Zinc In Milk Research Articles

Determinação direta de Ca, Mg, Mn e Zn em amostras de leite de búfala da Ilha de Marajó por espectrometria de absorção atômica com chama (FAAS)

This work proposes an analytical procedure for direct determination of calcium, magnesium, manganese and zinc in buffalo milk by flame atomic absorption spectrometry (FAAS). Samples were diluted with a solution containing 10% (v/v) of water-soluble tertiary amines (CFA-C) at pH 8. For comparison, buffalo milk samples were digested with HNO3 and H2O2. According to a paired t-test, the results obtained in the determination of Ca, Mg, Mn and Zn in digested samples and in 10% (v/v) CFA-C medium were in agreement at a 95% confidence level. The developed procedure is simple, rapid, decrease the possibility of contamination and can be applied for the routine determination of Ca, Mg, Mn and Zn in buffalo milk samples without any difficulty caused by matrix constituents, such as fat content, and particle size distribution in the milk emulsion.

Nutritional Status of Lactating Mothers and Their Breast Milk Concentration of Iron, Zinc and Copper in Rural Vietnam

Breast milk is considered to be the best nutrient source for infants. However, nutritional compositions of breast milk in developing countries, especially among malnourished women, have not been fully investigated. This study aimed to assess nutritional status and nutrient composition of breast milk in lactating mothers in rural Vietnam. Sixty breastfeeding mothers at 6 to 12 mo postpartum, free from any medical disorder and/or medication, and not pregnant were randomly selected in Yen The, Bac Giang, Vietnam. Their nutritional status, breast milk concentration and dietary intakes were assessed. Among the study participants, anemia (39.0%) and low serum zinc concentration (55.4%) were frequently observed. Dietary assessment revealed lower intakes of iron (10.2+/-2.5 mg/d) and zinc (10.4+/-2.2 mg/d) than estimated requirements. The breast milk concentration of iron, zinc and copper was 0.43+/-0.15 mg/L, 0.56 (0.37, 0.82) mg/L and 0.19+/-0.05 mg/L, respectively. The breast milk concentration of iron, zinc and copper was not correlated to the serum concentration or dietary intakes. In conclusion, we uncovered a high prevalence of anemia and zinc deficiency in lactating mothers in rural Vietnam. The findings demonstrate a low breast milk zinc concentration among the participants, but need further investigation.

Acrodermatitis enteropathica in a full-term breast-fed infant: case report and literature review

A male full-term infant, who had been exclusively breast-fed since birth, at 2 months of age developed an erythematous, scaling eruption involving the face (in a periorificial distribution, i.e. mouth, nose, ears, and eyes), hands, and feet, which did not respond to treatment with topical corticosteroids and oral antimicrobials. He was first seen at our institution at 5 months of age (1, 2). He had been irritable for the last 2 weeks, but had no diarrhea, alopecia, or anogenital lesions. A clinical diagnosis of acrodermatitis enteropathica was confirmed with a serum zinc level of 41.2 µg/dL (normal, 70–120 µg/dL). His mother had low–normal serum (70.5 µg/dL; normal, 70–120 µg/dL) and normal milk (0.43 µg/mL; normal, 0.2–0.72 µg/mL) zinc concentrations. Within 7 days of starting therapy with zinc sulfate, 10 mg/kg/day, all cutaneous lesions had resolved (Fig. 3). Figure 1Open in figure viewerPowerPoint Infant at 5 months of age showing an erythematous, scaling eruption involving the face (periorificial distribution, i.e. mouth, nose, and eyes) and hands Figure 2Open in figure viewerPowerPoint Infant with dermatophytosis-like lesions Figure 3Open in figure viewerPowerPoint Infant at 6 months of age after starting oral zinc supplementation. The lesions have resolved

Short-term effects of selenium supplementation of cows' feed on the content and distribution of selenium, copper and zinc in bovine milk, whey and blood plasma

The effect of selenium supplementation of feed on the Se content in bovine milk, whey and plasma, and on the distribution of Se, Zn and Cu in whey and plasma was investigated. In a cross-over study two groups of cows were given a basal feed with 0.16 ppm selenite (approx. 3 mg Se/d) with or without 25 mg yeast Se/d for 2 weeks. In the supplemented group the Se content increased 10-fold in milk, 10-fold in whey and 2-fold in plasma, and after the cessation of the supplementation, selenium in milk decreased with a calculated half-life of 3.5 d. In another experiment, two groups of cows were given either 100 mg yeast Se/d for 1 week or only the basal feed. The increase in Se content in both whole and defatted milk was 40-50-fold, and in whey it was approx. 20-fold. Size-exclusion chromatography of whey using inductively coupled plasma mass spectrometry for detection showed that supplementation increased the proportion of Se in the beta-lactoglobulin-alpha-lactalbumin fraction. Distribution of Cu and Zn was essentially unaffected. In plasma, supplementation increased the Se content in all major Se fractions like selenoprotein P, albumin and low-molecular-weight compounds, but the distribution profiles of Zn and Cu underwent no major changes. The study showed for the first time the rapid kinetics of the Se increase and decrease in milk after the initiation and cessation of supplementation, respectively, and the preferential appearance of Se in the beta-lactoglobulin-alpha-lactalbumin fraction of whey. Milk highly enriched in selenium will be a useful tool for different research purposes.

Milk trace elements in lactating cows environmentally exposed to higher level of lead and cadmium around different industrial units

The present investigation was carried out to assess the trace mineral profile of milk from lactating cows reared around different industrial units and to examine the effect of blood and milk concentration of lead and cadmium on copper, cobalt, zinc and iron levels in milk. Respective blood and milk samples were collected from a total of 201 apparently healthy lactating cows above 3 years of age including 52 cows reared in areas supposed to be free from pollution. The highest milk lead (0.85 ± 0.11 µg/ml) and cadmium (0.23 ± 0.02 µg/ml) levels were recorded in lactating cows reared around lead–zinc smelter and steel manufacturing plant, respectively. Significantly ( P < 0.05) higher concentration of milk copper, cobalt, zinc and iron compared to control animals was recorded in cows around closed lead cum operational zinc smelter. Analysis of correlation between lead and other trace elements in milk from lactating cows with the blood lead level > 0.20 µg/ml ( n = 79) revealed a significant negative correlations between milk iron and milk lead ( r = − 0.273, P = 0.015). However, such trend was not recorded with blood lead level < 0.20 µg/ml ( n = 122). The milk cobalt concentration was significantly correlated ( r = 0.365, P < 0.001) with cadmium level in milk and the highest milk cadmium (> 0.10 to 0.39 µg/ml) group had significantly ( P < 0.05) increased milk cobalt. It is concluded that increased blood and milk lead or cadmium level as a result of natural exposure of lactating cows to these environmental toxicants significantly influences trace minerals composition of milk and such alterations affect the milk quality and nutritional values.

DETERMINAÇÃO DE METAIS PESADOS EM LEITE INTEGRAL BOVINO PASTEURIZADO NO ESTADO DE GOIÁS

The lead texts, cadmium, zinc, copper and iron in pasteurized integral bovine milk produced in the months of September of 2003 to December of 2004, in the large regions of the State of Goias, they were analysed using spectrometry of atomic absorption with flame. Adopting the approach established in the statistical annual of the State of Goias, of the Clerkship of the Planning (SEPLAN, 2004), that it divided the State of Goias in five large regions, they were picked 27 samples of integral milk pasteurizade in each large region; with a total of 135 samples, and 675 analytic determinations for the five analyzed elements. Following the statistical model of sampling for conglomerate (SPIEGEL, 1978), it was picke samples in municipal districts with larger production milkmaid, so that they were representative for the State. The samples obtained in plastic packings of polietileno pigmentad, they were processed immediately, acomplishingt the physical-chemical analyses of routine initially to evaluate its quality. After the evaluation of the sample, it separated those that were in agreement with the physical-chemical patterns, and the determination of the metals was proceded by spectrophotometry of atomic absorption, according to official methodology (BRASIL, 1994). In relation to the obtained results, the were not found significant differences at 5 % of probability, among the averages of the lead texts, cadmium, zinc and copper in the integral milk, among several large regions. Contaminations were detected by lead and cadmium. The general average obtained for lead was of 0,238 mg/L, for the cadmium it was of 0,0482 mg/L, the medium texts of zinc 3,732 mg/L, copper 0,4869 mg/L and iron was of 0,9626 mg/L. Tends in view the medium resulted obtained in the present study, depreend-if that the analyzed milk, is a poor source in zinc, copper and iron. In relation to the results obtained for lead, in all the large regions of the State of Goias samples of milk contaminated. Key words: Spectrophotometry of atomic absorption, Lead, microelements

Simultaneous Determination of Cadmium, Mercury, Lead, Arsenic, Copper, and Zinc in Human Breast Milk by ICP‐MS/Microwave Digestion

An analytical method using microwave digestion and inductively coupled argon plasma-mass spectrometry (ICP‐MS) analysis was developed for the measurement of Cd, Hg, Pb, As, Cu, and Zn in human breast milk. We applied external calibration, internal calibration, and standard addition for reference material and pooled milk analysis. Method performances were defined in terms of detection limits, accuracy, and precision. Accuracy varied between 93% and 105% and precision between 3% and 8%. External calibration and background interferences were checked through a calibrator addition procedure. Our method has shown high accuracy, precision, and sensitivity, as well as linearity within a wide range of values. Our methodology, developed by treatment of reference material and pooled milk samples, was applied for determination of Cu, Zn, As, Cd, Hg, and Pb in 120 human breast milk samples.

Effects of several amendments on rice growth and uptake of copper and cadmium from a contaminated soil

Heavy metals in variable charge soil are highly bioavailable and easy to transfer into plants. Since it is impossible to completely eliminate rice planting on contaminated soils, some remediation and mitigation techniques are necessary to reduce metal bioavailability and uptake by rice. This pot experiment investigated the effects of seven amendments on the growth of rice and uptake of heavy metals from a paddy soil that was contaminated by copper and cadmium. The best results were from the application of limestone that increased grain yield by 12.5-16.5 fold, and decreased Cu and Cd concentrations in grain by 23.0%-50.4%. Application of calcium magnesium phosphate, calcium silicate, pig manure, and peat also increased the grain yield by 0.3-15.3 fold, and effectively decreased the Cu and Cd concentrations in grain. Cd concentration in grain was slightly reduced in the treatments of Chinese milk vetch and zinc sulfate. Concentrations of Cu and Cd in grain and straw were dependent on the available Cu and Cd in the soils, and soil available Cu and Cd were significantly affected by the soil pH.

Seasonal variations in the chemical composition of camel milk in Jordan

The principal chemical components of milk from the Arabian camel (Camelus dromedarius) were monitored in Jordan over one year. The analyses included total solids, fat, protein, vitamins, minerals and organic acids. Large seasonal variations in total solids and fat were apparent, with maxima in mid-winter of 139 and 39.0 g/l, respectively, and minima in August of 102 and 25.0 g/l. These differences may be sufficient to alter the sensory properties of the milk, and the fat: casein ratio may need standardisation for cheesemaking. The mean values of trace elements like zinc (5.8 mg/l), iron (4.4 mg/l) and manganese (0.05 mg/l) in Jordanian camel milk could provide valuable additions to the diet of urban populations, as could the mean concentration of vitamin C (33 mg/l). The levels of organic acids were generally higher than in bovine milk and, as with all the constituents of the milk, there were discernible patterns linking concentration and season of the year.

Relationships Among Plasma Zinc, Plasma Prolactin, Milk Transfer, and Milk Zinc in Lactating Women

The objective was to analyze interrelationships among plasma zinc (PZ), plasma prolactin (PRL), milk transfer, and milk zinc from a longitudinal study of lactating women with a range of zinc intakes. Sixteen of 26 women received a 15 mg/d zinc supplement, resulting in a significant increase in total zinc intake compared with nonsupplemented participants (P<.001). No significant differences in key variables were observed between the zinc-supplemented and non-zinc-supplemented women; data were thus combined. An inverse trend between PRL and PZ was observed at 0.5 (r=-.36, P=.08) and 7 months (r=-.38, P=.06). Correlations between PRL at 0.5 months and at 3, 5, and 7 months were significant (r>.50, P<.01). PRL concentrations and milk transfer were positively correlated at 5 (r=.67, P<.001) and 7 months (r=.53, P<.01), consistent with PRL role in lactation maintenance. Studies including zinc-deficient lactating women are required to clarify the interrelationships between zinc status and PRL secretion.

Effects of Dietary Zinc Supplement During Lactation on Longitudinal Changes in Plasma and Milk Zinc Concentration

Effects of dietary zinc supplement during lactation on maternal zinc plasma and milk zinc concentration through 5 months of lactation were examined. One hundred and thirty eight healthy lactating mothers received a weekly 100 mg elemental zinc supplement (ZS, n = 67) or placebo (PG, n = 71) starting one week postpartum in a double blind, randomized design. Milk and plasma zinc concentrations were determined by atomic absorption spectrophotometer. During the course of study, there was not a significantly difference between ZG and PG groups in dietary zinc and energy intake. The mean plasma zinc concentration at 1st week and 5th month were 134 +/- 49.1 and 115.6 +/- 23 microg dL(-1) (PV = 0.005) for PG group, respectively; that of the ZG group these figures were 124.9 +/- 52.8 and 121 +/- 27.1 microg dL(-1) (PV = 0.38), respectively. The mean serum alkaline phosphatase concentration at 1st week and 5th month were 94.8 +/- 37 and 92.6 +/- 29.9 iu L(-1) for PG group, respectively; that of the ZG group these fissures were 90.5 +/- 36 and 90 +/- 29 iu L(-1) (PV = 0.21), respectively. Milk zinc concentration declined significantly over the course of study for two groups, with the sharpest decline occurring during the first 2 months. The mean monthly zinc concentration of ZG group declined from 310 +/- 138 at 1st week to 118 +/- 64 microg dL(-1) at 5th month (declined by 52%). Corresponding means for PG group were 322 +/- 161 and 109 +/- 70 microg dL(-1) (declined by 60%), respectively. Milk zinc concentration significantly different between two groups at 3 and 4 months. A similar study, however, with different zinc dose and administration manner, in zinc marginal deficient lactating mothers is needed to assess the impact of zinc supplementation on milk zinc concentrations.

Breast milk levels of zinc and ω‐6 polyunsaturated fatty acids and growth of healthy Chinese infants

To examine the concentrations of zinc and omega-6 polyunsaturated fatty acids (omega-6 PUFAs) in breast milk, the impact of zinc on omega-6 PUFA metabolism, and the growth rate of infants. Forty-one mother-term infant pairs from a rural area of northern Beijing, China, who were 1 month (n = 18, group I) and 3 months (n = 23, group II) old and exclusively breastfed, were studied. The dietary records and the concentrations of zinc and omega-6 PUFAs in the milk of lactating women and the increase in weight and length of their infants during 1 and 3 postnatal months were analysed. The dietary intakes of mothers in the two groups were the same, i.e. high in carbohydrate and low in fat, protein and energy. The maternal zinc intake was 7.5mg/d and thus reached only 34.6% of the current Recommended Nutrient Intake (RNI). The levels of zinc and arachidonic acid (AA, C20:4 omega-6) in the milk of group I were significantly higher than those in group II. Furthermore, significant positive correlations were found between the concentrations of zinc and AA in the breast milk and between the level of milk AA and weight gain. Zinc may be a co-factor and essential for essential fatty acids (EFA) metabolism. Thus suboptimal zinc intake may cause EFA imbalance. Further studies of Chinese rural mother-infant pairs are necessary to determine whether zinc supplementation should be recommended when lactation exceeds 3 months.

Identification of a Mutation in SLC30A2 (ZnT-2) in Women with Low Milk Zinc Concentration That Results in Transient Neonatal Zinc Deficiency

Breast milk normally contains adequate zinc to meet infant requirements up to six months of age; however, transient neonatal zinc deficiency has been documented in exclusively breastfed infants of women with low milk zinc concentration. This condition is not corrected by maternal zinc supplementation, supporting the speculation that it results from an inherited genetic condition. We identified a family in which two exclusively breast-fed infants developed zinc deficiency that was associated with low milk zinc concentration in both women. Sequencing of genomic DNA detected a mis-sense mutation (Ade-->Gua) that substitutes a conserved histidine at amino acid 54 with arginine (H54R) in SLC30A2 (ZnT-2) that is present in both affected subjects and several other siblings. Gene knockdown of SLC30A2 in mammary epithelial cells reduced zinc secretion, illustrating the role of ZnT-2 in zinc secretion from this cell type. Expression of the H54R mutant in human embryonic kidney-293 cells resulted in reduced zinc secretion as a consequence of perinuclear, aggresomal accumulation, whereas co-expression of the H54R mutant and wild-type ZnT-2 did not abrogate increased zinc secretion in cells overexpressing wild-type ZnT-2 alone. Together, these data provide evidence that low milk zinc concentration in some women is a consequence of a genetic disorder resulting from a mutation in SLC30A2 and can result in neonatal zinc deficiency if unrecognized. Further studies are needed to evaluate the incidence and penetrance of this mutation in the human population.

The effect of Ramadan on maternal nutrition and composition of breast milk

There are many advantages of breast milk for infants. Many factors can affect the volume and composition of breast milk. One of them is the maternal diet. The objective of this study is to determine the effect of Ramadan fasting on maternal nutrition and breast milk composition. A total of 21 breast-feeding mothers aged between 17 and 38 years who fasted during Ramadan month and volunteered to give milk samples were surveyed. The ages of the infants were between 2 and 5 months. The study was performed during Ramadan and 2 weeks after the end of Ramadan. The results showed that during Ramadan, zinc, magnesium and potassium levels in breast milk decreased significantly (P<0.05). The mother's weight increased approximately 1 kg after Ramadan. Changes in body mass index of the mother were not statistically significant. A significant decrease in vitamin A intake was observed after Ramadan (P < 0.05). During Ramadan, energy and most nutrient intakes except protein and vitamins A and C were found below daily recommended dietary allowances necessary for lactating women. Ramadan fasting had no significant effect on the macronutrient composition of the breast milk and consequently the growth of the infants. There were significant differences in some of the micronutrients such as zinc, magnesium and potassium. The nutritional status of lactating women was affected by Ramadan fasting. All of the nutrient intakes (except vitamins A, E and C) decreased during Ramadan. For these reasons, it would seem prudent to excuse lactating women from fasting during Ramadan.

Influence of maternal dietary calcium levels on milk zinc, calcium and phosphorus contents and milk production in rats

The aim of this study was to analyze zinc (Zn), calcium (Ca) and phosphorus (P) contents in milk and the lactational performance in rats fed different Ca levels. Female Wistar rats were fed during pregnancy and lactation with experimental diets containing 20% protein and high (0.90%, HCa), normal (0.60%, NCa) or low (0.20%, LCa) Ca levels. Milk samples were collected after 15 days to determine the milk mineral composition. Pup weight was recorded from birth to weaning (litter size: 6–8 pups) to determine weight gain and calculate milk production. At delivery there were no significant differences in the body weight of the pups between the groups, but at day 15, the LCa group showed lower values than both NCa and HCa groups ( p < 0.05 ) . The weight gain of the LCa group was significantly lower than of the HCa and NCa groups, between delivery and day 5 ( p < 0.05 ) . This reduced rate of weight gain led to the LCa group reaching weaning weight later than the other groups. Milk production (g/pup/day) was significantly lower when dams were fed the LCa than the NCa and HCa diets ( p < 0.05 ) . There were no significant differences among the groups in milk Ca, P and Zn levels and Ca/P ratio. The body mineral composition of the pups at birth did not differ between the groups; at weaning, however, both LCa and HCa groups had lower element contents than the NCa group ( p < 0.05 ) . In conclusion, dams fed with a diet containing low Ca levels produced smaller volumes of milk and their pups reached weaning weights later than the other groups. As the milk mineral composition was not affected, it can be hypothesized that in dams fed low dietary Ca, the smaller milk yield might have been a way of maintaining milk quality. High Ca levels affected neither pregnancy outcome nor lactational performance.

Zinc Supplementation and Somatic Cell Count in Milk of Dairy Cows

The goal of the study was to test the possibility of raising milk zinc (Zn) concentration by increasing the supplementation of Zn, and to assess the effect on the somatic cell count. The experiment was performed at a farm with Czech Pied cattle, with 500 dairy cows and average milk yield 6,390 l. The experiment included 40 dairy cows, assigned to either an experimental (E, n = 20) or a control group (C, n = 20) based on the principle of balanced pairs (efficiency, lactation stage). The experimental group was supplemented Zn in the chelate form (Bioplex Zn, Alltech Inc., Nicholasville, KY), at the dose of 440 mg Zn per animal per day. Blood and milk samples were taken at the start of the experiment and at the end of months 1, 2 and 3. The average milk Zn concentration during the experiment was 57.36 ± 10.54 μmol l-1, ranging from 38.02 to 86.13 μmol l-1. A trend towards a positive effect of Zn supplementation on the health of the mammary gland was identified in association with the somatic cell count, which was significantly lower in the experimental group (114.90 ± 68.7 103 ml-1 vs. 208.60 ± 148.1 103 ml-1; p &lt; 0.05) by the end of month 3. A negative correlation was found between the somatic cell count and Zn concentration in milk (y = -0.0327 x + 61.557; r = -0.441; p &lt; 0.01). Our results indicate that milk Zn concentration is not directly affected by the level of zinc supplementation in the feed ration, but zinc supplementation has a positive effect on the somatic cell count.

Acrodermatite entéropathique chez un nourrisson né à terme nourri exclusivement au sein

Acrodermatitis enteropathica is a rare autosomal recessive disorder, caused by impaired absorption of zinc from the gastrointestinal tract. Symptoms of acrodermatitis enteropathica occur within the first few months after birth and tend to appear shortly after discontinuation of breast-feeding. We report a breast-fed infant with acrodermatitis enteropathica. A full term, 4-month-old girl, consulted in dermatologic department for persistent and refractory anogenital lesions since the age of 1 month, with progressive erythematous, vesiculous and squamous lesions, sometimes erosive in a peri orificial and acral pattern. She was calm and healthy baby. She was breast feeding. The diagnosis of acrodermatitis enteropathica was confirmed by decreased plasma zinc level (14 microg/100 ml). Breast milk zinc levels was low (46 microg/100 ml), as plasma zinc level of the mother (94 microg/100 ml). A genetic study showed that she was homozygous for the mutation, whereas her brother and parents were heterozygous. She was given zinc sulphate, and her condition has improved significantly. Acrodermatitis enteropathica is characterized by a characteristic clinical feature and the diagnosis is confirmed by decreased plasma zinc level. Acrodermatitis enteropathica in exclusively breast fed infant is rare, it was essentially reported in premature babies. Our case report is particular because it's concerning a full-term breast-fed infant, with zinc deficiency in breast milk and mother's decreased plasma zinc level.

Day‐to‐Day Variations in Iron, Zinc and Copper in Breast Milk of Guatemalan Mothers

ABSTRACTObjective: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 Bartolomé 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 ± SD, were 0.28 ± 0.13, 2.03 ± 0.37 and 0.29 ± 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.

Day-to-Day Variations in Iron, Zinc and Copper in Breast Milk of Guatemalan Mothers

To assess the within-subject and between-subject coefficients of variation (CV) of iron, zinc and copper concentrations in the milk of Guatemalan mothers. 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. 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 +/- SD, were 0.28 +/- 0.13, 2.03 +/- 0.37 and 0.29 +/- 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. 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.

Levels of Cytokines (IL‐1β, IL‐2, IL‐6, IL‐8, TNF‐α) and Trace Elements (Zn, Cu) in Breast Milk From Mothers of Preterm and Term Infants

It has been well documented that human milk contains several immunomodulator components which are important during infant period when the newborn's immune system is still under development. In this study, we aim at examining levels of cytokines, zinc (Zn), and copper (Cu) in milk from mothers of premature and mature infants, and comparing changes during lactation periods consequently. Milk was collected from total of 40 mothers (group M: mothers of mature infants, n = 20; group PM: mothers of premature infants, n = 20) from four lactation stages: colostrum (0–7 days), transitional (7–14 days), mature milk (21 days), and mature milk (2nd month). Levels of cytokines (interleukin [IL]-lβ, IL-2, IL-6, IL-8, tumor necrosis factor-alpha [TNF-α]) were determined by chemiluminesence method, whereas atomic absorption spectrophotometer was used for the determination of Zn and Cu levels. Cytokine levels were determined to be high in colostrum and transient milk from mothers of full-term infants, whereas their levels were reduced drastically in the 21st day and the 2nd month milk (P < .01 , P < .001). Similar trends were observed in milk from mothers of premature infants, but cytokine levels were significantly lower in colostrum compared to colostrum from mothers of mature infants (P < .01). The differences in cytokine levels were continuous in transient milk (P < .05) and mature milk (21 days) (P < .05), whereas there was no statistically significant differences between milk from both groups of mothers in the 2nd month (P > .05). Zn levels in milk from mothers of premature infants were significantly lower compared to the ones from mothers of mature infants (P < .01) and these differences continued through the 2nd month. Although Cu levels were lower in milk from mothers of premature infants, there was no statistically significant difference except colostrum (P > .05). Our results clearly demonstrate that the level of immunomodulating agents such as cytokines and trace elements in milk from mothers of premature infants is less than the level of the same agents in milk from mothers of full-term infants. Although there are commercially available products for infant feeding, human milk is still the best natural nutrient for newborns. Therefore, when premature infants are breastfed, necessary precautions such as supplemantary diets must be considered for possible infections and risks related with immune system deficiency.