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Ceballos-Rasgado M, Lowe NM, Mallard S, Clegg A, Moran VH, Harris C, Montez J, Xipsiti M. Adverse Effects of Excessive Zinc Intake in Infants and Children Aged 0-3 Years: A Systematic Review and Meta-Analysis. Adv Nutr 2022; 13:2488-2518. [PMID: 36055780 PMCID: PMC9776731 DOI: 10.1093/advances/nmac088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/18/2022] [Accepted: 08/17/2022] [Indexed: 01/29/2023] Open
Abstract
Zinc supplementation reduces morbidity, but evidence suggests that excessive intakes can have negative health consequences. Current guidelines of upper limits (ULs) of zinc intake for young children are extrapolated from adult data. This systematic review (PROSPERO; registration no. CRD42020215187) aimed to determine the levels of zinc intake at which adverse effects are observed in young children. Studies reporting potential adverse effects of zinc intake in children aged 0-3 y were identified (from inception to August 2020) in MEDLINE, Embase, and the Cochrane Library, with no limits on study design. Adverse clinical and physical effects of zinc intake were synthesized narratively, and meta-analyses of biochemical outcomes were conducted. Random effects models were used to generate forest plots to examine the evidence by age category, dose, dose duration, chemical formula of zinc, and zinc compared with placebo. The Joanna Briggs Institute Critical Appraisal Checklist, Cochrane Risk of Bias 2, and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) guideline were employed to assess risk of bias and to appraise the certainty of evidence. Fifty-eight studies assessed possible adverse effects of zinc doses ranging from 3 to 70 mg/d. Data from 39 studies contributed to meta-analyses. Zinc supplementation had an adverse effect on serum ferritin, plasma/serum copper concentration, serum transferrin receptor, hemoglobin, hematocrit, and the odds of anemia in ≥1 of the subgroups investigated. Lactulose:mannitol ratio was improved with zinc supplementation, and no significant effect was observed on C-reactive protein, erythrocyte superoxide dismutase, zinc protoporphyrin, blood cholesterol, and iron deficiency anemia. The certainty of the evidence, as assessed using GRADE, was very low to moderate. Although possible adverse effects of zinc supplementation were observed in some subgroups, it is unclear whether these findings are clinically important. The synthesized data can be used to undertake a dose-response analysis to update current guidelines of ULs of zinc intake for young children.
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Affiliation(s)
- Marena Ceballos-Rasgado
- Centre for Global Development, University of Central Lancashire, Preston, Lancashire, United Kingdom
| | | | | | - Andrew Clegg
- Synthesis, Economic Evaluation and Decision Science (SEEDS) Group, Applied Health Research Hub, University of Central Lancashire, Preston, Lancashire, United Kingdom
| | - Victoria H Moran
- Centre for Global Development, University of Central Lancashire, Preston, Lancashire, United Kingdom
| | - Catherine Harris
- Synthesis, Economic Evaluation and Decision Science (SEEDS) Group, Applied Health Research Hub, University of Central Lancashire, Preston, Lancashire, United Kingdom
| | - Jason Montez
- Department of Nutrition and Food Safety, World Health Organization, Geneva, Switzerland
| | - Maria Xipsiti
- Food and Nutrition Division, Food and Agriculture Organization of the United Nations, Rome, Italy
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Prevalence and associated factors of iron deficiency in Spanish children aged 1 to 11 years. Eur J Pediatr 2021; 180:2773-2780. [PMID: 33759019 DOI: 10.1007/s00431-021-04037-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 03/15/2021] [Accepted: 03/17/2021] [Indexed: 01/01/2023]
Abstract
Iron deficiency (ID) is the most common nutritional deficiency affecting children worldwide. Most traditional laboratory parameters to assess ID can be altered by infections or other inflammatory states, including obesity. The aims of this study were to determine the prevalence of ID in healthy children and to analyse associated factors, avoiding potential confounding factors through the use of serum transferrin receptor (sTfR), reticulocyte haemoglobin content and sTfR/log ferritin index. A cross-sectional population-based study was conducted on 951 children aged 1 to 11 years in Almería (Spain). ID was detected in 7.7% of children and iron deficiency anaemia in 0.9%. Multivariate analysis identified the following as independent risk factors: age under 5 years (OR: 2.2, 95% CI: 1.35-3.6); excessive consumption of cow's milk and dairy products (OR: 1.87, 95% CI: 1.13-3.1); and insufficient consumption of vegetables (OR: 2.7, 95% CI: 1.2-6.1).Conclusions: Using a combination of iron status parameters with greater discriminatory power than classical measures, this study detected a considerable iron deficiency prevalence in Spanish children. Younger children and specific dietary habits exhibit a particular risk for ID, so special attention should be paid to this population. What is Known: • Iron deficiency remains the most prevalent nutritional deficit worldwide, and children aged under 3 years are the most vulnerable to this condition. • Accurate assessment of iron status, based on a combination of biochemical indicators, can often be complicated. What is New: • Iron deficiency continues to present a health problem in Spanish children aged 1 to 11 years, considering the serum transferrin receptor and reticulocyte haemoglobin content for diagnosis. • Excessive consumption of dairy products and low consumption of vegetables are independent risk factors for iron deficiency.
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Restrepo-Gallego M, Díaz LE, Rondó PHC. Classic and emergent indicators for the assessment of human iron status. Crit Rev Food Sci Nutr 2020; 61:2827-2840. [PMID: 32619106 DOI: 10.1080/10408398.2020.1787326] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Iron deficiency is the leading cause of anemia, a significant global public health problem. Different methods exist for assessing iron nutritional status, including laboratory tests that focus on storage, transportation, and iron functional compartment parameters. Classical markers such as bone marrow, serum iron, ferritin, hemoglobin, erythrocyte parameters, transferrin, transferrin receptors, and zinc protoporphyrin are discussed in this review. Additional parameters calculated from these indicators, including transferrin saturation, ferritin index and Thomas plot, and some emergent parameters such as hepcidin, erythroferrone, and low hemoglobin density are also discussed. There is no a single indicator for assessing iron nutritional status. Therefore, the use of more than one indicator may be the best practice to obtain the correct diagnosis, also considering the influence of inflammation/infection on many of these indicators. The constant validation of the current parameters, the improvement of assessment methods, and the identification of new indicators will be the key to refine the assessment of iron nutritional status and the right choice of treatment for its improvement.
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Affiliation(s)
| | - Luis E Díaz
- Doctorate Program in Bioscience, La Sabana University, Chía, Colombia
| | - Patrícia H C Rondó
- Department of Nutrition, School of Public Health, University of São Paulo, São Paulo, Brazil
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The usefulness of reticulocyte haemoglobin content, serum transferrin receptor and the sTfR-ferritin index to identify iron deficiency in healthy children aged 1-16 years. Eur J Pediatr 2019; 178:41-49. [PMID: 30264352 DOI: 10.1007/s00431-018-3257-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 06/21/2018] [Accepted: 09/17/2018] [Indexed: 01/23/2023]
Abstract
This cross-sectional study, conducted on a population-based representative sample, evaluates the usefulness of reticulocyte haemoglobin content (CHr), serum transferrin receptor (sTfR) and sTfR/log ferritin (sTfR-F index) to recognise iron deficiency (ID) without anaemia, provides specific cut-off points for age and gender, and proposes a new definition of ID. A total of 1239 healthy children and adolescents aged 1-16 years were included. Complete blood count, iron biomarkers, erythropoietin, C-reactive protein, CHr, sTfR, and sTfR-F index were determined. ROC curves were obtained and sensitivity, specificity, predictive values, likelihood ratios, and accuracy for each specific cut-off points were calculated. Seventy-three had ID without anaemia. Area under the curve for sTfR-F index, sTfR and CHr were 0.97 (CI95% 0.95-0.99), 0.87 (CI95% 0.82-0.92) and 0.68 (CI95% 0.61-0.74), respectively. The following cut-off points defined ID: sTfR-F Index > 1.5 (1-5 years and 12-16 years boys) and > 1.4 (6-11 years and 12-16 years girls); sTfR (mg/L) > 1.9 (1-5 years), > 1.8 (6-11 years), > 1.75 (12-16 years girls) and > 1.95 (12-16 years boys); and CHr (pg) < 27 (1-5 years) and < 28.5 (6-16 years).Conclusions: CHr, sTfR and the sTfR-F index are useful parameters to discriminate ID without anaemia in children and adolescents, and specific cut-off values have been established. The combination of these new markers offers an alternative definition of ID with suitable discriminatory power. What is Known: • In adults, reticulocyte haemoglobin content (CHr), serum transferrin receptor (sTfR) and sTfR/log ferritin index (sTfR-F index) have been evaluated and recognised as reliable indicators of iron deficiency (ID). • Clinical manifestations of ID may be present in stages prior to anaemia, and the diagnosis of ID without anaemia continues to pose problems. What is New: • CHr, sTfR and the sTfR-F index are useful parameters in diagnosis of ID in childhood and adolescence when anaemia is not present. • We propose a new strategy for the diagnosis of ID in childhood and adolescence, based on the combination of these measures, which offer greater discriminatory power than the classical parameters.
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The prevalence and factors associated with stunting among infants aged 6 months in a peri-urban South African community. Public Health Nutr 2017; 20:3209-3218. [PMID: 28879827 DOI: 10.1017/s1368980017002087] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To determine the prevalence and factors associated with stunting in 6-month-old South African infants. DESIGN This cross-sectional study was part of the baseline of a randomized controlled trial. Weight-for-length, length-for-age and weight-for-age Z-scores were based on the WHO classification. Blood samples were analysed for Hb, plasma ferritin and soluble transferrin receptor (sTfR). Socio-economic, breast-feeding and complementary feeding practices were assessed by questionnaire. Setting/Subjects Infants aged 6 months (n 750) from a peri-urban area of Matlosana Municipality, North West Province of South Africa. RESULTS Stunting, underweight, wasting and overweight affected 28·5, 11·1, 1·7 and 10·1 % of infants, respectively. Exclusive breast-feeding to 6 months of age was reported in 5·9 % of the infants. Multivariable binary logistic regression showed that birth weight (OR=0·12; 95 % CI 0·07, 0·21, P8·3 mg/l) concentrations. CONCLUSIONS The association between stunting and lower birth weight, shorter maternal height and male sex reflects possibly the intergenerational origins of stunting. Therefore, interventions that focus on improving preconceptual and maternal nutritional status, combined with strategies to promote appropriate infant feeding practices, may be an important strategy to prevent stunting in vulnerable settings.
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Schümann K, Solomons NW. Perspective: What Makes It So Difficult to Mitigate Worldwide Anemia Prevalence? Adv Nutr 2017; 8:401-408. [PMID: 28507005 PMCID: PMC5421119 DOI: 10.3945/an.116.013847] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Anemia can be related to decreased production or increased loss of erythrocytes, or both, leading to many underlying and often overlapping causes. A largely cereal-based diet with plenty of phytates, polyphenols, and other ligands that inhibit intestinal iron absorption predominated in preindustrial Europe and predominates in present-day developing countries alike. In both situations, we find poor hygienic conditions, which frequently lead to anemia of inflammation. The large number of possible causes and their interaction shows why it is so difficult to mitigate anemia prevalence. Diagnostic biomarkers are required to differentiate the different types of anemia and to treat them appropriately. Some of them are well established in adults [e.g., concentrations of serum ferritin, soluble transferrin receptor (sTfR), and serum iron or the ratio of sTfR to log ferritin]. Others, such as serum hepcidin, hold considerable promise, although they are not yet widely used. A particular issue is to establish reference values for biomarkers in infants and children at different ages. The fact that resource-rich postindustrial societies have a very low prevalence of iron-deficiency anemia offers hope that common types of anemia can be eliminated. In contrast, inborn forms of anemia, such as thalassemia, and anemias related to underlying diseases (e.g., bleeding tumors or peptic ulcers, gynecologic blood losses, or renal diseases) require an operational health system to be addressed appropriately.
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Affiliation(s)
- Klaus Schümann
- Molecular Nutrition Unit, Central Institute for Nutrition and Food Science, Research Center for Nutrition and Food Science, Technische Universität München, Freising, Germany; and
| | - Noel W Solomons
- Center for Studies of Sensory Impairment, Aging, and Metabolism (CeSSIAM), Guatemala City, Guatemala
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Goheen MM, Wegmüller R, Bah A, Darboe B, Danso E, Affara M, Gardner D, Patel JC, Prentice AM, Cerami C. Anemia Offers Stronger Protection Than Sickle Cell Trait Against the Erythrocytic Stage of Falciparum Malaria and This Protection Is Reversed by Iron Supplementation. EBioMedicine 2016; 14:123-130. [PMID: 27852523 PMCID: PMC5161422 DOI: 10.1016/j.ebiom.2016.11.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 11/05/2016] [Accepted: 11/07/2016] [Indexed: 11/28/2022] Open
Abstract
Background Iron deficiency causes long-term adverse consequences for children and is the most common nutritional deficiency worldwide. Observational studies suggest that iron deficiency anemia protects against Plasmodium falciparum malaria and several intervention trials have indicated that iron supplementation increases malaria risk through unknown mechanism(s). This poses a major challenge for health policy. We investigated how anemia inhibits blood stage malaria infection and how iron supplementation abrogates this protection. Methods This observational cohort study occurred in a malaria-endemic region where sickle-cell trait is also common. We studied fresh RBCs from anemic children (135 children; age 6–24 months; hemoglobin < 11 g/dl) participating in an iron supplementation trial (ISRCTN registry, number ISRCTN07210906) in which they received iron (12 mg/day) as part of a micronutrient powder for 84 days. Children donated RBCs at baseline, Day 49, and Day 84 for use in flow cytometry-based in vitro growth and invasion assays with P. falciparum laboratory and field strains. In vitro parasite growth in subject RBCs was the primary endpoint. Findings Anemia substantially reduced the invasion and growth of both laboratory and field strains of P. falciparum in vitro (~ 10% growth reduction per standard deviation shift in hemoglobin). The population level impact against erythrocytic stage malaria was 15.9% from anemia compared to 3.5% for sickle-cell trait. Parasite growth was 2.4 fold higher after 49 days of iron supplementation relative to baseline (p < 0.001), paralleling increases in erythropoiesis. Interpretation These results confirm and quantify a plausible mechanism by which anemia protects African children against falciparum malaria, an effect that is substantially greater than the protection offered by sickle-cell trait. Iron supplementation completely reversed the observed protection and hence should be accompanied by malaria prophylaxis. Lower hemoglobin levels typically seen in populations of African descent may reflect past genetic selection by malaria. Funding National Institute of Child Health and Development, Bill and Melinda Gates Foundation, UK Medical Research Council (MRC) and Department for International Development (DFID) under the MRC/DFID Concordat. P. falciparum laboratory and field strains invade and grow less efficiently in RBCs from anemic children. Deficits in invasion and growth for erythrocytic stage P. falciparum are reversed when RBCs are used from anemic children receiving iron supplementation for 49 and 84 days. The population level impact of protection against malaria from anemia was greater than that for sickle-cell trait.
The long-term consequences of anemia are severe, and it is easily treatable. However, concerns remain about the safety of iron supplements, particularly for children in malaria-endemic countries lacking adequate access to health services. We used RBCs from Gambian children before, during, and after 12 weeks of daily iron supplementation for in vitro P. falciparum assays. P. falciparum invasion and growth was decreased in anemic RBCs and increased after 49 days of iron supplementation relative to baseline (p < 0.001), paralleling increases in young RBCs, which the parasite prefers. The parasite growth protection from anemia was substantial, providing greater population level impact than sickle-cell trait.
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Affiliation(s)
- M M Goheen
- Department of Microbiology and Immunology, University of North Carolina School of Medicine, CB# 7435, Chapel Hill, NC 27599-7435, USA.
| | - R Wegmüller
- MRC Unit The Gambia, MRC International Nutrition Group, Keneba, P.O. Box 273, Banjul, Gambia
| | - A Bah
- MRC Unit The Gambia, MRC International Nutrition Group, Keneba, P.O. Box 273, Banjul, Gambia
| | - B Darboe
- MRC Unit The Gambia, MRC International Nutrition Group, Keneba, P.O. Box 273, Banjul, Gambia
| | - E Danso
- MRC Unit The Gambia, MRC International Nutrition Group, Keneba, P.O. Box 273, Banjul, Gambia
| | - M Affara
- MRC Unit The Gambia, MRC International Nutrition Group, Keneba, P.O. Box 273, Banjul, Gambia
| | - D Gardner
- University of North Carolina School of Medicine, CB# 9535, Chapel Hill, NC 27599-9535, USA
| | - J C Patel
- Department of Epidemiology, University of North Carolina Gillings School of Global Public Health, CB# 7435, Chapel Hill, NC 27599-7435, USA
| | - A M Prentice
- MRC Unit The Gambia, MRC International Nutrition Group, Keneba, P.O. Box 273, Banjul, Gambia; London School of Hygiene & Tropical Medicine, Keppel Street, WC1E 7HT London, UK
| | - C Cerami
- MRC Unit The Gambia, MRC International Nutrition Group, Keneba, P.O. Box 273, Banjul, Gambia
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