Supply Of Trace Elements Research Articles

The role of zinc in beer production

Fermentation of wort is the most critical step of beer production. Fermentation difficulties may be caused by inadequate wort composition, i.e. insufficient supply of trace elements. Wort provides trace elements for yeast. Among them zinc, which is essential for beer fermentation, is not available in the required amount in wort. Zinc utilization in fermentation was studied in beers made with adjunct (maize, barley). Inductively coupled plasma-atomic emission spectrometry was used as analytical method for the determination of zinc concentration. Addition of zinc made the fermentation faster. The best result was achieved at 0.4 mg l -1 . Synthesis of aroma compounds was also promoted at this concentration. Concentrations higher than 0.4 mg l -1 did not affect significantly either the fermentation rate or the maximal ethanol concentration. Addition of zinc at the end of wort boiling did not prove to be practical, it is better to supply yeast with zinc.

Assessing the needs of sheep for trace elements

NO progress can be made in assessing the trace element needs of sheep without first addressing the question of ‘status’. This term means different things to different people but, for...

Selenium and the Control of Thyroid Hormone Metabolism

Thyroid hormone synthesis, metabolism and action require adequate availability of the essential trace elements iodine and selenium, which affect homeostasis of thyroid hormone-dependent metabolic pathways. The three selenocysteine-containing iodothyronine deiodinases constitute a novel gene family. Selenium is retained and deiodinase expression is maintained at almost normal levels in the thyroid gland, the brain and several other endocrine tissues during selenium deficiency, thus guaranteeing adequate local and systemic levels of the active thyroid hormone T(3). Due to their low tissue concentrations and their mRNA SECIS elements deiodinases rank high in the cellular and tissue-specific hierarchy of selenium distribution among various selenoproteins. While systemic selenium status and expression of abundant selenoproteins (glutathione peroxidase or selenoprotein P) is already impaired in patients with cancer, disturbed gastrointestinal resorption, unbalanced nutrition or patients requiring intensive care treatment, selenium-dependent deiodinase function might still be adequate. However, disease-associated alterations in proinflammatory cytokines, growth factors, hormones and pharmaceuticals modulate deiodinase isoenzyme expression independent from altered selenium status and might thus pretend causal relationships between systemic selenium status and altered thyroid hormone metabolism. Limited or inadequate supply of both trace elements, iodine and selenium, leads to complex rearrangements of thyroid hormone metabolism enabling adaptation to unfavorable conditions.

Atmospheric Supply of Trace Elements Studied by Peat Samples from Ombrotrophic Bogs

Concentrations of Fe and 12 trace elements in peat from ombrotrophic bogs were used to estimate the atmospheric deposition of these elements on a temporal and spatial scale. Peat samples were collected at 21 different sites in Norway encompassing large geographical differences in marine influence and air pollution. The study demonstrates that surface peat is an excellent medium to study geographical differences in heavy metal deposition, provided that effects of the surface plant cover are properly considered. Long-range atmospheric transport of pollutants is the main source for As, Cd, Pb, Sb, and Zn, and to a lesser extent for Cu and Se. Biogenic emissions from the ocean appear to be the main source of Se to the peat. The metals Co, Cr, Fe, and Ni are mainly associated with wind-blown local soil dust. Surface enrichment of Mn, and in part Zn, is mainly caused by nutrient circulation between the surface peat and vascular plants growing on it. Deposition of marine salts appears to be the main reason for lower Mn concentrations in the peat near the coast.

Invited review: formation of keratins in the bovine claw: roles of hormones, minerals, and vitamins in functional claw integrity.

Keratins are the characteristic structural proteins of the highly cornified epidermis of the skin, feathers, and hoof. Keratin proteins provide the structural basis for the unique properties of the biomaterial horn and its protective function against a wide range of environmental factors. Hoof horn is produced through a complex process of differentiation (keratinization) of epidermal cells. Formation and biochemical binding of keratin proteins and synthesis and exocytosis of intercellular cementing substance (ICS) are the hallmarks of keratinization. It is finalized by the programmed death of the living epidermal cells, i.e., cornification, that turns the living epidermal cells into dead horn cells. The latter become connected by the intercellular cementing substance. The functional integrity of hoof horn essentially depends on a proper differentiation, i.e., keratinization of hoof epidermal cells. Keratinization of hoof epidermis is controlled and modulated by a variety of bioactive molecules and hormones. This process is dependent on an appropriate supply of nutrients, including vitamins, minerals, and trace elements. Regulation and control of differentiation and nutrient flow to the epidermal cells play a central role in determining the quality and, consequently, the functional integrity of hoof horn. Decreasing nutrient supply to keratinizing epidermal cells leads to horn production of inferior quality and increased susceptibility to chemical, physical, or microbial damage from the environment. A growing body of evidence suggests that hormones, vitamins, minerals, and trace elements play critical roles in the normal development of claw horn and correct keratin formation.

Geochemistry and the mineral nutrition of agricultural livestock and wildlife

Relations between the geochemical nature of soils and their parent materials and the occurrence of nutritional deficiencies and excesses in grazing livestock have been documented since the 1960s and earlier, with notable work in Australia, New Zealand, United Kingdom, Ireland, USA and the Soviet Union. Studies at Imperial College London, into the development of regional geochemical mapping techniques as a means of delineating nutritional problems commenced in the 1960s and have continued to the present. Research has mainly focussed on deficiencies of Cu, Co and Se in cattle and sheep, and the role of Mo and S in the soil/plant system in both clinical and sub-clinical hypocuprosis in cattle. Exposure to heavy metals, in particular Pb, Zn, Cd and the metalloid As have also received attention in areas contaminated by past mining and smelting activities. Soil and plant factors influencing the dietary supply of both essential trace elements and toxic metals have been studied, including their speciation and bioavailability. Soil ingestion has been recognised as an important exposure pathway of heavy metal contamination to grazing cattle, and as an antagonist of Cu supply and a source of dietary Co in sheep. Relations between soil geochemistry and the mineral status of wildlife species, in particular impala and black rhinoceros, have been established in Kenya and recent work, presented elsewhere in this Symposium, has concerned the supply of nutrients to the Roosevelt sable in Kenya. The compilation of regional and national multi-purpose geochemical atlases, based on the systematic sampling of soils or stream sediments, is now recognised as a priority in many countries of the developed and developing world. This paper explores the opportunities for future research into the application of geochemical maps for the optimisation of land use, efficient livestock production, and improving conservation of wildlife.

Diagenetic cycling of trace elements in the bottom sediments of the Swan River Estuary, Western Australia

Teflon strips were used in-situ in the bottom sediments at two sites in the Swan River Estuary to collect diagenetic Fe–Mn oxyhydroxides and monitor monthly changes in their morphology and trace element geochemistry. This study demonstrates that substantial concentrations of trace elements accumulate at the redox front during the formation of diagenetic Fe–Mn oxyhydroxides. It is likely that the Fe–Mn oxyhydroxides initially nucleate and grow on the Teflon strips via bacterial activity. Trace element geochemistry of the diagenetic Fe–Mn oxyhydroxides is influenced by changes in the supply of trace elements from either the bottom sediments and/or water column or changes in the physico-chemical status of bottom and porewaters. If sufficient diagenetic Fe–Mn oxyhydroxides are preserved in the upper layer(s) of the bottom sediment it is possible that diagenetic (secondary) trace element enrichment profiles may be produced which modify the historical input of natural or anthropogenic trace element sources. Alternatively, partial or complete dissolution of the diagenetic Fe–Mn oxyhydroxides in response to temporal changes in the redox status of the bottom sediment may lead to a substantial underestimate of trace element fluxes in historical bottom sediment profiles. This study highlights that considerable care must be taken when interpreting short- to long-term geochemical profiles in bottom sediments due to the possible occurrence of rapid, seasonally mediated diagenetic processes.

Zinc deficiency in rapidly growing preterm infants

Symptomatic zinc deficiency was observed in a 24‐week gestation, 640 g birthweight infant fed exclusively with maternal breast milk. Our hypothesis was that subclinical Zn deficiency is not uncommon in very low birthweight infants because fortified human milk and preterm formula may contain little Zn. Zinc serum concentrations determined in 26 consecutive very low birthweight infants (gestational age 23‐32, median 27 weeks), prior to discharge, at a chronological age of 37‐121 (median 72) d, were found between 1.0 and 14.0 (median 6.4) μmol/l, in 14 infants they were below the normal range of 7.6–15.0 μmol/l. Serum alkaline phosphatase and iron intake did not correlate with Zn concentrations. Nutritional supply of Zn and other trace elements by breast milk fortifiers and infant formulas currently used in Germany does not appear to meet the demands of rapidly growing extremely low birthweight infants during the first months of life.

Evolution of the nutritional support pattern in pediatric intensive care.

To evaluate patterns of usage and monitoring of nutritional support in a Pediatric ICU of a teaching hospital and the role of an education program in nutritional support given throughout the resident physician training. In a historical cohort study, records from children who received nutritional support during the year 1992 were analyzed. Thereafter a continuing education program in Nutritional Support was conveyed to the residents. In a second phase of the study, the same parameters were reevaluated in children who received nutritional support throughout the year 1995. Pediatric Intensive Care Unit of Department of Pediatrics, Escola Paulista de Medicina. All the children who were given nutritional support during a period of five days or more. Based on this criteria 37 children were selected for the first phase of this study, and 35 for the second one. The education program included theoretical lectures about basic themes of nutritional support and journal article reading sessions. It was given to successive groups of residents on a weekly schedule. Daily records of fluid, protein, caloric and micronutrient supply, nutritional assessment and metabolic monitoring. In the first phase of the study, an exclusively parenteral route was utilized for 80.5%, and a digestive route 19.5% of the time period. Nutritional assessment was performed on 3 children; no patient had the nutritional goals set. The nitrogen to nonprotein calories ratio and the vitamin supply were inadequate, whilst the supply of trace elements was adequate except for zinc. Nutritional monitoring was performed on almost all patients but without uniformity. In the second phase, the exclusive parenteral route was used for 69.7% and the digestive route for 30.3% of the time period; no significant increase in the use of the digestive route was detected. The nonprotein calories to nitrogen ratio and micronutrient supply were adequate. The frequency of nutritional assessment increased, but deficiency in nutritional monitoring and infrequent enteral feeding were still detected. There were deficiencies in the implementation of nutritional support, which were partially corrected in the second phase of the study by the training of the residents. Reinforcement of the education program, which should be applied to the whole medical staff, and the organization of a multidisciplinary team in charge of coordinating the provision of nutritional support are suggested.

Evolution of the nitrogen cycle and its influence on the biological sequestration of CO2 in the ocean

Over geological time, photosynthetic carbon fixation in the oceans has exceeded respiratory oxidation of organic carbon. The imbalance between the two processes has resulted in the simultaneous accumulation of oxygen in, and drawdown of carbon dioxide from, the Earth's atmosphere, and the burial of organic carbon in marine sediments1–3. It is generally assumed that these processes are limited by the availability of phosphorus4,5, which is supplied by continental weathering and fluvial discharge5–7. Over the past two million years, decreases in atmospheric carbon dioxide concentrations during glacial periods correlate with increases in the export of organic carbon from surface waters to the marine sediments8–11, but variations in phosphorus fluxes appear to have been too small to account for these changes12,13. Consequently, it has been assumed that total oceanic primary productivity remained relatively constant during glacial-to-interglacial transitions, although the fraction of this productivity exported to the sediments somehow increased during glacial periods12,14. Here I present an analysis of the evolution of biogeochemical cycles which suggests that fixed nitrogen, not phosphorus, limits primary productivity on geological timescales. Small variations in the ratio of nitrogen fixation to denitrification can significantly change atmospheric carbon dioxide concentrations on glacial-to-interglacial timescales. The ratio of these two processes appears to be determined by the oxidation state of the ocean and the supply of trace elements, especially iron.

Reference Values for the Trace Elements Copper, Manganese, Selenium, and Zinc in the Serum / Plasma of Children, Adolescents, and Adults

Up to now few plasma or serum reference or serum reference values have been available for the assessment of the essential trace element supply status in different age groups covering the whole range of life range. In the present investigation, the concentrations of copper, manganese, selenium, and zinc were determined in the serum of 137 healthy children and in the plasma of 68 blood-donors. The age distribution within these groups ranged from 1 month to 18 years and from 22 to 75 years. The determinations were carried out directly by means of electrothermal atomic absorption spectrophotometry with Zeeman background compensation. The adult plasma reference values (mean +/- 2 SD) were 1.65 +/- 8.6 mumol/1 for copper, 14.3 +/- 11.4 nmol/1 for manganese, 0.80 +/- 0.36 mumol/1 for selenium, and 16.6 +/- mumol/1 for zinc. No correlation between concentration of elements and sex could be established. In the child and adolescent group, the manganese levels exhibited an age-dependent linear decrease (54% of the starting value, slope 0.92, r = 0.4, p < 0.001), the copper and the selenium concentrations, respectively, exhibited an exponential increase (107%, r = 0.59 and 174%, r = 0.61), with the highest value in the age group of 6 to 10 years. Reference ranges are established for 9 different age groups. The results reflect the known physiological data on the trace element content in the tissue of children and their diet. The present study is an important pre-requisite for diagnosis and therapy of trace element deficiencies in all age groups.

Available iron and zinc in major lean meat cuts and their contribution to the recommended trace element supply in Switzerland.

The objective of the present study was to analyze iron and zinc in major lean meat cuts in order to estimate the contribution of the average lean meat consumption in Switzerland (1995) for these trace elements. Iron, heme iron and zinc contents were analyzed in following muscles: pork (longissimus dorsi muscle and shoulder), beef (longissimus dorsi muscle and shoulder), veal (longissimus dorsi muscle) and chicken (breast and thigh). Beef and pork shoulder were the best sources of iron, heme iron and zinc. Pork and veal longissimus dorsi muscle and chicken were relatively poor in these trace elements. With an average daily lean meat consumption of 105 g, iron and zinc intake were about 1.1 mg/d and 3.8 mg/d, respectively. Recommendations for daily iron intake were met to 11% (men) and 7% (women) and for zinc to 25% (men) and 32% (women). Applying a modified Monsen model, the requirements for absorbed iron were met in the range of 10-30% and 7-20% for men and women, respectively. Taking into account a zinc absorption rate from meat of about 20-36%, the daily requirements for absorbed zinc were covered to 32-56%. In conclusion, the average amount of lean meat as consumed in Switzerland was high enough to be an important source of available iron and zinc, particularly for people with low iron and zinc status.

Formation of some manganese minerals from ferromanganese factory waste disposed in the Krka River Estuary

The identification, characterisation and formation of managanese minerals takanelite and kutnahorite calcian found in the Krka River Estuary, is described. These minerals originated from the hydrochemical transformation of waste disposed from a ferromanganese factory. Industrial slag, dust settled inside a chimney, and marine sediments in the vicinity of the ferromanganese plant “Crnica”, situated in the suburb of the city of Šibenik were analysed in details. The samples of slag and dust were equilibrated with estuarine waters for 20 d. In marine sediment, calcite is predominant, while quartz, aragonite, kutnahorite calcian and dolomite were found as minor components. Iron is present in all samples as an amorphous phase. Strontium, titanium, copper, zinc, lead and rubidium were found as microcomponents. It was found that slag and dust particles partly dissolve in contact with estuarine water of different salinities, and present renewable supply of manganese, iron and numerous trace elements. A possible way of the formation of manganese minerals takanelite and kutnahorite is discussed. Takanelite mineral was obtained in laboratory by partial disolution of slag containing bustamite ferroan. For kutnahorite calcian it is suggested that it forms in the process of dolomitization. With respect to aqueous environment of the Krka River Estuary, the slag and dust from a ferromanganese industry upon contact with water transform into scavengers (gypsum, calcite, quartz, takanelite) which help purifying the water column from other micro-impurities.

Effect of dietary antioxidant trace element supply on cardiac tolerance to ischmia—reperfusion in the rat

Over a 10-week period, female Wistar rats received a diet containing various levels of four trace elements (Zn, Cu, Mn, Se), co-factors of antioxidant enzymes (superoxide dismutase SOD, glutathione peroxidase GPx), in order to examine the influence of supplementation or deficiency of these elements (i) on tissue antioxidant enzyme defence systems, and (ii) on the susceptibility of the myocardium to ischemia-reperfusion injury. At the end of the dietary treatment, hearts were perfused at constant flow (11 ml/min) before being subjected to 15 min of total global normothermic ischemia, followed by reperfusion. The effects of the various diets (deficient, standard or supplemented) were estimated by studying functional recovery of various cardiac parameters (left ventricular developed pressure LVDP, dP/dtmax, heart rate x LVDP) as well as ultrastructural tissue characteristics. Furthermore, SOD and GPx activities were measured before ischemia and at the end of the reperfusion period. Results suggest that: (a) the activity of antioxidant enzymes increased or decreased significantly when diet was respectively supplemented with, or deficient in, trace elements, but was not further modified by an ischemia-reperfusion episode: (b) the recovery of cardiac function during reperfusion, and ventricular myocardial ultrastructure were significantly improved under the influence of trace element supplementation when compared to both standard and deficient groups. These results illustrate the protective effect of trace elements which are co-factors of antioxidant enzymes in limiting ischemia-reperfusion induced injury, and suggest a possible use in the field of anti-ischemic therapy.

Preliminary assessment of the distributions of some trace elements (As, Cd, Cu, Fe, Ni, Pb and Zn) in a pristine aquatic environment: The Lena River estuary (Russia)

Dissolved and particulate trace elements have been determined in the Lena River and its mixing zone in the Laptev Sea during September 1989. Average dissolved concentrations (in nM) in river water were: As = 2.0, Cd = 0.05, Cu = 9.7, Ni = 5.2, Pb = 0.08, Zn = 5.3 and Fe = 410. These concentrations are comparable to and often lower than those observed in large unpolluted world rivers. In the mixing zone, the suspended matter composition in the surface plume varies from 90% detrital to 50% detrital (estimated) and the distribution of particulate trace metals reflects the relative proportions of these particles. Particulate Cu and Ni are preferentially associated to organic matter and clay minerals, respectively, whereas no distinct trend is seen for Pb and Zn. The distribution of dissolved concentrations shows little consistent evidence of elemental transfers between the dissolved and particulate phases (Cd, Ni, Pb, Zn), with the exception of the usual Fe removal, and a possible As uptake by phytoplankton. Some Cu uptake probably also occurs, but its effect does not alter significantly the apparent conservative behaviour of Cu. On the whole, terrigenous trace element supply does not appear to be significantly altered by transfer processes in the summer period, but this conclusion only relies on a limited number of preliminary measurements.

Nutritional behavior of non-insulin-dependent type II diabetes patients using the KALI 2.1.2 computer program

Forty patients with non-insulin-dependent diabetes mellitus (NIDDM) were investigated regarding their individual diet history, including dietary pattern and dietary habits. The energy intake in men was 2,180 +/- 460 kcal/day. The carbohydrate content was 192 +/- 57 g/day (38 +/- 7%), protein 93 +/- 20 g/day (19 +/- 3%) and fat 96 +/- 26 g/day (43 +/- 7%). Nutritional intake of saturated fatty acids was 37 +/- 11 g/day, whereas the intake of polyenic acid was 14 +/- 5 g/day. Thus the p/s-quotient was 0.4 +/- 0.1. The cholesterol intake amounted to 396 +/- 165 mg/day. The dietary fibre content was 33 +/- 21 g/day. The caloric intake of women was 1,800 kcal/day. The daily amount of carbohydrate was 154 +/- 46 g/day (37 +/- 6%), of protein 82 +/- 21 g/day (20 +/- 4%), of fat 82 +/- 32 g/day (43 +/- 6%). Saturated fatty acids were 33 +/- 14 g/day, polyenic acid 11 +/- 5 g/day, the p/s-quotient 0.4 +/- 0.2. The cholesterol intake was calculated to be 341 +/- 118 mg/day. The supply of electrolytes, trace elements and vitamins was often marginal. We found that usually practiced diabetes diet is too fatty, rich in cholesterol and poor in carbohydrate and fibre. As a result of the high amount of fat, which comprises 43% of the total calories and the low p/s-quotient of 0.4, the diet must be considered atherogenic.

Fe and Cu content in bones, muscles and whole body of growing rats with different Fe and Cu supplies

The Fe and Cu contents in the femur and in the skeleton muscle were investigated in a trial series with factorial Fe and Cu supplies of growing rats (0, 25, 250, and 625 micrograms of Fe supply; 0, 10, 100, and 250 micrograms Cu supply per g of the diet). In addition, the reaction of the carcass to the different trace element supply was compared to the changes of the Fe and Cu contents in organs and tissues. In the femur, the Fe contents clearly increase in all grades of the Cu supply with increasing Fe supply. But because of the reduced live weight of the trial animals without Fe supply, this is valid only from 25 micrograms Fe/g diet on. For all Fe levels, the influence of the Cu supply on the concentration and the content of Cu results in a plateau in the range of 10-100 micrograms Cu/g diet; it is not reached with Cu deficiency and exceeded with an excessive Cu supply (250 micrograms/g). A clear increase of the Fe concentration in the muscle occurs only at a supply of 250 micrograms Fe/g diet. A further increase at 625 micrograms Fe/g only occurs at a Cu supply of 250 micrograms/g. Generally, the Fe concentration is reduced in the Cu deficiency. The Cu concentration in the muscle increases in all cases with the Cu supply, and the extent of this increase is strongly influenced by the Fe supply. The Fe contents in the carcass primarily depend on the Fe dosage. For the total contents of copper there are hints of a homeostatical regulation in the range of 10-100 micrograms Cu/g, but it seems to be disturbed if the Fe supply (0 or 25 micrograms/g) is insufficient. The comparison of the Fe and Cu contents in organs and tissues to those in the carcass shows that the reactions to the different supply levels, which are clearly different in the tissues, can be reproduced but insufficiently by the trace element analysis in the carcass.

Mineral and trace element supply of sheep on grass silage based feeding

Balance trials were made with adult Finnsheep rams to obtain more information on the mineral supply when the animals arc fed on grass silage based diets. The experimental silages were prepared with three different preservatives: 1) AIV I solution (25% formic acid and 20 % hydrochloric acid), 2) formic acid and 3) Viher solution (26 % formic acid and 70 % formalin). Together with the silage the animals received sucrose, starch and cellulose supplements at the levels of 0 %, 15 % or 30 % of the dry matter of the daily rations, representing 0, 2 ½ and 5 g/kg animal liveweight per day. Data were obtained on the Ca, P Mg, K, Na, Fe, Cu, Zn and Mn intake by the animals and on the excretion of these minerals in the faeces and urine. The levels of these minerals in the blood were also determined. The mineral contents of the silage were sufficient for animals fed at the maintenance level, except in the case of Na and P. Suckling ewes and growing lambs on silage based feeding may suffer from a deficiency of Ca as well as Na and P. The silage preservatives did not differ in their effect on the mineral balance. The mineral balances of the animals receiving the various carbohydrate supplements were also fairly similar to those of animals on pure silage diets.

Untersuchungen über den Mineralstoffgehalt von Deschampsia flexuosa (L.) P. B. als Bestandteil von Fichtenforst-Ökosystemenl

On acid soils with Ao horizons in the Erzgebirge Deschampsia flexuosa is widely distributed in spruce forests. On soils overlying various basic rock in the Tharandt Forest 35 samples of sterile grass were collected and five samples in the region bordering the Baltic Sea and all of them were investigated with regard to macro- and micronutrients (N, P, K, Ca, Mg, Fe, Mn, Cu, Zn, Mo) as well as ballast substances (Si, Al) and trace elements having an injurious effect on environment (Cr, Co, Ni, Cd, Pb). The accuracy of the analytical method is determined for six trace elements and with given accuracy the necessary number of grass samples for the characterization of a forest region is communicated. Conditioned by locality and thus also by species the grass possesses a low content of alkali earths, Si and Mo as well as a high Fe and Mn content. Significant correlations exist in the content of nutrient elements in leaves in the case of N/P, Si/Al, Al/Fe, Co/Fe and Co/Ni. In the investigation areas the contents of Cu, Zn, Co, Cd, and Pb in the grass lie within the normal limits for Gramineae, for Al the variation is 37—250 ppm, for Cr 0.4—2.8, and for Ni 1.4—15 ppm. In continuous sward the amount of nutrient elements stored in green grass (without rhizomes) per hectare diminishes from 25 kg Kover 0.5 kg Mn and 3 g Pb to 0.2 g Co. It seems possible to use the grass for evaluating the trace element supply and pollution respectively of forest sites on the northern slope of the Central-German ridge.

Supply of some essential trace elements to the Hungarian population

The authors determined the copper, zinc, chromium, cobalt, manganese, iron and nickel contents in 703 samples of animal foods (meat, offals, milk, eggs) from different parts of Hungary and of 370 samples of fruits and vegetables. Calculations based on consumption data from the Central Board of Statistics showed that the copper and iron intakes of the population are lower than those suggested the FAO/WHO. When infants are given exclusively ready-to-use baby foods produced on a milk-only basis (Hungarian products and products imported from western countries), their supply is still less favourable than that to adults. Whereas human milk meets also the requirements of trace elements optimally, ready-to-use baby foods produced on a milk-only basis supply not more than 10--15% on the required copper and 20--35% of the required iron. The authors focus attention on the risk of inadequate supply of trace elements in childhood, the negative implications of which will still manifest themselves in adulthood for a long time.