Scientific Opinion on Dietary Reference Values for zinc

Assessment of genetically modified maize Bt11 × MIR162 × MIR604 × 1507 × 5307 × GA21 and subcombinations, for food and feed uses, under Regulation (EC) No 1829/2003 (application EFSA-GMO-DE-2011-103)

Maize Bt11 × MIR162 × MIR604 × 1507 × 5307 × GA21 (six-event stack maize) was produced by conventional crossing to combine six single events: Bt11, MIR162, MIR604, 1507, 5307 and GA21. The GMO Panel previously assessed the six single events and 22 of their combinations and did not identify safety concerns. No new data on the maize single events or their 22 combinations that could lead to modification of the original conclusions on their safety have been identified. The molecular characterisation, comparative analysis (agronomic, phenotypic and compositional characteristics) and the outcome of the toxicological, allergenicity and nutritional assessment indicate that the combination of the single maize events and of the newly expressed proteins in the six-event stack maize does not give rise to food and feed safety and nutritional concerns. The GMO Panel concludes that the six-event stack maize, as described in this application, is as safe as and nutritionally equivalent to its non-GM comparator and the non-GM reference varieties tested. In the case of accidental release of viable grains of the six-event stack maize into the environment, this would not raise environmental safety concerns. The GMO Panel assessed the likelihood of interactions among the single events in the 34 maize subcombinations not previously assessed and concludes that these are expected to be as safe as and nutritionally equivalent to the single events, the previously assessed subcombinations and the six-event stack maize. The post-market environmental monitoring plan and reporting intervals are in line with the intended uses of the six-event stack maize. Post-market monitoring of food/feed is not considered necessary. The GMO Panel concludes that the six-event stack maize and its subcombinations are as safe as its non-GM comparator and the tested non-GM reference varieties with respect to potential effects on human and animal health and the environment.

Zinc intake and status in Austria in the light of different reference values

Zinc has been identified as a critical micronutrient also in high-income countries. There is still some uncertainty about the evaluation of zinc sufficiency due to divergent daily intake reference values. We wanted to exemplify this issue using data from the Austrian Study on Nutritional Status 2012. Plasma zinc concentrations were measured in a nationally representative sample of 872 persons aged 6-80 years (55.5 % female). Dietary zinc intake was estimated from two 24h dietary recalls. Additionally, parameters of the antioxidative status (plasma malondialdehyde (MDA), total antioxidative capacity) and activities of alkaline phosphatase (AP), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px)) were determined. Zinc status was marginal in schoolchildren (40 % of boys and 22 % of girls) and in elderly (28 % of men and 33 % of women). Dietary zinc intake was also unsatisfactory in these groups with 38 % of boys and 32 % of girls and 64.5 % of older men below the nationally recommended intake levels. However, the adequacy of zinc intake varied with different reference values. Adults were more likely to meet the D-A-CH reference values and those from the European Food Safety Authority than the recommendations of the International Zinc Nutrition Consultative Group (IZiNCG) and the Institute of Medicine, whereas children met the IZiNCG values best. Zinc status correlated weakly with AP activity (r = -0.298, p < 0.001) and some antioxidant status markers (CAT, MDA, GSH-PX, SOD), especially in the elderly (MDA: r = -0.527, p < 0.001, and SOD: r = -0.466, p = 0.002). Our results suggest a suboptimal zinc supply in Austria particularly among schoolchildren and older adults.

Excess micronutrient intake: defining toxic effects and upper limits in vulnerable populations

Excessive micronutrient intake causes a variety of adverse health effects, depending on dose and duration. The risk of excess intake carries significant implications for micronutrient delivery interventions, particularly when such programs are overlapping. To minimize risk and provide public health guidance, several countries and the Food and Agriculture Organization of the United Nations/World Health Organization have set upper intake levels (ULs) for various life-stage populations using the risk assessment framework. However, there is a lack of international consensus on the actual ULs due to variability in application of this framework and a scarcity of evidence from which to draw upon, especially for children. Often ULs for children are established through a downward weight-based extrapolation from adult ULs, which is not always appropriate. The published ULs of nine organizations are compared, recent population nutrient intake evidence is presented, and the toxic effects of key minerals and vitamins are reviewed. Finally, the evidence for toxicity and setting of ULs for each nutrient is discussed including a comment on our degree of confidence in the strength of existing individual ULs. Challenges with risk assessment and opportunities for strengthening the definition of ULs are discussed.

Dietary intake of cadmium, chromium, copper, manganese, selenium and zinc in a Northern Italy community

This study provides the dietary intakes of six trace elements (cadmium, chromium, copper, manganese, selenium and zinc), generally characterized by both nutritional and toxicological features depending on their exposure. Being diet the most relevant source of exposure to trace elements in non-professionally exposed subjects, we measured content of these trace elements in foods composing the typical Italian diet using inductively coupled plasma-mass spectrometry, and assessing dietary habits using a validated semi-quantitative food frequency questionnaire we eventually estimated dietary daily intake of trace elements in a Northern Italian community. In the 890 analyzed food samples, the main contributors to cadmium intake are cereals, vegetables and sweets, while cereals, beverages and vegetable are to primary source of manganese. The primary contributors for copper are cereals, fresh fruits and vegetables, while for chromium are beverages, cereals and meat. The main source of selenium intake are cereals and meat, followed by fish, seafood and milk and dairy products, while of zinc intake are meat, cereals, milk and dairy products. In our Italian population sample, the estimated median (interquartile range) dietary daily intakes are 5.00 (3.17-7.65), 56.70 (36.08-86.70) and 66.53 (40.04-101.32) μg/day for cadmium, chromium and selenium, and corresponding figures are 0.98 (0.61-1.49), 2.34 (1.46-3.52) and 8.50 (5.21-12.48) mg/day for copper, manganese and zinc. The estimated intakes are generally within the average intake reported in other European populations, and in such cases well above the daily dietary intakes recommended by national international agencies, avoiding the risk of excess or deficiency. The present estimated intake data can be used to examine a specific trace element of interest and would afford enhanced health protection from those trace elements characterized by both nutritional and toxicological effects.

The bivalve Ruditapes decussatus: A biomonitor of trace elements pollution in Sardinian coastal lagoons (Italy)

The anthropogenic contamination of water bodies with metals via fertilizer, industrial sewage and urban wastewater has resulted in widespread problems in aquatic organisms, but also poses a risk to consumer health. Shellfish from coastal and estuarine environments bioaccumulate toxic metals in their tissues due to their ability to concentrate inorganic contaminants several orders of magnitude above ambient levels. The aim of this study was to evaluate the presence of trace elements in adult specimens of indigenous clams (Ruditapes decussatus). To this end, wild clams were collected from four different brackish areas of Sardinia (Western Mediterranean Sea, Italy) devoted to extensive aquacultural practices. The concentration of 16 trace elements (Al, Ag, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sn, Tl and Zn) in the tissues of the clams was quantified. The legal limits set by European Regulations for cadmium; mercury and lead were never exceeded. However, unexpectedly high values for aluminium and iron (mean 207 mg kg⁻¹ and 113 mg kg⁻¹ wet weight) were found in Santa Gilla lagoon, which is close to industrial settlements and had the highest values for the majority of chemical elements investigated. The highest values of the metalloid arsenic (As) were reported in the Porto Pozzo and San Teodoro lagoons (9.6 and 6.8 mg kg⁻¹ w.w., respectively). The clam R. decussatus confirmed the capacity of bivalves as suitable bioindicators of trace elements pollution. Further investigations are necessary for constant monitoring of clams, 32 which constitute an important traditional resource for the fishing activity in Sardinia.

Approaches used to estimate bioavailability when deriving dietary reference values for iron and zinc in adults

This review aims to describe approaches used to estimate bioavailability when deriving dietary reference values (DRV) for iron and zinc using the factorial approach. Various values have been applied by different expert bodies to convert absorbed iron or zinc into dietary intakes, and these are summarised in this review. The European Food Safety Authority (EFSA) derived zinc requirements from a trivariate saturation response model describing the relationship between zinc absorption and dietary zinc and phytate. The average requirement for men and women was determined as the intercept of the total absorbed zinc needed to meet physiological requirements, calculated according to body weight, with phytate intake levels of 300, 600, 900 and 1200 mg/d, which are representative of mean/median intakes observed in European populations. For iron, the method employed by EFSA was to use whole body iron losses, determined from radioisotope dilution studies, to calculate the quantity of absorbed iron required to maintain null balance. Absorption from the diet was estimated from a probability model based on measures of iron intake and status and physiological requirements for absorbed iron. Average dietary requirements were derived for men and pre- and post-menopausal women. Taking into consideration the complexity of deriving DRV for iron and zinc, mainly due to the limited knowledge on dietary bioavailability, it appears that EFSA has made maximum use of the most relevant up-to-date data to develop novel and transparent DRV for these nutrients.

Biogenic and Risk Elements in Wines from the Slovak Market with the Estimation of Consumer Exposure

Wine consumption delivers macroelements and microelements necessary for the proper metabolism. On the other hand, wine can be an important source of toxic metals. The aim of this study was to estimate the concentrations of Ca, Cd, Cu, Fe, Hg, Mg, Ni, Pb, and Zn in the Slovak and non-Slovak wines. The concentration of metals was evaluated with respect to the type, the alcohol content, and the age of Slovak wine. The general scheme of concentrations found was as follows Ca > Mg > Fe > Zn > Pb > Cd > Ni > Cu > Hg. The type of wine and the alcohol content do not have a significant impact on metal concentrations. Also, the age of wine has no influence on the mean concentration of metals, except for Zn. Metal concentrations in Slovak and non-Slovak wines indicate similar contents of metals, except for Ni. The contribution to both dietary reference values (DRVs) and provisional tolerable weekly intake (PTWI) evaluations in the Slovak wine suggested low dietary exposure to Ca, Cu, Fe, Mg, Ni, Zn, Cd, Hg, and Pb, respectively. However, we do not suggest that the consumption of all Slovak wines is healthy. The maximum Pb concentrations in Slovak wines exceed the maximum permitted level proposed by the European Commission. This might be proved by the results of the margin of the exposure (MOE) value evaluation in the samples containing the maximum Pb concentrations, showing a high risk of CKD and SBP in high and extreme consumption groups.

Trace metal occurrence in Mediterranean seaweeds

Seaweeds have been used as animal feed since a long time and are consumed as food in several cultures. In fact, macroalgae are a source of protein, fiber, polyunsaturated fat, and minerals. The concentration of trace elements was determined in dominant macroalga species from three sites of the northwestern Mediterranean Sea. A high interspecies variability was observed, with higher metal levels in brown and green than those in red seaweeds. The maximum values set by European regulations for arsenic, mercury, and cadmium in food and feed were never exceeded, but a few samples were very close to limits set for mercury. Conversely, the maximum limit for lead in feed was exceeded in all species from one of the considered sites. Analogously, lead in seaweeds could constitute a potential risk for human health, due to the exceeding of the maximum value set for food supplements.

Dietary species richness as a measure of food biodiversity and nutritional quality of diets

Biodiversity is key for human and environmental health. Available dietary and ecological indicators are not designed to assess the intricate relationship between food biodiversity and diet quality. We applied biodiversity indicators to dietary intake data from and assessed associations with diet quality of women and young children. Data from 24-hour diet recalls (55% in the wet season) of n = 6,226 participants (34% women) in rural areas from seven low- and middle-income countries were analyzed. Mean adequacies of vitamin A, vitamin C, folate, calcium, iron, and zinc and diet diversity score (DDS) were used to assess diet quality. Associations of biodiversity indicators with nutrient adequacy were quantified using multilevel models, receiver operating characteristic curves, and test sensitivity and specificity. A total of 234 different species were consumed, of which <30% were consumed in more than one country. Nine species were consumed in all countries and provided, on average, 61% of total energy intake and a significant contribution of micronutrients in the wet season. Compared with Simpson's index of diversity and functional diversity, species richness (SR) showed stronger associations and better diagnostic properties with micronutrient adequacy. For every additional species consumed, dietary nutrient adequacy increased by 0.03 (P < 0.001). Diets with higher nutrient adequacy were mostly obtained when both SR and DDS were maximal. Adding SR to the minimum cutoff for minimum diet diversity improved the ability to detect diets with higher micronutrient adequacy in women but not in children. Dietary SR is recommended as the most appropriate measure of food biodiversity in diets.

Oral bioaccessibility of toxic and essential elements in raw and cooked commercial seafood species available in European markets

The oral bioaccessibility of several essential and toxic elements was investigated in raw and cooked commercially available seafood species from European markets. Bioaccessibility varied between seafood species and elements. Methylmercury bioaccessibility varied between 10 (octopus) and 60% (monkfish). Arsenic (>64%) was the toxic element showing the highest bioaccessibility. Concerning essential elements bioaccessibility in raw seafood, selenium (73%) and iodine (71%) revealed the highest percentages. The bioaccessibility of elements in steamed products increased or decreased according to species. For example, methylmercury bioaccessibility decreased significantly after steaming in all species, while zinc bioaccessibility increased in fish (tuna and plaice) but decreased in molluscs (mussel and octopus). Together with human exposure assessment and risk characterization, this study could contribute to the establishment of new maximum permissible concentrations for toxic elements in seafood by the European food safety authorities, as well as recommended intakes for essential elements.

Zinc in Infection and Inflammation

Micronutrient homeostasis is a key factor in maintaining a healthy immune system. Zinc is an essential micronutrient that is involved in the regulation of the innate and adaptive immune responses. The main cause of zinc deficiency is malnutrition. Zinc deficiency leads to cell-mediated immune dysfunctions among other manifestations. Consequently, such dysfunctions lead to a worse outcome in the response towards bacterial infection and sepsis. For instance, zinc is an essential component of the pathogen-eliminating signal transduction pathways leading to neutrophil extracellular traps (NET) formation, as well as inducing cell-mediated immunity over humoral immunity by regulating specific factors of differentiation. Additionally, zinc deficiency plays a role in inflammation, mainly elevating inflammatory response as well as damage to host tissue. Zinc is involved in the modulation of the proinflammatory response by targeting Nuclear Factor Kappa B (NF-κB), a transcription factor that is the master regulator of proinflammatory responses. It is also involved in controlling oxidative stress and regulating inflammatory cytokines. Zinc plays an intricate function during an immune response and its homeostasis is critical for sustaining proper immune function. This review will summarize the latest findings concerning the role of this micronutrient during the course of infections and inflammatory response and how the immune system modulates zinc depending on different stimuli.

Safety and efficacy of zinc chelate of methionine sulfate for all animal species

The additive 'Zinc chelate of methionine sulfate' is zinc chelated with methionine in a molar ratio 1:1, with a minimum zinc content of 19.1%. Owing to the limitations of the tolerance study, it could not be used for the assessment of safety for target animals; therefore, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP Panel) cannot conclude on the safety of zinc chelate of methionine sulfate for the target species. No concerns for consumer safety are expected from the use of the zinc chelate of methionine sulfate in animal nutrition when used up to the maximum EU authorised zinc levels in feed. Zinc chelate of methionine sulfate should be considered as a skin and eye irritant, and as a skin sensitiser; it is considered to pose a risk by inhalation to the users. The additive under assessment, zinc chelate of methionine sulfate, is intended to be a substitute for other authorised zinc additives and will not further increase the environmental burden of zinc; therefore, the FEEDAP Panel considers that the use of the additive in animal nutrition would not pose an additional risk for the environment. Based on literature studies and a specific study conducted with the additive under assessment, zinc chelate of methionine sulfate is an available source of zinc for all animal species.

Predictors of the Size of the Exchangeable Zinc Pool Differ between Children and Adults

BACKGROUND

The size of the rapidly exchanging pool of body zinc has been suggested as having potential utility as a biomarker of zinc status. Knowledge of the relations of exchangeable zinc pool (EZP) size to relevant variables is necessary to adequately evaluate its use as a biomarker.

OBJECTIVE

We used regression analysis to investigate associations of EZP with age, sex, body size, and zinc nutrition variables.

METHODS

Data were compiled from 18 isotope tracer studies of zinc absorption in 247 children and adults (248 observations) in which EZP and relevant variables (e.g., weight, age, absorbed zinc) were measured. Linear regression analyses were performed separately on data from adults and children.

RESULTS

In children, EZP was most strongly associated with weight (r = 0.78). The best-fitting regression models of EZP (R² ≥ 0.68) had weight or age and weight-for-age z score as predictors. Other variables had little effect on EZP when controlling for weight. Absorbed zinc was observed to be a predictor of EZP only in zinc intervention trials of infants. The mean EZP/wt was 4 mg/kg between 8 and 120 mo of age. In adults, EZP was observed to vary in a complex manner with (in order of importance) age, absorbed zinc, weight, sex, and plasma zinc concentration. EZP data from zinc-deprived subjects were lower than the 95% prediction interval of a model of normative data.

CONCLUSIONS

EZP was observed to maintain a constant size relative to weight and was influenced only slightly by other factors in children. In contrast, EZP in adults varied with several factors, including absorbed zinc, and was statistically smaller in zinc-deprived individuals. The findings suggest that EZP may have utility as an indicator of zinc status in adults, but there is less evidence for this in children. Additional data are needed to reach a definitive conclusion.

The bioavailability of iron, zinc, protein and vitamin A is highly variable in French individual diets: Impact on nutrient inadequacy assessment and relation with the animal-to-plant ratio of diets

Nutritional adequacy depends on nutrient intakes and bioavailability which strongly varies with the plant- or animal-origin of foods. The aim was to estimate iron, zinc, protein and vitamin A bioavailability from individual diets, and investigate its relation with the animal-to-plant ratio (A/P) of diets. Bioavailability was estimated in 1899 French diets using diet-based algorithms or food-group specific conversion factors. Nutrient inadequacy was estimated based on i) bioavailability calculated in each individual diet and ii) average bioavailability assumed for Western-diets. Mean iron absorption, zinc absorption, protein quality and β-carotene conversion factor were 13%, 30%, 92%, and 17:1, respectively. Bioavailability displayed a high variability between individual diets, poorly explained by their A/P. Using individual bioavailability led to different inadequacy prevalence than with average factors assumed for Western-diets. In this population, the A/P does not seem sufficient to predict nutrient bioavailability and the corresponding recommended intakes. Nutritional adequacy should be assessed using bioavailability accounting for individual diets composition.

Detection of heavy metals in common vegetables at Varaždin City Market, Croatia

The present study was aimed at the estimation of heavy metal content in vegetables sold at the city market of one of the densely populated Croatian cities, Varaždin, and to establish the relationship between their levels and possible sources of contamination. Twenty-eight samples of the most common diet vegetables (red and white potato, onion, carrot, common bean, lettuce, and cabbage) were randomly bought at the market in September and October 2013. Using the atomic absorption spectrometry method, concentrations of nine heavy metals (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn) were measured in the selected samples. The results showed that, in five out of 28 samples analysed, six concentrations exceeded the maximum levels provided for in the regulations: five for Pb and one for Cd. Maximum regulated levels for Pb were exceeded in two samples of red potato, two samples of common bean, and one sample of carrot (17.9 %), and for Cd in a sample of red potato (3.6 %). In conclusion, the cause of the overstepping of the maximum levels for Pb and Cd in the vegetables analysed was most likely the contaminated soil. The possible sources of soil contamination include traffic, nearby industry, floodwaters of rivers and streams, and the use of pesticides and fertilisers in agricultural production.

Availability of zinc from infant formula by in vitro methods (solubility and dialyzability) and size-exclusion chromatography coupled to inductively coupled plasma-mass spectrometry

Zinc bioaccessibility from infant formula was estimated by in vitro methods (solubility and dialyzability) and size-exclusion chromatography (SEC) coupled to inductively coupled plasma-mass spectrometry (ICP-MS). Infant formula samples were first characterized in terms of Zn bound to lipids and proteins and Zn distribution in the aqueous soluble protein fraction. We found that Zn is not incorporated into the lipid fraction of the samples, being mainly associated with the protein fraction (around 100%). Fractionation of Zn-containing proteins in the soluble protein fraction was achieved by SEC-ICP-MS after performing protein extraction with a solution of 100mM (pH 6.8) Tris-HCl. The percentages of zinc in the soluble protein fraction in the soy-based and lactose-free infant formula were very low, around 7 and 24%, respectively, whereas the content of Zn in the soluble protein fraction of milk-based formula was around 90%. By SEC-ICP-MS, we found that Zn is associated with low-molecular weight compounds (around 10kDa) in all the infant formulas tested. The percentages of Zn estimated in the in vitro gastrointestinal digests of the infant formula ranged from 30 to 70% and from 1 to 10% for solubility and dialyzability assays, respectively. The dialyzability test resulted in lower than expected scores, as SEC-ICP-MS analysis of the gastrointestinal extracts revealed that Zn is bound to biomolecules with a molecular weight ranging from 1 to 7kDa, which suggests that dialysis data should be interpreted with caution. Speciation studies are a valuable tool for establishing availability of nutrients and for validating data from dialyzable in vitro methods.

Human exposure to metals due to consumption of fish from an artificial lake basin close to an active mining area in Katanga (D.R. Congo)

The concentrations of 14 essential and nonessential trace elements were determined in fish from Lake Tshangalele, Katanga province, Democratic Republic of Congo. This province has been a place of intensive mining activities for centuries, which have increased in recent years, due to the use of metals such as copper and cobalt for the industries of fast-growing countries. Lake Tshangalele, which receives effluents from metallurgical and mining plants in Likasi, is home to several fish species that are an important part of the diet of the local population, and, therefore, it constitutes a relevant site for documenting the human exposure to metals as a result of a fish diet. The highest concentrations (median levels, dry weight) of cobalt (7.25mgkg(-1)), copper (88.1mgkg(-1)), iron (197.5mgkg(-1)), manganese (65.35mgkg(-1)), zinc (122.9mgkg(-1)) and aluminum (135.4mgkg(-1)) were found in fish collected closest to the copper mining plant, with decreasing concentrations along the lake, up to the dam. In the most contaminated fish samples, values of up to 270.1mgkg(-1) for Al, 173.1mgkg(-1) for Cu, 220.9mgkg(-1) for Zn, 211.0mgkg(-1) for Mn, 324.2mgkg(-1) for Fe, 15.1mgkg(-1) for Co, 4.2mgkg(-1) for Cr, 1.6mgkg(-1) for Cd, 1.9mgkg(-1) for Pb, and 1.8mgkg(-1) for Ni were found. Metal contamination from mining activity resulted in being of great concern because of potential health risks to the local inhabitants due to the consumption of heavily contaminated fish.

CAPSULE

High levels of metals, especially cobalt, aluminum, iron, manganese, zinc and cadmium were found in fish from Tshangalele water system.

Trace elements in free-range hen eggs in the Campania region (Italy) analyzed by inductively coupled plasma mass spectrometry (ICP-MS)

Eggs from hens raised on rural or domestic farms are a good indicator of environmental contamination, as the hens are in close contact with the ground and the air and can therefore accumulate heavy metals and other toxic contaminants from the environment as well as from the diet. In this paper, we report the results of the determination of 19 trace elements (As, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Se, Sn, Sr, Tl, U, V, Zn) in 39 hen egg samples collected from domestic poultry farms in the territory dubbed the "Land of fires" in the Campania region (Italy). This area is characterized by environmental problems caused by the illegal dumping of industrial or domestic waste in fields or by roadsides. In some cases, these wastes have been burned, thereby spreading persistent contaminants into the atmosphere. The content of trace elements in whole egg samples was determined by mass spectrometer after a microwave-assisted digestion procedure. Because European legislation does not indicate maximum values of these elements in this foodstuff, the results were compared with the content of trace elements reported in literature for eggs, in particular home-produced eggs, in various countries. In some cases (Cd, Cu, Ni, Mn), the content determined in this study was in line with those reported elsewhere, in other cases (Pb, Cr), lower values were found.

Fractional Zinc Absorption for Men, Women, and Adolescents Is Overestimated in the Current Dietary Reference Intakes

BACKGROUND

The fractional zinc absorption values used in the current Dietary Reference Intakes (DRIs) for zinc were based on data from published studies. However, the inhibitory effect of phytate was underestimated because of the low phytate content of the diets in the studies used.

OBJECTIVE

The objective of this study was to estimate the fractional absorption of dietary zinc from the US diet by using 2 published algorithms.

METHODS

Nutrient intake data were obtained from the NHANES 2009-2010 and the corresponding Food Patterns Equivalents Database. Data were analyzed with the use of R software by taking into account the complex survey design. The International Zinc Nutrition Consultative Group (IZiNCG; Brown et al. Food Nutr Bull 2004;25:S99-203) and Miller et al. (Br J Nutr 2013;109:695-700) models were used to estimate zinc absorption.

RESULTS

Geometric means (95% CIs) of zinc absorption for all subjects were 30.1% (29.9%, 30.2%) or 31.3% (30.9%, 31.6%) with the use of the IZiNCG model and Miller et al. model, respectively. For men, women, and adolescents, absorption values obtained in this study with the use of the 2 models were 27.2%, 31.4%, and 30.1%, respectively, for the IZiNCG model and 28.0%, 33.0%, and 31.6%, respectively, for the Miller et al. model, compared with the 41%, 48%, and 40%, respectively, used in the current DRIs. For preadolescents, estimated absorption values (31.1% and 32.8% for the IZiNCG model and Miller et al. model, respectively) compare well with the conservative estimate of 30% used in the DRIs. When the new estimates of zinc absorption were applied to the current DRI values for men and women, the results suggest that the Estimated Average Requirement (EAR) and RDA for these groups need to be increased by nearly one-half of the current values in order to meet their requirements for absorbed zinc.

CONCLUSIONS

These data suggest that zinc absorption is overestimated for men, women, and adolescents in the current DRI. Upward adjustments of the DRI for these groups are recommended.

Chromium, zinc and magnesium status in type 1 diabetes

PURPOSE OF REVIEW

Chromium, zinc, and magnesium are involved in insulin signal transduction, glucose metabolism, and cellular antioxidative defense. This review details the statuses of chromium, zinc, and magnesium in type 1 diabetes patients.

RECENT FINDINGS

Blood levels of trace elements (especially magnesium and zinc) were lower in type 1 diabetes patients than in controls and were even lower in type 1 diabetes patients with poor glycemic control. Studies with mouse models have shown that chromium and magnesium supplementation alleviated diabetes-induced complications and improved glycemic control.

SUMMARY

Many studies indicated positive correlations between decreased levels of serum chromium, zinc, and magnesium and poor glycemic control. The supplementation of type 1 diabetes patients with zinc, magnesium, and chromium may help to control diabetes and prevent diabetes-related oxidative injuries, but require further study.

Dietary intake of trace elements by the population of Catalonia (Spain): results from a total diet study

This study aimed to analyse the concentrations of Al, Ba, Bi, Cu, Cr, Ge, Mn, Mo, Ni, Sb, Se, Sr and Zn in food samples collected in 2008 in Catalonia (Spain). The dietary intake of these 13 trace elements was subsequently estimated by different age-gender groups of the population: children, adolescents, adults and seniors. In general terms, fish and shellfish, cereals, and pulses were the food groups showing the highest levels for most elements. Higher dietary intakes were associated with male groups (adolescents, adults and seniors). However, none exceeded the tolerable levels. When exposure was estimated based on body weight, children were the group with the highest dietary intake. Notwithstanding, only the weekly intake of Al by children exceeded the recommendations of the European Food Safety Authority (EFSA). It is a consequence of the higher intake of cereals in relation to their respective body weights. In addition to the periodical food surveillance of toxic metals (As, Cd, Hg and Pb), it is also important to determine the levels of other trace elements in order to ensure that the dietary exposure by the Catalan population is under control.