Copper, iron, and Zinc contents in human milk during the first three months of lactation

The aim of the study has been to analyze the evolution of copper, iron, and zinc contents in human milk, from colostrum to the third postpartum month, following a longitudinal design, under specific conditions of sample collection and to apply an analytical procedure previously optimized to reduce any variation outside physiological lactation. The copper, iron, and zinc concentrations in 144 milk samples from 39 healthy puerpera women, were analyzed in five stages by flame atomic absorption spectrometry, following a standardized protocol. Copper presented a gradual decrease from 0.38 mg/L to 0.19 mg/L by the 90th day; the particular analysis from colostrum to transitional milk manifested the following two tendencies. Whereas an increase from 0.19 to 0.42 mg/L was observed in some women, a decrease from 0.53 to 0.45 mg/L was detected in others; therefore, copper presented two significant behaviors in the evolution from colostrum to transitional milk. In both cases, the evaluated changes were significant. The iron content varied from 0.56 to 0.40 mg/L by the 30th day, remaining constant until the first trimester concluded. The average zinc concentration decreased sharply from 7.99 to 3.3 mg/L on d 15; the rate of decrease slowed down gradually until 1.05 mg/L.     

Changes in selenium, zinc, copper and cadmium contents in human milk during the time when selenium has been supplemented to fertilizers in Finland

Sodium selenate has been supplemented to all agricultural fertilizers used in Finland since 1984. We followed the changes in selenium, cadmium, zinc and copper content in Finnish human milk between the years 1987 and 1993-1995. A total of 257 milk samples was collected, four weeks after delivery, in two areas: In Helsinki, an urban area, and in Kuopio, a rural area, where elevated copper concentrations have been found in the bedrock. Direct atomic absorption spectrophotometric methods without digestion were used for the analyses. The dependence of trace element content on study time, living area, smoking habits, fish eating frequency, and parity of mothers was studied by analysis of covariance. Inter-element correlations and correlations with mothers' age and fat content in milk were studied by partial correlation. Significant increases were observed in mean selenium (16.4 microg/l and 18.9 microg/l, p < 0.001) and in fat contents (3.4% and 4.0%, p < 0.001), whereas significant decreases were seen in mean zinc (3.00 mg/l and 1.47 mg/l, p < 0.001), copper (0.52 mg/l and 0.43 mg/l, p < 0.001) and cadmium contents (0.095 microg/l and 0.062 microg/l, p < 0.01). In 1987, zinc had a positive correlation with copper and fat. Copper correlated inversely with the mothers' age. In 1993-1995, selenium correlated positively with copper, and zinc correlated inversely with mothers' age. Mothers living area had an effect on copper content in milk. Our results confirm that selenium supplementation to fertilizers in Finland has increased the selenium level in human maternal milk and most likely it also has an effect on the zinc and copper concentrations in maternal milk.     

Association Between Zinc, Copper, and Iron Concentrations in Breast Milk and Growth of Healthy Infants in Tabriz, Iran

The aims of this study were to determine the effect of breast milk zinc, copper, and iron concentrations on infants’ growth and their possible correlations with maternal dietary intake. Milk samples and information on food intake were collected from 182 lactating women. Concentrations of zinc, copper, and iron in milk were analyzed using atomic absorption spectrophotometry. The infant’s weight for age Z-score (WAZ) and height for age Z-score (HAZ) were calculated. The mean milk zinc, copper, and iron concentrations were 1.85?±?0.5, 0.53?±?0.3, and 0.85?±?0.2 mg/l, respectively. Only zinc mean level was lower than the recommended range. Association between zinc, copper, and iron concentrations of milk and WAZ or HAZ of infants were not significant. However, the WAZ of infants whose mothers' milk zinc was more than 2 mg/l was significantly (P?<?0.039) higher than for others. The mean dietary zinc (5.31?±?2.3 mg/day) and copper (1.16?±?0.7 mg/day) intake of mothers was significantly less than the required daily intake (RDA) recommendations (P?<?0.05). The mean dietary iron intake (11.8?±?8.2 mg/day) was significantly higher than RDA recommendation (P?<?0.001). No significant association was found between maternal mean dietary zinc, copper, and iron intakes with their concentrations in milk. Dietary consultation or/and zinc supplementation is suggested for lactating women and infants.     

Magnesium,Calcium, and Trace Elements Excretion in 24-h Urine

Urine is a clinical specimen often used in medical diagnostics for monitoring of elements concentrations and kidneys function. We determined the contents of magnesium (Mg), calcium (Ca), zinc (Zn), copper (Cu), iron (Fe), lead (Pb), and cadmium (Cd) in 74 samples of 24-h urine (from 46 women and 28 men). The measurements were realized by the atomic absorption spectrometry (AAS) with atomization in the flame (FAAS) and in the graphite furnace (GFAAS). The received results were the subject of statistical analysis including the sex and age of volunteers. Moreover, correlations between the elements and the relationships between age and amounts of excreted elements with urine were tested. We found the statistically significant higher content of Zn in men’s urine than in women^’s one. Moreover, both adult women and men (>18 years) excreted much more Ca in urine in comparison to young subjects. Only in case of Pb the significant positive correlation between its amount in 24-h urine of all donors and age was stated. The correlation analysis has shown the significant positive relationships between Ca–Mg, Ca–Fe, Mg–Fe, Cu–Fe, Cu–Cd, Fe–Cd, and Pb–Cd in total samples of urine. Basing on our results, we concluded that the gender and age of donors may impact on the elemental status of 24-h urine.     

Effects of Short-Term Over-supplementation of Copper in Milk on Hematology,Serum Proteins,Weight Gain,and Health in Dairy Calves

Thirty-six calves were used in the present study. The animals were divided equally into three groups (control, test 1, and test 2). The three groups of calves were homogeneous for parity of dams, sex, and month of birth. From 14 days of age, in the test 1 group copper as copper sulfate (Merck Co, Germany) was added to each meal of milk at a rate of 10 mg/kg of milk for 14 days and in test 2 group copper as copper sulfate was added to each meal of milk at a rate of 20 mg/kg of milk for 14 days. Blood samples were taken by jugular venipuncture using disposable syringes at 14 (before Cu supplementation), 30, 60, and 80 days of age. Anticoagulated blood was used for CBC determination. Plane tubes were used for harvesting of serum and the amounts of total serum protein, albumin, iron, and copper were measured. Calves were weighted at birth and at the end of trial (day 80) and total gain and mean daily gain were calculated. Days of treatment for ill calves were also recorded during experiment. Group (treatment) had no significant effect on the amounts of measured parameters except MCH values (p < 0.05) which were significantly lower in test 1 group than other trial groups. Age (sampling time) had significant effects on the values of most measured parameters (p < 0.05) except WBC, lymphocyte, total protein, and fibrinogen. Significant interactions between sampling time and group were not seen for any of measured parameters. No significant differences were seen for total weight gain and mean daily gain between trial groups. Chi-square test revealed no significant difference for the days of treatment between trials groups.     

Maternal Milk Concentration of Zinc,Iron, Selenium,and Iodine and Its Relationship to Dietary Intakes

The dietary intake of zinc (Zn), iron (Fe), selenium (Se), and iodine (I) of 31 lactating Mexican–American women attending the Hidalgo County WIC program in Rio Grande Valley (RGV), Texas was estimated from 24-h dietary recall interviews. Milk samples were obtained from lactating mothers who had infants 3 months of age and younger. Milk samples were collected in two visits to assess change in breast milk composition after 1–3 months postpartum: group A—after 30–45 days and group B—75–90 days. Dietary intakes indicated that the study participants had significantly inadequate percent energy intakes than the DRI (Dietary Recommended Intakes) percent recommended kilocalorie values but protein intakes were substantially higher than the percent recommended values. The estimated percent Zn, Fe, Se, and I intakes were also significantly lower than the DRI percent recommended values. The lactating mothers consumed significantly less Zn, Se, and I when compared to the Recommended Dietary Allowances (RDA) even though Fe intake was higher than the RDA value. Breast milk concentration of Zn, Fe, and Se were in agreement within the range of representative values for Constituents of Human Milk but I has significantly less concentration than the representative value. There was no statistically significant correlation observed between dietary intake and milk concentration of Zn, Fe, Se, and I. This study compares the estimated dietary intake of zinc, iron, selenium, and iodine to the concentration of these trace elements in the maternal milk of lactating women of Mexican–American heritage who attend the Rio Grande Valley WIC clinic.     

The effect of formalin fixation on the levels of brain transition metals in archived samples

Reports that iron, zinc and copper homeostasis are in aberrant homeostasis are common for various neurodegenerative diseases, particularly for Huntington’s disease, Parkinson’s disease, and Alzheimer’s disease. Manipulating the levels of these elements in the brain through the application of chelators has been and continues to be tested therapeutically in clinical trials with mixed results. Much of the data indicating that these metals are abnormally concentrated in Alzheimer’s disease and Parkinson’s disease brain tissue was generated through the analysis of post-mortem human tissue which was archived in formalin. In this study, we evaluated the effect of formalin fixation of brain on the levels of three important transition metals (iron, copper, and zinc) by atomic absorption spectroscopy. Paired brain specimens were obtained at autopsy for each case; one was conserved by formalin archival (averaging four years), the other was rapidly frozen. Both white and grey matter samples were analyzed and the concentrations of iron and zinc were found to decrease with fixation. Iron was reduced by 40% (P < 0.01), and zinc by 77% (P < 0.0001); copper concentrations increased by 37% (P < 0.05) by the paired T-test. The increase in copper is likely due to contamination from trace copper in the formalin. These results indicate that transition metal data obtained from fixed tissue may be heavily distorted and care should be taken in interpreting this data.     

Zinc and copper in human milk

Studies of zinc and copper contents of breast milk were performed in 34 mothers during their lactation period until 5 days postpartum. They experienced no problems during pregnancy and delivery. All women had full term healthy infants, 22 were multiparous and 12 primiparous. The highest zinc concentration was found in the colostrum, and subsequently the concentration declined. Copper content was stable during the 5 days of lactation. Significantly lower zinc concentration and higher copper concentration were found in the serum of lactating women 3 days post partum, when compared with non-lactating women. Factors including lactation history, age of lactating women, serum levels of zinc and copper did not affect the contents of these trace minerals in breast milk.     

Serum Copper and Zinc Levels in Healthy Greek Children and Their Parents

The aim of this study was to investigate whether there is a correlation between copper (Cu) and zinc (Zn) levels in children and their parents, considering their nutritional habits. Cu and Zn concentrations were measured by flame atomic absorption spectrophotometry in the serum of 66 healthy children, aged 3–14 years, and their parents, residing in a region of Greece (Thrace). Cu levels were higher in mothers than those in fathers, but they were lower in both parents than those in children. They also tended to decrease with age in both parents and children, whereas Zn levels significantly increased with age in children. There was a positive correlation between children's and mothers' Zn levels, as well as children's and both parents' Cu levels. Children used to eat meat, fish, vegetables, and legumes as frequently as their parents, but they were consuming more eggs, milk, and fruits than the latest. Regarding parents' diet, higher Zn levels were depended on the consumption of meat and milk, whereas higher Cu levels were depended on the consumption of milk. Consequently, children’s Cu and Zn levels are related to their parents’ levels, which can be influenced by their nutritional habits.     

Zinc and copper intake and sources in healthy adults living in Bangkok and surrounding districts

The levels of intake and food sources of zinc and copper in 231 20–80 yr old healthy adults living in Bangkok and surrounding districts were determined. Dietary data from 3-d food records collected and validated at Research Center, Ramathibodi Hospital were analyzed. Levels of zinc and copper intake were compared between sexes and age groups (20–39, 40–59, and 60–80 yr). Mean daily zinc and copper intakes (±SEM) in men were 6.3 ±0.2 and 1.9 ±0.1 mg, respectively. Mean daily zinc and copper intakes (±SEM) estimated in women (5.5 ±0.2 and 1.6 +-0.1 mg) were significantly lower. Higher zinc and copper intakes were found in the younger (20-39 yr) age group of both sexes. This could be explained by higher density and percentage from animal source of both nutrients. Consumption of various types of meat, fish, egg, and milk accounted for 42 and 22%, and rice, the staple food of Thai people for 9 and 23% of total dietary zinc and copper, respectively.     

Macronutrient, mineral and trace element composition of breast milk from Japanese women

The aim of the study was to determine the concentrations of macronutrients and the mineral and trace element composition in maternal milk of Japanese women. We collected human milk samples from mothers living throughout Japan from December 1998 to September 1999, and defined as group A the 1197 samples among them that met the following conditions: breast milk of mothers who were under 40 years old, not in the habit of smoking and/or using vitamin supplements, and whose babies showed no symptoms of atopy and whose birth weights were 2.5 kg or more. We then analyzed their contents individually. We also analyzed the amino acid and free amino acid composition of the breast milk of pooled samples from various lactation stages. Large differences were found to exist among the contents of individual human milk samples. The mean contents of each component were as follows: energy, 66.3+/-13.3 kcal/100 mL; solid matter, 12.46+/-1.56 g/100 mL; ash, 0.19+/-0.06 g/100 mL; total nitrogen, 0.19+/-0.04 g/100 mL; lipids, 3.46+/-1.49 g/100 mL; carbohydrates, 7.58+/-0.77 g/100 mL; lactose, 6.44+/-0.49 g/100 mL; pH, 6.5+/-0.3; osmotic pressure, 299+/-14 mOsm/kg.H2O; chloride, 35.9+/-16.2 mg/100 mL; sodium, 13.5+/-8.7 mg/100 mL; magnesium, 2.7+/-0.9 mg/100 mL; phosphorus, 15.0+/-3.8 mg/100 mL; potassium, 47.0+/-12.1 mg/100 mL; calcium, 25.0+/-7.1 mg/100 mL; chromium, 5.9+/-4.7 microg/100 mL; manganese, 1.1+/-2.3 microg/100mL; iron, 119+/-251 microg/100 mL; copper, 35+/-21 microg/100 mL; zinc, 145+/-135 microg/100 mL; and selenium, 1.7+/-0.6 microg/100 mL. The content of each component varied greatly as the duration of lactation increased. In conclusion, it appears to be necessary to evaluate individual differences of human milk in order to perform valid research regarding infant formula.     

Associations among plasma selenium,zinc, copper,and iron concentrations and immunoregulatory cytokine levels in patients with cutaneous leishmaniasis

Plasma essential trace elements, selenium, copper, zinc, and iron concentrations and the levels of immunoregulatory cytokines, interleukin-1β (IL-1β), interleukin-2 receptor (IL-2r), IL-6, IL-8, and tumor necrosis factor-α (TNF-α) were evaluated in patients with cutaneous leishmaniasis (CL) to investigate a possible role of these cytokines on selenium, zinc, copper, and iron homeostasis in CL patients. Plasma albumin levels were measured as an index of nutritional status. Plasma selenium, zinc, and iron concentrations, and IL-2r levels were significantly lower, and copper concentrations and IL-1β, IL-8, IL-6 and TNF-α levels were significantly higher in patients with CL than those of healthy controls. There was no significant difference in plasma albumin levels between two groups. There were positive important correlations between plasma selenium and IL-2r, copper and IL-6, and copper and IL-1β, and negative correlations between selenium and IL-8, iron and TNF-α, and zinc and IL-1β contents in patients with CL. Our results showed that plasma trace element contents change in patients with CL. These changes may not be a result of a specific deficiency from dietary inadequacies or imbalances, but, probably, a result of a part of the defense strategies of an organism that is regulated by immunoregulatory cytokines.     

Determination of Select Trace Elements in Hair of College Students in Jinzhou, China

Select trace elements (Fe, Cu, Zn, Al, K, Na, Ba, Sb, Pb, As) were determined by ICP-AES after nitric acid-perchloric acid wet digestion in samples of scalp hair of University students. Some metal-to-metal intercorrelations were found. The more often the hair was dyed and marcelled, the higher were the contents of iron, copper, potassium, sodium, barium, lead, and arsenic. Copper levels increased with the degree of myopia, while zinc, lead, aluminum, iron, and potassium decreased with the myopic degree. Copper, zinc, iron, and arsenic levels were lower in white hair, while sodium and lead were higher. The levels of the elements were generally higher in the hair samples of students who drink and smoke. The hair metal contents were found to be influenced by alcohol use and smoking. Hair element analyses thus could be used as noninvasive means of detecting unhealthy lifestyles in college students.     

Hair and serum calcium, iron, copper, and zinc levels during normal pregnancy at three trimesters

The hair and serum levels of calcium, iron, copper, and zinc levels were measured in a group of 70 healthy pregnant women and in 66 age-matched healthy controls living in the Tianjin city of the People’s Republic of China. The study subjects were classified into three subgroups according to gestational age. The hair concentrations were measured by X-ray fluorescence spectrometry, whereas those in sera were established by atomic absorption spectrometry. The hair concentrations of Ca, Fe, Cu, and Zn in the three groups of gravida were lower or significantly lower than those in controls. In sera, the differences did not show statistical significance in most cases. A deficiency of calcium was observed in subjects in the last trimester of gestation. This reinforces the importance of supplementation with calcium during pregnancy.     

A Comparison of Levels of Select Minerals in Scalp Hair Samples with Estimated Dietary Intakes of These Minerals in Women of Reproductive Age

The objective of this study was to evaluate daily intake of minerals and concentrations of minerals in hair in women of reproductive age. The study included 77 menstruating women, aged 35.9?±?9.7?years. Subjects were divided into three groups according to age. All women were healthy. Hair samples were taken from several points of the occipital scalp. The content of minerals in hair samples was determined by flame atomic absorption spectrometry. Dietary intake of the analysed minerals was assayed on the basis of dietary intake interviews from three preceding days and evaluated using the dietetic computer programme. It was shown that calcium and iron daily intake by the women was below the recommended value. Only few women had low concentrations (below reference values) of magnesium, copper and zinc in hair. Statistically significant differences were shown between age groups. Generally, the concentrations of minerals in hair in the younger (19-30?years) and the older women (41-50?years) were higher than in hair of middle-aged women (31-40?years). The content of calcium, magnesium, iron and zinc in daily diets of women correlated inversely with copper level in their hair. Food products with good bioavailability of iron and calcium should be recommended for women of childbearing age in all age groups.     

Effects of iron,zinc, calcium,and vitamins on the activity and contents of human placental copper/zinc and manganese superoxide dismutases

One hundred seventy-nine pregnant women, ages 15–45 yr, were divided into three groups. Group A was orally given one spansule per day containing 150 mg dried ferrous sulfate, 61.8 mg zinc sulfate, and 500 μg folic acid, starting from the first 4 wk of pregnancy and ending at the day of delivery. Similarly, group B was given one tablet containing 625 mg calcium carbonate, 1000 mg vitamin C, 300 IU Vitamin D, 1350 mg citric acid, and 15 mg Vitamin B6. Group C was without any supplements and served as a control. Mothers who received iron/zinc supplements (group A) during pregnancy had significantly higher copper/zinc superoxide dismutase activity in their placentae than calcium/vitamin-supplemented mothers (group B) or unsupplemented mothers (group C). The enzyme activity increased with age of the mothers from 15 to 40 yr, then decreased after in both supplemented groups, whereas this increase and decrease occurred at early age in the unsupplemented group. Immunochemical quantitation of the enzyme contents showed no significant difference between the supplemented and unsupplemented groups, suggesting that the observed increase in the enzyme activity might arise from posttranslational processing of the enzyme. The placental manganese superoxide dismutase activity and contents, however, were similar in the supplemented groups, whereas they were slightly higher in the unsupplemented group; the overall superoxide dismutase-like activities in the placentae were the highest in iron-zinc supplemented group and the lowest in the unsupplemented group.     

Neonatal,maternal, and intrapartum factors and their relationship to cord-and maternal-plasma trace-element concentration

The study was carried out to examine the relationship of neonatal sex, birthweight, maternal parity, hemoglobin status, gestational age at term, and duration of labor to cord- and maternal-plasma zinc, copper, and iron levels, measured by atomic absorption spectrophotometry. Significant differences were observed between maternal-and neonatal-cord plasma concentrations of the different trace elements at term. Maternal parity had no significant influence on the distribution of plasma trace elements, except in the case of maternal plasma iron levels. However, maternal hemoglobin status was observed as an important covariate of maternal zinc and iron levels at term. Neonatal birthweight was observed to be an index of maternal plasma zinc status at term. On the other hand, although gestational age at term had no significant influence on maternal-plasma trace-element concentrations, it was observed to influence neonatal-cord plasma levels. Long durations of labor (≥18 h) were associated with relatively lower, but not significant, maternal-plasma iron levels, whereas neonatal-cord-plasma iron levels seemed to show sex differences.     

Correlation Analysis Between Bone Mineral Density and Serum Element Contents of Postmenopausal Women in Xi’an Urban Area

The objective of this paper is to investigate the correlation between serum macro-element and trace element contents and bone mineral density (BMD) as well as the occurrence of osteoporosis. After the epidemiological investigation of 290 postmenopausal women from ages 45 to 65 in the Xi’an urban area, their blood was collected and serum concentrations of macro-elements, calcium, phosphonium, potassium, sodium, magnesium, and trace elements, zinc, iron, copper, and selenium were determined using atomic absorption spectrometry. Their BMD was measured by QDR-2000 dual-energy X-ray absorptiometry (DEXA). The correlation analysis between BMD and serum element contents was done with the software of SPSS 13.0. The correlation analysis of serum elements of postmenopausal women showed that there was a significant correlation between serum calcium and the other elements, and also a significant correlation between serum phosphonium and the others except serum potassium. The serum potassium content had a significant correlation with serum calcium, sodium and iron, but sodium content showed a significant correlation with the others except iron and selenium. In addition, copper had a significant correlation with the others except potassium and selenium. In correlation analysis between BMD and the elements contents, only did the potassium content show a significant positive correlation with BMD of lumbar vertebra and proximal femora. The comparison results between osteoporosis group, osteopenia group, and healthy group showed that there was no significant difference in the element contents between the groups, but there existed a tendency that potassium content increased with the rise of BMD. There exist significant correlations between the contents of serum elements such as calcium, phosphonium, sodium, potassium, magnesium, zinc, iron, copper, and selenium, but no significant differences in these elements contents between the osteoporosis group, osteopenia group, and healthy group. Serum potassium content shows a significant positive correlation with BMD, suggesting potassium may be involved in the development of osteoporosis in postmenopausal women.     

Effect of dietary nickel and iron on the trace element content of rat liver

The level and/or form of dietary iron, dietary nickel, and the interaction between them affected the trace element content of rat liver. Livers were from the offspring of dams fed diets containing 10–16 ng, or 20 μg, of nickel/g. Dietary iron was supplied as ferric chloride (30 μg/g) or ferric sulfate (30 μg, or 60 μg). In nickel-deprived rats fed 60 μg of iron/g of diet as ferric sulfate, at age 35 days, levels of iron and zinc were depressed in liver and the level of copper was elevated. At age 55 days, iron was still depressed, copper was still elevated, but zinc also was elevated. In rats fed 30 μg of iron/g of diet as ferric chloride, liver iron content was higher in nickel-deprived than in nickel-supplemented rats at 30, but not at 50, days of age. Also manganese and zinc were lower in nickel-deprived than in nickel-supplemented rats at age 35 days if their dams had been on experiment for an extended period of time (i.e., since age 21 days). Thus, the levels of copper, iron, manganese, and zinc in liver were affected by nickel deprivation, but the direction and extent of the affects depended upon the iron status of the rat.