Factors influencing zinc status of apparently healthy indians.
TL;DR: RBCMZn was a more sensitive indicator of long-term zinc status than plasma zinc and SOD and showed negative association with iron and family size.
Abstract: Objectives: To identify dietary, environmental and socio-economic factors associated with mild zinc deficiency, three zinc status indices; erythrocyte membrane zinc (RBCMZn), plasma zinc and super oxide dismutase (SOD) were assessed in free living and apparently healthy Indian population.Methods: Dietary patterns of 232 men and 223 women (20–65 yr) from rural, industrial and urban regions of Western India were evaluated by food frequency questionnaire. RBCMZn was estimated using atomic absorption spectrometry, hemoglobin and serum ceruloplasmin by spectrophotometer. On a sub sample (48 men and 51 women) plasma zinc and SOD were also assessed.Results: Mean RBCMZn was 0.5 ± 0.1 μmols/g protein with 46% individuals showing zinc deficiency. Mean plasma zinc was 0.98 ± 0.12 μg/mL with 25% men and 2.5% women having values below normal range. Mean SOD was 0.97 ± 0.1 (u/mL cells). A significant positive correlation was observed between intakes of green leafy vegetables, other vegetables and milk products with RBC...
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TL;DR: Dietary practices that increase zinc bioavailability, the consumption of foods fortified with zinc or low-dose supplementation are strategies that should be considered for improving the zinc status of vegetarians with low zinc intakes or serum zinc concentrations at the lower end of the reference range.
Abstract: Plant-based diets contain less saturated fat and cholesterol and more folate, fibre and phytochemicals than omnivorous diets, but some micronutrients, especially zinc, are poorly bioavailable. The findings of studies exploring the zinc intake and zinc status in populations that habitually consume vegetarian diets are inconsistent. This study aims to investigate the effects of plant-based diets on dietary zinc intake and status in humans using systematic review and meta-analysis techniques. Thirty-four studies were included in the systematic review. Of these, 26 studies (reporting 48 comparisons) compared males and/or females consuming vegetarian diets with non-vegetarian groups and were included in meta-analyses. Dietary zinc intakes and serum zinc concentrations were significantly lower (−0.88 ± 0.15 mg day−1, P < 0.001 and −0.93 ± 0.27 µmol L−1, P = 0.001 respectively; mean ± standard error) in populations that followed habitual vegetarian diets compared with non-vegetarians. Secondary analyses showed greater impact of vegetarian diets on the zinc intake and status of females, vegetarians from developing countries and vegans. Populations that habitually consume vegetarian diets have low zinc intakes and status. Not all vegetarian categories impact zinc status to the same extent, but a lack of consistency in defining vegetarian diets for research purposes makes dietary assessment difficult. Dietary practices that increase zinc bioavailability, the consumption of foods fortified with zinc or low-dose supplementation are strategies that should be considered for improving the zinc status of vegetarians with low zinc intakes or serum zinc concentrations at the lower end of the reference range. © 2013 Society of Chemical Industry
76 citations
TL;DR: Zinc, vitamin B(12), and iron constitute the principal micronutrient deficiencies in these women and existing supplementation programs should be extended to include 18- to 30-y-old nonpregnant women as the majority of childbearing occurs within this timeframe.
55 citations
Cites background from "Factors influencing zinc status of ..."
...These low serum zinc concentrations could be attributed to a low zinc intake [25,26], the poor bioavailability of zinc, and a high phytate content of the traditional Indian cereal-pulse-based diets [27]....
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TL;DR: Zinc homeostasis can be different in different age groups and depends on sex, thus zinc dyshomeostasis refers to changes in its metabolism that deviate from the normal rates for a particular age group and sex.
Abstract: To accomplish its multifunctional biological roles, zinc requires precise homeostatic mechanisms. There are efficient mechanisms that regulate zinc absorption from the alimentary tract and its excretion by the kidney depending on the organism demands. The regulatory mechanisms of cellular zinc inflow, distribution, and zinc outflow are so efficient that symptoms of zinc deficiency are rare, and symptoms connected with its massive accumulation are even more rare. The efficiency of homeostatic mechanisms that prevent zinc deficiency or excessive zinc accumulation in the organism is genetically conditioned. It seems that an essential element of zinc homeostasis is the efficiency of zinc transmembrane exchange mechanisms. Intracellular free zinc concentration is higher than in extracellular space. Physiologically, the active outflow of zinc ions from the cell depends on the increase of its concentration in extracellular space. The ion pumps activity depends on the efficiency by which the cell manages energy. Considering the fact that zinc deficiency accelerates apoptosis and that excessive zinc accumulation inside cells results in a toxic effect that forces its death brings about several questions: Is intensification and acceleration of changes in zinc metabolism with age meaningful? Is there a real zinc deficiency occurring with age or in connection with the aforementioned pathological processes, or is it just a case of tissue and cell redistribution? When discussing factors that influence zinc homeostasis, can we consider zinc supplementation or regulation of zinc balance in the area of its redistribution? To clarify these aspects, an essential element will also be the clear understanding of the nomenclature used to describe changes in zinc balance. Zinc homeostasis can be different in different age groups and depends on sex, thus zinc dyshomeostasis refers to changes in its metabolism that deviate from the normal rates for a particular age group and sex. This concept is very ample and implies that zinc deficiency may result from a low-zinc diet, poor absorption, excessive loss of zinc, zinc redistribution in intra- and extracellular compartments, or a combination of these factors that is inadequate for the given age and sex group. Such factor or factors need to be considered for preventing particular homeostasis disorders (or dyshomeostasis). Regulation of zinc metabolism by influencing reversal of redistribution processes ought to be the main point of pharmacologic and nonpharmacologic actions to reestablish zinc homeostasis. Supplementation and chelation are of marginal importance and can be used to correct long-term dietary zinc deficiency or zinc poisoning or in some cases in therapeutic interventions. In view of its biological importance, the problem posed by the influence of zinc metabolism requires further investigation. To date, one cannot consider, for example, routine zinc supplementation in old age, because changes of metabolism with age are not necessarily a cause of zinc deficiency. Supplementation is warranted only in cases in which deficiency has been established unambiguously. An essential element is to prevent sudden changes in zinc metabolism, which lead to dyshomeostasis in the terms defined here. The primary prophylaxes, regular physical activity, efficient treatment of chronic diseases, are all elements of such prevention.
41 citations
TL;DR: Zn may have a therapeutic potential in treatment of oxidative liver damage along with enhanced nicotinic acid absorption and there was no influence on riboflavin and ascorbic acid status.
Abstract: Dietary zinc (Zn) status exerts a powerful influence on the degree of oxidative damage caused by free radicals. We examined the effect of dietary Zn variations with oxidative stress (OS) treatment on antioxidant status, liver function, and status of vitamins in male Wistar rats. Oxidative stress was generated by intraperitoneal injections of tert-butyl hydroperoxide; and dietary Zn variations done were Zn deficient, normal, and excess, with 8, 30, and 60 mg Zn per kilogram diet, respectively. After 21-day dietary regimen, the animals were killed; and plasma aspartate aminotransferase, alanine aminotransferase, hepatic antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase), Zn, reduced glutathione, lipid peroxidation (LPO), and hepatic riboflavin, nicotinic acid, and ascorbic acid estimations were done. The alanine aminotransferase and aspartate aminotransferase levels were elevated in rats with OS and Zn-deficient diet, which were restored to normal levels with excess dietary Zn. Hepatic antioxidant enzymes and reduced glutathione levels were significantly decreased with concomitant increase in LPO due to OS induction in animals with Zn-deficient diet. Corresponding enhanced enzyme activities, higher hepatic Zn, and lowered LPO were observed in animals with normal- and excess-Zn diet. A dose-dependent increase in hepatic nicotinic acid accumulation was observed as the dietary Zn level increased from deficient to excess; however, there was no influence on riboflavin and ascorbic acid status. The results suggest that Zn may have a therapeutic potential in treatment of oxidative liver damage along with enhanced nicotinic acid absorption.
30 citations
Cites result from "Factors influencing zinc status of ..."
...Our previous studies with erythrocytes, Caco-2 cells, hepatocytes, mice, and humans [13-20] have demonstrated effect of water-soluble vitamins on Zn bioavailability, indicating interactions between them....
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TL;DR: The findings of this cross-sectional study indicated that dietary zinc intake was inversely associated with hyperuricaemia in middle-aged and older males, but not in females.
Abstract: Objective To examine the associations between dietary zinc intake and hyperuricaemia. Design Cross-sectional study. Setting This study was conducted in a health examination centre of China. Participants A total of 5168 middle-aged and older participants (aged 40 years or above) (2697 men and 2471 women) were included. Outcome measures Dietary zinc intake was assessed using a validated semiquantitative food frequency questionnaire. Hyperuricaemia was defined as uric acid ≥416 µmol/L for males and ≥360 µmol/L for females. Results For males, the prevalence of hyperuricaemia was 22.9%. After adjusting for age, body mass index (BMI) and energy intake, the ORs were 0.68 (95% CI 0.45 to 0.92) in the second quintile, 0.63 (95% CI 0.45 to 0.89) in the third quintile, 0.68 (95% CI 0.46 to 1.00) in the fourth quintile and 0.55 (95% CI 0.35 to 0.87) in the fifth quintile comparing the lowest quintile of Zn intake, respectively (p for trend=0.03). In the multivariable adjusted model, the relative odds of hyperuricaemia were significantly decreased by 0.71 times in the second quintile of zinc intake (OR 0.71, 95% CI 0.52 to 0.98), 0.64 times in the third quintile (OR 0.65, 95% CI 0.44 to 0.94) and 0.55 times in the fifth quintile (OR 0.56, 95% CI 0.32 to 0.97) compared with those in the lowest quintile, and p for trend was 0.064. For females, the prevalence of hyperuricaemia was 10.0%, and unadjusted, minimally adjusted as well as multivariable adjusted ORs all suggested no significant association between dietary zinc intake and hyperuricaemia. Conclusions The findings of this cross-sectional study indicated that dietary zinc intake was inversely associated with hyperuricaemia in middle-aged and older males, but not in females. The association was significant after considering the influence of age, BMI and energy intake, and after that, minimum adjustment remained independent of further confounding factors such as vitamin C intake, alcohol drinking status and nutrient supplementation.
28 citations
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TL;DR: Zinc clearly has an important role in infant and childhood infectious diseases; programs to increase the intake of zinc among deficient populations are needed.
Abstract: Zinc is an essential micronutrient for human growth, development, and immune function. Zinc deficiency impairs overall immune function and resistance to infection. Mild to moderate zinc deficiency can be best detected through a positive response to supplementation trials. Zinc supplementation has been shown to have a positive effect on the incidence of diarrhea (18% reduction, 95% CI: 7-28%) and pneumonia (41% reduction, 95% CI: 17-59%), and might lead to a decrease in the incidence of malaria. Zinc has also proven to decrease the duration of diarrhea by 15% (95% CI: 5-24%). Maternal zinc supplementation may lead to a decrease in infant infections. Studies assessing the role of zinc supplementation among persons with HIV, tuberculosis, and the common cold have not been conclusive. Two studies have shown zinc supplementation to decrease child mortality by more than 50%. Zinc clearly has an important role in infant and childhood infectious diseases; programs to increase the intake of zinc among deficient populations are needed.
470 citations
"Factors influencing zinc status of ..." refers background in this paper
...The deficiency of zinc, an essential micronutrient for human growth, development, and immune function, impairs overall immune function and resistance to infection [14,15]....
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TL;DR: Analysis of available methods of evaluating zinc status in individuals and populations indicates that nearly half of the world's population is at risk for inadequate zinc intake, suggesting that public health programs are urgently needed to control zinc deficiency.
Abstract: This paper summarizes recent research on the importance of zinc for human health, and reviews available methods of evaluating zinc status in individuals and populations. The lack of generally accepted biomarkers of zinc status has impeded estimation of the global prevalence of zinc deficiency. Although measurement of zinc consumption and/or plasma zinc concentration can be used to assess population zinc status, few countries have collected adequate data to permit estimation of the prevalence of zinc deficiency. An alternative method, described herein, is to estimate the zinc content of national food supplies, using FAO food balance sheets; the assumed bioavailability of that zinc based on phytate: zinc molar ratios; and the relation between absorbable zinc and theoretical requirements according to country-specific demographics. The results of these analyses indicate that nearly half of the world's population is at risk for inadequate zinc intake, suggesting that public health programs are urgently needed ...
405 citations
"Factors influencing zinc status of ..." refers background in this paper
...It has been stipulated that nearly half of the world’s population is at the risk of inadequate zinc intake suggesting that public health programmes are urgently needed to control zinc deficiency [1]....
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TL;DR: Understanding of the dietary, physiologic, pathologic and environmental factors that may adversely affect these processes, and therefore zinc homeostasis, will be critical to preventing and treating zinc deficiency in human populations.
Abstract: Zinc homeostasis is primarily maintained via the gastrointestinal system by the processes of absorption of exogenous zinc and gastrointestinal secretion and excretion of endogenous zinc. Although these processes modulate net absorption and the size of the readily exchangeable zinc pools, there are limits to the effectiveness of the homeostatic mechanisms of these and other systems. As a result of the interplay of the subcellular regulation of these mechanisms and host, dietary and environmental factors, zinc deficiency is not uncommon, especially on a global basis. This overview briefly reviews current understanding about the subcellular mechanisms of zinc absorption and transport. Factors recognized to affect zinc absorption at the whole body level are reviewed and include the amount and form of zinc consumed; dietary promoters, such as animal protein and low-molecular-weight organic compounds; dietary inhibitors, such as phytate and possibly iron and calcium when consumed as supplements; and physiologic states, such as pregnancy, lactation and early infancy, all of which increase the demand for absorbed zinc. The control of endogenously secreted zinc is less well understood. Available data suggest that the quantity of secreted zinc with each meal may be considerable and that efficient reabsorption is critical to the maintenance of normal zinc balance. Factors that have been proposed to interfere with the normal reabsorption of endogenous zinc include phytate and unabsorbed fat. Understanding of the dietary, physiologic, pathologic and environmental factors that may adversely affect these processes, and therefore zinc homeostasis, will be critical to preventing and treating zinc deficiency in human populations.
329 citations
TL;DR: Vitamin A and beta-carotene may form a complex with iron, keeping it soluble in the intestinal lumen and preventing the inhibitory effect of phytates and polyphenols on iron absorption.
Abstract: After the rapid decrease in the prevalence of iron deficiency and iron-deficiency anemia in the Venezuelan population when a national program for fortification of flours with iron and vitamins was instituted, we studied micronutrient interactions in Venezuelan diets. One hundred human adults were fed three cereal-based diets, labelled with either 59Fe or 55Fe in six studies. Each diet contained different concentrations of vitamin A (from 0.37 to 2.78 micromol/100 g cereal) or beta-carotene (from 0.58 to 2.06 micromol/100 g cereal). The presence of vitamin A increased iron absorption up to twofold for rice, 0.8-fold for wheat and 1.4-fold for corn. beta-carotene increased absorption more than threefold for rice and 1.8-fold for wheat and corn, suggesting that both compounds prevented the inhibitory effect of phytates on iron absorption. Increasing the doses of vitamin A or beta-carotene did not further significantly increase iron absorption. We measured the iron remaining in solution performing in vitro studies in which the pH of solutions was adjusted from 2 to 6 in the presence of vitamin A or beta-carotene. All of the iron from ferrous fumarate was soluble after changing the pH of the solution containing 3.4 micromol of beta-carotene to 6.0. Vitamin A was less effective. However, 78 +/- 18% of iron was soluble in the presence of 3.3 micromol of vitamin A, whereas with no vitamin addition, only 26 +/- 13% of iron was soluble (<0.05). Vitamin A and beta-carotene may form a complex with iron, keeping it soluble in the intestinal lumen and preventing the inhibitory effect of phytates and polyphenols on iron absorption.
298 citations
"Factors influencing zinc status of ..." refers background in this paper
...Vitamin A and beta-carotene can improve nonheme iron absorption from rice, wheat, and corn by humans [26]....
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