Zinc deficiency in children with environmental enteropathy-development of new strategies: report from an expert workshop

Meta-QTL s and haplotypes for efficient zinc biofortification of rice

Biofortification of rice with improved grain zinc (Zn) content is the most sustainable and cost-effective approach to address Zn malnutrition in Asia. Genomics-assisted breeding using precise and consistent Zn quantitative trait loci (QTLs), genes, and haplotypes can fast-track the development of Zn biofortified rice varieties. We conducted the meta-analysis of 155 Zn QTLs reported from 26 different studies. Results revealed 57 meta-QTLs with a significant reduction of 63.2% and 80% in the number and confidence interval of the Zn QTLs, respectively. Meta-quantitative trait loci (MQTLs) regions were found to be enriched with diverse metal homeostasis genes; at least 11 MQTLs were colocated with 20 known major genes involved in the production of root exudates, metal uptake, transport, partitioning, and loading into grains in rice. These genes were differentially expressed in vegetative and reproductive tissues, and a complex web of interactions were observed among them. We identified superior haplotypes and their combinations for nine candidate genes (CGs), and the frequency and allelic effects of superior haplotypes varied in different subgroups. The precise MQTLs with high phenotypic variance, CGs, and superior haplotypes identified in our study are useful for an efficient Zn biofortification of rice and to ensure Zn as an essential component of all the future rice varieties through mainstreaming of Zn breeding.

Tyrosol inhibits NF-κB pathway in the treatment of enterotoxigenic Escherichia coli-induced diarrhea in mice

Tyrosol is one of the main polyphenol compounds in white wine and extra virgin olive oil (EVOO), which plays an antioxidant and anti-inflammatory role in vitro. In the present study, we investigated the possible anti-inflammatory mechanism of tyrosol in Escherichia coli (ETEC)-induced diarrhea in mice. ICR mice were randomly divided into control group, ETEC group, and ETEC + Tyrosol group with 10 mice in each group. In addition to the control group, a bacterial diarrhea model was induced in mice by continuous administration of 0.2 ml × 10⁹ CFU/ml ETEC. After 7 days, the ETEC + Tyrosol group was given tyrosol (20 mg/kg) once a day by gavage, during which the body weight of mice and the degree of diarrhea were measured daily. On the 15th day, all animals in this experiment were sacrificed, colon tissue was collected, and colon length was recorded. Our results indicate that tyrosol significantly attenuated the extent of ETEC-induced diarrhea, including inhibition of pro-inflammatory cytokine, repair of the intestinal epithelial mechanical barrier, and significant inhibition of NF-κB activation. This finding is helpful for the development and further application of tyrosol in the treatment of diarrhea.

Nutritional Care in Children with Cystic Fibrosis

Patients with cystic fibrosis (CF) are prone to malnutrition and growth failure, mostly due to malabsorption caused by the derangement in the chloride transport across epithelial surfaces. Thus, optimal nutritional care and support should be an integral part of the management of the disease, with the aim of ameliorating clinical outcomes and life expectancy. In this report, we analyzed the nutrition support across the different ages, in patients with CF, with a focus on the relationships with growth, nutritional status, disease outcomes and the use of the CF transmembrane conductance regulator (CFTR) modulators. The nutrition support goal in CF care should begin as early as possible after diagnosis and include the achievement of an optimal nutritional status to support the growth stages and puberty development in children, that will further support the maintenance of an optimal nutritional status in adult life. The cornerstone of nutrition in patients with CF is a high calorie, high-fat diet, in conjunction with a better control of malabsorption due to pancreatic enzyme replacement therapy, and attention to the adequate supplementation of fat-soluble vitamins. When the oral caloric intake is not enough for reaching the anthropometric nutritional goals, supplemental enteral feeding should be initiated to improve growth and the nutritional status. In the last decade, the therapeutic possibilities towards CF have grown in a consistent way. The positive effects of CFTR modulators on nutritional status mainly consist in the improvement in weight gain and BMI, both in children and adults, and in an amelioration in terms of the pulmonary function and reduction of exacerbations. Several challenges need to be overcome with the development of new drugs, to transform CF from a fatal disease to a treatable chronic disease with specialized multidisciplinary care.

Nutritional Status of Adolescent Afghan Refugees Living in Peshawar, Pakistan

Pakistan has hosted millions of Afghan refugees over the last several decades. Due to poor socioeconomic status, food insecurity and inadequate access to health care, these refugees are considered to be at high risk of malnutrition. Previous studies on nutritional assessment of high-risk populations (refugees) have focused mainly on women and children (0-59 months). The current study aims to assess nutritional status of adolescent Afghan refugees; the population who are equally vulnerable to malnutrition and its consequences. In this cross sectional study, the nutritional status of 206 adolescent (10-19 years old) Afghans boys and girls living in a refugee camp in Peshawar, Pakistan was assessed using standard methods. The results indicate a prevalence of stunting, thinness, and overweight and obesity at 35.3%, 4.4% and 14.8%, respectively. Furthermore, there was a significantly high prevalence of micronutrient deficiencies (vitamin D, 80.5%; vitamin B12, 41.9%; and folate, 28.2%); and anemia (10.1%). Together, these findings indicate that this vulnerable population group suffers from the double burden of malnutrition and are thus at serious risk of impaired psychosocial cognitive development, general ill-health and diminished wellbeing. This study therefore highlights the urgent need to include adolescents in regular screening and intervention programs of such at-risk populations.

Rotavirus vaccines performance: dynamic interdependence of host, pathogen and environment

INTRODUCTION

As of January 2021, rotavirus vaccination programs have been implemented in 109 countries and their use has resulted in a positive impact on rotavirus-related diarrheal hospitalizations and mortality in children below 5 years of age. Despite these successes, several countries in Africa and Asia where disease burden is high have not yet implemented rotavirus vaccination at all or at a scale sufficient enough to demonstrate impact. This could be, among other reasons, due to poor vaccine coverage and the modest levels of efficacy and effectiveness of the vaccines in these resource-limited settings.

AREAS COVERED

We review various factors related to the human host (malnutrition, maternally derived antibodies and breastfeeding, genetic factors, blood group, and co-administration with oral polio vaccine), rotavirus pathogen (force of infection, strain diversity and coinfections), and the environment (related to the human microbiome) which reflect complex and interconnected processes leading to diminished vaccine performance in resource-limited settings.

EXPERT OPINION

Addressing the limiting factors for vaccine efficacy is needed but likely to take a long time to be resolved. An immediate solution is to increase the immunization coverage to higher values generating an overall effect of adequate proportion of protected population to reduce the prevalence of rotavirus disease.

Zinc treatment modulates hematological and morphological changes in rat erythrocytes following arsenic exposure

The aim of this study was to understand the effects of zinc supplementation on antioxidant defense systems, hematological indices, and erythrocyte morphology in conditions of chronic arsenic toxicity. Male Wistar rats were segregated into four groups: control, arsenic treated, zinc supplemented, and arsenic + zinc treated. The animals in the arsenic-treated group were given arsenic orally in drinking water in the form of sodium arsenite at a dose level of 100 mg L^-1, and zinc was administered to zinc-treated animals in the form of zinc sulfate orally in drinking water at a dose level of 227 mg L^-1. The animals were subjected to different treatments for a period of 12 weeks, and various investigations were undertaken that included serum zinc content, activity of antioxidant enzymes, and hematological indices. Further, scanning electron microscopic (SEM) studies were performed to assess morphological changes in erythrocytes. Arsenic treatment significantly reduced serum zinc concentrations, which, however, were restored to near-normal levels upon zinc supplementation. The activities of enzymes involved in antioxidant defense systems were altered in the erythrocyte lysates of arsenic-treated rats, which interestingly revealed a significant improvement upon simultaneous zinc supplementation. A significant reduction in the counts of total leukocytes, neutrophils, and lymphocytes was observed following arsenic intoxication, which came back to near control levels following zinc supplementation. Also, protective effects of zinc were evident from SEM that revealed maintenance of topographical appearances of erythrocytes in conditions of arsenic toxicity. Thus, this study clearly shows the protection afforded by zinc on erythrocytes during arsenic-induced toxicity.

Zinc Absorption and Endogenous Fecal Zinc Losses in Bangladeshi Toddlers at Risk for Environmental Enteric Dysfunction

OBJECTIVES

Environmental enteric dysfunction (EED) impairs zinc absorption from food, and zinc deficiency may contribute to the poor growth associated with EED. We examined zinc absorption from a standardized aqueous zinc dose, and habitual daily endogenous fecal zinc excretion (EFZ) and compared these outcomes between children grouped by the lactulose to mannitol ratio (L:M).

METHODS

Bangladeshi toddlers (18-24 months) with low (<0.09) and high (≥0.09) L:M were administered isotope-labeled 3 mg aqueous zinc in the fasted state. Fractional absorption of zinc (FAZ) and EFZ were measured by dual stable isotope tracer method and an isotope dilution method, respectively. Secondary aims included examining relationships of biomarkers of systemic and intestinal inflammation and gut function with FAZ and EFZ.

RESULTS

Forty children completed the study; nearly all had evidence of EED. No differences in zinc homeostasis measurements (mean ± SD) were observed between high and low L:M groups: FAZ was 0.38 ± 0.19 and 0.31 ± 0.19, respectively; both figures were within estimated reference range. Means of EFZ were 0.73 ± 0.27 and 0.76 ± 0.20 mg/day for high and low L:M, respectively, and were 10% to 15% above estimated reference range. Regression analyses indicated that biomarkers of systemic inflammation were directly associated with increasing FAZ, consistent with increased gut permeability. Biomarkers of intestinal inflammation were negatively associated with EFZ, consistent with low-zinc intake and chronic deficiency.

CONCLUSIONS

In these children at risk of EED, endogenous zinc losses were not markedly increased. Results suggest that efforts to improve zinc status in EED should focus on substantially improving zinc intakes.

A murine model of diarrhea, growth impairment and metabolic disturbances with Shigella flexneri infection and the role of zinc deficiency

Shigella is one of the major enteric pathogens worldwide. We present a murine model of S. flexneri infection and investigate the role of zinc deficiency (ZD). C57BL/6 mice fed either standard chow (HC) or ZD diets were pretreated with an antibiotic cocktail and received S. flexneri strain 2457T orally. Antibiotic pre-treated ZD mice showed higher S. flexneri colonization than non-treated mice. ZD mice showed persistent colonization for at least 50 days post-infection (pi). S. flexneri-infected mice showed significant weight loss, diarrhea and increased levels of fecal MPO and LCN in both HC and ZD fed mice. S. flexneri preferentially colonized the colon, caused epithelial disruption and inflammatory cell infiltrate, and promoted cytokine production which correlated with weight loss and histopathological changes. Infection with S. flexneri ΔmxiG (critical for type 3 secretion system) did not cause weight loss or diarrhea, and had decreased stool shedding duration and tissue burden. Several biochemical changes related to energy, inflammation and gut-microbial metabolism were observed. Zinc supplementation increased weight gains and reduced intestinal inflammation and stool shedding in ZD infected mice. In conclusion, young antibiotic-treated mice provide a new model of oral S. flexneri infection, with ZD promoting prolonged infection outcomes.

Zinc Nutritional Status in Patients with Cystic Fibrosis

BACKGROUND

Zinc is an essential nutrient for all forms of life and its deficiency affects the normal growth and development of human beings.

OBJECTIVE

The main aim was to investigate zinc nutritional status by serum zinc concentration (SZC) and dietary zinc intake and their association in cystic fibrosis (CF) patients.

METHODS

A cross-sectional study was conducted in CF patients. Anthropometric measurements and respiratory and pancreatic tests were conducted. Hypozincemia was determined by SZC while using atomic absorption spectrophotometry and dietary zinc deficiency by prospective 72-h dietary surveys.

RESULTS

Mean SZC (87.2 ± 16.7 μg/dL) and dietary zinc intake (97 ± 26.9% Dietary Reference Intake) were normal. Three of 17 patients with CF (17.6%) had hypozincemia and four (23.5%) had a dietary zinc deficiency. No patient with dietary zinc deficiency had hypozincemia. A positive and significant association was observed between SZC and Z-score of BMI-for-age (p = 0.048) and weight-for-height (p = 0.012) and between dietary zinc intake and energy intake (EI, p = 0.036) and Z-score of weight-for-high (p = 0.029).

CONCLUSION

SZC was associated with the nutritional status, expressed as BMI (Body Mass Index) and weight-for-height Z score, and dietary zinc intake with EI and weight-for-height Z-score. No patient with hypozincemia had dietary zinc deficiency. This situation should alert us to a marginal zinc deficiency and it may explain why there were no overlapping cases between the two groups. We suggest that probably 41% of the cases in this study would be at elevated risk of zinc deficiency and a zinc supplementation may be considered.

Zinc Absorption from Micronutrient Powders Is Low in Bangladeshi Toddlers at Risk of Environmental Enteric Dysfunction and May Increase Dietary Zinc Requirements

Background

Environmental enteric dysfunction (EED), a chronic inflammatory disorder of the small bowel, is suspected to impair absorption of micronutrients, including zinc.

Objective

The objective of this study was to compare zinc absorption from micronutrient powder (MNP) over a range of zinc doses in young children screened for EED with use of the lactulose:mannitol ratio (L:M).

Methods

Bangladeshi children aged 18-24 mo, grouped according to high and low L:M (≥0.09 and <0.09, respectively), were randomly assigned to MNP with 0, 5, 10, or 15 mg Zn/sachet (10 subjects per dose per L:M group). Over a day, fractional absorption of zinc was measured from an MNP-fortified meal and from unfortified meals with stable isotope tracers; total daily absorbed zinc (TAZ, milligrams per day) was determined as the primary outcome. Secondary outcomes included investigation of relations of TAZ to intake, to physiologic requirement, and to other variables, including biomarkers of systemic and intestinal inflammation, using nonlinear models. TAZ was also compared with published data on child zinc absorption.

Results

In 74 subjects who completed the study, zinc absorption did not differ by L:M grouping. Most biomarkers of intestinal inflammation were elevated in both L:M groups. For combined L:M groups, mean ± SD TAZ for each MNP dose (0, 5, 10, and 15 mg/sachet) was 0.57 ± 0.30, 0.68 ± 0.31, 0.90 ± 0.43, and 1.0 ± 0.39 mg/d, respectively (P = 0.002), and exceeded the estimated physiologic requirement only for the 10- and 15-mg MNP doses. Zinc absorption was notably lower at all intake levels compared with published data (P < 0.0001) and was inversely related to serum α-1 acid glycoprotein and to fecal Entamoeba histolytica (P = 0.02).

Conclusion

Results indicate impaired absorption of zinc, which may predispose to zinc deficiency in young children with evidence of enteropathy. These findings suggest that current doses of zinc in MNP may be insufficient to yield zinc-related preventative benefits in similar settings. This study is registered at clinicaltrials.gov as NCT02758444.

Critical Role of Zinc in a New Murine Model of Enterotoxigenic Escherichia coli Diarrhea

Enterotoxigenic Escherichia coli (ETEC) is a major cause of traveler's diarrhea as well as of endemic diarrhea and stunting in children in developing areas. However, a small-mammal model has been badly needed to better understand and assess mechanisms, vaccines, and interventions. We report a murine model of ETEC diarrhea, weight loss, and enteropathy and investigate the role of zinc in the outcomes. ETEC strains producing heat-labile toxins (LT) and heat-stable toxins (ST) that were given to weaned C57BL/6 mice after antibiotic disruption of normal microbiota caused growth impairment, watery diarrhea, heavy stool shedding, and mild to moderate intestinal inflammation, the latter being worse with zinc deficiency. Zinc treatment promoted growth in zinc-deficient infected mice, and subinhibitory levels of zinc reduced expression of ETEC virulence genes cfa1, cexE, sta2, and degP but not of eltA in vitro Zinc supplementation increased shedding and the ileal burden of wild-type (WT) ETEC but decreased shedding and the tissue burden of LT knockout (LTKO) ETEC. LTKO ETEC-infected mice had delayed disease onset and also had less inflammation by fecal myeloperoxidase (MPO) assessment. These findings provide a new murine model of ETEC infection that can help elucidate mechanisms of growth, diarrhea, and inflammatory responses as well as potential vaccines and interventions.

Effectiveness of zinc-fortified water on zinc intake, status and morbidity in Kenyan pre-school children: a randomised controlled trial

OBJECTIVE

Zn deficiency and diarrhoea are prevalent and may coexist in children living in low-resource settings. Recently, a novel approach for delivering Zn via microbiologically treated, Zn-fortified water was shown to be effective in improving Zn status in West African schoolchildren. We assessed the effectiveness of Zn-fortified, microbiologically purified water delivered as a household intervention on Zn intake, status and morbidity in children aged 2-6 years from rural western Kenya.

DESIGN

Randomised controlled trial. Intervention included households assigned to water treatment device with (ZFW) or without (FW) Zn delivery capability SETTING: Rural households in Kisumu, western Kenya.

SUBJECTS

Children aged 2-6 years.

RESULTS

The ZFW group had higher dietary Zn intake compared with the FW group. ZFW contributed 36 and 31 % of daily requirements for absorbable Zn in children aged 2-3 and 4-6 years, respectively, in the ZFW group. Consumption of Zn-fortified water resulted in lower prevalence of reported illness (risk ratio; 95 % CI) in the ZFW group compared with the FW group: for cold with runny nose (0·91; 0·83, 0·99; P=0·034) and abdominal pain (0·70; 0·56, 0·89; P=0·003) in the intention-to-treat analysis and for diarrhoea (0·72; 0·53, 0·96; P=0·025) in the per-protocol analysis. We did not detect an effect of treatment on plasma Zn concentration.

CONCLUSIONS

Daily consumption of Zn-fortified, microbiologically treated water results in increased intake of absorbable dietary Zn and may help in preventing childhood infections in pre-school children in rural Africa.

Differences of Rotavirus Vaccine Effectiveness by Country: Likely Causes and Contributing Factors

Rotaviruses are a major cause of acute gastroenteritis in infants and young children worldwide and in many other mammalian and avian host species. Since 2006, two live-attenuated rotavirus vaccines, Rotarix^® and RotaTeq^®, have been licensed in >100 countries and are applied as part of extended program of vaccination (EPI) schemes of childhood vaccinations. Whereas the vaccines have been highly effective in high-income countries, they were shown to be considerably less potent in low- and middle-income countries. Rotavirus-associated disease was still the cause of death in >200,000 children of <5 years of age worldwide in 2013, and the mortality is concentrated in countries of sub-Saharan Africa and S.E. Asia. Various factors that have been identified or suggested as being involved in the differences of rotavirus vaccine effectiveness are reviewed here. Recognition of these factors will help to achieve gradual worldwide improvement of rotavirus vaccine effectiveness.

Drug-development concepts as guides for optimizing clinical trials of supplemental zinc for populations at risk of deficiency or diarrhea

Studies on the efficacy of zinc supplementation for treatment or prevention of diarrhea have shown an inconsistent effect in populations at risk for zinc deficiency. Unlike drugs, which have no preexisting presence in the body, endogenous zinc must be assessed pharmacokinetically by isotope tracer studies. Although such methods have produced much data, very few studies have estimated the dose and the timing of dosing of zinc supplementation. This review examines drug kinetics used to establish the best dose, the timing of such doses, and the mechanism of action through pharmacodynamic markers and applies them, where possible, to zinc supplements. The findings reveal that little is known, especially in children at highest risk of zinc deficiency. Key data missing to inform proper dosing, whether for treatment of disease or for preventive nutrient supplementation, are noted. Addressing these uncertainties could improve study design, leading to future studies of zinc supplements that might be of greater benefit.

Nutrition meets the microbiome: micronutrients and the microbiota

There is increasing evidence that food is an important factor that influences and shapes the composition and configuration of the gut microbiota. Most studies have focused on macronutrients (fat, carbohydrate, protein) in particular and their effects on the gut microbiota. Although the microbiota can synthesize different water-soluble vitamins, the effects of vitamins synthesized within the microbiota on systemic vitamin status are unclear. Few studies exist on the shuttling of vitamins between the microbiota and intestine and the impact of luminal vitamins on the microbiota. Studying the interactions between vitamins and the microbiota may help to understand the effects of vitamins on the barrier function and immune system of the intestinal tract. Furthermore, understanding the impact of malnutrition, particularly low micronutrient supply, on microbiota development, composition, and metabolism may help in implementing new strategies to overcome the deleterious effects of malnutrition on child development. This article reviews data on the synthesis of different micronutrients and their effects on the human microbiota, and further discusses the consequences of malnutrition on microbiota composition.

A Combined Intervention of Zinc, Multiple Micronutrients, and Albendazole Does Not Ameliorate Environmental Enteric Dysfunction or Stunting in Rural Malawian Children in a Double-Blind Randomized Controlled Trial

BACKGROUND

Environmental enteric dysfunction (EED) and linear growth stunting affect many rural agrarian children in the developing world and contribute to the persistently high rates of stunting that are observed worldwide. Effective interventions to consistently ameliorate EED are lacking.

OBJECTIVE

We tested whether a bundle of safe and affordable interventions would decrease EED and stunting over 12-24 wk in a cohort of rural Malawian children 12-35 mo old.

METHODS

This was a randomized, double-blind, placebo-controlled clinical trial in which the intervention group received a single dose of albendazole and 14 d of zinc at enrollment and after 20 wk. The intervention group also received a daily multiple micronutrient powder throughout the 24 wk of study. The primary outcomes were improvements in EED, as measured by the urinary lactulose-to-mannitol ratio (L:M ratio) from dual-sugar absorption testing, and linear growth. Urinary L:M ratios and anthropometric measurements were evaluated after 12 and 24 wk of intervention and compared with a placebo group that did not receive any of these interventions.

RESULTS

A total of 254 children were enrolled at a mean age of 24 mo; 55% were female. Their mean weight-for-age z score was -1.5, and their mean length-for-age z score was -0.9. After 12 and 24 wk of study, increases in the L:M ratio did not differ between the intervention group (0.071 and 0.088 units, respectively) and the placebo group (0.073 and 0.080 units, respectively) (P = 0.87 and 0.19, respectively). Relative changes in length and weight also did not differ significantly between groups at any time point.

CONCLUSION

The combined usage of albendazole, zinc, and a daily multiple micronutrient powder did not decrease EED or stunting in this population of agrarian children 12-35 mo old in rural Malawi. Alternative interventions to improve these diseases should be investigated. This trial was registered at clinicaltrials.gov as NCT02253095.

New insights into environmental enteric dysfunction

Environmental enteric dysfunction (EED) has been recognised as an important contributing factor to physical and cognitive stunting, poor response to oral vaccines, limited resilience to acute infections and ultimately global childhood mortality. The aetiology of EED remains poorly defined but the epidemiology suggests a multifactorial combination of prenatal and early-life undernutrition and repeated infectious and/or toxic environmental insults due to unsanitary and unhygienic environments. Previous attempts at medical interventions to ameliorate EED have been unsatisfying. However, a new generation of imaging and '-omics' technologies hold promise for developing a new understanding of the pathophysiology of EED. A series of trials designed to decrease EED and stunting are taking novel approaches, including improvements in sanitation, hygiene and nutritional interventions. Although many challenges remain in defeating EED, the global child health community must redouble their efforts to reduce EED in order to make substantive improvements in morbidity and mortality worldwide.

Environmental enteropathy

PURPOSE OF REVIEW

Environmental enteropathy has long been recognized as an important intermediary condition leading to chronic malnutrition in children in developing countries. Interest has lately renewed in this topic because of increased focus on improving the quality of lives as opposed to just saving them. Here, we provide an overview of recent scientific literature and our perspective about this disorder.

RECENT FINDINGS

Current understanding of the disorder of environmental enteropathy is based on studies conducted decades ago. Results of some new studies on histopathologic characterization of environmental enteropathy are currently awaited. Given the challenges of diagnosing environmental enteropathy using the gold standard test of intestinal biopsy, different biomarkers have been tested as proxies of environmental enteropathy and eventually, chronic malnutrition. Available data fail to point toward a single ideal biomarker, though considerable work is still ongoing. A few interventional studies have also been conducted with improvement in environmental enteropathy as outcome.

SUMMARY

The basic histopathology of environmental enteropathy has been defined previously, and more advanced analysis to study the pathophysiology of this disorder is currently being carried out. Many biomarkers, which represent the different mechanisms involved in environmental enteropathy, have been tested as proxies of environmental enteropathy. Although no single biomarker fits the description of an ideal biomarker yet, a few of the more promising biomarkers are being validated in different studies. Finally, the few interventions which have been tried to treat environmental enteropathy, thus far, are summarized.

Rural Beninese Children Are at Risk of Zinc Deficiency According to Stunting Prevalence and Plasma Zinc Concentration but Not Dietary Zinc Intakes

BACKGROUND

Three commonly recommended indicators for risk assessment of population zinc deficiency are stunting rates among children aged <5 y, prevalence of inadequate dietary zinc intake, and prevalence of low plasma zinc (PZn). Data on zinc status in Benin are mainly drawn from stunting rates and data on PZn and dietary zinc intake are lacking.

OBJECTIVES

The aims of this study were 1) to assess the risk of zinc deficiency in preschool and school-age children from rural communities in northern Benin by means of the 3 indicators for population assessment, 2) to evaluate their level of agreement, and 3) to identify predictors of PZn and height-for-age z scores (HAZ).

METHODS

We analyzed preintervention data collected during 2 efficacy trials and cross-sectionally assessed the risk of zinc deficiency in preschool (1-5 y, n = 326) and school-age children (5-10 y, n = 272) by 1) conducting a 3-d weighed food record survey, coupled with direct zinc and phytic acid analysis of consumed foodstuffs, and calculating usual dietary zinc intakes in a subsample of school-age children (n = 36); 2) analyzing PZn in all children (n = 598); and 3) measuring anthropometry indexes for assessment of stunting (HAZ <-2 SD) in all children (n = 594) and in <5-y-old children only (n = 273). We derived predictors of PZn and HAZ by using multivariate regression with mixed-effect models.

RESULTS

Prevalence of inadequate intakes of zinc ranged from 11% to 80% depending on whether the estimated average requirements (EARs) by the International Zinc Nutrition Consultative Group or the EARs derived from the WHO's recommended nutrient intakes were used. Prevalence of low PZn adjusted for acute-phase protein status was 45.7%, with higher rates among preschoolers than school-age children (P = 0.002). The stunting rate in <5-y-old children was 51.3%. PZn was predicted by age, methodologic factors, and socioeconomic status, whereas HAZ was predicted by age, sex, hemoglobin, and socioeconomic status.

CONCLUSIONS

The prevalence of <5-y stunting and the prevalence of low PZn indicate that the risk of zinc deficiency is elevated in this population. Risk estimates based on the prevalence of inadequacy of zinc intakes varied depending on the EARs used, and a consensus would facilitate nutrition survey evaluations. These trials were registered at clinicaltrials.gov as NCT01472211 and NCT01790321.