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Zinc Malnutrition in Children and Its Consequences on Health
Abstract
Zinc is a mineral that is important to all forms of life due to its fundamental role in various metabolic process such as DNA replication, gene expression and protein synthesis. The function that zinc has in human health has been acknowledged by researchers for nearly half a century since the discovery of the syndrome of zinc deficiency among adolescents in Iran. This chapter looks at both elements of zinc malnutrition in children, that is, zinc deficiency and zinc toxicity, and its consequences on health. Severe forms of zinc deficiency are considered to be quite rare, while mild zinc deficiency is more commonly found, mainly within the developing world. Controlled research trails of supplemented zinc at areas that have intrinsically low levels of zinc intake have shown that low intake of zinc has an adverse influence on child health; particularly leading to deficits in neuropsychological functioning and motor development in children. On the other hand, zinc toxicity is rare in children as compared to adults. Zinc toxicity in children is due to oversupplement of zinc intake and can lead to the obesity and other issues such as high blood pressure and cholesterol. Furthermore, this chapter looks at possible precautions and measures to handle the issues associated with zinc malnutrition along with indicating additional research work essential in the field.
... According to the World Health Organization (WHO), nearly 800,000 deaths annually are attributed to Zn deficiency, with a substantial number occurring among children under five (Arfi et al., 2021;Waqeel and Khan, 2021). This widespread deficiency leads to severe health problems such as stunted growth, weakened immune function, and severe neural developmental disorders ( Figure 1). ...
... The role of Zn in apoptosis and cell death, particularly brain injury, highlights the complexity of its biological impact and the delicate balance required for homeostatic regulation (Plum et al., 2010). Furthermore, excessive Zn intake in children can result in obesity and related health issues (Arfi et al., 2021). The environmental footprint of Zn NPs and biochar extends beyond the terrestrial boundaries. ...
The integration of zinc nanoparticles (Zn NPs) with biochar offers a transformative approach to sustainable agriculture by enhancing plant productivity and human nutrition. This combination improves soil health, optimizes nutrient uptake, and increases resilience to environmental stressors, leading to superior crop performance. Our literature review shows that combining Zn NPs with biochar significantly boosts the crop nutrient composition, including proteins, vitamins, sugars, and secondary metabolites. This enhancement improves the plant tolerance to environmental challenges, crop quality, and shelf life. This technique addresses the global issue of Zn deficiency by biofortifying food crops with increased Zn levels, such as mung beans, lettuce, tomatoes, wheat, maize, rice, citrus, apples, and microgreens. Additionally, Zn NPs and biochar improve soil properties by enhancing water retention, cation exchange capacity (CEC), and microbial activity, making soils more fertile and productive. The porous structure of biochar facilitates the slow and sustained release of Zn, ensuring its bioavailability over extended periods and reducing the need for frequent fertilizer applications. This synergy promotes sustainable agricultural practices and reduces the environmental footprint of the traditional farming methods. However, potential ecological risks such as biomagnification, nanoparticle accumulation, and toxicity require careful consideration. Comprehensive risk assessments and management strategies are essential to ensure that agricultural benefits do not compromise the environmental or human health. Future research should focus on sustainable practices for deploying Zn NPs in agriculture, balancing food security and ecological integrity and positioning this approach as a viable solution for nutrient-efficient and sustainable agriculture.
... Zinc deficiency is an important cause of morbidity due to infectious diseases and growth faltering among young children. Increased demand of zinc due to rapid growth and decreased intake of zinc due to inadequate feeding practices predispose pre-school children, especially living in communities of low socioeconomic level, to an elevated risk of zinc deficiency (5). Zinc deficiency in children leads to retardation in growth and also morbidity from many diseases such as diarrhea, pneumonia, and malaria. ...
... Zinc deficiency is an important cause of morbidity due to infectious diseases and growth faltering among young children. Increased demand of zinc due to rapid growth and decreased intake of zinc due to inadequate feeding practices predispose pre-school children, especially living in communities of low socioeconomic level, to an elevated risk of zinc deficiency (5). Iron deficiency results from depletion of iron stores and occurs when iron absorption cannot keep pace over an extended period with the metabolic demands for iron to sustain growth and to replenish iron loss, which is primarily related to blood loss (15). ...
... This puts nutrition at the center stage of life. Several reports have shown that malnutrition, micromineral deficiency and polluted water affects the health, growth and development of humans (Shukla et al., 2018;Godswill et al., 2020;Arfi et al., 2022). There is therefore the need for stakeholders to support in finding a lasting solution to these global challenges. ...
... Zinc malnutrition remains a major health concern in the developing world due to the monotonous consumption of less nutritious cereals and lack of dietary diversity (Arfi et al. 2022;Wessells and Brown 2012). Biofortified crop varieties are cheaper, easily accessible, and sustainable sources of daily nutrition (Bouis and Saltzman 2017;Nuthalapati et al. 2022;Pradhan et al. 2020). ...
Zinc (Zn) biofortification of rice can address Zn malnutrition in Asia. Identification and introgression of QTLs for grain Zn content and yield (YLD) can improve the efficiency of rice Zn biofortification. In four rice populations we detected 56 QTLs for seven traits by inclusive composite interval mapping (ICIM), and 16 QTLs for two traits (YLD and Zn) by association mapping. The phenotypic variance (PV) varied from 4.5% (qPN4.1) to 31.7% (qPH1.1). qDF1.1, qDF7.2, qDF8.1, qPH1.1, qPH7.1, qPL1.2, qPL9.1, qZn5.1, qZn5.2, qZn6.1 and qZn7.1 were identified in both dry and wet seasons; qZn5.1, qZn5.2, qZn5.3, qZn6.2, qZn7.1 and qYLD1.2 were detected by both ICIM and association mapping. qZn7.1 had the highest PV (17.8%) and additive effect (2.5 ppm). Epistasis and QTL co-locations were also observed for different traits. The multi-trait genomic prediction values were 0.24 and 0.16 for YLD and Zn respectively. qZn6.2 was co-located with a gene (OsHMA2) involved in Zn transport. These results are useful for Zn biofortificatiton of rice.
... Zinc is a vital micronutrient required for the structural and functional integrity of the biological membrane and the detoxification of free radicals, with an essential role in maintaining cell and organ integrity and as an antioxidant and anti-inflammatory agent [61]. According to the World Health Organization, zinc deficiency is a worldwide public health problem that affects 31%, with the prevalence rates ranging from 4 to 73% in various regions of the world population [62]. Here, we can discuss the soil-related origins of metal concentration transferred from plants to essential oil. ...
Natural ecosystems are polluted with various contaminants, and among these heavy metals raise concerns due to their side effects on both environment and human health. An investigation was conducted on essential oil samples, comparing similar products between seven producers, and the results indicated a wide variation of metal content. The recommended limits imposed by European Union regulations for medicinal plants are exceeded only in Mentha × pipperita (Adams, 0.61 mg/kg). Except for Thymus vulgaris, the multivariate analysis showed a strong correlation between toxic and microelements (p < 0.001). We verified plant species-specific bioaccumulation patterns with non-metric multidimensional scaling analysis. The model showed that Adams, Doterra, Hypericum, and Steaua Divina essential oils originated from plants containing high micro and macroelement (Cu, Mn, Mg, Na) levels. We noted that the cancer risk values for Ni were the highest (2.02 × 10-9-7.89 × 10-7). Based on the target hazard quotient, three groups of elements were associated with a possible risk to human health, including As, Hg, and Cd in the first group, Cr, Mn, Ni, and Co in the second, and Zn and Al in the third. Additionally, the challenge of coupling inter-element relationships through a network plot analysis shows a considerable probability of associating toxic metals with micronutrients, which can address cumulative risks for human consumers.
Severe Acute Malnutrition (SAM) is a critical public health issue affecting millions of people globally. Objective: To evaluate the status of micronutrients and their relationship with malnutrition severity. Methods: A cross-sectional study was conducted over six months from November 2023 to April 2024 at Pead’s Department Of Khairpur Medical College, KhairpurMirs. The study included 384 participants diagnosed with SAM. Micronutrient levels were assessed using quantitative colorimetry. Statistical analyses were descriptive, independent t-tests, Pearson and Spearman correlation analyses to evaluate micronutrient deficiencies. Results: The mean age of the children was 24.5 months, with a male predominance of 54.7%. Micronutrient levels showed significant variation between children with mild and severe malnutrition: p = 0.03), zinc (62.7 vs. 55.8 µg/dl, p = 0.01), vitamin B12 (312.4 vs. 278.6 pg/ml, p = 0.02), copper (97.3 vs. 89.2 µg/dl, p = 0.03), and selenium (45.7 vs. 40.2 µg/l, p < 0.05). Positive correlations between micronutrient levels and anthropometric variables were found by correlation analysis. Logistic regression indicated that deficiencies in Vitamin B12 (OR: 1.45, p = 0.02), Zinc (OR: 1.62, p = 0.01), and Copper (OR: 1.35, p = 0.03) were significant predictors of severe malnutrition. Conclusions: The findings emphasized that the need for targeted nutritional interventions addressing Vitamin B12, Zinc, and Copper deficiencies to improve health outcomes in malnourished children. Further research was essential to evaluate the impact of supplementation strategies on growth and recovery
A cross-sectional study was performed in Al-Azizyia general hospital in Wasit province for a sample of one hundred ten cases which was conveniently collected from the words and the outpatient clinic throughout July, August, and September 2020. All mothers were chosen and aged from 18 to 41 years old. 110 cases of infants of both sexes were included, their ages range from 1 to 12 months. By using the questionnaire data concerning, acute gastroenteritis, age of the infants, the sex of the infant, residency, type of feeding, level of education of mother, mother age, the job of father, and the job of mother. We found that 85 (77.2 %) of the collected sample were found to be non-beast-fed infants, while the rest of the sample 25 (22.7 %), breast-fed infants. Most of our patients were from rural areas 60(54.5 %) and the rest from urban areas 50 (45.4 %). Most of our patients were male 71 (64.5 %) and the rest were females (35.5 %). The infants below six months of age 61 (55.4 %) are more than those above six months 49 (44.5 %). The age of mothers between 20, and 30 years old 73 (66.36 %) is more than that of mothers aged above 30 to 37 years (25.45 %) which is more than that of mothers aged below 20 to 9 (8.18 %). Most of the mothers were housewives 105 (95.4 %) and the rest were workers 5 (4.6 %). Most of the fathers were unemployed 87 (79.1 %) and the rest were employed 23 (20.9 %). Mothers with a primary level of education are 80 (72.7 % are more than the mothers with a secondary level 24 (21.8 %) which is more than those with a higher level 6 (5.4 %).
Zinc, a metal found in the Earth’s crust, is indispensable for human health. In the human body, around 60% of zinc is present in muscles, 30% in bones, and the remaining 10% in skin, hair, pancreas, kidneys and plasma. An adequate zinc balance is essential for the maintenance of skeletal growth, development and function. It is also necessary for basic cellular functions including enzyme activation, cell signaling and energy metabolism. Inadequate zinc status is associated with a wide variety of systemic disorders including cardiovascular impairment, musculoskeletal dysfunctions and oromaxillary diseases. In this article, we briefly discuss the role of zinc deficiency in the genesis of various oromaxillary diseases, and explain why adequate zinc homeostasis is vital for the maintenance of oral and general health.
Zinc absorption in the small intestine is one of the main mechanisms regulating the systemic homeostasis of this essential trace element. This review summarizes the key aspects of human zinc homeostasis and distribution. In particular, current knowledge on human intestinal zinc absorption and the influence of diet-derived factors on bioaccessibility and bioavailability as well as intrinsic luminal and basolateral factors with an impact on zinc uptake are discussed. Their investigation is increasingly performed using in vitro cellular intestinal models, which are continually being refined and keep gaining importance for studying zinc uptake and transport via the human intestinal epithelium. The vast majority of these models is based on the human intestinal cell line Caco-2 in combination with other relevant components of the intestinal epithelium, such as mucin-secreting goblet cells and in vitro digestion models, and applying improved compositions of apical and basolateral media to mimic the in vivo situation as closely as possible. Particular emphasis is placed on summarizing previous applications as well as key results of these models, comparing their results to data obtained in humans, and discussing their advantages and limitations.
In recent years, nanoparticles are being used extensively in personal healthcare products such as cosmetics, sunscreens, soaps, and shampoos. Particularly, metal oxide nanoparticles are gaining competence as key industrial constituents, progressing toward a remarkable rise in their applications. Zinc oxide and titanium oxide nanoparticles are the most commonly employed metal oxide nanoparticles in sunscreens, ointments, foot care, and over the counter topical products. Dermal exposure to these metal oxides predominantly occurs through explicit use of cosmetic products and airway exposure to nanoparticle dusts is primarily mediated via occupational exposure. There is a compelling need to understand the toxicity effects of nanoparticles which can easily enter the cells and induce oxidative stress. Consequently, these products have become a direct source of pollution in the environment and thereby greatly impact our ecosystem. A complete understanding of the toxicity mechanism of nano-ZnO is intended to resolve whether and to what extent such nanoparticles may pose a threat to the environment and to human beings. In this review article, we have discussed the characteristics of metal oxide nanoparticles and its applications in the cosmetic industry. We have also highlighted about their toxicity effects and their impact on human health.
Objective:
Diminished blood levels of zinc have been reported to be associated with T-cell-mediated autoimmunity, which has been implicated in multiple sclerosis (MS). We aimed to compare the distribution of serum zinc status in MS patients with that in healthy controls (HCs) and to investigate a potential correlation with clinical state, through analysis of serum zinc concentration in MS patients suffering from different disease subtypes.
Methods:
Serum zinc concentrations of 133 patients with relapsing (RMS) and 18 patients with the progressive form of MS (PMS), according to the McDonald criteria of 2010, were measured. Clinical status was quantified using the Expanded Disability Status Scale (EDSS). Zinc concentrations were also determined in the sera of 50 HCs, matched for age and sex at a group level.
Results:
MS patients showed significantly lower zinc concentrations (mean (SD)) than HCs (12.5 (2.1) µmol/L vs. 14.6 (2.3) µmol/L, p < 0.001). In contrast, we did not find any difference between RMS (12.4 (2.0) µmol/L) and PMS (13.0 (3.0) µmol/L) cases (p = 0.8). Patients receiving disease-modifying treatment showed lower mean (SD) serum zinc levels than untreated cases (12.3 (1.9) µmol/L vs. 13.5 (3.2) µmol/L, p < 0.03). Zinc levels were not related to disease duration, EDSS, annual relapse rate, or the median number of relapses.
Conclusions:
The data suggest that a diagnosis of MS is related to lower serum zinc concentrations than in HCs, and concentrations were lower still under disease-modifying therapy. However, zinc levels did not predict disease subtypes or disability status.
The neuroscience nurse is in the ideal position to assess and educate the patient in regard to the use of zinc-containing denture adhesives. Overuse of these products has been linked to ill-fitting dentures, a problem that can be remedied with proper dental attention. In general, a 2.4-ounce container of dental adhesive should last the patients approximately 7Y8 weeks. If the patient experiences symptoms of numbness and weakness, he or she should be evaluated by a physician, and zinc and copper levels should be included in laboratory studies. This is a devastating but fully preventable disease with a severe residual functional deficit, even after treatment.
Although zinc has been the most intensely studied trace element, much remains to be learned about its metabolism. Little is known about the normal mechanisms of absorption and transport across the intestinal tract. In addition, numerous unknowns surround the intricacies of bodily zinc homeostasis. Part two of this five-part review presents current views on the normal intestinal absorption, intracellular and extracellular metabolism, transport, excretion and homeostasis of zinc in the human body. The alterations in zinc metabolism that occur with age and changing physiological conditions are also discussed.
Minor illnesses, such as colds and influenza, are frequent, widespread and a major cause of absenteeism from work and education. Yet the clinical symptoms of such illnesses may not be so great as to stop people from working or from carrying out everyday activities. It is therefore important to determine whether these viral infections alter central nervous system function and change performance efficiency. Data on this topic are almost non-existent, which in part reflects the difficulties inherent in carrying out such studies. In real life it is almost impossible to predict when such illnesses will occur, and difficult to establish which virus produced the illness. This problem was overcome by studying experimentally induced infections and illnesses at the Medical Research Centre (MRC) Common Cold Unit in Salisbury. Results from this research programme show that: (i) colds and influenza have selective effects on performance; (ii) even sub-clinical infections can produce performance impairments; (iii) performance may be impaired during the incubation period of the illness; (iv) performance impairments may still be observed after the clinical symptoms have gone. These results have strong implications for occupational safety and efficiency and it is now essential to assess the impact of naturally occurring colds and influenza on real-life activities.
Zinc (Zn) is one of the trace minerals which is required for huge range of bodily functions. Since last two decades, Zn as micronutrient is being used indiscriminately in agricultural and hus-bandry practices and also in baby foods and multivitamin supplements since Zn is non-toxic and promotes body weight in the consumers. Thus, the concentration of Zn in some vegetables and animals food products and other dietary food items has been increased. So far, the effects of long term Zn overload in the body have not been reviewed. Consumption of excess Zn in diet for longer period of time may contribute obesity and related diseases in adolescence, copper (Cu)-deficiency related abnormalities in the adults and pregnant women. Excess Zn in diet makes diabetic patients more vulnerable due to increase in glycosylated haemoglobin level in the blood. The various aspects about harmful effect of excess Zn in diet is given in this commu-nication.
Since its first discovery in an Iranian male in 1961, zinc deficiency in humans is now known to be an important malnutrition problem world-wide. It is more prevalent in areas of high cereal and low animal food consumption. The diet may not necessarily be low in zinc, but its bio-availability plays a major role in its absorption. Phytic acid is the main known inhibitor of zinc. Compared to adults, infants, children, adolescents, pregnant, and lactating women have increased requirements for zinc and thus, are at increased risk of zinc depletion. Zinc deficiency during growth periods results in growth failure. Epidermal, gastrointestinal, central nervous, immune, skeletal, and reproductive systems are the organs most affected clinically by zinc deficiency. Clinical diagnosis of marginal Zn deficiency in humans remains problematic. So far, blood plasma/serum zinc concentration, dietary intake, and stunting prevalence are the best known indicators of zinc deficiency. Four main intervention strategies for combating zinc deficiency include dietary modification/diversification, supplementation, fortification, and bio-fortification. The choice of each method depends on the availability of resources, technical feasibility, target group, and social acceptance. In this paper, we provide a review on zinc biochemical and physiological functions, metabolism including, absorption, excretion, and homeostasis, zinc bio-availability (inhibitors and enhancers), human requirement, groups at high-risk, consequences and causes of zinc deficiency, evaluation of zinc status, and prevention strategies of zinc deficiency.
The critical importance of adequate zinc status to human health, including normal growth and development, is indisputable. The high prevalence of zinc deficiency on a global basis and its importance to public health have been well documented through large-scale randomized controlled zinc supplementation trials. Similar evidence in the clinical setting, however, is much less widely available due to the nonspecific features of zinc deficiency and to the lack of sensitive biomarkers to detect zinc deficiency, especially that of a mild degree of severity. The current understanding of zinc homeostasis indicates that the primary determinants of zinc absorption are the amount of zinc ingested and dietary phytate, the latter having a major effect on zinc bioavailability. In normal as well as in many pathologic conditions, the gastrointestinal tract is the major site of zinc losses resulting from secretion of endogenous zinc into the lumen and subsequent excretion in the feces. The amount excreted is dependent on host status, the amount reabsorbed, and sometimes the presence of pathophysiologic conditions, including diarrhea and steatorrhea. Assessment in the clinical setting dictates that the clinician obtain a careful medical and diet history, recognize clinical presentations in which zinc adequacy may be compromised, and link this risk with nonspecific but plausible manifestations of deficiency. Examples discussed in this article include primary zinc deficiency due to dietary inadequacy (older breastfed infants or toddlers without zinc-rich complementary foods); genetically based deficiency (acrodermatitis enteropathica, acquired zinc deficiency of lactogenic origin), and acquired secondary deficiency in low birth weight and prematurity, gastrointestinal and hepatic disease, and cystic fibrosis. Evidence for efficacy of zinc therapy with pharmacologic doses for two conditions, Wilson's disease and viral upper respiratory infections, is also discussed.
This article attempts to highlight the gravity of prevalence of zinc deficiency and its health and economic consequences in South Asian developing countries and to shed light on possible approaches to combat zinc deficiency. A computer-based search was performed on PubMed, Google, and Science Direct.com to retrieve relevant scientific literature published between 2000 and 2012; the search yielded 194 articles, of which 71 were culled. Studies were further screened on the basis of population groups, age and sex, pregnancy, and lactation. The most relevant articles were included in the review. Cutoffs for serum zinc concentration defined for zinc deficiency were 65 µg/dL for males and females aged <10 years, 66 µg/dL for non-pregnant females, and 70 µg/dL for males aged ≥10 years. Population segments from rural and urban areas of South Asian developing countries were included in the analysis. They comprised pregnant and lactating women, preschool and school children. The analysis reveals that zinc deficiency is high among children, pregnant and lactating women in India, Pakistan, Bangladesh, Sri Lanka, and Nepal. Diarrhea has been established as a leading cause to intensify zinc deficiency in Bangladesh. Little has been done in Sri Lanka and Nepal to estimate prevalence of zinc deficiency precisely. A substantial population segment of the South Asian developing countries is predisposed to zinc deficiency which is further provoked by increased requirements for zinc under certain physiological conditions. Supplementation, fortification, and dietary diversification are the most viable strategies to enhancing zinc status among various population groups
Ananda S Prasad first suspected zinc deficiency in 1958 after he, at the request of James A Halsted, evaluated a patient with severe iron deficiency. In addition to iron deficiency, the patient appeared ∼10 y old and was severely stunted and prepubertal, though his chronological and bone age were much older. He also had hepatosplenomegaly and ate clay. The condition was not rare in that 11 cases were reported. In 1961 Prasad joined the Vanderbilt Nutrition Group led by William J. Darby at the US Naval Medical Research Unit-3, Cairo, Egypt. Prasad et al. studied 40 males similar to the index case. Contrasts with the index case included no clay eating and infection with schistosomiasis and hookworm. Zinc kinetics confirmed the zinc deficiency. Endocrine studies showed hypopituitarism. Treatment with zinc and an omnivorous diet was more efficacious for growth than no treatment, diet alone, or iron and diet. Later, Halsted et al. confirmed these findings in stunted Iranian farmers. The key role of diet in the illness became evident when Prasad found 16 severely stunted farmers from 2 oases who were not infected with schistosomiasis or hookworm. Later, Reinhold et al., in Halsted's group, reported that phytate and other indigestible zinc-binding ligands in unleavened bread prepared from high-extraction wheat flour suppress zinc absorption.
BACKGROUND: Adequate zinc nutrition is essential for adequate growth, immunocompetence and neurobehavioral development, but limited information on population zinc status hinders the expansion of interventions to control zinc deficiency. The present analyses were conducted to: (1) estimate the country-specific prevalence of inadequate zinc intake; and (2) investigate relationships between country-specific estimated prevalence of dietary zinc inadequacy and dietary patterns and stunting prevalence. METHODOLOGY AND PRINCIPAL FINDINGS: National food balance sheet data were obtained from the Food and Agriculture Organization of the United Nations. Country-specific estimated prevalence of inadequate zinc intake were calculated based on the estimated absorbable zinc content of the national food supply, International Zinc Nutrition Consultative Group estimated physiological requirements for absorbed zinc, and demographic data obtained from United Nations estimates. Stunting data were obtained from a recent systematic analysis based on World Health Organization growth standards. An estimated 17.3% of the world's population is at risk of inadequate zinc intake. Country-specific estimated prevalence of inadequate zinc intake was negatively correlated with the total energy and zinc contents of the national food supply and the percent of zinc obtained from animal source foods, and positively correlated with the phytate: zinc molar ratio of the food supply. The estimated prevalence of inadequate zinc intake was correlated with the prevalence of stunting (low height-for-age) in children under five years of age (r = 0.48, P
Objective To study the effects of zinc supplementation on malaria and other causes of morbidity in young children living in an area holoendemic for malaria in west Africa. Design Randomised, double blind, placebo controlled efficacy trial. Setting 18 villages in rural northwestern Burkina Faso. Participants 709 children were enrolled; 685 completed the trial. Intervention Supplementation with zinc (12.5 mg zinc sulphate) or placebo daily for six days a week for six months. Main outcome measures The primary outcome was the incidence of symptomatic falciparum malaria. Secondary outcomes were die severity of malaria episodes, prevalence of malaria parasites, mean parasite densities, mean packed cell volume, prevalence of other morbidity, and all cause mortality. Results The mean number of malaria episodes per child (defined as a temperature greater than or equal to 37.5 degreesC with greater than or equal to 5000 parasites/mul) was 1.7, 99.7% due to infection with Plasmodium falciparum. No difference was found between the zinc and placebo groups in the incidence of falciparum malaria (relative risk 0.98, 95% confidence interval 0.80 to 1.11), mean temperature, and mean parasite densities during malaria episodes, nor in malaria parasite rates, mean parasite densities, and mean packed cell volume during cross sectional surveys. Zinc supplementation was significantly associated with a reduced prevalence of diarrhoea (0.87, 0.79 to 0.95). All cause mortality was non-significantly lower in children given zinc compared with those given placebo (5 v 12, P= 0.1). Conclusions Zinc supplementation has no effect on morbidity from falciparum malaria in children in rural west Africa, but it does reduce morbidity associated with diarrhoea.
Results of randomized controlled trials evaluating zinc for the treatment of the common cold are conflicting. We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of zinc for such use.
We searched electronic databases and other sources for studies published through to Sept. 30, 2011. We included all randomized controlled trials comparing orally administered zinc with placebo or no treatment. Assessment for study inclusion, data extraction and risk-of-bias analyses were performed in duplicate. We conducted meta-analyses using a random-effects model.
We included 17 trials involving a total of 2121 participants. Compared with patients given placebo, those receiving zinc had a shorter duration of cold symptoms (mean difference -1.65 days, 95% confidence interval [CI] -2.50 to -0.81); however, heterogeneity was high (I(2) = 95%). Zinc shortened the duration of cold symptoms in adults (mean difference -2.63, 95% CI -3.69 to -1.58), but no significant effect was seen among children (mean difference -0.26, 95% CI -0.78 to 0.25). Heterogeneity remained high in all subgroup analyses, including by age, dose of ionized zinc and zinc formulation. The occurrence of any adverse event (risk ratio [RR] 1.24, 95% CI 1.05 to 1.46), bad taste (RR 1.65, 95% CI 1.27 to 2.16) and nausea (RR 1.64, 95% CI 1.19 to 2.27) were more common in the zinc group than in the placebo group.
The results of our meta-analysis showed that oral zinc formulations may shorten the duration of symptoms of the common cold. However, large high-quality trials are needed before definitive recommendations for clinical practice can be made. Adverse effects were common and should be the point of future study, because a good safety and tolerance profile is essential when treating this generally mild illness.
Changes in plasma glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), triiodothyronine (T3), and thyroxin (T4) of male rats, following 8 weeks of administration of different concentrations of elemental iron (EI), sodium iron ethylenediaminetetraacetate (NaFeEDTA), zinc sulfate (ZnSO(4)), and zinc oxide (ZnO) in whole wheat flour were investigated. Liver enzymes and thyroid hormones were determined using colorimetric methods and enzyme immune assay, respectively. Ingestion of fortified diets by the male rats did not show a marked effect on GOT and GPT, the exception being NaFeEDTA fed alone and EI with ZnO-fortified diets indicating a significant (p < 0.05) decrease in GOT levels in rats. Similarly, only NaFeEDTA significantly (p < 0.05) increased thyroxin, while EI, ZnSO(4), and ZnO either alone or in any combination did not alter thyroid secretions. Changes in GOT, GPT, T3, and T4 levels, as a result of ingesting iron and zinc-fortified diets by rats, ranged in the safe limits.
Chelation therapy is the preferred medical treatment for reducing the toxic effects of metals. Chelating agents are capable of binding to toxic metal ions to form complex structures which are easily excreted from the body removing them from intracellular or extracellular spaces. 2,3-Dimercaprol has long been the mainstay of chelation therapy for lead or arsenic poisoning, however its serious side effects have led researchers to develop less toxic analogues. Hydrophilic chelators like meso-2,3-dimercaptosuccinic acid effectively promote renal metal excretion, but their ability to access intracellular metals is weak. Newer strategies to address these drawbacks like combination therapy (use of structurally different chelating agents) or co-administration of antioxidants have been reported recently. In this review we provide an update of the existing chelating agents and the various strategies available for the treatment of heavy metals and metalloid intoxications.
Compared to several other metal ions with similar chemical properties, zinc is relatively harmless. Only exposure to high doses has toxic effects, making acute zinc intoxication a rare event. In addition to acute intoxication, long-term, high-dose zinc supplementation interferes with the uptake of copper. Hence, many of its toxic effects are in fact due to copper deficiency. While systemic homeostasis and efficient regulatory mechanisms on the cellular level generally prevent the uptake of cytotoxic doses of exogenous zinc, endogenous zinc plays a significant role in cytotoxic events in single cells. Here, zinc influences apoptosis by acting on several molecular regulators of programmed cell death, including caspases and proteins from the Bcl and Bax families. One organ where zinc is prominently involved in cell death is the brain, and cytotoxicity in consequence of ischemia or trauma involves the accumulation of free zinc. Rather than being a toxic metal ion, zinc is an essential trace element. Whereas intoxication by excessive exposure is rare, zinc deficiency is widespread and has a detrimental impact on growth, neuronal development, and immunity, and in severe cases its consequences are lethal. Zinc deficiency caused by malnutrition and foods with low bioavailability, aging, certain diseases, or deregulated homeostasis is a far more common risk to human health than intoxication.
This chapter reviews key aspects of human zinc nutrition providing an insight on the etiology of zinc deficiency and current policies on the assessment of the risk of zinc deficiency in populations using stunting rates and other indicators. Zinc is an essential trace element in human nutrition, and it is critical to various basic molecular functions. Zinc depletion of the organism thus virtually affects any organ system in the human body, and it encompasses a number of diverse biochemical changes resulting in a generalized metabolic dysfunctions. Marginal zinc deficiency mainly occurs when zinc intakes from the diet are inadequate to provide for increased requirements, increased losses, decreased absorption, or decreased utilization. This form of zinc deficiency carries most of the public health significance of zinc deficiency. Marginal zinc deficiency adversely affects physiological, biochemical, and immunological functions. Typical signs are growth retardation, hypogonadism in male adolescents, rough skin, poor appetite, mental lethargy, abnormal dark adaptation, abnormal neurosensory changes, and delayed wound healing. A more severe form of zinc deficiency can be inherited or acquired due to iatrogenic-induced zinc-free diet or severely impaired intestinal uptake. Acrodermatitis enteropathica is a rare autosomal recessive genetic disorder that results in impaired zinc absorption. In population surveys, the risk of zinc deficiency is considered to be elevated and of public health concern when the prevalence of low serum zinc concentrations is greater than 20%, the prevalence of inadequate intakes is greater than 25%, or the prevalence of stunting is at least 20%. In such cases, an intervention to improve population zinc status or increase dietary zinc intake is recommended. Approximately 17.3% of the world's population are at risk of inadequate intake of absorbable zinc, with the highest risk carried by countries in South and Southeast Asia, sub-Saharan Africa, and Central America. The global mortality burden due to zinc deficiency is of 116,000 deaths per year, the second most important cause of mortality due to micronutrient deficiency after vitamin A deficiency.
Smoke grenades are used during drills, police and military exercises, and crowd control. We report on a 25-year-old man who was exposed to a Superior 3C smoke bomb. He was initially stable but developed respiratory distress after 3 days and ultimately developed pulmonary fibrosis with marked loss in pulmonary function. The Superior 3C smoke bomb is similar in composition to the British Military's L83A1/2 and L132A1 and the US M18 smoke grenades, all commonly used as multipurpose smoke-producing devices for combat and training. They are primarily composed of zinc oxide and hexachlorethane, the combustion of which produces zinc chloride. These devices are safe when used properly in open air but can cause significant morbidity in an enclosed space. This case emphasizes the potential hazards of using smoke bombs even in semienclosed spaces and the potential delay in the development of significant pulmonary complications. 2018.
Although ending world hunger remains the most important goal, increasingly the focus is on simultaneously improving world malnutrition. Paradoxically, nutritionally important trace elements essential for human health are both deficient and over-abundant in soils in many regions of the world. Using a multidisciplinary approach, Development and Uses of Biofortified Agricultural Products provides new strategies and techniques for the production of biofortified agricultural products from different soils. Seventeen contributors from twelve countries explore the effects of environmental and biological factors on the accumulation and speciation of nutritionally important trace elements in agricultural products. They explore novel strategies regarding the functional foods and animal feed and other forms of biofortified agricultural products. The text addresses alternative biosources and bioproducts produced from phytoremediation processes as well as the bioavailability and the effects of bioproduct compounds. The editors comprehensively synthesize the ever-mounting body of new information on biofortification, including theoretical, practical, and practiced agricultural-based strategies in micronutrient management and improvement in different types of soils. The book provides a unique and useful platform to further the understanding of nutritionally important trace elements in the context of biogeochemistry, food chain transfer, and health-related issues.
Background
Despite growing evidence that early life experiences and exposures can impact child development, there is limited research on how prenatal and early life nutrition and early life parenting practices predict specific domains of child development in resource‐limited settings. This study examines the association between prenatal factors, birth outcomes, and early life characteristics with motor, cognitive/language, and socioemotional development in Tanzania.
Methods
We assessed motor, cognitive/language, and socioemotional development among a cohort of 198 children aged 20–39 months in Dar es Salaam, Tanzania, whose mothers were previously enrolled in a randomized, placebo‐controlled trial of prenatal vitamin A and zinc supplementation. Linear regression models were used to assess standardized mean differences in child development scores for randomized prenatal regimen and pregnancy, delivery, and early childhood factors.
Results
Children born to mothers randomized to prenatal vitamin A had significantly lower reported motor scores in minimally adjusted and multivariate analyses, −0.29 SD, 95% CI [−0.54, −0.04], p = 0.03, as compared with children whose mothers did not receive vitamin A. There was no significant effect of randomized prenatal zinc on any development domain. Greater caregiver–child stimulation was associated with 0.38 SD, 95% CI [0.14, 0.63], p < 0.01, better cognitive/language scores, whereas children who experienced both verbal and physical punishment had 0.29 SD, 95% CI [−0.52, −0.05], p = 0.02, lower scores in socioemotional development. Maternal completion of primary school was associated with higher reported motor and cognitive/language development. Further, children of mothers who were <155 cm tall had lower cognitive and language scores.
Conclusion
Prenatal vitamin A supplements in a setting with low levels of vitamin A deficiency may not provide child development benefits. However, integrated environmental, educational, parenting, and stimulation interventions may have large positive effects across child development domains in resource‐limited settings.
Background
Subclinical micronutrient deficiencies have been gradually becoming more important as a public health problem and drawing attention of the health authorities. Today it has been known that detecting and treating people having deficiency symptoms alone is no longer sufficient. It is important to detect and prevent any deficiency before it displays clinical manifestations. Zinc deficiency is one of the most widespread micronutrient deficiencies. In this study, we aimed to evaluate the zinc status and the associated factors in healthy school-age children. Methods
The study was carried out in schools in Altindag, the district of Ankara. A total of 1063 healthy children, 585 girls and 478 boys, aged 5-16 years were included in the study. Serum zinc, high-sensitivity C-reactive protein levels and white blood cell count were measured. A serum zinc level <65 μg/dL was considered as subclinical zinc deficiency for children <10 years of age. For children ≥10 years of age the cutoffs for serum zinc concentration were set at 66 μg/dL for females and 70 μg/dL for males. A questionnaire was developed to collect socioeconomic and demographic information of the participants. ResultsThe prevalence of subclinical zinc deficiency in children attending the study was detected to be 27.8%. This high ratio showed zinc deficiency was an important health problem in the Altindag district of Ankara, Turkey. Conclusion
Evaluating the indicators of zinc deficiency such as serum zinc concentration, dietary zinc intake and stunting prevalence, this study is the most comprehensive epidemiological study performed in children in Turkey. This study reveals the high prevalence of subclinical zinc deficiency and indicates that zinc deficiency is a public health concern for the study population.
The effect of administration of large amounts of zinc on immune response and serum lipoproteins was examined. Eleven healthy adult men ingested 150 mg of elemental zinc twice a day for six weeks. This was associated with a reduction in lymphocyte stimulation response to phytohemagglutinin as well as chemotaxis and phagocytosis of bacteria by polymorphonuclear leukocytes. Serum high-density lipoprotein concentration decreased significantly and low-density lipoprotein level increased slightly. The common food fad of zinc supplementation with resultant excessive intake could have deleterious effects in healthy persons.
(JAMA 1984;252:1443-1446)
The kidney is recognized as one of the most common target organs of toxicity of drugs and environmental chemicals. It is particularly susceptible because of the high blood flow to this organ relative to its mass and the unique property of renal tubular epithelium in concentrating urine and its constituents, including drugs and chemicals. The gold standard method for identification of renal toxicity potential of new products is light microscopic examination of the kidney, supplemented with renal function tests and biochemical biomarkers of renal cell injury in blood and urine. Purposely designed time-course studies that utilize ultrastructural pathology play a pivotal role in continued development of products exhibiting nephrotoxic potential. To refine the risk assessment, establishment of the cellular and subcellular organelle targets of xenobiotic injury by the pathologist forms a cornerstone in expanding the mechanistic understanding of the injury process. Demonstration of the pathogenesis of the full spectrum of toxic lesions enables the definition of primary or secondary changes and reversible, irreversible, or progressive processes. Through identification of cellular or subcellular organelle target sites, the most sensitive biomarkers can be identified to non-invasively monitor for the presence of a specific xenobiotic insult in laboratory animals and eventually in humans. This chapter emphasizes the structural and biochemical changes that occur in nephrotoxicity and the potential mechanisms involved. The rat is the species of focus, since it is the most important model in renal toxicologic pathology. Gross, microscopic, and ultrastructural anatomy is presented, followed by physiologic considerations, notable species, sex- and age-related differences in susceptibility to nephrotoxicity, and occurrence of common spontaneous renal diseases in laboratory animals. Screening strategies for new chemicals, potential mechanisms of renal injury, and the methods to characterize these mechanisms are reviewed on a sub-topographical basis using specific drug and chemical examples for illustration.
Clinical and experimental examinations showed a close relationship between zinc as an essential trace element and the immune system. Thus, cellular and humoral components from both the innate and the adaptive immune system are affected by zinc. Human zinc deficiencies are frequently connected with disturbed immune functions. Controlled zinc substitution results in a normalization of zinc serum levels, zinc homeostasis, and the immunological parameters. As shown in in vitro experiments, low zinc concentrations stimulate functional parameters of immune cells, but high zinc concentrations are suppressive or cytotoxic for these cells. Recently, the immunosuppressive effect of zinc was demonstrated in animal models of T-cell-dependent autoimmune diseases, like experimental autoimmune encephalomyelitis. Moreover, decreased serum/plasma zinc concentrations have been detected in patients with different autoimmune diseases. Prospective studies should verify the possibility of controlled immunosuppressive zinc therapies for these diseases.
A patient with the clinical history of recurring zinc fume fever underwent an experimental welding exposure; this resulted in a systemic reaction and a distinct self-limiting response in the periphery of the lung, demonstrated by pulmonary function tests and bronchoalveolar lavage. These pulmonary changes observed for the first time in man were reproducible.
Introduction:
Inhalational exposure to metal-containing fumes generated by welding and related processes may result in the development of the clinical syndrome known as "metal fume fever." Polymer fume fever is a separate and distinct but related disorder that has been associated with inhalational exposure to specific fluorinated polymer products, such as polytetrafluoroethylene or Teflon(®). We undertook a review of the peer-reviewed medical literature as it relates to these two disease entities in order to describe their epidemiology, pathophysiology, clinical presentation, diagnosis, treatment, prevention, and prognosis.
Methodology:
We performed a search of the PubMed ( www.pubmed.com ) and Ovid MEDLINE (ovidsp.tx.ovid.com) databases for keywords "metal fume fever," "polymer fume fever," and "fume fever," covering the period 1946 to September 2014, which resulted in a total of 141 citations. Limiting the search to articles published in the English language yielded 115 citations. These 115 articles were manually reviewed for relevance. In addition, the reference lists in each article retrieved were reviewed for additional relevant references. This left 48 relevant citations.
Epidemiology:
Metal fume fever occurs most commonly as an occupational disease in individuals who perform welding and other metal-joining activities for a living. It is estimated that 1,500-2,500 cases of metal fume fever occur annually in the United States. Polymer fume fever was initially identified as an occupational disease but increased regulations have resulted in decreased incidence in the occupational setting. Overheating of Teflon(®)-coated cookware is one of the more common mechanisms for exposure.
Pathophysiology:
While the precise pathophysiology associated with the development of metal fume fever is yet to be elucidated, suggested pathophysiologic mechanisms include pro-inflammatory cytokine release, neutrophil activation, and oxygen radical formation. The pathophysiologic mechanism for polymer fume fever has not been definitively elucidated but may involve similar mechanisms to those proposed for metal fume fever.
Clinical presentation:
Metal fume fever typically presents with generally non-specific complaints including influenza-like symptoms, fever, shaking chills, arthalgias, myalgias, headache, and malaise. Onset of symptoms typically occurs 4-10 h following the exposure to metal-containing fumes. While metal fume fever is typically benign and self-limited, severe cases of the disease have been reported. In patients with ongoing metal fume exposure over the course of a workweek, tachyphylaxis occurs resulting in improvement in symptoms over the course of the workweek and maximal symptoms occurring after an exposure-free period such as a weekend. The clinical presentation of polymer fume fever is indistinguishable from metal fume fever, with an exposure history being necessary to distinguish the two entities.
Diagnosis:
Chest radiographs are typically normal in cases of metal fume fever and polymer fume fever; however, mild vascular congestion may be demonstrated and severe cases may feature diffuse patchy infiltrates. Laboratory studies are typically not necessary but may demonstrate leukocytosis with leftward shift or an elevated erythrocyte sedimentation rate.
Treatment:
The primary treatment for both metal fume fever and polymer fume fever is supportive and directed at symptom relief. Oral hydration, rest, and the use of antipyretics and anti-inflammatory medications (e.g., non-steroidal anti-inflammatory drugs and aspirin) are recommended. A careful workplace exposure assessment analysis conducted by an occupational medicine specialist or clinical toxicologist in concert with a qualified industrial hygienist should be performed.
Prevention:
A careful workplace exposure assessment including measurement of ambient zinc and other metal (e.g., chrome, nickel, copper and manganese) fume concentrations or concentrations of fluorocarbon polymer decomposition products at different locations within the workplace should be performed.
Prognosis:
Metal fume fever is typically a benign and self-limited disease entity that resolves over 12-48 h following cessation of exposure.
Conclusions:
Metal and polymer fume fevers generally follow a benign course with spontaneous resolution of symptoms, though both have the potential to be serious, especially in those with significant preexisting cardiorespiratory disease.
Zinc deficiency is a significant public health problem in low- and middle-income countries. Zinc is essential for the formation and migration of neurons, along with the formation of neuronal interconnections called synapses. Its deficiency could interfere with the formation of neural pathways and neurotransmission, thus affecting behavior and development. Zinc supplementation provided to infants and children is a possible strategy to improve the mental and motor development of infants and children at high risk of zinc deficiency. The review authors searched the medical literature for studies that evaluated mental and motor development in infants and children randomly assigned to receive either zinc supplements or a 'placebo' (fake) supplement. We found 13 relevant studies. Eight studies measured development using the Mental Development Index and the Psychomotor Development Index of the Bayley Scales of Infant Development. We found no difference between the results for those who had taken zinc supplements and those who had taken a placebo. Two studies measured children's attainment of motor milestones. Again, no difference as found whether zinc supplements were taken or not. No study measured possible side effects of zinc supplementation such as vomiting, diarrhea or anemia. Overall, the results of the studies provided no convincing evidence that zinc supplements had any beneficial effect on mental and motor development in infants and children.
Presents a systems model for understanding the effects of self-produced locomotion on development. Four discrete subsystems or component processes (visual-vestibular adaptation, visual attention to changes in the environment, social referencing, and differentiation of emotions) are proposed that are functionally linked to the movements of the infant. Each process is shown to undergo a significant change following the onset of self-produced locomotion. Developmental changes in locomotor skill are also considered. The practical utility of the model is explored in an evaluation of how well it accounts for the relation between fear of heights and locomotor experience. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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Using a prospective study based on cases and controls selected from a geographical population, we have investigated the effects of housing on the health of very preterm infants ( 32 weeks’ gestation) during the first year of life. Information on health morbidity of the 117 preterm and 226 term babies was collected using a parent-held record, and housing data by a validated self-completion questionnaire. The most common health problems in the first year – upper (UR) and lower (LR) respiratory tract infection, otitis media (OM) and diarrhoea and vomiting (DV) – were all more frequent in the preterm group, There were no significant differences in the housing conditions to which preterm and control infants were exposed. Relative risks (RR) and 95% confidence intervals (CI) associated with each housing factor were calculated for preterm and control infants separately. Significant (P < 0.05) interaction effects were found for overcrowding and gas cooking. Overcrowding was associated with an increased incidence of LR [RR = 1.53; CI 0.96–2.42] and DV [RR = 1.57; CI 0.92–2.67] in the preterm, but with a decreased incidence of LR [RR = 0.28; CI 0.04–1.86] and DV [RR = 0.85; CI 0.30–2.38] in the term controls. The use of gas ovens was found to be associated in preterm infants with an increase in LR [RR = 1.48; CI 0.96–2.28] and DV [RR = 2.24; CI 1.28–3.93] but the controls did not show this effect for LR [RR = 0.67; CI 0.40–1.09] or DV [RR = 0.93; CI 0.56–1.56]. These associations are robust – even after allowing for confounding social factors – but causality has not been proved. This work suggests that preterm infants may be vulnerable to specific adverse housing factors, and further studies are now indicated to clarify potential mechanisms and interactive effects behind these associations.
Zinc is an important element in wound healing. Zinc compounds hasten the healing of gastric ulcers, by an unknown mechanism(s). We studied the effect of the induction of zinc deficiency on gastric ulcer healing. Rats were given a control or zinc-deficient diet for six weeks and then subjected to the induction of acetic acid-induced chronic gastric ulcers. Four days later, zinc-deficient rats were divided into two groups. In the first group, the zinc-deficient diet was continued. In the second group, the diet was changed to the control diet. Zinc-deficient rats had a mean serum zinc concentration approximately 70% of that in controls. Zinc deficiency did not affect the formation of gastric ulcers; however, it reduced cell proliferation by day 4 and delayed ulcer healing. Zinc supplementation brought zinc to control levels within a week, but failed to reverse the delay in ulcer healing. We conclude that zinc is crucial for healing of gastric ulcers, especially at the early stage.
Objectives: This study assessed the effects of zinc supplementation in the prevention of diarrhea and pneumonia with the use of a pooled analysis of randomized controlled trials in children in developing countries. Study design: Trials included were those that provided oral supplements containing at least one half of the United States Recommended Daily Allowance (RDA) of zinc in children <5 years old and evaluated the prevention of serious infectious morbidity through household visits. Analysis included 7 “continuous” trials providing 1 to 2 RDA of elemental zinc 5 to 7 times per week throughout the period of morbidity surveillance and 3 “short-course” trials providing 2 to 4 RDA daily for 2 weeks followed by 2 to 3 months of morbidity surveillance. The effects on diarrhea and pneumonia were analyzed overall and in subgroups defined by age, baseline plasma zinc concentration, nutritional status, and sex. The analysis used random effects hierarchical models to calculate odds ratios (OR) and 95% CIs. Results: For the zinc-supplemented children compared with the control group in the continuous trials, the pooled ORs for diarrheal incidence and prevalence were 0.82 (95% CI 0.72 to 0.93) and 0.75 (95% CI 0.63 to 0.88), respectively. Zinc-supplemented children had an OR of 0.59 (95% CI 0.41 to 0.83) for pneumonia. No significant differences were seen in the effects of the zinc supplement between the subgroups examined for either diarrhea or pneumonia. In the short-course trials the OR for the effects of zinc on diarrheal incidence (OR 0.89, 95% CI 0.62 to 1.28) and prevalence (OR 0.66, 95% CI 0.52 to 0.83) and pneumonia incidence (OR 0.74, 95% CI 0.40 to 1.37) were similar to those in the continuous trials. Conclusions: Zinc supplementation in children in developing countries is associated with substantial reductions in the rates of diarrhea and pneumonia, the 2 leading causes of death in these settings. (J Pediatr 1999;135:689-97)
In 4 young pediatric patients with presymptomatic Wilson disease, we found zinc monotherapy beginning at time of diagnosis to be safe and highly effective for follow-up intervals between 1 and 2 years. Such maintenance therapy with zinc can maintain urinary copper excretion between 1 and 3 μg · kg(-1) · day.
Chronic, excess zinc intake can result in copper deficiency and profound neurologic disease. However, when hyperzincemia is identified, the source often remains elusive. We identified four patients, one previously reported, with various neurologic abnormalities in the setting of hypocupremia and hyperzincemia. Each of these patients wore dentures and used very large amounts of denture cream chronically.
To determine zinc concentration in the denture creams used by the patients as a possible source of excess zinc ingestion.
Detailed clinical and laboratory data for each patient were compiled. Tubes of denture adhesives were analyzed for zinc content using dynamic reaction cell-inductively coupled plasma-mass spectrometry. Patients received copper supplementation. Copper and zinc levels were obtained post-treatment at varying intervals.
Zinc concentrations ranging from about 17,000 to 34,000 mug/g were identified in Fixodent and Poli-Grip denture creams. Serum zinc levels improved in three patients following cessation of denture cream use. Copper supplementation resulted in mild neurologic improvement in two patients who stopped using denture cream. No alternative source of excess zinc ingestion or explanation for hypocupremia was identified.
Denture cream contains zinc, and chronic excessive use may result in hypocupremia and serious neurologic disease.
The common cold is one of the most widespread illnesses and is a leading cause of visits to the doctor and absenteeism from school and work. Trials conducted since 1984 investigating the role of zinc for the common cold symptoms have had mixed results. Inadequate treatment masking and reduced bioavailability of zinc from some formulations have been cited as influencing results.
To assess the effect of zinc on common cold symptoms.
We searched CENTRAL (2010, Issue 2) which contains the Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to May week 3, 2010) and EMBASE (1974 to June 2010).
Randomised, double-blind, placebo-controlled trials using zinc for at least five consecutive days to treat, or for at least five months to prevent the common cold.
Two review authors independently extracted data and assessed trial quality.
We included 13 therapeutic trials (966 participants) and two preventive trials (394 participants). Intake of zinc is associated with a significant reduction in the duration (standardized mean difference (SMD) -0.97; 95% confidence interval (CI) -1.56 to -0.38) (P = 0.001), and severity of common cold symptoms (SMD -0.39; 95% CI -0.77 to -0.02) (P = 0.04). There was a significant difference between the zinc and control group for the proportion of participants symptomatic after seven days of treatment (OR 0.45; 95% CI 0.2 to 1.00) (P = 0.05). The incidence rate ratio (IRR) of developing a cold (IRR 0.64; 95% CI 0.47 to 0.88) (P = 0.006), school absence (P = 0.0003) and prescription of antibiotics (P < 0.00001) was lower in the zinc group. Overall adverse events (OR 1.59; 95% CI 0.97 to 2.58) (P = 0.06), bad taste (OR 2.64; 95% CI 1.91 to 3.64) (P < 0.00001) and nausea (OR 2.15; 95% CI 1.44 to 3.23) (P = 0.002) were higher in the zinc group.
Zinc administered within 24 hours of onset of symptoms reduces the duration and severity of the common cold in healthy people. When supplemented for at least five months, it reduces cold incidence, school absenteeism and prescription of antibiotics in children. There is potential for zinc lozenges to produce side effects. In view of this and the differences in study populations, dosages, formulations and duration of treatment, it is difficult to make firm recommendations about the dose, formulation and duration that should be used.
To evaluate zinc status in Alzheimer's disease and Parkinson's disease, 29 patients with Alzheimer's disease, 30 patients with Parkinson's disease, and 29 age- and sex-matched controls were studied. All patients and controls were older than age 50, and all zinc and copper supplements were prohibited beginning 30 days prior to study. Patients were diagnosed by standard criteria. Blood zinc and urine zinc were measured. Urine zinc was measured in a casual specimen, standardized for dilution by reference to creatinine content. Results showed a significantly lower blood zinc in patients with Alzheimer's and patients with Parkinson's than in controls. Urine zinc excretion, normalized to urine creatinine excretion, was not significantly different in either patient group compared to controls. These patients are probably zinc deficient because of nutritional inadequacy.
A 7-day reduction in duration of common colds was shown by Eby et al. in 1984 using 23mg zinc gluconate throat lozenges. Over the following 25years, 14 double-blind, placebo-controlled, randomized clinical trials produced widely differing results with about one-half showing success and the remainder showing failure. Positively charged, ionic zinc (iZn), but not bound zinc, is strongly astringent, antirhinoviral, increases interferon-gamma (IFN-gamma) 10-fold, inhibits intercellular adhesion molecule-1 (ICAM-1) and inhibits the release of vasoactive ingredients from mast cell granules. Solution equilibrium chemistry analytical techniques showed lozenge iZn fraction varying from 0% to 100% of total lozenge zinc between trials, with zinc acetate (ZA) releasing 100% iZn, zinc gluconate (ZG) releasing 72% iZn and other zinc compounds releasing much less or none at physiologic pH 7.4. Since only iZn has in vitro benefits, iZn variations are hypothesized to have produced the widely varying clinical results. In support of the iZn hypothesis, lozenge iZn and total daily iZn in trials were found highly correlated with reductions in common cold durations with statistical significance for mean duration (P<0.001) and median duration (P<0.004), while total zinc (iZn plus bound) showed no correlation with changes in duration. Duration reductions (mean 0 days, median 0.43 days) for multi-ligand ZG and ZA lozenges differed significantly from duration reductions (mean 3.37 days, median 2.9 days) for single ligand ZA and ZG lozenges (P<0.001) showing that additive ligands as flavor-masks damaged or eliminated efficacy. Five of 6 trials with lozenges whose zinc compositions had a first stability constant of 1.7 or less succeeded, while only 2 of 9 trials of lozenges with higher stability succeeded (P<0.02). From the strong, multiple statistical relationships found, it is inferred that iZn is the active ingredient in zinc lozenges for colds, as it is in vitro against rhinoviruses, and that solution chemistry analytical techniques used at physiological pH are correct means for lozenge iZn analysis. Zinc lozenges slowly dissolving in the mouth over a 20-30 min period releasing adequate iZn (18 mg) used each 2h are hypothesized to shorten common colds by 6-7 days, which is a cure for the common cold. Due to inadequate lozenge iZn very few of more than 40 different brands of zinc lozenges on the US market are expected to have any effect on the duration or severity of common colds.
Zinc plays an essential role in numerous biochemical pathways. Zinc deficiency affects many organ systems, including the integumentary, gastrointestinal, central nervous system, immune, skeletal, and reproductive systems. This article aims to discuss zinc metabolism and highlights a few of the diseases associated with zinc deficiency.
Zinc deficiency results in dysfunction of both humoral and cell-mediated immunity and increases the susceptibility to infection. Supplementation of zinc has been shown to reduce the incidence of infection as well as cellular damage from increased oxidative stress. Zinc deficiency is also associated with acute and chronic liver disease. Zinc supplementation protects against toxin-induced liver damage and is used as a therapy for hepatic encephalopathy in patients refractory to standard treatment. Zinc deficiency has also been implicated in diarrheal disease, and supplementation has been effective in both prophylaxis and treatment of acute diarrhea.
This article is not meant to review all of the disease states associated with zinc deficiency. Rather, it is an introduction to the influence of the many roles of zinc in the body, with an extensive discussion of the influence of zinc deficiency in selected diseases. Zinc supplementation may be beneficial as an adjunct to treatment of many disease states.