Mother's milk is the fundamental food for infants. It contains proteins, fat, carbohydrates and essential metals which are necessary to ensure correct functioning of the organism. Unfortunately, breast milk is a potential source of toxic metals, which are dangerous for a baby. In Poland, previous research concerning the content of metals in breast milk was very scarce or its results were unavailable. The present study aimed at assessing the content of Cd, Pb, Cu and Zn in human breast milk, as well as estimating the mean weekly intake of these metals by breast-fed infants from Poland. The average concentrations of Cd, Pb, Cu and Zn were 2.114 μg/l, 6.331 μg/l, 0.137 mg/l and 1.623 mg/l, respectively. The admissible levels of supply of these toxic metals has not been exceeded, but their contents were high, particularly in 6-month-old infants (nearly 85 % TWI for Cd and nearly 70 % BMDL01 for Pb). The daily intake of Cu and Zn did not fully satisfy the infant's requirements determined by Polish standards and WHO recommendations. Since the lifestyle of lactating women has a direct influence on the content of these elements in breast milk, women should be educated in this respect with particular focus on eliminating tobacco smoking, both by breastfeeding mothers and by their direct environment.

https://link.springer.com/content/pdf/10.1007%2Fs12011-013-9870-x.pdf

Cadmium, Lead, Copper and Zinc in Breast Milk in Poland

Breastmilk is the only dietary source of zinc for exclusively breastfed young infants, and it remains a potentially important source of zinc for older infants and young children who continue breastfeeding beyond early infancy. Therefore, we examined available information on breastmilk zinc concentration and total milk consumption to develop estimates of the amount of zinc transferred in breastmilk to children of different ages. Breastmilk zinc concentration declines rapidly during the first few months postpartum and more slowly thereafter. Breastmilk supplies all of the theoretical zinc needs for at least the first several months of life, although the period during which breastmilk alone remains sufficient is uncertain. Breastmilk continues to provide more than half of children's estimated zinc requirements after the introduction of complementary foods, even into the second year of life. Public health programs to promote and support breastfeeding should be included among the strategies to ensure adequate zinc status of young children.

https://journals.sagepub.com/doi/pdf/10.1177/15648265090301S108

Dietary intervention strategies to enhance zinc nutrition: promotion and support of breastfeeding for infants and young children

Background Breast milk is the recommended source of nutrients for infant growth, but its adequacy to meet infants' mineral and trace element needs is unknown. Objectives We used breast-milk mineral and trace element concentrations of Guatemalan mothers at 3 lactation stages to estimate total daily intakes and to determine whether intakes were associated with early infant growth. Methods In this cross-sectional study, breast-milk samples were collected from Mam-Mayan mothers during transitional (5-17 d, n = 56), early (18-46 d, n = 75), and established (4-6 mo, n = 103) lactation; z scores for weight (WAZ), length (LAZ), and head circumference (HCAZ) were measured. Concentrations of 11 minerals (calcium, potassium, magnesium, sodium, copper, iron, manganese, rubidium, selenium, strontium, and zinc) were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). WHO equations were used to calculate the estimated energy requirement, which was divided by the energy density of breast milk to estimate daily milk volume, and this number was multiplied by breast-milk mineral concentrations to estimate intakes. Principal component analyses identified clusters of minerals; principal components (PCs) were used in regression analyses for anthropometric outcomes. Results Estimated breast-milk intakes during established lactation were insufficient to compensate for the lower milk sodium, copper, manganese, and zinc concentrations in male infants and the lower sodium, iron and manganese concentrations in female infants. Estimated intakes of calcium, magnesium, potassium, sodium, and selenium were below the Institute of Medicine Adequate Intake for both sexes at all 3 stages of lactation. In early lactation, multiple linear regressions showed that PC1 (calcium, magnesium, potassium, rubidium, and strontium intakes) was positively associated with WAZ, LAZ, and HCAZ. In established lactation, the same PC with sodium added was positively associated with all 3 anthropometric outcomes; a second PC (PC2: zinc, copper, and selenium intakes) was associated with WAZ and LAZ but not HCAZ. Conclusions Breast milk may be inadequate in selected minerals and trace elements where higher estimated intakes were associated with greater infant growth.

/pdf/minerals-and-trace-elements-in-human-breast-milk-are-324n9pw2a3.pdf

Minerals and Trace Elements in Human Breast Milk Are Associated with Guatemalan Infant Anthropometric Outcomes within the First 6 Months

Backround: As breast milk is normally the only source of food in the early stages of life, the dietary levels of the essential elements in the milk of lactating mothers are significantly important Ethiopia is a country of many nations and nationalities with distinct dietary habits This variation in food habit may result in the variation of the nutritional quality of milk of lactating mothers who live in different part of the country, which in turn may affect the intake of nutrients by breast-fed infants Therefore, a cross-sectional study of the levels of Ca, Mg, Fe, Zn and Cu in milk of mothers from societies with cereal and ‘enset’ based dietary habits was carried out to assess the influence of maternal diet on the levels of the elements in human milk Methods : Milk samples were collected from 27 voluntary mothers in Jimma and in 18 rural areas of Welkite Breast milk samples were collected within four days postpartum and the concentrations of the elements were determined by using FAAS Results: Average concentrations (mg/L) of the elements determined in the milk of mothers from Jimma and rural Welkite respectively were: Ca (758 ± 107, 579 ± 168); Mg (226 ± 787, 305 ± 134); Fe (050 ± 008, 041 ± 017); Zn (23 ± 12, 249 ± 088) and Cu (028 ± 014, 016 ± 008) Conclusions : Milk samples from Jimma were found to have significantly higher levels of Ca and Cu than those of rural Welkite (P < 005) Breast milk Ca and Cu levels were thus found to be influenced by dietary intake Keywords: Human milk, Ethiopia, Welkite, Jimma, Essential elements, ‘Teff’, ‘Enset’

/pdf/calcium-magnesium-iron-zinc-and-copper-compositions-of-human-2jp6c84kvn.pdf

Calcium, Magnesium, Iron, Zinc and Copper, Compositions of Human Milk from Populations with Cereal and ‘Enset’ Based Diets

The aims of this study were to evaluate zinc, copper, and iron concentrations in the transitory milk of Korean lactating mothers and to investigate the relationship between these concentrations and maternal diet. Human milk samples were collected between 5 and 15 days postpartum from 96 healthy, lactating mothers in postpartum care centers in Seoul, Korea. Dietary intake during lactation was determined based on a 3-day dietary record. The mean zinc, copper, and iron concentrations in the human milk samples collected were 3.88 ± 1.74 mg/L, 0.69 ± 0.25 mg/L, and 5.85 ± 8.53 mg/L, respectively. The mothers who consumed alcoholic beverages during pregnancy had tended to have lower concentrations of zinc and copper, as well as significantly lower concentrations of iron, in their milk (p < 0.047). In contrast, the mothers who took daily supplements had much higher iron concentrations in their milk (p = 0.002). Dietary intakes of zinc, copper, and iron during lactation did not affect the concentrations of zinc, copper, and iron in the milk samples analyzed. Intakes of vitamin C, selenium, and iodine were associated with the concentration of copper in the milk samples analyzed, and consumption of food categorized as 'meat and meat products' was positively associated with the concentration of zinc. Consumption of rice was the top contributor to the concentrations of all three minerals. In conclusion, associations between maternal diet and nutrient concentrations in transitory human milk can provide useful information, particularly in regard to infant growth.

/pdf/association-of-maternal-diet-with-zinc-copper-and-iron-3l56cqp9ye.pdf

Association of Maternal Diet With Zinc, Copper, and Iron Concentrations in Transitional Human Milk Produced by Korean Mothers

Objective: To assess the within-subject and between-subject coefficients of variation (CV) of iron, zinc and copper concentrations in the milk of Guatemalan mothers. Methods: We performed a cross-sectional study in lactating women who had delivered a healthy infant 1 to 6 months previously in two low-income peri-urban areas (San Bartolome ´ Milpas Altas and Ciudad Peronia) and a low-income rural area (San Juan Chamelco) in Guatemala. Women infested with Ascaris lumbricoides or Trichuris trichiura received a single dose of albendazole (400 mg) or placebo. Two weeks after treatment, milk samples were collected on 3 or 4 consecutive days. Trace element concentrations in milk were measured by inductively coupled plasma/atomic emission spectrometry. Results: The instrumental error of the inductively coupled plasma/atomic emission spectrometry method, expressed as SD, was 0.04, 0.27 and 0.02 mg/L for iron, zinc and copper, respectively. Concentrations in milk samples collected from 47 mothers on 3 or 4 consecutive days, expressed as mean 6 SD, were 0.28 6 0.13, 2.03 6 0.37 and 0.29 6 0.07 mg/L for iron, zinc and copper, respectively. The within-subject CV was 46.1%, 18.2%, and 22.8% and the between-subject CV was 61.2%, 48.3% and 31.7% for iron, zinc and copper, respectively. Stage of lactation, infestation with intestinal parasites and residential area had a significant influence on milk zinc, copper and iron concentrations. Conclusions: One sample of milk is sufficient to give a reliable estimate of the zinc concentration in milk. Two samples taken on consecutive days are required for a reliable estimate of iron and copper concentrations. JPGN 40:128–134, 2005.

Clive E West

Papers

Day-to-day variations in iron, zinc and copper in breast milk of Guatemalan mothers.