Zinc Nutrition Research Articles

Dietary intervention strategies to enhance zinc nutrition: promotion and support of breastfeeding for infants and young children.

Breastmilk is the only dietary source of zinc for exclusively breastfed young infants, and it remains a potentially important source of zinc for older infants and young children who continue breastfeeding beyond early infancy. Therefore, we examined available information on breastmilk zinc concentration and total milk consumption to develop estimates of the amount of zinc transferred in breastmilk to children of different ages. Breastmilk zinc concentration declines rapidly during the first few months postpartum and more slowly thereafter. Breastmilk supplies all of the theoretical zinc needs for at least the first several months of life, although the period during which breastmilk alone remains sufficient is uncertain. Breastmilk continues to provide more than half of children's estimated zinc requirements after the introduction of complementary foods, even into the second year of life. Public health programs to promote and support breastfeeding should be included among the strategies to ensure adequate zinc status of young children.

Relative Bioavailability of Zinc in Yogurt Using Body Weight Gain, Femur Weight and Bone Zinc Content in Rats as Markers

Objective: some previous works have shown the importance of zinc in nutrition, and even evaluated different zinc sources for food supplementation with this micronutrient. The aim of this work was to evaluate zinc gluconate stabi- lized with glycine (BZ) as a zinc source for food fortification by employing yogurt as the vehicle and zinc sulfate (SZ) as the standard zinc source. Materials and methods: weaned Sprague Dawley rats were separated in 7 groups of 10 rats each, which were fed with diets according to the scheme: Group 1- 2ppm Zn; Groups 2, 3 and 4 - 9, 20 and 34 ppm Zn as SO4Zn.7H2O (SZ) and Groups 5, 6 and 7 - 9, 20 and 34 ppm Zn as zinc gluconate stabilized with glycine (BZ) during 21 days. Zinc sources were provided in a vehicle as yogurt, added in the final diet at 10%. Body weight gain, femur weight and femur zinc content were evaluated at the end of the treatments in order to determine zinc bioavailability, as previously described by others. In this way, body weight gain and femur weight were analyzed by a non linear regression according to equation: Y = Ymax (1-e (-kX) ) and femur zinc content was analyzed by a linear regression, all of them as a function of dietary zinc from each source. Results: relative zinc bioavailability of BZ was 0.95; 0.95 and 1.10 according to body weight gain, femur weight and femur zinc content, respectively. Conclusion: zinc gluconate stabilized with glycine may be considered as a suitable source of zinc for food fortification in a yogurt matrix.

Plasma zinc concentrations of mothers and the risk of oral clefts in their children in Utah

The role of maternal zinc nutrition in human oral clefts (OCs) is unclear. We measured plasma zinc concentrations (PZn) of case and control mothers to evaluate the associations between PZn and risk of OCs with and without other malformations. Case mothers were ascertained by the Utah Birth Defects Network and control mothers were selected from Utah birth certificates by matching for child gender and delivery month and year. Maternal blood was collected >1 year after the last pregnancy. PZn was available for 410 case mothers who were divided into four subgroups: isolated cleft lip with or without cleft palate (CL/P-I, n = 231), isolated cleft palate (CP-I, n = 74), CL/P with other malformations (CLP-M, n = 42), and CP with other malformations (CP-M, n = 63). PZn was available for 447 control mothers. The mean age of children at blood sampling was 3.7 years for all cases combined and 4.3 years for controls. Mean PZns of all groups were similar, and low PZn (<11.0 micromol/L) was found in 59% of cases and 62% of controls. Risk of OCs did not vary significantly across PZn quartiles for the four subgroups individually and all OC groups combined. We previously reported that poor maternal zinc status was a risk factor for OCs in the Philippines, where OC prevalence is high and maternal PZn is low. In Utah, however, no such association was found, suggesting that poor maternal zinc status may become a risk factor only when zinc status is highly compromised.

Iron and zinc biofortification strategies in dicot plants by intercropping with gramineous species. A review

The lack of micronutrients such as iron and zinc is a widespread nutrition and health problem in developing countries. Biofortification is the process of enriching the nutrient content of staple crops. Biofortification provides a sustainable solution to iron and zinc deficiency in food around the world. Reports have highlighted the current strategies for the biofortification of crops, including mineral fertilization, conventional breeding and transgenic approaches. Any approach which could increase root growth and result in a high transfer of Fe and Zn from the soil to the plant is crucial for biofortification. In addition to these approaches, we draw attention to another important aspect of Fe and Zn biofortification: intercropping between dicots and gramineous species. Intercropping, in which at least two crop species are grown on the same plot of land simultaneously, can improve utilization of resources while significantly enhancing crop productivity, whereas monocropping is a traditional cropping system of only one crop growth. Monocropping has maintained crop productivity through heavy chemical inputs including the application of fertilizers and pesticides. Monocropping has therefore resulted in substantial eutrophication, environmental pollution, a food security crisis and economic burdens on farmers. Monocropping has also reduced the plant and microorganism diversity in the ecosystem. Compared with monocropped plants, intercropped plants can use nutrients, water and light better due to the spatial and temporal differences in the growth factors and a variety of species-specific mechanisms of physiological response to environmental stress. Intercropping is common in developing countries such as China, India, Southeast Asia, Latin America and Africa. In particular, interspecific interaction facilitates the iron and zinc nutrition of intercropping systems such as peanut/maize, wheat/chickpea and guava/sorghum or maize. Intercropping also increases iron and zinc content in the seeds. In a peanut/maize case study, the Fe concentrations in peanut shoots and seed were 1.47–2.28 and 1.43 times higher than those of peanut in monocropping, respectively. In intercropping of chickpea and wheat, the Fe contents in wheat and chickpea seed were increased 1.26 and 1.21 times, respectively, and Zn concentration in chickpea seed was 2.82 times higher than that in monocropping. In this review, we focus on exemplary cases of dicot/gramineous species intercropping that result in improved iron and zinc nutrition of the plants. We present the current understanding of the mechanisms of improvement of iron and zinc in intercropping. The available literature shows that a reasonable intercropping system of nutrient-efficient species could prevent or mitigate iron and zinc deficiency of plants. Here, we propose that intercropping can potentially offer an effective and sustainable pathway to iron and zinc biofortification.

Zinc Deficiency Induces Vascular Pro-Inflammatory Parameters Associated with NF-κB and PPAR Signaling

Objectives: Marginal intake of dietary zinc can be associated with increased risk of cardiovascular diseases. In the current study we hypothesized that vascular dysfunction and associated inflammatory events are activated during a zinc deficient state.Design: We tested this hypothesis using both vascular endothelial cells and mice lacking the functional LDL-receptor gene.Results: Zinc deficiency increased oxidative stress and NF-κB DNA binding activity, and induced COX-2 and E-selectin gene expression, as well as monocyte adhesion in cultured endothelial cells. The NF-κB inhibitor CAPE significantly reduced the zinc deficiency-induced COX-2 expression, suggesting regulation through NF-κB signaling. PPAR can inhibit NF-κB signaling, and our previous data have shown that PPAR transactivation activity requires adequate zinc. Zinc deficiency down-regulated PPARα expression in cultured endothelial cells. Furthermore, the PPARγ agonist rosiglitazone was unable to inhibit the adhesion of monocytes to endothelial cells during zinc deficiency, an event which could be reversed by zinc supplementation. Our in vivo data support the importance of PPAR dysregulation during zinc deficiency. For example, rosiglitazone induced inflammatory genes (e.g., MCP-1) only during zinc deficiency, and adequate zinc was required for rosiglitazone to down-regulate pro-inflammatory markers such as iNOS. In addition, rosiglitazone increased IκBα protein expression only in zinc adequate mice. Finally, plasma data from LDL-R-deficient mice suggest an overall pro-inflammatory environment during zinc deficiency and support the concept that zinc is required for proper anti-inflammatory or protective functions of PPAR.Conclusions: These studies suggest that zinc nutrition can markedly modulate mechanisms of the pathology of inflammatory diseases such as atherosclerosis.

Zinc in Broiler Feeding and Nutrition

Zinc is an essential trace mineral for birds, functioning elaborately in enzyme systems and being involved in protein synthesis, carbohydrate metabolism, and many other biochemical reactions. Zinc is required for normal growth, reproduction, and glandular development of birds. A severe zinc deficiency causes numerous physical and pathological changes including skin lesions, decreased growth, general disability of bones and joints, very poor feathering, reproductive failure, and reduced immunity to infection of several diseases. In skin, it is five to six times more concentrated in the epidermis than the dermis. In addition, zinc is associated with wound healing because of its role in collagen and keratin syntheses. All proliferating cells, including inflammatory cells, epithelial cells, and fibroblast, require zinc. Furthermore, zinc is an essential element of more than 200 metalloenzymes and affects their conformity, stability, and activity. The superoxide dismutase, one of the zinc-containing antioxidant enzyme, has a critical role in keeping broiler skin healthy and increasing the shelf-life of broiler meat. However, a clear appreciation of the role of this element in broiler production is still limited. This article provides an overview on the role of zinc in broiler feeding and nutrition, immunity, reproduction, and meat quality in particular.

Indicators of zinc status at the population level: a review of the evidence

The role of zinc deficiency as an important cause of morbidity and impaired linear growth has prompted the need to identify indicators of population zinc status. Three indicators have been recommended - prevalence of zinc intakes below the estimated average requirement (EAR), percentage with low serum zinc concentrations, and percentage of children aged < 5 years who are stunted. This review outlines steps to estimate the prevalence of inadequate intakes, and confirm their validity based on the EARs set by International Zinc Nutrition Collaborative Group. Next, the appropriateness of serum zinc as a biochemical marker for population zinc status is confirmed by a summary of: (a) the response of serum zinc concentrations to zinc intakes; (b) usefulness of serum zinc concentrations to predict functional responses to zinc interventions; (c) relationship between initial serum zinc and change in serum zinc in response to interventions. Height- or length-for-age was chosen as the best functional outcome after considering the responses of growth, infectious diseases (diarrhoea, pneumonia), and developmental outcomes in zinc supplementation trials and correlation studies. The potential of other zinc biomarkers such as zinc concentrations in hair, cells, zinc-metalloenzymes, and zinc-binding proteins, such as metallothionein, is also discussed. Molecular techniques employing reverse transcriptase (RT)-polymerase chain reaction to measure mRNA in metallothionein and ZIP1 transporter hold promise, as do kinetic markers such as exchangeable zinc pools (EZP) and plasma zinc turnover rates. More research is needed to establish the validity, specificity, sensitivity, and feasibility of these new biomarkers, especially in community-settings.

Genomic analysis and expression pattern of OsZIP1, OsZIP3, and OsZIP4 in two rice (Oryza sativa L.) genotypes with different zinc efficiency

The ZRT-and IRT-like proteins (ZIP) comprise a large family of transition metal transporters in plants that have diverse functions to transport zinc, iron, copper, etc. Here, we provided a complete overview of this gene family in rice (Oryza sativa L.). Based on the hidden Markov model and BLAST analysis, a total of 17 ZIP-coding genes were identified and further studied by semi-quantitative RT-PCR analysis. Sequence analysis revealed 17 putative genes distributed randomly on eight chromosomes. Although most of the predicted proteins had typical characteristics of the ZIP protein family, the extent of their sequence similarity varied considerably. The expression patterns of OsZIP1, OsZIP3, and OsZIP4, which encode Zn2+ transporters in rice, were studied in the Zn-efficient and Zn-inefficient rice genotypes (IR8192 and Erjiufeng) by semi-quantitative RT-PCR analysis of roots, shoots, and panicle from the plants grown under Zn deficiency and normal conditions. OsZIP1 was expressed only in the roots and very weakly if at all in the panicles, while the other two genes were expressed in all parts of plants under study. The Zn-deficient conditions up-regulated the expression of OsZIP1, OsZIP3, and OsZIP4 in the roots and that of OsZIP4 in the shoots of both genotypes, indicating that all these genes may participate in rice zinc nutrition. Furthermore, the expression of OsZIP3 and OsZIP4 was found to be much stronger in the roots of IR8192 than those of Erjiufeng, which suggests that these genes may contribute to high Zn efficiency in rice. The expression patterns and the roles of other OsZIPs are also discussed on the basis of the phylogenetic tree of ZIP proteins and RT-PCR analysis of the two rice genotypes with different zinc efficiency.

Treatment of zinc deficiency without zinc fortification

Zinc (Zn) deficiency in animals became of interest until the 1950s. In this paper, progresses in researches on physiology of Zn deficiency in animals, phytate effect on bioavailability of Zn, and role of phytase in healing Zn deficiency of animals were reviewed. Several studies demonstrated that Zn is recycled via the pancreas; the problem of Zn deficiency was controlled by Zn homeostasis. The endogenous secretion of Zn is considered as an important factor influencing Zn deficiency, and the critical molar ratio is 10. Phytate (inositol hexaphosphate) constituted up to 90% of the organically bound phosphorus in seeds. Great improvement has been made in recent years on isolating and measuring phytate, and its structure is clear. Phytate is considered to reduce Zn bioavailability in animal. Phytase is the enzyme that hydrolyzes phytate and is present in yeast, rye bran, wheat bran, barley, triticale, and many bacteria and fungi. Zinc nutrition and bioavailability can be enhanced by addition of phytase to animal feeds. Therefore, using phytase as supplements, the most prevalent Zn deficiency in animals may be effectively corrected without the mining and smelting of several tons of zinc daily needed to correct this deficiency by fortification worldwide.

The effect of Zn supplementation on Zn status depends on the iron status in physically active women

Exercise can cause change of mineral levels by electrolyte and water loss through sweat. Zinc is known to be involved in exercise‐induced metabolic responses during exercise, so adequate zinc nutrition seems to improve exercise tolerance. The prevalence of iron deficiencies are known to be high in some physically active women. The iron nutrition status influences Zn status through competing for a common transporter in the intestinal absorption. This study investigates whether the iron status can influence the effect of Zn supplementation on serum Zn level. Female basketball collegiate players were supplemented 2 months with zinc 50mg as zinc gluconate. Bloods were collected before and after exercise at the beginning and end of 2‐mo. study period. The serum concentrations of Fe and Zn were measured by neutron activation analysis method. Half of athletic females before Zn supplementation showed a state of iron depletion (ID, serum ferritin &lt;20 μg/L). Before supplementation, the serum Zn concentration was lower in athletes with ID than athletes without ID. After 2‐mo. Zn supplementation, the serum Zn level was higher in athletes with ID than without ID. showing lower Zn status with normal Fe status. Conclusively, this study suggests that the effect of Zn supplementation on serum zinc level in physical active women can depend on the iron status before supplementation. The 2‐mo. Zn supplementation can enhance the serum Zn concentration of athletic females with low iron status, but not with normal iron status. This study was supported by the MOST of Korea

Gestational zinc deficiency leads to differential modulation of mitogen activated kinases in fetal brain

We previously showed that in neuroblastoma IMR‐32 cells, decreased zinc availability alters the modulation of the mitogen activated kinases (MAPKs) ERK1/2, p38 and JNK in association with decreased cell proliferation and increased apoptosis. We have now investigated the effects of feeding diets containing adequate (25 μg Zn/g, C) or marginal zinc (10 μg/g, MZD) concentrations throughout gestation on the modulation of MAPKs and the downstream activation of transcription factor AP‐1 in E19 rat fetal brain. Food intake, pregnancy and fetal outcome were similar between groups. A differential activation of MAPKs, as evaluated by MAPKs phosphorylation levels, was observed. Low levels of ERK1/2 activation and high levels of JNK and p38 activation were measured in fetal brain from the MZD group compared to the C group. Relative to controls, the AP‐1‐DNA binding activity in MZD fetal brain was significantly higher than in controls. These results show that marginal zinc nutrition imposed to rats during gestation affect MAPKs modulation and AP‐1 activation in E19 fetal brain. The pattern of MAPKs activation is similar to that previously observed in zinc deficient neuronal cells. Thus, alterations in MAPKs and AP‐1 activation could underlie the adverse effects of Zn deficiency on neurodevelopment. Supported by grants from the University of California, Davis, and NIH (HD 01743).

Zinc Nutrition of Onion: Proposed Diagnostic Criteria

ABSTRACT Zinc (Zn) deficiency is a global nutritional problem in crops grown in calcareous soils. However, plant analysis criteria, a good tool for interpreting crop Zn requirement, is scarcely reported in literature for onion (Allium cepa L.). In a greenhouse experiment, Zn requirement, critical concentrations in diagnostic parts and genotypic variation were assessed using four onion cultivars (‘Swat-1’, ‘Phulkara,’ ‘Sariab Red,’ and ‘Chilton-89’) grown in a Zn-deficient (AB-DTPA extractable, 0.44 Zn mg kg−1), calcareous soil of Gujranwala series (Typic Hapludalf). Five rates of Zn, ranging from 0 to 16 mg Zn kg−1 soil, were applied as zinc sulphate (ZnSO4·7H2O) along with adequate basal fertilization of nitrogen (N), phosphorus (P), potassium (K), and boron (B). Four onion seedlings were transplanted in each pot. Whole shoots of two plants and recently matured leaves of other two plants were sampled. Zinc application significantly increased dry bulb yield and maximum yield was produced with 8 mg Zn kg−1. Application of higher rates did not improve yield further. The cultivars differed significantly in Zn efficiency and cv. ‘Swat-1’ was most Zn-efficient. Fertilizer requirement for near-maximum dry bulb yield was 2.5 mg Zn kg−1. Plant tissue critical Zn concentrations were 30 mg kg−1 in young whole shoots, 25 mg kg−1 in matured leaves, 16 mg kg−1 in tops and 14 mg Zn kg−1 in bulb. Zinc content in mature bulb also appeared to be a good indicator of soil Zn availability status.

The role of arbuscular mycorrhizas in improving plant zinc nutrition under low soil zinc concentrations: a review

Many of the world’s soils are zinc (Zn) deficient. Consequently, many crops experience reduced growth, yield and tissue Zn concentrations. Reduced concentrations of Zn in the edible portions of crops have important implications for human Zn nutrition; this is a cause of global concern. Most terrestrial plant species form arbuscular mycorrhizas (AM) with a relatively limited number of specialized soil fungi. Arbuscular mycorrhizal fungi (AMF) can take up nutrients, including Zn, and transfer them to the plant, thereby enhancing plant nutrition. Under high soil Zn concentrations the formation of AM can also ‘protect’ against the accumulation of Zn in plant tissues to high concentrations. Here, a short review focusing on the role of AM in enhancing plant Zn nutrition, principally under low soil Zn concentrations, is presented. Effects of Zn on the colonisation of roots by AMF, direct uptake of Zn by AMF, the role of AM in the Zn nutrition of field grown plants, and emerging aspects of Zn molecular physiology of AM, are explored. Emergent knowledge gaps are identified and discussed in the context of potential future research.

Zinc supplementation boosts the stress response in the elderly: Hsp70 status is linked to zinc availability in peripheral lymphocytes

Chaperones and zinc are indispensable for proper immune function. All the zinc status, the immune function and the stress response decline during aging. Here we studied the effect of nutritional zinc and zinc homeostasis on the stress response in healthy old subjects recruited during the ZincAge European Union project that either underwent or not a 48-day zinc supplementation. Inducible Hsp70 levels were determined at basal conditions as well as after heat shock in the CD3+ and CD3− subset of lymphocytes by a two-color FACS analysis. Short term zinc supplementation resulted in a marked increase in both basal as well as stress-induced Hsp70 levels in lymphocytes from healthy elderly donors with a higher impact on CD3+ cells. Heat inducibility showed a strong correlation with basal Hsp70 level, and both basal as well as stress-induced Hsp70 highly correlated with intracellular zinc availability. In conclusion, short term oral supplementation with zinc safely and efficiently induces the stress response in lymphocytes of old donors. The stress response may be a candidate pathway connecting zinc deficiency with aging and immunosenescence. Thus, proper dietary zinc intake may emerge as a chaperone inducer and an anti-aging mechanism in the immune system.

Significance of intracellular and secreted acid phosphatase enzyme activities, and zinc and calcium interactions, on phosphorus efficiency in wheat, sunflower, chickpea, and lentil cultivars

Phosphorus efficiency (PE), and its relationship with intracellular (APase) and secreted (S-APase) acid phosphatases, anthocyanin accumulation, and calcium and zinc nutrition, were compared among 8 cultivars of each of wheat, sunflower, chickpea, and lentil grown under greenhouse conditions with low and high rates of P supply in a P-deficient calcareous soil. Except for the chickpea cultivars, deficiency of P resulted in significant decreases in shoot dry weight of all the crop cultivars and led to significant decreases in root dry weight in wheat and sunflower, significant increases in root dry weight in chickpea, and no significant difference in root dry weight in lentil. PE differed greatly among species and their cultivars. On average, shoot P concentration in cultivars of wheat, sunflower, chickpea, and lentil increased by 44%, 54%, 47%, and 8%, respectively, with P supply, and the increases in P concentration differed greatly among cultivars of all species. Intracellular leaf APase activity of wheat and lentil cultivars was slightly decreased by P supply, while it was unchanged in sunflower and chickpea cultivars. However, root-secreted acid phosphatase (S-APase) activity was significantly reduced by P supply in wheat, sunflower, and chickpea cultivars. Under low-P conditions, S-APase activities of all species except sunflower were negatively correlated with PE. Phosphorus deficiency increased the anthocyanin concentration of the cultivars of wheat and sunflower, whereas it was usually decreased in cultivars of the P-efficient species chickpea and lentil. In general, concentration of Ca was found to be lower, but Zn concentration was higher, in P-efficient cultivars than in P-inefficient cultivars. The results demonstrated that PE of the cultivars clearly depends on their ability to take up P and Zn, and on secretion of acid phosphatases from their roots under P deficiency. The results also suggest that characteristics of Zn and Ca nutrition should be taken into consideration when screening cultivars of crop species for their P efficiency.

A Food-Based Approach to Improving Zinc Nutrition Through Increasing the Zinc Content of Rice in Bangladesh

ABSTRACT Improvements in micronutrient content or bioavailability of staples can impact diet. We aimed to assess variability of rice zinc at field, household, and village levels, and its association with dietary zinc and nutritional status of children. Rice samples were collected from farmers and 156 households in 4 villages in Bangladesh. Hair samples were used to assess zinc nutritional status. Soil pH, soil zinc, and rice variety were associated with rice zinc content. In 2 villages milling losses of zinc were very different: 24±10% and 39±11% (p < 0.001). Rice supplied 66±16% of zinc in the diet of 2–10 yr old children. Dietary zinc density was 1.00±0.24 and 1.35±0.24 mg/1000kJ (p < 0.001) respectively in the village with the lowest compared to the highest rice zinc. Hair zinc was positively associated with rice zinc (r = 0.24 p = 0.001) suggesting improvements to the nutrient content of rice could result in nutritional benefit. Optimizing rice zinc through choice of varieties, soil management, and processing could improve zinc nutrition in Bangladesh.

In vitro and in vivo effects of zinc on cytokine signalling in human T cells

Aging is associated with changes in the immune response which are collectively called immunosenescence. The changes mainly affect the adaptive immune response and especially the T cell-mediated cellular immune response. There are a few data indicating that the cytokine signalling in T cells is altered with aging. Zinc has been specifically shown to have potent immunomodulatory effects. The aim of the present work was to study the IL-2 and IL-6 cytokine signalling and activation induced cell death (AICD) in T cells of elderly subjects of various ages and from various European countries. These experiments were performed in the frame of European Community financed project called ZINCAGE “Nutritional zinc, oxidative stress and immunosenescence: biochemical, genetic and lifestyle implications for healthy ageing”, assembling 17 laboratories from 8 countries through Europe. The study was carried out in a total of 312 French and a group of 201 (26 from Italy, 63 from France, 57 from Greece, 24 from Poland and 30 from Germany) healthy non-institutionalized men and women older than 60 years of age, with available dietary data. Human peripheral blood mononuclear cells (PBMC) were obtained from heparinized blood and were stimulated in vitro by IL-2 or IL-6 for various periods and the phosphorylation of STAT3 and STAT5 was measured by FACScan. The activation induced cell death (AICD) was measured after anti-CD3 and CD28 restimulation for 48h by using the Annexin:FITC Apoptosis Kit. We found that there is an IL-2 signalling defect with aging up to 90 years of age which cannot be modulated by zinc. In contrast at 90 years and over the zinc could reverse the negative signalling effect of IL-2. There is also a signalling defect for STAT3 and STAT5 activation in T cells under IL-6 stimulation with aging and the zinc supplementation could potentiate only the STAT5 activation in the age-group 90 years and over. Studying signalling in PBL from different countries we detected less activation in T cells of subjects from France and the most changes occurred in T cells of subjects from Poland, suggesting no correlation with the plasma zinc status observed in these countries. In vivo zinc supplementation had no effect on IL-2 and IL-6-modulated STAT3 and STAT5 activation. Zinc added in vitro to these T cells even inhibited the stimulation either by IL-2 or by IL-6. Zinc supplementation improved the susceptibility of T cells to AICD in both age-groups, with more efficiency in later ages. Our results suggest that zinc can have a potent immunomodulatory effect via the modulation of cytokine signalling and AICD, however this effect depends on the function and the activation status of the T cells.

Zinc supplementation for the treatment or prevention of disease: Current status and future perspectives

Zinc is a nutritionally essential trace element, and thus zinc deficiency may severely affect human health. Many studies were published in which the effect of nutritional zinc supplementation on the incidence or severity of a certain disease was investigated. This review summarizes the main observations and aims to evaluate the use of nutritional zinc supplementation for prevention and treatment of human disease.

Possible roles of zinc nutriture in the fetal origins of disease

Risk of diseases of metabolism such as atherosclerosis and adult onset diabetes mellitus is increased by fetal malnutrition. Deficiencies of micronutrients essential for methylation are believed to contribute to the phenomenon in part through epigenetic abnormalities. Zinc is one of the nutrients essential for the epigenome. Because the worldwide prevalence of zinc deficiency is at least 20%, fetal zinc deficiency is common. We suggest fetal zinc deficiency contributes to the pathogenesis of metabolic diseases in adults. In support of our thesis, research in experimental models and humans established the essentiality of zinc at all stages of intrauterine and infant life. Experiments in rodents and/or non-human primates found that fetal and/or suckling zinc deficiency impairs neuropsychological functions of progeny and that the effects persist in spite of nutritional rehabilitation. In addition, maternal zinc deficiency in mice is reported to impair immunity of progeny; effects persist in spite of nutritional rehabilitation into the next generation. We suspect that zinc deficiency is a far greater human health problem than is generally recognized.

Role of Phosphatases, Iron Reducing, and Solubilizing Activity on the Nutrient Acquisition in Mixed Cropped Peanut and Barley

ABSTRACT The effect of interspecific complementary and competitive root interactions and rhizosphere effects on primarily phosphorus (P) and iron (Fe) but also nitrogen (N), potassium (K), calcium (Ca), zinc (Zn), and manganese (Mn) nutrition between mixed cropped peanut (Arachis hypogaea L.) and barley (Hordeum vulgare L.). In order to provide more physiological evidence on the mechanisms of interspecific facilitation, phosphatase activities in plant and rhizosphere, root ferric reducing capacity (FR), Fe-solubilizing activity (Fe-SA), and rhizosphere pH were determined. The results of the experiment revealed that biomass yield of peanut and barley was decreased by associated plant species as compared to their monoculture. Rhizosphere chemistry was strongly and differentially modified by the roots of peanut and barley and their mixed culture. In the mixed cropping of peanut/barley, intracellular alkaline and acid phosphatases (AlPase and APase), root secreted acid phosphatases (S-APase), acid phosphatases activity in rhizosphere (RS-APase), and bulk soil (BS-APase) were higher than that of monocultured barley. Regardless of plant species and cropping system, the rhizosphere pH was acidified and concomitantly to this available P and Fe concentrations in the rhizosphere were also increased. The secretion Fe-solubilizing activity (Fe-SA) and ferric reducing (FR) capacity of the roots were generally higher in mixed culture relative to that in monoculture treatments which may improve Fe and Zn nutrition of peanut. Furthermore, mixed cropping improved N and K nutrition of peanut plants, while Ca nutrition was negatively affected by mixed cropping.