Minor and trace elements in human milk from Guatemala,Hungary, Nigeria,Philippines, Sweden,and Zaire

Concentrations of As, Ca, Cd, Cl, Co, Cr, Cu, F, Fe, Hg, I, K, Mg, Mn, Mo, Na, Ni, P, Pb, Sb, Se, Sn, V, and Zn were determined in human whole milk samples from Guatemala, Hungary, Nigeria, Philippines, Sweden, and Zaire; in most of these countries, three groups of subjects representing different socioeconomic conditions were studied. Analytical quality control was a primary consideration throughout. The analytical techniques used were atomic absorption spectrophotometry, atomic emission spectrometry with an inductively coupled plasma, colorimetry, electrochemistry, using an ion-selective electrode and neutron activation analysis. The differences between median concentrations of Ca, Cl, Mg, K, Na, and P (minor elements) were lower than 20% among the six countries. Among trace elements, concentrations observed in Filipino milk for As, Cd, Co, Cr, Cu, F, Fe, Mn, Mo, Ni, Pb, Sb, Se, and V were higher than for milk samples from other countries. The remaining five countries showed a mixed picture of high and low values. In the case of at least some elements, such as, F, I, Hg, Mn, Pb, and Se, the environment appears to play a major role in determining their concentrations in human milk. The nutritional status of the mother, as reflected by her socioeconomic status, does not appear to influence significantly the breast milk concentrations of minor and trace elements. Significant differences exist between the actual daily intakes observed in this study and current dietary recommendations made by, for example, WHO and the US National Academy of Sciences. These differences are particularly large (an order of magnitude or more!) for Cr, F, Fe, Mn, and Mo; for other elements, such as, Ca, Cu, Mg, P, and Zn, they amount to at least a factor 2. In the opinion of the present authors, these findings point to the need for a possible reassessment of the dietary requirements of young infants with respect to minor and trace elements, particularly for the elements Ca, Cr, Cu, F, Fe, Mg, Mn, Mo, P, and Zn.     

Inorganic Vanadium Supplementation in Crossbred Calves: Effects on Antioxidant Status,Immune Response and Haemato-Biochemical Attributes

This study aims to investigate the contents of trace elements in the brain and serum of male chickens and the effect of selenium–chromium(VI) interaction. A chronic experimental model was established by supplementing 22.14 mg/kg K₂Cr₂O₇ with 0.00, 0.31, 0.63, 1.25, 2.50, and 5.00 mg/kg Na₂SeO₃ mg/kg B.W. to water for chicken daily. After 14, 28, and 42 days of exposure to the solution, the brain and serum of chickens from each group were collected to detect the levels of Ca, Cu, Mn, Fe, Zn, and Mg by inductively coupled plasma mass spectrometer (ICP-MS). Cr(VI) time-dependently accumulated in the brain and serum. The contents of Cr increased both in the brain and serum with prolonged exposure. Cr contents in the brain and serum decreased in all Se groups compared with those in only Cr-treated groups. Ca contents decreased with prolonged exposure and increasing Se dosage. The contents of Cu and Mn increased on the 28th day but decreased on the 42nd day in the brain and serum. Fe and Zn contents decreased in the serum under prolonged exposure and increased on the 28th day but decreased on the 42nd day in the brain. Cr exposure did not significantly affect Mg contents in the brain but slightly decreased those in the serum. Therefore, appropriate doses of Se affected Cr accumulation, leading to adjustments in the contents and correlations of trace elements.     

奉节脐橙不同器官元素含量分布特征

对奉节脐橙果、叶、干、根中的必需大量元素 (N、K、Ca、Mg、P、S)、微量元素 (Fe、Mn、Cu、Zn、B、Mo)、有益元素 (Si、Co、F、Se、Ni、Sr)、有毒有害元素 (Hg、As、Cr、Cd、Pb、Sb、Bi)的分布特征进行分析 ,结果表明 :果、叶、干、根对各元素的吸收与富集特征具有明显的规律性 ,如叶、干、根中大量元素含量次序均为 Ca>N>K>Mg,叶、干、根中微量元素含量均有 Fe>Mn>Zn>Cu>Mo的规律 ,根、干、叶中有益微量元素含量次序均为 Si>Sr>F>Ni>Co>Se,叶、干、根中有毒有害元素含量次序均有 Pb>As>Sb >Hg的规律 ;在脐橙各器官中 ,叶是大量元素与有毒有害元素最富集的器官 ,根则是有益元素最富集的器官 ,有毒有害元素的 Cr、微量元素的 Mn、Fe、Mo也以根最为富集 ,干则是上述元素最不富集的器官 ,所有元素中 ,仅 Zn在干中最富集 ;大量元素 (除 N外 )、微量元素、有益元素在脐橙各器官的分配含量与地壳土壤背景值的分异含量趋势基本一致 ,土壤背景是这三类元素的主要控制因素。但有毒有害元素的分配形式则明显受人类活动的影响     

Trace element contents in hair of residents from Harbin (China), Medan (Indonesia), and Tokushima (Japan)

The concentrations of 19 trace element in hair samples from 1273 residents of Harbin (China), Medan (Indonesia), and Tokushima (Japan) were measured by inductively coupled plasma emission spectrometry. The mean concentrations of Ba, Ca, and Se were significantly higher in the Harbin hair samples when compared to those from Medan, but Al, B, Cu, Fe, Mn, Na, Pb, Ti, Zn, and K were significantly higher in Medan than in Harbin hair samples. The differences in the mean concentrations of As, Cr, Mg, P, Sn, and Sr between the Medan and Harbin lots were not significant. In the Tokushima hair samples, Na and K were significantly higher, but As, B, Ba, Ca, Cr, Mg, Mn, Pb, Sn, Sr, and Se were significantly lower than in the Harbin hair samples. The differences in the mean concentrations of Al, Cu, Fe, P, Ti, and Zn between Harbin and Tokushima were not significant. In the Medan hair samples, Al, As, B, Ba, Ca, Cr, Cu, Fe, Mg, Mn, Pb, Sn, Sr, Ti, and Zn were significantly higher, but P and Se were significantly lower than in Tokushima hair samples. Differences in mean concentrations of Na and K between Tokushima and Medan were not significant.     

A search for trace elements in some human intracranial tumors by instrumental neutron activation analysis

A investigation was undertaken to measure the presence of trace elements in some intracranial tumors using the instrumental neutron activation analysis technique. The following 20 minor and trace elements were investigated: Na, Mg, Al, P, Cl, K, Ca, Cr, Mn, Fe, Co, Cu, Zn, As, Se, Br, Rb, Sb, I, and Cs. Our results are compared with other trace element analyses in human brain tissue.     

Assessment of reference values for hair minerals of Korean preschool children

Hair samples of 655 children (3–6 yr of age) from metropolitan and small cities in Korea were analyzed to determine the content of 23 minor and trace elements with the aim of assessing reference values. Fifteen essential elements (Fe, Zn, Cu, Ca, Mg, Mn, P, Na, K, Cr, Se, Li, V, Co, Mo) and 8 harmful elements (Pb, Al, Hg, As, Cd, Ba, Bi, U) were taken into account. Measurements were performed by inductively coupled plasma-mass spectrometry. The overall mean values were as follows (μ/g): Al, 8.78; As, 0.11; Ba, 0.32; Bi, 0.04; Ca, 212.47; Cd, 0.08; Co, 0.01; Cr, 0.47; Cu, 15.51; Fe, 12.62; Hg, 0.49; K, 34.10; Li, 0.01; Mg, 12.29; Mn, 0.29; Mo, 0.07; Na; 27.14; P, 121.21; Pb, 1.68; Se, 0.75; U. 0.04; V. 0.08; Zn, 69.99. There was no significant difference in hair mineral content between children living in metropolitan and small cities. There were positive correlations between age and the level of Zn, Ca, Na, P, Mn, and Li, but negative correlations between age and the level of Cr, V, and U. The proposed reference values for hair Zn, Mg, Ca, As, and Cd of Korean children were lower than those of other countries, but the values for other elements of hair were not significantly different from those of other countries.     

An elemental correlation study in cancerous and normal breast tissue with successive clinical stages by neutron activation analysis

Influence of trace elements in body metabolism and their physiological importance in various diseases have motivated their accurate and quantitative determination in biological tissues and fluids. Instrumental Neutron Activation Analysis (INAA) using short and long term irradiation has been employed to determine five minor elements (Cl, K, Na, Mg, P) and 15 trace elements (As, Br, Co, Cr, Cs, Cu, Fe, Hg, Mn, Rb, Sb, Se, Sc, Sr, and Zn) in cancerous and normal breast tissue from 30 patients of four clinical stages. Several elements show enhancement in cancerous breast tissue. Selenium shows maximum enhancement of 94.7% followed by K (81.6%), Sc (66.7%), Cu (58.2%), Na (48.5%), P (44.4%), and Zn (39.2%). Some element, such as Fe, Cr, and Mn, are depressed by 30.8, 30.1, and 12.8%, respectively. These elements compete for binding sites in the cell, change its enzymatic activity and exert direct or indirect action on the carcinogenic process accelerating the growth of tumors. This is further evidenced by histopathological examination of cancerous cells showing poor cytological differentiation. An attempt has been made to correlate trace element concentrations of Se, Cu, Zn, Rb, Br, Hg, As, Co, Fe, Cr, and Mn and the ratios of Se/Zn, K/P, Cu/Zn, Na/K, and Se/Fe with the clinical stages of cancer. Inhibition of enzymatic activity caused by variation in trace element concentrations results in immunological breakdown of the body system.     

Plasma metallomics reveals potential biomarkers and insights into the ambivalent associations of elements with acute myocardial infarction

Acute myocardial infarction (AMI) is a leading cause of mortality and morbidity worldwide. Using a validated and efficient ICP-MS/MS-based workflow, a total of 30 metallomic features were profiled in a study comprising 101 AMI patients and 66 age-matched healthy controls. The metallomic features include 12 essential elements (Ca, Co, Cu, Fe, K, Mg, Mn, Na, P, S, Se, Zn), 8 non-essential/toxic elements (Al, As, Ba, Cd, Cr, Ni, Rb, Sr, U, V), and 10 clinically relevant element-pair product/ratios (Ca/Mg, Ca×P, Cu/Se, Cu/Zn, Fe/Cu, P/Mg, Na/K, Zn/Se). Preliminary linear regression with feature selection confirmed smoking status as a predominant determinant for the non-essential/toxic elements, and revealed potential routes of action. Univariate assessments with adjustments for covariates revealed insights into the ambivalent relationships of Cu, Fe, and P with AMI, while also confirming cardioprotective associations of Se. Also, beyond their roles as risk factors, Cu and Se may be involved in the response mechanism in AMI onset/intervention, as demonstrated via longitudinal data analysis with 2 additional time-points (1-/6-month follow-up). Finally, based on both univariate tests and multivariate classification modelling, potentially more sensitive markers measured as element-pair ratios were identified (e.g., Cu/Se, Fe/Cu). Overall, metallomics-based biomarkers may have utility for AMI prediction.     

The Dietary Acrylamide Intake Adversely Affects the Serum Trace Element Status

Acrylamide is an organic chemical which occurs in foods widespreadly consumed in diets worldwide. The purpose of this study was to evaluate the serum trace element levels (Fe, Cu, Zn, Mn, Cr, Se, Co, Ni, V, As, Mg, P, Li, K, Al) in Wistar rats exposed to acrylamide. Acrylamide was administered to the treatment groups at 2 and 5 mg/kg?body weight (bw)/day via drinking water for 90 days. Inductively coupled plasma mass spectrometry was used for the determination of serum trace element concentrations. Serum Zn, Se, Co, V and Mg concentrations of 5 mg/kg bw/day acrylamide-treated male rats were lower, whereas serum As concentration was higher than the same parameters of the controls rats. Similarly, serum Zn, Se, Co, V and Mg concentrations were decreased in 5 mg/kg?bw/day acrylamide-treated female rats compared with control rats. On the other hand, there were no significant differences between serum Fe, Cu, Mn, Cr, Ni, P, Li, K and Al concentrations of all groups. The results from this study provide evidence that dietary acrylamide intake adversely affects the serum trace elements status.     

Evaluation of Essential and Toxic Trace Elements in Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma

Pseudoexfoliation syndrome (PEX), an age-related disorder of the eye, is associated with significant ophthalmic morbidity and can lead to pseudoexfoliation glaucoma (PEG). The etiology of this disorder has not been clearly understood. Trace elements have been suggested to have roles in the pathogenesis of several disorders. This study aimed to determine whether trace element levels have a role in the development of PEX and/or PEG. Levels of zinc (Zn), copper (Cu), selenium (Se), manganese (Mn), chromium (Cr), cobalt (Co), molybdenum (Mo), nickel (Ni), vanadium (V), arsenic (As), aluminum (Al), mercury (Hg), cadmium (Cd), and strontium (Sr) were determined in serum samples of 32 cases of PEX, 30 cases of PEG, and 32 control subjects using inductively coupled plasma–mass spectrometry. Mn, Mo, and Hg concentrations were found to be significantly increased in patients with PEX. Logistic regression revealed Mn and Hg as the strongest determinants of PEX and Mo as the strongest determinant of PEG in the studied Turkish subjects. Levels of Mn, Cr, Co, Mo, Al, Hg, Sr, Ni, V, and As were determined for the first time in these ophthalmological disorders. Increased levels of serum Mn, Mo, and Hg suggest a possible role of these elements in the pathobiology of PEX.     

人工饲养与野生川金丝猴体毛10种微量元素的含量及比较

测定了秦岭人工饲养(10只)和野生(14只)川金丝猴体毛中的10种微量元素含量。锌、铁、铜、钙、镁5种元素采用火焰原子吸收法;锰、铬、铅采用石墨炉原子吸收法;铝采用等离子光谱;硒经硝解后采用原子吸收法测定。结果表明,铬、锰、镁、铅、锌和硒的含量,人工猴极显著或显著高于野生猴;铁含量,人工猴极显著低于野生猴;钙、铜和铝的含量,人工猴与野生猴无显著差异。以人类毛发10种微量元素的正常范围为参照,人工猴铅、铬、锰与锌4种含量均显著超出正常范围的上限,属于严重超量。这可能与金丝猴饲养过程中添加营养制剂有关。     

The Prediction of Cardiovascular Disease Based on Trace Element Contents in Hair and a Classifier of Boosting Decision Stumps

The early discovery of cardiovascular disease (CVD) is crucial for performing successful treatments. This study aims at exploring the feasibility of Adaboost (ensemble from machining learning) using decision stumps as weak classifier, combined with trace element analysis of hair, for accurately predicting early CVD. A total of 124 hair samples composed of two groups of samples (one is healthy group from 100 healthy persons aged 24–72 while the other is patient group from 24 cardiovascular disease patients aged 36–81) were used. Nine kinds of trace elements, i.e., chromium (Cr), manganese (Mn), cadmium (Cd), copper (Cu), zinc (Zn), selenium (Se), iron (Fe), aluminum (Al), and nickel (Ni), were selected. In a preliminary analysis, no obvious linear correlations between elements can be observed and the concentration of Cr, Fe, Al, Cd, Ni, or Se for healthy group is higher than that for patient group while the opposite is true for Mn, Cu, or Zn, indicating that both low Se/Fe and high Mn/Cu can be identified as major risk factors. Based on the proposed approach, the final ensemble classifier, constructed on the training set and contained only four decision stumps, achieved an overall identification accuracy of 95.2%, a sensitivity of 100% and a specificity of 94% on the independent test set. The results suggested that integrating Adaboost and trace element analysis of hair sample can serve as a useful tool of diagnosing CVD in clinical practice.     

Determination of trace elements in aerosol samples by Instrumental Neutron Activation Analysis

Two nuclear techniques, Energy-Dispersive X-Ray Fluorescence Analysis (EDXRF) and Instrumental Neutron Activation Analysis (INAA), were used to analyze aerosol samples collected in the city of São Paulo, Brazil. Na, Cl, Mn, V, Al, Sm, Mo, W, La, As, Br, Sb, K, Ba, Se, Th, Cr, Rb, Ca, Fe, Ce, and Sc were determined by INAA, and Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Hg, and Pb were determined by EDXRF. A preliminary identification of the main source of the atmospheric aerosol was performed based on enrichment factor and correlation coefficient calculations.

     

Concentrations of trace elements in sera of newborns, young infants, and adults

Concentrations of trace elements in newborns, infants, and adults may be significantly different from each other. Serum trace element reference ranges for different age groups are of value for diagnostic purposes. Inductively coupled plasma-mass spectrometry was applied to the determination of the 21 trace elements Ba, Be, Bi, Ca, Cd, Co, Cs, Cu, La, Li, Hg, Mg, Mn, Mo, Pb, Rb, Sb, Sn, Sr, TI, and Zn in a total of 117 sera of individuals representing different age groups. After microwave-assisted acid digestion with high-purity reagents, 20 umbilical cord sera, 5 sera of fully breast-fed infants, 6 sera of formula-fed infants, 66 sera of patients suffering internal diseases, and 20 sera of healthy blood donors were analyzed for trace elements. One serum and two whole-blood reference materials were analyzed for quality control. Experimental concentrations were in good agreement with certified values. Umbilical cord serum concentrations of the essential elements Ca, Co, Cu, and Mg and of the nonessential and toxic elements Ba, Be, Li, Pb, and Sb were elevated compared to the elemental concentrations in the sera of infants and adults. Serum levels of Ba, Ca, Co, Mn, Pb, and Sb of infants were much higher and serum Cu was significantly lower than in adults. Serum Cu increased significantly with age (newborns: 353 microg/L; infants: 755 microg/L; healthy adults: 810 microg/L), whereas for other trace elements no age-dependence could be established.     

Selenium and selenium-antagonistic elements in nutritional cancer prevention

Selenium is an essential trace element with antioxidative, antimutagenic, antiviral and anticarcinogenic properties. There is increasing evidence that the dietary selenium intakes are sub-optimal in the populations of many countries and that human cancer mortalities would significantly decline if additional selenium was made available either through supplementation or the fortification of certain foods. An important property of selenium is its interaction with other elements that may be present in foods, the water, the workplace and the environment, e.g. As, Cu, Ni, Co, Cr, Mn, Zn, Cd, Sn, Pb, Hg, Bi, Mo, Ag, Au, etc. The sequestration of elements by selenium represents an efficient natural detoxification mechanism for some of these elements but also results in the physiological inactivation of selenium. Animal experiments confirm that the chronic exposure to low levels of these elements abolishes the cancer-protective effect of selenium. Human cancer is likewise significantly determined by the interactions of selenium with other elements, as evidenced by epidemiological, ecological and case-control studies. Cadmium, for example, is a key risk-increasing element for prostate cancer; for breast cancer, Cd, Cr, Zn are mainly contributing; for bronchial cancer (in smelter workers), Cd, As, Cr, Sb, Co, La, all these elements are in a reciprocal relationship with Se. While selenium remains the key cancer-protective trace element, the interpretation of its mode of action necessitates consideration of the effects of selenium antagonistic elements.     

Effect of sildenafil citrate (Viagra?) on trace element concentration in serum and brain of rats

As a vasodilator with good hemodynamic effects, sildenafil has been successfully used in the treatment of patients with pulmonary hypertension and cardiovascular diseases. By selectively inhibiting phosphodiestrase type 5 (PDE-5) and thus effectively reducing the breakdown of c GMP, sildenafil administration can markedly improve the erectile dysfunction. Sildenafil also elevates localized cerebral blood flow in rat brain. The objective of the present study was to investigate the effect of sildenafil on the level of trace elements (Zinc (Zn), copper (Cu), iron (Fe), selenium (Se), cobalt (Co), and chromium (Cr)) in blood and brain of rats. Sixteen male albino rats weighing 180-200 g were divided into two groups (8 rats/group). Sildenafil (Viagra, Pfizer Inc.) was dissolved in saline and administered at a dose of 10mg/kg i.p. (0.5 ml volume) to rats in the treated group every 72 h for 12 injections. Rats in the control group were administered the same volume of saline as in treated group. All rats were sacrificed 24h after the last injection. Blood samples were collected and serum was separated and stored at -20°C. Brains were dissected and stored frozen until analysis. Trace elements concentrations were determined by flame emission atomic absorption spectrophotometer. Results showed that sildenafil injection significantly (P<0.05) increased serum and brain Se and Cu concentrations. Moreover, sildenafil increased the Cr concentration in the brain tissue. It was concluded that sildenafil citrate administration increased serum Se and Cu as well as, increased brain Se, Cu, and Cr concentrations in rats.     

Serum and tissue levels of six trace elements and copper/zinc ratio in patients with cervical cancer and uterine myoma

The aim of this study is to investigate the relationship between trace elements and the incidence of cervical cancer. Tissue and serum levels of six elements (Cu, Zn, Fe, Mn, Ca, and Se) and the Cu/Zn ratio in 40 cases of patients with cervical cancer, 30 cases of uterine myoma, and 50 healthy subjects were measured by atomic absorption spectrophotometry; the selenium content was determined by atomic fluorescence spectrometry. The results showed that the tissue contents of Zn, Se, and Ca were significantly lower and the Cu and Fe concentrations and Cu/Zn ratio were significantly higher in cervical cancer tissue than that for paired nonlesion tissue (p<0.02 and p<0.001, respectively). The serum levels of Zn, Se, Ca, and Fe were lower and Cu and Mn levels and Cu/Zn ratio were higher in patients with cervical cancer than in healthy subjects (p<0.01 and p<0.001, respectively) and in the uterine myoma group compared with healthy subjects (p< 0.05–0.001). There are no significant differences in the contents of six elements and the Cu/Zn ratio between uterine myoma tissue and paired nonlesion tissue. The results showed also that the Fe level and Cu/Zn ratio were significantly higher and the Zn and Se levels were significantly lower in cervical cancer tissue than in uterine myoma tissue (p<0.01 and p<0.001, respectively). The serum Cu level and Cu/Zn ratio were significantly higher in the cervical cancer group than the uterine myoma group (p<0.01). Data were also analyzed using multivarate logistic regression. After adjustment for age, occupation, life habit, and other covariates for the development of cervical cancer, the odds ratios were 22.64 (95% confidence interval [CI]: 5.64–90.88, p=0.001) for Cu, 0.11 (95% CI: 0.034–0.373; p=0.005) for Zn, and 0.60 (95% CI: 0.36–0.99, p=0.01) for Se. Thus, the serum and tissue levels of Cu increase and the deficiency of Zn and Se may be risk factors for the development of cervical cancer.     

Effect of magnesium deficiency on enterocyte Ca, Fe, Cu, Zn, Mn and Se content

In previous studies based on indirect procedures, we reported that Mg deficit increased the bioavailability of a number of elements such as calcium, zinc, iron, copper, manganese and decreased selenium absorption. The present study was designed to verify these findings by direct methods. We investigated the effect of dietary magnesium deficiency on enterocyte Ca, Fe, Zn, Cu, Mn and Se concentrations. Male Wistar rats were fed a Mg-deficient diet (129 mg Mg/kg food) for 70 days. Whole enterocytes from the upper jejunum were isolated and Ca, Fe, Zn, Cu, Mn and Se were determined. The results were compared with findings in a control group that was pair-fed with an identical diet except that it covered this species's nutritional requirements for Mg (480 mg Mg/kg food). The Mg-deficient diet significantly increased enterocyte content of Ca, Fe, Zn, Cu and Mn; however, we found no significant changes in the Se content of these cells. These data support the results obtained by indirect methods.     

Plasma manganese, selenium, zinc, copper, and iron concentrations in patients with schizophrenia

A number of essential trace elements play a major role in various metabolic pathways. Selenium (Se), manganese (Mn), copper (Cu), zinc (Zn), and iron (Fe) are essential trace elements that have been studied in many diseases, including autoimmune, neurological, and psychiatric disorders. However, the findings of previous research on the status of trace elements in patients with schizophrenia have been controversial. We studied these elements in patients with a DSM-IV diagnosis of schizophrenia and compared them with sex- and age-matched healthy controls. Plasma Cu concentrations were significantly higher (p<0.01) and Mn and Fe concentrations were lower (p<0.05 and p<0.05, respectively) in schizophrenic patients than in controls. Se and Zn concentrations and protein levels did not differ between patients and healthy controls. These observations suggest that alterations in essential trace elements Mn, Cu, and Fe may play a role in the pathogenesis of schizophrenia. However, findings from trace element levels in schizophrenia show a variety of results that are difficult to interpret.     

Evaluation of trace element status of organic dairy cattle

The present study aimed to evaluate trace mineral status of organic dairy herds in northern Spain and the sources of minerals in different types of feed. Blood samples from organic and conventional dairy cattle and feed samples from the respective farms were analysed by inductively coupled plasma mass spectrometry to determine the concentrations of the essential trace elements (cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), iodine (I), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se) and zinc (Zn)) and toxic trace elements (arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb)). Overall, no differences between organic and conventional farms were detected in serum concentrations of essential and toxic trace elements (except for higher concentrations of Cd on the organic farms), although a high level of inter-farm variation was detected in the organic systems, indicating that organic production greatly depends on the specific local conditions. The dietary concentrations of the essential trace elements I, Cu, Se and Zn were significantly higher in the conventional than in the organic systems, which can be attributed to the high concentration of these minerals in the concentrate feed. No differences in the concentrations of trace minerals were found in the other types of feed. Multivariate chemometric analysis was conducted to determine the contribution of different feed sources to the trace element status of the cattle. Concentrate samples were mainly associated with Co, Cu, I, Se and Zn (i.e. with the elements supplemented in this type of feed). However, pasture and grass silage were associated with soil-derived elements (As, Cr, Fe and Pb) which cattle may thus ingest during grazing.