have adverse consequences for the developing infant. Iron deficiency during this critical period of growth can affect brain development and cognitive function, problems that can be lifelong despite subsequent correction of the iron deficit. Therefore, it is critical that the suckling infant has sufficient iron for their developmental needs. Much of the iron used in the immediate post-natal period is stored iron that was acquired from the mother in the final trimester of pregnancy, however, despite having low iron levels, breast milk can also make a significant contribution to infant iron needs. This reflects the ability of the suckling infant to absorb dietary iron far more efficiently than is possible after weaning. The mechanisms underlying this enhanced iron absorption are poorly understood. The iron export protein ferroportin is essential for this process, as it is in adults, however, the role of other molecules normally involved in iron absorption following weaning is less clear. The composition and distribution of iron in breast milk may be important, as could the contribution of more distal parts of the gastrointestinal tract. This review discusses the potential role of each of the above components in intestinal iron absorption during suckling and highlights the need for further research into this important process.

Breast Milk Iron Concentrations may be Lower than Previously Reported: Implications for Exclusively Breastfed Infants

Objective: Atomic Absorption Spectrophotometry (AAS) is the most common technique for detecting iron in human milk. Quantifying the iron in human milk is essential for determining the amount of dietary iron available to the exclusively breastfed infant. To determine whether more sensitive procedures for iron analyses would yield different values than those obtained using the AAS, flame atomic absorption, we investigated and compared three different analytical techniques using AAS. Methods: The present experiment was conducted as part of a larger study on the iron supplementation of 77 exclusively breast-fed infants. Breastmilk samples were collected from 10 mothers of full-term infants at one and 3½ months of age. Each sample was analyzed with a Perkin-Elmer 2380 Atomic Absorption Spectrophotometer by the following analytical methods: flame atomic absorption spectrophotometry (FAAS), direct sample analysis with graphite furnace atomic absorption spectrophotometry (GFAAS) and the method-of-standard-additions with GFAAS. Results: While all values were within reported ranges, there was significant inter-method variability. The decrease in iron concentration between 1-month and 3.5-month milk samples found in the present study is in agreement with a previous report. GFAAS methods produced consistently lower values than did FAAS: 1 month: direct GFAAS, 0.50 (0.33-0.86) μg/ml; method-of-addition GFAAS, 0.45 (0.31-0.66) μg/ml; FAAS 0.76 (0.25-1.60 μg/ml), mean (range): 3.5-month: direct GFAAS, 0.29 (0.13-0.46 μg/ml; method-of-addition GFAAS, 0.29 (0.11-0.44 μg/ml); FAAS method 0.78 (0.19-1.64) μg/ml. There was no difference between the two GFAAS methods at either time point. Conclusion: The findings obtained from this study suggest that much of the variability seen in the reported values of human milk iron concentrations could be due to the use of different analytical procedures. GFAAS results are consistently lower than those determined by FAAS suggesting that the exclusively breastfed infant consumes less iron than previously thought.

Balancing Benefits and Risks of Iron Fortification in Resource-Rich Countries

In the recommendations, the contrast in the iron exposure of formula-fed infants vs breastfed infants has primarily focused on the better bioavailability of the iron in breast milk. Although an absorption efficiency of approximately 50% is often quoted, some studies have actually reported absorption in the range of 12%-16%, 7,8 making that bioavailability distinction much less potent. This also suggeststhat absorptionof substantialamountsof dietary ironsimply isnot critical during the early monthsof life in healthy infants of normal birth weight. Among all the compositional differences between human milk and formula, the differences in iron content are the most extreme. Virtually all mammalian milks are low in iron, with the exception of rodents, inwhichpostnatalgrowth isextremely rapid.Itseemsimplausiblethatthisconservedbiologicalpatterniswithoutpurpose.Itis also clear that iron deficiency occurs in breastfed infants only after the very early months of life. The practical challenge is to identify when the birth iron endowment is exhausted, at which point the infant needs a source of iron from the diet. This article will discuss the potential advantages of a low iron intake for the infant and the potential adverse effects of drastically altering this, especially in the first 6 months of life. From the outset, two realities must be acknowledged. First, iron deficiency (especially without anemia) in infants remains common, particularly in high-risk groups, including older normal breastfed infants and premature and/or in low birth weight infants. Whether this mild iron deficiency has adverse effects on development is not known. Second, research on potential adverse effects of early and excessive iron exposure is limited, and the evidence base for caution is suggestive but not yet demonstrated by rigorously designed trials. Thus, this represents an emerging area of consideration, and, given the advances in understanding of iron metabolism, the interaction between iron and inflammation, and the importance of early influences on the immature gut and immune system, it is an area that warrants much stronger scientific investigation.

Maternal intestinal HIF-2α is necessary for sensing iron demands of lactation in mice

The mechanisms that are essential for the maintenance of nutrient status in breast milk are unclear. Our data demonstrate that the intestine via hypoxia-inducible factor (HIF)-2α is an essential regulatory mechanism for maintaining the quality of breast milk. During lactation, intestinal HIF-2α is highly increased, leading to an adaptive induction of apical and basolateral iron transport genes. Disruption of intestinal HIF-2α (but not HIF-1α) or the downstream target gene divalent metal transporter (DMT)-1 in lactating mothers did not alter systemic iron homeostasis in the mothers, but led to anemia, decreased growth, and truncal alopecia in pups which was restored following weaning. Moreover, pups born from mothers with a disruption of intestinal HIF-2α led to long-term cognitive defects. Cross-fostering experiments and micronutrient profiling of breast milk demonstrated that the defects observed were due to decreased maternal iron delivery via milk. Increasing intestinal iron absorption by activation of HIF-2α or parenteral administration of iron-dextran in HIF-2α knockout mothers ameliorated anemia and restored neonatal development and adult cognitive functions. The present work details the importance of breast milk iron in neonatal development and uncovers an unexpected molecular mechanism for the regulation of nutritional status of breast milk through intestinal HIF-2α.

Оценка содержания микроэлементов (йода и железа) в грудном молоке

Проведена оценка содержания йода и железа в грудном молоке (n = 88). В исследовании показано, что концентрация йода и железа в материнском молоке у обследованных женщин не соответствует физиологической потребности ребенка грудного возраста. Продемонстрировано, что применение железосодержащих витаминно-минеральных комплексов во время лактации не оказывает значимого влияния на уровень железа в грудном молоке. Содержание йода в молоке матери напрямую зависит от йодной дотации. Показано, что на уровень микронутриентов в грудном молоке не влияет наличие у матери гестационной анемии и зоба, срок родов и место проживания семьи. Сделан вывод о статистически значимом влиянии на уровень йода в грудном молоке сочетанной йодной профилактики (прием матерью во время лактации препаратов калия йодида (200 мкг/сут) на фоне употребления йодированной соли).

Iron Supplementation in Pregnancy and Breastfeeding and Iron, Copper and Zinc Status of Lactating Women From a Human Milk Bank

This study evaluated the influence of iron supplementation in pregnancy and breastfeeding on iron status of lactating women from a Brazilian Human Milk Bank. Blood and mature breast milk samples were collected from 145 women for assessment of iron status, as well as copper and zinc status. Haemoglobin, serum iron and ferritin were determined, respectively, by electronic counting, colorimetry and chemiluminescence. Transferrin and ceruloplasmin were analysed by nephelometry. Serum copper and zinc were measured by atomic absorption spectrophotometry, and serum alkaline phosphatase was measured by a colorimetric method. Iron, zinc and copper in breast milk were determined by spectrometry. Mean values of iron, copper and zinc (blood and breast milk) were compared by ANOVA, followed by Tukey's test. Iron supplementation was beneficial to prevent anaemia in pregnancy but not effective to treat anaemia. During breastfeeding, iron supplementation had a negative effect on maternal copper status, confirming an interaction between these micronutrients.

Iron content and its speciation in human milk from mothers of preterm and full-term infants at early stages of lactation: A comparison with commercial infant milk formulas

Total and speciation analyses of iron in human milk from mothers of preterm and full-term infants at different stages of lactation and formula milk were performed by ICP-MS and SEC-ICP-MS respectively. Total iron content of preterm human milk samples was 0.5μg/ml as compared with 0.4μg/ml of full-term samples. Breast milk iron concentration did not vary significantly during the first month of lactation nor according to preterm or full-term gestations. Pre-term and full-term formulas from different manufacturers showed a media total iron content (9.5μg/ml and 6.0μg/ml, respectively) significantly higher than the iron content of human milk samples. Only 3 preterm and 2 full-term formulas had total iron contents higher than the minimum recommended level of fortification. Iron distribution patterns in milk proteins for human and formula milk samples were obtained. Whereas iron was mostly spread over the high molecular mass region of biomolecules in human milk samples, iron was mostly spread over fractions eluting at low molecular mass in formulas and these differences were statistically significant. Thus, speciation of iron is clearly different in formula milk than in natural milk.

Intestinal iron absorption during suckling in mammals

The maintenance of appropriate iron levels is important for mammalian health, particularly during the rapid growth period following birth. Too little iron can lead to irreversible damage to the developing central nervous system and too much iron at this point can have adverse long term consequences, possibly due to excessive free radical production. In order to maintain iron levels, intestinal iron absorption is very efficient in young mammals, such that almost all of the iron in breast milk is utilized. However this high level of absorption is unable to be down regulated in response to excess iron as it can be in adults, implying that different regulatory processes are involved during suckling. Various mechanisms have been proposed to explain this high absorption, including enhanced expression of the proteins involved in iron absorption in adults (particularly DMT1 and ferroportin), non-specific uptake via pinocytosis, and the uptake of lactoferrin bound iron by the lactoferrin receptor. However, at present the precise mechanism is unclear. It is possible that all of these components contribute to the high intestinal iron absorption seen during suckling, or a novel, as yet undescribed, mechanism could be involved. This review summarises the evidence for and against each of the mechanisms described above and highlights how little is known about iron homeostasis in this vital stage of development.

The Factors That Affect Milk-to-Serum Ratio for Iron During Early Lactation

To determine the factors that affect milk iron content at the second week of lactation and whether the supplementation to lactating mother with iron might increase breast milk iron content between 2 weeks and 4 months postpartum. Healthy mothers were enrolled 10 to 20 days postpartum, if their babies were term, normal gestational age, and exclusive breastfed. Maternal blood samples for hemoglobin (Hb), iron, iron binding capacity, serum ferritin, and breast milk samples for iron and zinc were taken and mothers were randomized into iron supplemented and placebo groups. At the end of the fourth month, blood and milk samples were taken again. Forty-seven healthy mothers were included into the study. Milk iron content was lower; however, milk-to-serum iron ratio was higher in cases with low maternal iron reserves than cases with adequate iron reserves. Mothers with low Hb level (<12 g/dL) had higher milk zinc content and lower milk iron/zinc content than mothers with normal Hb value. Iron supplementation to lactating nonanemic mothers did not change milk iron content and the decline in milk iron content and milk-to-serum iron ratio. Milk iron content and milk-to-serum iron ratio of iron could be regulated by active transport in cooperation with maternal iron status.