Dietary zinc supplements: beneficial health effects and application in food, medicine and animals

Zinc, a crucial trace element is vital for the growth and development of humans. It is frequently described as 'the flower of life' and 'the source of intelligence'. Zinc supplements play a pivotal role in addressing zinc deficiency by serving as a vital source of this essential micronutrients, effectively replenishing depleted zinc levels in the body. In this paper, we first described the biological behavior of zinc in the human body and briefly described the physiological phenomena associated with zinc levels. The benefits and drawbacks of various zinc supplement forms are then discussed, with emphasis on the most recent zinc supplement formulations. Finally, the application of zinc supplements in food, medicine, and animal husbandry is further summarized. © 2024 Society of Chemical Industry.

The distribution, fate, and environmental impacts of food additive nanomaterials in soil and aquatic ecosystems

Nanomaterials in the food industry are used as food additives, and the main function of these food additives is to improve food qualities including texture, flavor, color, consistency, preservation, and nutrient bioavailability. This review aims to provide an overview of the distribution, fate, and environmental and health impacts of food additive nanomaterials in soil and aquatic ecosystems. Some of the major nanomaterials in food additives include titanium dioxide, silver, gold, silicon dioxide, iron oxide, and zinc oxide. Ingestion of food products containing food additive nanomaterials via dietary intake is considered to be one of the major pathways of human exposure to nanomaterials. Food additive nanomaterials reach the terrestrial and aquatic environments directly through the disposal of food wastes in landfills and the application of food waste-derived soil amendments. A significant amount of ingested food additive nanomaterials (> 90 %) is excreted, and these nanomaterials are not efficiently removed in the wastewater system, thereby reaching the environment indirectly through the disposal of recycled water and sewage sludge in agricultural land. Food additive nanomaterials undergo various transformation and reaction processes, such as adsorption, aggregation-sedimentation, desorption, degradation, dissolution, and bio-mediated reactions in the environment. These processes significantly impact the transport and bioavailability of nanomaterials as well as their behaviour and fate in the environment. These nanomaterials are toxic to soil and aquatic organisms, and reach the food chain through plant uptake and animal transfer. The environmental and health risks of food additive nanomaterials can be overcome by eliminating their emission through recycled water and sewage sludge.

Dietary Zn deficiency, the current situation and potential solutions

Zinc (Zn) deficiency is a worldwide problem, and this review presents an overview of the magnitude of Zn deficiency with a particular emphasis on present global challenges, current recommendations for Zn intake, and factors that affect dietary requirements. The challenges of monitoring Zn status are clarified together with the discussion of relevant Zn bioaccessibility and bioavailability issues. Modern lifestyle factors that may exacerbate Zn deficiency and new strategies of reducing its effects are presented. Biofortification, as a potentially useful strategy for improving Zn status in sensitive populations, is discussed. The review proposes potential actions that could deliver promising results both in terms of monitoring dietary and physiological Zn status as well as in alleviating dietary Zn deficiency in affected populations.

Loading of zinc and iron in grains of different wheat genotypes in the calcareous and floodplain soils of Bangladesh

Major malnutrition in Bangladesh is zinc (Zn) and iron (Fe) deficiency as most people commonly depend on cereals, chiefly rice and wheat. The main objectives are to enhance Zn and Fe concentrations through the use of selected varieties and the application of respective fertilizers. Field experiments were conducted at Bangladesh Agricultural University (BAU) farm, Mymensingh (AEZ 9, non-calcareous soil) and at Bangladesh Institute of Nuclear Agriculture (BINA) substation, Ishwardi (AEZ 11, calcareous soil) for two consecutive wheat seasons (2014-15 and 2015-16) with 10 varieties and 15 advanced lines. Varieties BARI Gom 25, 27, 28 & 29 and breeding lines Vijay, HPYT-5, 15 & 21 and BL-1883 have been recognized as Zn-enriched wheat varieties (24-30 μg g-1). Among the genotypes, Zn further increased by 4-8 μg g-1 due to Zn fertilization. Concerning Fe-enriched wheat genotypes (24-30 μg g-1), five varieties viz. Shatabdi, Prodip, BARI Gom 25 & 28 and Sufi, and four lines such as HPYT-12, BL-1883, BL-1040 and Fery-60 have been identified. The grain Fe concentration of wheat genotypes increased when Fe was added, the increment being 6-12 μg g-1. A positive relationship between Zn and N is observed with increased protein content. The grain yield of wheat was increased by 3.8-25.7% due to Zn application over the varieties and locations but Fe addition had no effect. The result of the current study showed that a potential breeding line with appropriate fertilization can improve Zn and Fe levels in wheat grain, without incurring loss to wheat yield.

Zinc supplementation for preventing mortality, morbidity, and growth failure in children aged 6 months to 12 years

BACKGROUND

Zinc deficiency is prevalent in low- and middle-income countries, and is considered a significant risk factor for morbidity, mortality, and linear growth failure. The effectiveness of preventive zinc supplementation in reducing prevalence of zinc deficiency needs to be assessed.

OBJECTIVES

To assess the effects of zinc supplementation for preventing mortality and morbidity, and for promoting growth, in children aged 6 months to 12 years.

SEARCH METHODS

A previous version of this review was published in 2014. In this update, we searched CENTRAL, MEDLINE, Embase, five other databases, and one trials register up to February 2022, together with reference checking and contact with study authors to identify additional studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) of preventive zinc supplementation in children aged 6 months to 12 years compared with no intervention, a placebo, or a waiting list control. We excluded hospitalized children and children with chronic diseases or conditions. We excluded food fortification or intake, sprinkles, and therapeutic interventions.

DATA COLLECTION AND ANALYSIS

Two review authors screened studies, extracted data, and assessed the risk of bias. We contacted study authors for missing information and used GRADE to assess the certainty of evidence. The primary outcomes of this review were all-cause mortality; and cause-specific mortality, due to all-cause diarrhea, lower respiratory tract infection (LRTI, including pneumonia), and malaria. We also collected information on a number of secondary outcomes, such as those related to diarrhea and LRTI morbidity, growth outcomes and serum levels of micronutrients, and adverse events.

MAIN RESULTS

We included 16 new studies in this review, resulting in a total of 96 RCTs with 219,584 eligible participants. The included studies were conducted in 34 countries; 87 of them in low- or middle-income countries. Most of the children included in this review were under five years of age. The intervention was delivered most commonly in the form of syrup as zinc sulfate, and the most common dose was between 10 mg and 15 mg daily. The median duration of follow-up was 26 weeks. We did not consider that the evidence for the key analyses of morbidity and mortality outcomes was affected by risk of bias. High-certainty evidence showed little to no difference in all-cause mortality with preventive zinc supplementation compared to no zinc (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.84 to 1.03; 16 studies, 17 comparisons, 143,474 participants). Moderate-certainty evidence showed that preventive zinc supplementation compared to no zinc likely results in little to no difference in mortality due to all-cause diarrhea (RR 0.95, 95% CI 0.69 to 1.31; 4 studies, 132,321 participants); but probably reduces mortality due to LRTI (RR 0.86, 95% CI 0.64 to 1.15; 3 studies, 132,063 participants) and mortality due to malaria (RR 0.90, 95% CI 0.77 to 1.06; 2 studies, 42,818 participants); however, the confidence intervals around the summary estimates for these outcomes were wide, and we could not rule out a possibility of increased risk of mortality. Preventive zinc supplementation likely reduces the incidence of all-cause diarrhea (RR 0.91, 95% CI 0.90 to 0.93; 39 studies, 19,468 participants; moderate-certainty evidence) but results in little to no difference in morbidity due to LRTI (RR 1.01, 95% CI 0.95 to 1.08; 19 studies, 10,555 participants; high-certainty evidence) compared to no zinc. There was moderate-certainty evidence that preventive zinc supplementation likely leads to a slight increase in height (standardized mean difference (SMD) 0.12, 95% CI 0.09 to 0.14; 74 studies, 20,720 participants). Zinc supplementation was associated with an increase in the number of participants with at least one vomiting episode (RR 1.29, 95% CI 1.14 to 1.46; 5 studies, 35,192 participants; high-certainty evidence). We report a number of other outcomes, including the effect of zinc supplementation on weight and serum markers such as zinc, hemoglobin, iron, copper, etc. We also performed a number of subgroup analyses and there was a consistent finding for a number of outcomes that co-supplementation of zinc with iron decreased the beneficial effect of zinc.

AUTHORS' CONCLUSIONS

Even though we included 16 new studies in this update, the overall conclusions of the review remain unchanged. Zinc supplementation might help prevent episodes of diarrhea and improve growth slightly, particularly in children aged 6 months to 12 years of age. The benefits of preventive zinc supplementation may outweigh the harms in regions where the risk of zinc deficiency is relatively high.

Soil zinc deficiency and child stunting: Evidence from Nepal

We examine the negative child health impacts of soil zinc (Zn) deficiency in Nepal. Soil Zn deficiency limits both crop yields and the Zn concentration in food crops, leading many to speculate that it underlies human Zn deficiency and child stunting, globally and particularly in South Asia. We find strong evidence that soil Zn deficiency does have a causal impact on child stunting in Nepal's Tarai region, the breadbasket of the country. Using causal bounds, we find that a 1 part per million increase in plant-available soil Zn - achievable with application of Zn-enriched fertilizer - decreases child stunting by between 1 and 7.5 percentage points. Multiple statistical sensitivity tests indicate that this relationship is unlikely to be manufactured by omitted, relevant variables.

Applying Zinc Nutrient Reference Values as Proposed by Different Authorities Results in Large Differences in the Estimated Prevalence of Inadequate Zinc Intake by Young Children and Women and in Cameroon

Nutrient reference values (NRVs) for zinc set by several expert groups differ widely and may affect the predicted prevalence of inadequate zinc intake. We examined this possibility using NRVs published by four different authorities and nationally representative dietary intake data collected among children aged 12–59 months and women in Cameroon. Usual zinc intake was estimated from 24 h recall data using the National Cancer Institute method. Prevalences of total zinc intake below the dietary requirement and of “absorbable zinc intake” below the physiological requirement were estimated using NRVs published by the World Health Organization (WHO), US Institute of Medicine (IOM), International Zinc Nutrition Consultative Group (IZiNCG), and European Food Safety Authority (EFSA). The prevalence of inadequate zinc intake ranged from 10% (IZiNCG—physiological requirement, 95% CI 7–13%) to 81% (EFSA—physiological requirement, 95% CI 78–84%) among children and 9% (WHO—physiological requirement, 95% CI 8–11.0%) to 94% (IOM—physiological requirement, 95% CI 92–95%) among women These differences in the prevalence of inadequate intake translated into sizeable differences in the predicted benefit and cost-effectiveness of zinc fortification programs. Depending on the NRVs applied, assessments differ regarding the need for and design of zinc fortification programs. Efforts are needed to harmonize NRVs for zinc.

Effects of Foods Fortified with Zinc, Alone or Cofortified with Multiple Micronutrients, on Health and Functional Outcomes: A Systematic Review and Meta-Analysis

Seventeen per cent of the world's population is estimated to be at risk of inadequate zinc intake, which could in part be addressed by zinc fortification of widely consumed foods. We conducted a review of efficacy and effectiveness studies to ascertain the effect of zinc fortification [postharvest fortification of an industrially produced food or beverage; alone or with multiple micronutrients (MMN)] on a range of health outcomes. Previous reviews have required that the effect of zinc be isolated; because zinc is always cofortified with MMN in existing fortification programs, we did not impose this condition. Outcomes assessed were zinc-related biomarkers (plasma or serum, hair or urine zinc concentrations, comet assay, plasma fatty acid concentrations, and the proportion of and total zinc absorbed in the intestine from the diet), child anthropometry, morbidity, mortality, cognition, plasma or serum iron and copper concentrations, and for observational studies, a change in consumption of the food vehicle. Fifty-nine studies were included in the review; 54 in meta-analyses, totaling 73 comparisons. Zinc fortification with and without MMN increased plasma zinc concentrations (efficacy, n = 27: 4.68 μg/dL; 95% CI: 2.62-6.75; effectiveness, n = 13: 6.28 μg/dL; 95% CI: 5.03-7.77 μg/dL) and reduced the prevalence of zinc deficiency (efficacy, n = 11: OR: 0.76, 95% CI: 0.60-0.96; effectiveness, n = 10: OR: 0.45, 95% CI: 0.31-0.64). There were statistically significant increases in child weight (efficacy, n = 11: 0.43 kg, 95% CI: 0.11-0.75 kg), improvements in short-term auditory memory (efficacy, n = 3: 0.32 point, 95% CI: 0.13-0.50 point), and decreased incidence of diarrhea (efficacy, n = 3: RR: 0.79, 95% CI: 0.68-0.92) and fever (efficacy, n = 2: RR: 0.85, 95% CI: 0.74-0.97). However, these effects cannot be solely attributed to zinc. Our review found that zinc fortification with or without MMN reduced the prevalence of zinc deficiency and may provide health and functional benefits, including a reduced incidence of diarrhea.

Characteristics that modify the effect of small-quantity lipid-based nutrient supplementation on child anemia and micronutrient status: an individual participant data meta-analysis of randomized controlled trials

BACKGROUND

Small-quantity lipid-based nutrient supplements (SQ-LNSs) have been shown to reduce the prevalence of child anemia and iron deficiency, but effects on other micronutrients are less well known. Identifying subgroups who benefit most from SQ-LNSs could support improved program design.

OBJECTIVES

We aimed to identify study-level and individual-level modifiers of the effect of SQ-LNSs on child hemoglobin (Hb), anemia, and inflammation-adjusted micronutrient status outcomes.

METHODS

We conducted a 2-stage meta-analysis of individual participant data from 13 randomized controlled trials of SQ-LNSs provided to children 6-24 mo of age (n = 15,946). We generated study-specific and subgroup estimates of SQ-LNSs compared with control, and pooled the estimates using fixed-effects models. We used random-effects meta-regression to examine potential study-level effect modifiers.

RESULTS

SQ-LNS provision decreased the prevalence of anemia (Hb < 110 g/L) by 16% (relative reduction), iron deficiency (plasma ferritin < 12 µg/L) by 56%, and iron deficiency anemia (IDA; Hb < 110 g/L and plasma ferritin <12 µg/L) by 64%. We observed positive effects of SQ-LNSs on hematological and iron status outcomes within all subgroups of the study- and individual-level effect modifiers, but effects were larger in certain subgroups. For example, effects of SQ-LNSs on anemia and iron status were greater in trials that provided SQ-LNSs for >12 mo and provided 9 (as opposed to <9) mg Fe/d, and among later-born (than among first-born) children. There was no effect of SQ-LNSs on plasma zinc or retinol, but there was a 7% increase in plasma retinol-binding protein (RBP) and a 56% reduction in vitamin A deficiency (RBP < 0.70 µmol/L), with little evidence of effect modification by individual-level characteristics.

CONCLUSIONS

SQ-LNSs can substantially reduce the prevalence of anemia, iron deficiency, and IDA among children across a range of individual, population, and study design characteristics. Policy-makers and program planners should consider SQ-LNSs within intervention packages to prevent anemia and iron deficiency.This trial was registered at www.crd.york.ac.uk/PROSPERO as CRD42020156663.

Overview of Important Micronutrients Supplementation in Preterm Infants after Discharge: A Call for Consensus

Preterm infants have a lower level of nutrient body stores and immature body systems, resulting in a higher risk of malnutrition. Imbalanced complementary feeding could lead to further risk of nutritional deficits and excesses. However, evidence on their nutritional requirements following hospital discharge is limited. When planning complementary feeding, appropriate micronutrient intake should be considered for their critical role in supporting various body functions. This narrative review summarizes the need for iron, zinc, vitamin D, calcium, phosphate and long-chain polyunsaturated fatty acids (LCPUFAs) supplementation in preterm infants during complementary feeding. Regarding iron and vitamin D, the scientific community is reaching an agreement on supplementation in some categories of prematures. On the contrary, there is still not enough evidence to detail possible recommendations for LCPUFAs, zinc, calcium and phosphorus supplementation. However, these micronutrients are paramount for preterms' health: LCPUFAs can promote retinal and brain development while calcium and phosphorus supplementation is essential to prevent preterms' metabolic bone disease (MBD). Waiting for a consensus on these micronutrients, it is clear how the knowledge of the heterogeneity of the prematures population can help adjust the nutritional planning regarding the growth rate, comorbidities and comprehensive clinical history of the preterm infant.

Multinutrient Biofortification of Maize (Zea mays L.) in Africa: Current Status, Opportunities and Limitations

Macro and micronutrient deficiencies pose serious health challenges globally, with the largest impact in developing regions such as subSaharan Africa (SSA), Latin America and South Asia. Maize is a good source of calories but contains low concentrations of essential nutrients. Major limiting nutrients in maize-based diets are essential amino acids such as lysine and tryptophan, and micronutrients such as vitamin A, zinc (Zn) and iron (Fe). Responding to these challenges, separate maize biofortification programs have been designed worldwide, resulting in several cultivars with high levels of provitamin A, lysine, tryptophan, Zn and Fe being commercialized. This strategy of developing single-nutrient biofortified cultivars does not address the nutrient deficiency challenges in SSA in an integrated manner. Hence, development of maize with multinutritional attributes can be a sustainable and cost-effective strategy for addressing the problem of nutrient deficiencies in SSA. This review provides a synopsis of the health challenges associated with Zn, provitamin A and tryptophan deficiencies and link these to vulnerable societies; a synthesis of past and present intervention measures for addressing nutrient deficiencies in SSA; and a discussion on the possibility of developing maize with multinutritional quality attributes, but also with adaptation to stress conditions in SSA.

Iron- and Zinc-Fortified Lentil (Lens culinaris Medik.) Demonstrate Enhanced and Stable Iron Bioavailability After Storage

Lentil (Lens culinaris Medik.) is a quick-cooking, rapidly expanding protein-rich crop with high iron (Fe) and zinc (Zn), but low bioavailability due to the presence of phytate, similar to other grains. Lentils dual fortified with Fe and Zn can significantly improve the bioavailable Fe and Zn content. Three milled lentil product types (LPTs) were fortified with Fe using NaFeEDTA [ethylenediaminetetraacetic acid iron (III) sodium salt] (Fe fortified) or Zn from ZnSO₄·H₂O (Zn fortified), or both (dual fortified). Fe, Zn, phytic acid (PA) concentration, and relative Fe bioavailability (RFeB%) were assessed for samples from two fortified batches (initial and for 1 year stored). Fe, Zn, and RFeB% increased significantly in two batches of samples from the three LPTs, and decreased by 5–15% after 1 year of storage. PA concentration decreased from 8 to 15% after fortification of all samples from two batches of the three LPTs but showed different patterns of influence after storage. Dual-fortified lentil fortified with 24 mg Fe and 12 mg Zn 100 g⁻¹ lentil had the highest amount of Fe and Zn, and the lowest PA concentration, and RFeB% was increased from 91.3 to 519.5%. Significant (p ≤ 0.01) Pearson correlations were observed between Fe concentration vs. PA:Fe molar ratio (MR), Fe concentration vs. RFeB%, RFeB% vs. PA:Fe MR, and Zn concentration vs. PA:Zn MR in all samples from two batches of the three LPTs. In conclusion, dual-fortified lentil can contribute significant bioavailable Fe and Zn to populations at risk of Fe and Zn deficiency.

Does zinc with and without iron co-supplementation have effect on motor and mental development of children? A systematic review and meta-analysis

BACKGROUND

Effects of zinc with and without iron co-supplementation on child development are uncertain therefore the aims of this systematic review were to explore whether supplementation with zinc alone and zinc with iron in children aged 0-5 years old have beneficial or adverse effects on their mental and motor development.

METHOD

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, CINAHL, Web of Science and Scopus until July 2020 and included randomized controlled trials, which assessed effects of zinc supplementation with and without iron in children less than 5 years old on mental and motor development. Data were pooled by random effects model and the Standardized Mean Differences (SMDs) with 95% confidence interval were estimated. The heterogeneity was assessed by I2.

RESULTS

Twenty-five studies with 11,559 participants were eligible to be included in this systematic review. Meta-analysis was conducted with eight articles that used Bayley Scales of Infant and Toddler Development II. We concluded that zinc alone and zinc with iron co-supplementation do not have beneficial or adverse effect on child mental and motor development at 6 and 12 months of age with low to moderate quality of the evidence. Furthermore, Zinc supplementation does not have any long term effect on child development in preschool and school age children.

CONCLUSION

Most included studies did not show the efficacy of zinc with and without iron co-supplementation on child mental and motor development up to 9 years old age. Further Randomized Controlled Trials (RCTs) need to be taken into considerations the context-based differences between countries with special focus on socio-economic differences.

Zinc deficiency in low- and middle-income countries: prevalence and approaches for mitigation

This review addresses the prevalence of zinc deficiency in Low- and Middle-income Countries (LMICs) and assesses the available strategies for its alleviation. The paucity of national-level data on the zinc deficiency in LMICs is partially a result of the lack of a reliable biomarker. Zinc deficiency appears to be a public health problem in almost all the LMICs, irrespective of the recommended indicators (plasma zinc concentration, dietary zinc adequacy and stunting prevalence) used. Based on plasma/serum zinc concentration (PZC), which is the most appropriate indicator at present, the prevalence of zinc deficiency in LMICs is of concern. Among the 25 countries for which national PZC data were available, 23 had a zinc deficiency prevalence of >20% for at least one physiological group. Zinc supplementation is largely restricted as an adjunct therapy for diarrhoea management in children, and the best platform and the most effective way of preventive zinc supplementation delivery remains to be established. Impact assessment for current zinc fortification programmes in LMICs and the effectiveness of zinc supplementation as part of a multi-micronutrient powder is to be determined. Dietary diversification, though promising for LMICs, is in the nascent stages of development at present. Inclusion of meat and animal products can be an important way of improving zinc status. Programmatic experience with the promotion of home processing techniques to increase absorbable zinc in the diet is lacking. Conventional biofortification techniques are gaining recognition in LMICs; however, transgenic biofortification as a strategy remains controversial.

Multi-Micronutrient Fortified Rice Improved Serum Zinc and Folate Concentrations of Cambodian School Children. A Double-Blinded Cluster-Randomized Controlled Trial

BACKGROUND

Within Cambodia, micronutrient deficiencies continue to be prevalent in vulnerable groups, such as women and children. Fortification of staple foods such as rice could be a promising strategy for Cambodia to improve micronutrient status.

OBJECTIVE

Our objective was to investigate the impact of multiple-micronutrient fortified rice (MMFR), distributed through a World Food Program school-meals program (WFP-SMP) on serum zinc concentrations and folate status in a double-blind, cluster-randomized, placebo-controlled trial.

METHODS

Sixteen schools were randomly assigned to receive one of three different types of extruded-fortified rice (UltraRice Original (URO), UltraRice New (URN), or NutriRice) or unfortified rice (placebo) six days a week for six months. A total of 1950 schoolchildren (6-16 years old) participated in the study. Serum zinc (all groups) and folate (only in NutriRice and placebo group) concentrations were assessed from morning non-fasting antecubital blood samples and were measured at three time points (baseline and after three and six months).

RESULTS

After six months of intervention, serum zinc concentrations were significantly increased in all fortified rice group compared to placebo and baseline (0.98, 0.85 and 1.40 µmol/L for URO, URN and NutriRice, respectively) (interaction effect: p < 0.001 for all). Children in the intervention groups had a risk of zinc deficiencies of around one third (0.35, 039, and 0.28 for URO, URN, and NutriRice, respectively) compared to the placebo (p < 0.001 for all). The children receiving NutriRice had higher serum folate concentrations at endline compared to children receiving normal rice (+ 2.25 ng/mL, p = 0.007).

CONCLUSIONS

This study showed that the high prevalence of zinc and folate deficiency in Cambodia can be improved through the provision of MMFR. As rice is the staple diet for Cambodia, MMFR should be considered to be included in the school meal program and possibilities should be explored to introduce MMFR to the general population.

Identifying Dietary Strategies to Improve Nutrient Adequacy among Ethiopian Infants and Young Children Using Linear Modelling

Nutrient adequacy of young children's diet and best possible strategies to improve nutrient adequacy were assessed. Data from the Ethiopian National Food Consumption Survey were analysed using Optifood (software for linear programming) to identify nutrient gaps in diets for children (6-8, 9-11 and 12-23 months), and to formulate feasible Food-Based Dietary Recommendations (FBDRs) in four regions which differ in culture and food practices. Alternative interventions including a local complementary food, micronutrient powders (MNPs), Small quantity Lipid-based Nutrient Supplement (Sq-LNS) and combinations of these were modelled in combination with the formulated FBDRs to compare their relative contributions. Risk of inadequate and excess nutrient intakes was simulated using the Estimated Average Requirement cut-point method and the full probability approach. Optimized local diets did not provide adequate zinc in all regions and age groups, iron for infants <12 months of age in all regions, and calcium, niacin, thiamine, folate, vitamin B12 and B6 in some regions and age-groups. The set of regional FBDRs, considerably different for four regions, increased nutrient adequacy but some nutrients remained sub-optimal. Combination of regional FBDRs with daily MNP supplementation for 6-12 months of age and every other day for 12-23 months of age, closed the identified nutrient gaps without leading to a substantial increase in the risk of excess intakes.

Health effects of micronutrient fortified dairy products and cereal food for children and adolescents: A systematic review

INTRODUCTION

Micronutrient (MN) deficiencies cause a considerable burden of disease for children in many countries. Dairy products or cereals are an important food component during adolescence. Fortification of dairy products or cereals with MN may be an effective strategy to overcome MN deficiencies, but their specific impact on health in this age group is poorly documented.

METHODS

We performed a systematic review and meta-analysis (registration number CRD42016039554) to assess the impact of MN fortified dairy products and cereal food on the health of children and adolescents (aged 5-15 years) compared with non-fortified food. We reviewed randomised controlled trials (RCT) using electronic databases (MEDLINE, EMBASE, Cochrane library; latest search: January 2018), reference list screening and citation searches. Three pairs of reviewers assessed 2048 studies for eligibility and extracted data. We assessed the risk of bias and applied GRADE to rate quality of evidence.

RESULTS

We included 24 RCT (often multi MN fortification) with 30 pair-wise comparisons mainly from low- and middle income countries. A very small and non-significant increase of haemoglobin values emerged (0.09 g/dl [95%-CI: -0.01 to 0.18]; 13 RCT with iron fortification; very low quality of evidence). No significant difference was found on anaemia risk (risk ratio 0.87 [95%-CI: 0.76 to 1.01]; 12 RCT; very low quality), but a significant difference in iron deficiency anaemia favouring fortified food was found (risk ratio 0.38 [95%-CI: 0.18 to 0.81]; 5 RCT; very low quality). Similar effects were seen for fortified dairy products and cereals and different fortification strategies (mono- vs. dual- vs. multi-MN). Follow-up periods were often short and the impact on anthropometric measures was weak (low quality of evidence) Very low quality of evidence emerged for the improvement of cognitive performance, functional measures and morbidity.

CONCLUSIONS

Fortification of dairy products and cereal food had only marginal health effects in our sample population from 5-15 years. Further evidence is needed to better understand the health impact of fortified dairy products and cereals in this age group.

SYSTEMATIC REVIEW REGISTRATION

The study protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 26 May 2016 (registration number CRD42016039554).

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.

How Could Agronomic Biofortification of Rice Be an Alternative Strategy with Higher Cost-Effectiveness for Human Iron and Zinc Deficiency in China?

Background:

Iron and zinc deficiencies affect human health globally, especially in developing countries. Agronomic biofortification, as a strategy for alleviating these issues, has been focused on small-scale field studies, and not widely applied while lacking of cost-effectiveness analysis (CEA).

Objective:

We conducted the CEA of agronomic biofortification, expressed as USD per disability-adjusted life years (DALYs) saved, to recommend a cost-effectiveness strategy that can be widely applied.

Methods:

The DALYs were applied to quantify the health burden due to Fe and/or Zn deficiency and health cost of agronomic biofortification via a single, dual, or triple foliar spray of Fe, Zn, and/or pesticide in 4 (northeast, central China, southeast, and southwest) major Chinese rice-based regions.

Results:

The current health burden by Fe or Zn malnutrition was 0.45 to 1.45 or 0.14 to 0.84 million DALYs for these 4 regions. Compared to traditional rice diets, the daily Fe and/or Zn intake from Fe and/or Zn-biofortified rice increased, and the health burden of Fe and/or Zn deficiency decreased by 28% and 48%, respectively. The cost of saving 1 DALYs ranged from US$376 to US$4989, US$194 to US$2730, and US$37.6 to US$530.1 for the single, dual, and triple foliar Fe, Zn, and/or pesticide application, respectively, due to a substantial decrease in labor costs by the latter 2 applications.

Conclusions:

Agronomic biofortification of rice with the triple foliar spray of Fe, Zn, and pesticide is a rapidly effective and cost-effectiveness pathway to alleviate Fe and Zn deficiency for rice-based dietary populations.

Iron, zinc, vitamin A and selenium status in a cohort of Indonesian infants after adjusting for inflammation using several different approaches

Inflammation confounds the interpretation of several micronutrient biomarkers resulting in estimates that may not reflect the true burden of deficiency. We aimed to assess and compare the micronutrient status of a cohort of Indonesian infants (n 230) at aged 6, 9 and 12 months by ignoring inflammation (unadjusted) and adjusting four micronutrient biomarkers for inflammation with C-reactive protein (CRP) and α-1-glycoprotein (AGP) using the following methods: (1) arithmetic correction factors with the use of a four-stage inflammation model; and (2) regression modelling. Prevalence of infants with any inflammation (CRP>5 mg/l and/or AGP>1 g/l) was about 25% at each age. Compared with unadjusted values, regression adjustment at 6, 9 and 12 months generated the lowest (P50 % across all ages. In conclusion, without inflammation adjustment, Fe deficiency was grossly under-estimated and vitamin A and Zn deficiency over-estimated, highlighting the importance of correcting for the influence of such, before implementing programmes to alleviate micronutrient malnutrition. However, further work is needed to validate the proposed approaches with a particular focus on assessing the influence of varying degrees of inflammation (i.e. recurrent acute infections and low-grade chronic inflammation) on each affected nutrient biomarker.

Combination of different antifungal agents in oil-in-water emulsions to control strawberry jam spoilage

The combination of antifungal agents (cinnamon bark oil, zinc gluconate and trans-ferulic acid) in oil-in-water emulsions to control the fungal spoilage of strawberry jams, minimising essential oil's sensory impact, was evaluated in this work. The in vitro assays of free antifungal agents were performed against five fungal strains; meanwhile, the emulsions assays were conducted against Aspergillus niger given its strong resistance and its relevance in strawberry products. The emulsion formulated with 0.08mg/g of essential oil was able to inhibit mould growth after the incubation period. The incorporation of zinc gluconate or trans-ferulic acid, independently of the concentration used, allowed to reduce a 25% the amount of essential oil needed to inhibit the microbial growth. The combination of antifungal agents in the emulsions has demonstrated to be an effective alternative to reduce the amount of essential oil employed, maintaining the hygienic quality and sensory profile of the strawberry jam.

A moderate increase in dietary zinc reduces DNA strand breaks in leukocytes and alters plasma proteins without changing plasma zinc concentrations

BACKGROUND

Food fortification has been recommended to improve a population's micronutrient status. Biofortification techniques modestly elevate the zinc content of cereals, but few studies have reported a positive impact on functional indicators of zinc status.

OBJECTIVE

We determined the impact of a modest increase in dietary zinc that was similar to that provided by biofortification programs on whole-body and cellular indicators of zinc status.

DESIGN

Eighteen men participated in a 6-wk controlled consumption study of a low-zinc, rice-based diet. The diet contained 6 mg Zn/d for 2 wk and was followed by 10 mg Zn/d for 4 wk. To reduce zinc absorption, phytate was added to the diet during the initial period. Indicators of zinc homeostasis, including total absorbed zinc (TAZ), the exchangeable zinc pool (EZP), plasma and cellular zinc concentrations, zinc transporter gene expression, and other metabolic indicators (i.e., DNA damage, inflammation, and oxidative stress), were measured before and after each dietary-zinc period.

RESULTS

TAZ increased with increased dietary zinc, but plasma zinc concentrations and EZP size were unchanged. Erythrocyte and leukocyte zinc concentrations and zinc transporter expressions were not altered. However, leukocyte DNA strand breaks decreased with increased dietary zinc, and the level of proteins involved in DNA repair and antioxidant and immune functions were restored after the dietary-zinc increase.

CONCLUSIONS

A moderate 4-mg/d increase in dietary zinc, similar to that which would be expected from zinc-biofortified crops, improves zinc absorption but does not alter plasma zinc. The repair of DNA strand breaks improves, as do serum protein concentrations that are associated with the DNA repair process. This trial was registered at clinicaltrials.gov as NCT02861352.

Fortification of staple foods with zinc for improving zinc status and other health outcomes in the general population

BACKGROUND

Zinc deficiency is a global nutritional problem, particularly in children and women residing in settings where diets are cereal based and monotonous. It has several negative health consequences. Fortification of staple foods with zinc may be an effective strategy for preventing zinc deficiency and improving zinc-related health outcomes.

OBJECTIVES

To evaluate the beneficial and adverse effects of fortification of staple foods with zinc on health-related outcomes and biomarkers of zinc status in the general population.

SEARCH METHODS

We searched the following databases in April 2015: Cochrane Central Register of Controlled Trials (CENTRAL, Issue 3 of 12, 2015, the Cochrane Library), MEDLINE & MEDLINE In Process (OVID) (1950 to 8 April 2015), EMBASE (OVID) (1974 to 8 April 2015), CINAHL (1982 to April 2015), Web of Science (1900 to 9 April 2015), BIOSIS (1969 to 9 April 2015), POPLINE (1970 to April 2015), AGRICOLA, OpenGrey, BiblioMap, and Trials Register of Promoting Health Interventions (TRoPHI), besides regional databases (April 2015) and theses. We also searched clinical trial registries (17 March 2015) and contacted relevant organisations (May 2014) in order to identify ongoing and unpublished studies.

SELECTION CRITERIA

We included randomised controlled trials, randomised either at the level of the individual or cluster. We also included non-randomised trials at the level of the individual if there was a concurrent comparison group. We included non-randomised cluster trials and controlled before-after studies only if there were at least two intervention sites and two control sites. Interventions included fortification (central/industrial) of staple foods (cereal flours, edible fats, sugar, condiments, seasonings, milk and beverages) with zinc for a minimum period of two weeks. Participants were members of the general population who were over two years of age (including pregnant and lactating women) from any country.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of studies for inclusion, extracted data from included studies, and assessed the risk of bias of the included studies.

MAIN RESULTS

We included eight trials (709 participants); seven were from middle-income countries of Asia, Africa, Europe, and Latin America where zinc deficiency is likely to be a public health problem. Four trials compared the effect of zinc-fortified staple foods with unfortified foods (comparison 1), and four compared zinc-fortified staple foods in combination with other nutrients/factors with the same foods containing other nutrients or factors without zinc (comparison 2). The interventions lasted between one and nine months. We categorised most trials as having unclear or high risk of bias for randomisation, but low risk of bias for blinding and attrition. None of the studies in comparison 1 reported data on zinc deficiency.Foods fortified with zinc increased the serum or plasma zinc levels in comparison to foods without added zinc (mean difference (MD) 2.12 µmol/L, 95% confidence interval (CI) 1.25 to 3.00 µmol/L; 3 studies; 158 participants; low-quality evidence). Participants consuming foods fortified with zinc versus participants consuming the same food without zinc had similar risk of underweight (average risk ratio 3.10, 95% CI 0.52 to 18.38; 2 studies; 397 participants; low-quality evidence) and stunting (risk ratio (RR) 0.88, 95% CI 0.36 to 2.13; 2 studies; 397 participants; low-quality evidence). A single trial of addition of zinc to iron in wheat flour did not find a reduction in proportion of zinc deficiency (RR 0.17, 95% CI 0.01 to 3.94; very low-quality evidence). We did not find a difference in serum or plasma zinc levels in participants consuming foods fortified with zinc plus other micronutrients when compared with participants consuming the same foods with micronutrients but no added zinc (MD 0.03 µmol/L, 95% CI -0.67 to 0.72 µmol/L; 4 studies; 250 participants; low-quality evidence). No trial in comparison 2 provided information about underweight or stunting.There was no reported adverse effect of fortification of foods with zinc on indicators of iron or copper status.

AUTHORS' CONCLUSIONS

Fortification of foods with zinc may improve the serum zinc status of populations if zinc is the only micronutrient used for fortification. If zinc is added to food in combination with other micronutrients, it may make little or no difference to the serum zinc status. Effects of fortification of foods with zinc on other outcomes including zinc deficiency, children's growth, cognition, work capacity of adults, or on haematological indicators are unknown. Given the small number of trials and participants in each trial, further investigation of these outcomes is required.

Micronutrient Fortified Condiments and Noodles to Reduce Anemia in Children and Adults--A Literature Review and Meta-Analysis

Micronutrient deficiencies impose a considerable burden of disease on many middle and low income countries. Several strategies have been shown to be effective in improving micronutrient deficiencies. However, the impact of fortified condiments as well as fortified noodles is less well documented. We aimed to investigate existing evidence on the impact of micronutrient fortified condiments and noodles on hemoglobin, anemia, and functional outcomes in children and adults (age: 5 to 50 years). We conducted a literature review in electronic databases. In addition, we screened the homepages of relevant organizations and journals. We included randomized controlled trials (RCT). Of 1046 retrieved studies, 14 RCT provided data for the meta-analysis. Micronutrient fortification of condiments and noodles increased hemoglobin concentrations by 0.74 g/dL (95%-confidence intervals (95%-CI): 0.56 to 0.93; 12 studies) and 0.3 g/dL (95%-CI: 0.12 to 0.48; 1 study), respectively. Micronutrient fortification also led to a reduced risk of having anemia (risk ratio 0.59 (95%-CI 0.44 to 0.80)). Ferritin concentrations increased with fortified condiments. Functional outcomes were rarely assessed and showed mixed results. The use of micronutrient fortified condiments can be a strategy to reduce anemia in children and adults due to micronutrient deficiencies. The effect of fortified noodles seems to be smaller.

Zinc Absorption by Adults Is Similar from Intrinsically Labeled Zinc-Biofortified Rice and from Rice Fortified with Labeled Zinc Sulfate

BACKGROUND

Biofortification of staple food crops is a promising strategy to combat zinc deficiency, and it is of particular interest for rice and crops that are not consumed as flours and therefore not suitable for postharvest fortification. Because zinc absorption is decreased by phytic acid (PA) and perhaps other dietary components, it is important to measure the absorption of zinc from a biofortified crop before determining its efficacy.

OBJECTIVE

In this study, we compared the zinc absorption from zinc-biofortified rice (hydroponically enriched with (70)Zn) with that from a control rice of the same variety fortified with (70)ZnSO4 at point of use to reach the same total zinc content of 1.1 mg/meal. Both rice meals had a PA:Zn molar ratio of 12.

METHODS

Fractional absorption of zinc (FAZ) was measured with the use of the double-isotope tracer ratio method in 16 apparently healthy adults [18-45 y old; BMI (in kg/m(2)) 19-25] who consumed 2 single meals at 4-wk intervals in random order in a crossover design.

RESULTS

The FAZ from the biofortified rice (mean ± SD: 25.1 ± 8.7%) did not differ significantly from that of the point-of-use fortified rice (mean ± SD: 20.8 ± 7.1%) (P = 0.08).

CONCLUSIONS

These results suggest that the native zinc accumulated in the biofortified rice was readily released from the rice matrix and that its absorption by adults was influenced by PA and other food components in a similar way to the inorganic zinc compound added to the rice at point of use. Moreover, rice biofortification is likely to be as good as postharvest zinc fortification as an intervention strategy to combat zinc deficiency. This trial was registered at clinicaltrials.gov as NCT01633450.

Bioavailability of iron, vitamin A, zinc, and folic acid when added to condiments and seasonings

Seasonings and condiments can be candidate vehicles for micronutrient fortification if consumed consistently and if dietary practices ensure bioavailability of the nutrient. In this review, we identify factors that may affect the bioavailability of iron, vitamin A, zinc, and folic acid when added to seasonings and condiments and evaluate their effects on micronutrient status. We take into consideration the chemical and physical properties of different forms of the micronutrients, the influence of the physical and chemical properties of foods and meals to which fortified seasonings and condiments are typically added, and interactions between micronutrients and the physiological and nutritional status of the target population. Bioavailable fortificants of iron have been developed for use in dry or fluid vehicles. For example, sodium iron ethylenediaminetetraacetic acid (NaFeEDTA) and ferrous sulfate with citric acid are options for iron fortification of fish and soy sauce. Furthermore, NaFeEDTA, microencapsulated ferrous fumarate, and micronized elemental iron are potential fortificants in curry powder and salt. Dry forms of retinyl acetate or palmitate are bioavailable fortificants of vitamin A in dry candidate vehicles, but there are no published studies of these fortificants in fluid vehicles. Studies of zinc and folic acid bioavailability in seasonings and condiments are also lacking.

Effect of zinc added to a daily small-quantity lipid-based nutrient supplement on diarrhoea, malaria, fever and respiratory infections in young children in rural Burkina Faso: a cluster-randomised trial

OBJECTIVE

Preventive zinc supplementation in the form of tablets or syrup reduces the incidence of diarrhoea and acute lower respiratory tract infections (RTI), but its effect on malaria is inconsistent. When zinc is administered with other micronutrients or foods, its effect is also uncertain. We assessed the effects of different amounts and sources of zinc on the frequency of diarrhoea, malaria, fever and RTI in young children.

DESIGN, SETTING AND POPULATIONS

This community-based, double-blind, placebo-controlled, cluster-randomised trial of 2435 children 9 months of age was carried out between April 2010 and July 2012 in rural southwestern Burkina Faso.

INTERVENTIONS

Participants were randomly assigned at the concession level to receive daily 1 of 4 interventions for 9 months: (1) 20 g small-quantity lipid-based nutrient supplement (SQ-LNS) without zinc and placebo tablet, (2) 20 g SQ-LNS with 5 mg zinc and placebo tablet, (3) 20 g SQ-LNS with 10 mg zinc and placebo tablet or (4) 20 g SQ-LNS without zinc and 5 mg zinc tablet. Participants were visited weekly in their homes for morbidity surveillance for 9 months, and those with uncomplicated diarrhoea and malaria received treatment from the study field workers in the community.

MAIN OUTCOMES

Incidence and longitudinal prevalence of diarrhoea, malaria, fever, and lower and upper RTI by intervention group.

RESULTS

The incidence of diarrhoea, malaria and fever was 1.10 (±1.03 SD), 0.61 (±0.66 SD) and 1.49 (±1.12 SD) episodes per 100 child-days at risk, respectively, and did not differ by intervention group (p=0.589, p=0.856 and p=0.830, respectively). The longitudinal prevalence of acute lower RTI (0.1%; 95% IC 0.1-0.2%) and of upper RTI (7.8%; 95% IC 7.1-8.4%) did not differ among groups (p=0.234 and p=0.501, respectively).

CONCLUSIONS

Inclusion of 5 or 10 mg zinc in SQ-LNS and provision of 5 mg zinc dispersible tablet along with SQ-LNS had no impact on the incidence of diarrhoea, malaria and fever or the longitudinal prevalence of RTI compared with SQ-LNS without zinc in this population.

TRIAL REGISTRATION NUMBER

NCT00944281.

The potential for zinc stable isotope techniques and modelling to determine optimal zinc supplementation

It is well recognised that zinc deficiency is a major global public health issue, particularly in young children in low-income countries with diarrhoea and environmental enteropathy. Zinc supplementation is regarded as a powerful tool to correct zinc deficiency as well as to treat a variety of physiologic and pathologic conditions. However, the dose and frequency of its use as well as the choice of zinc salt are not clearly defined regardless of whether it is used to treat a disease or correct a nutritional deficiency. We discuss the application of zinc stable isotope tracer techniques to assess zinc physiology, metabolism and homeostasis and how these can address knowledge gaps in zinc supplementation pharmacokinetics. This may help to resolve optimal dose, frequency, length of administration, timing of delivery to food intake and choice of zinc compound. It appears that long-term preventive supplementation can be administered much less frequently than daily but more research needs to be undertaken to better understand how best to intervene with zinc in children at risk of zinc deficiency. Stable isotope techniques, linked with saturation response and compartmental modelling, also have the potential to assist in the continued search for simple markers of zinc status in health, malnutrition and disease.

Selecting desirable micronutrient fortificants for plant-based complementary foods for infants and young children in low-income countries

The World Health Organization (WHO) recommends that both breast-fed and non-breast-fed children are fed micronutrient fortified complementary foods designed to meet their high nutrient requirements from aged 6 to 23 months of age. This paper summarises the steps recommended by WHO/FAO to identify the country-specific micronutrient shortfalls in complementary diets and establish desirable levels of bioavailable fortificants for centrally processed plant-based complementary foods for infant and young child feeding. The goal of the WHO/FAO guidelines is to achieve a desirably low prevalence of inadequate micronutrient intakes in the target group whilst simultaneously ensuring minimal risk of excessive intakes.

Rice fortification with zinc during parboiling may improve the adequacy of zinc intakes in Bangladesh

BACKGROUND

Zinc deficiency is prevalent among children and women in Bangladesh and parboiled rice is the major staple food consumed. Parboiling offers an opportunity to increase the zinc and iron content of rice by adding fortificants to the soaking water.

RESULTS

Rice zinc content increased with increasing amounts of zinc sulfate added to the parboil soaking water. Addition of 1300 mg zinc L(-1) increased raw polished rice zinc content from 16.6 to 44.9 mg kg(-1) and from 12.6 to 32.9 mg kg(-1) in the open and closed parboiling systems, equivalent to 170% and 161% increases, respectively. Retention of zinc after washing and cooking was 70-81% across all concentrations tested. Addition of iron-ethylenediaminetetraacetic acid and zinc sulfate together increased zinc, but not iron, content of polished rice. The simulated prevalence of inadequate zinc intake was reduced by more than half among children and nearly two-thirds among women if 50% of the population were to consume the 1300 mg zinc L(-1) parboiled fortified rice.

CONCLUSION

Addition of zinc sulfate to soaking water during parboiling increases the zinc content of rice and, if found to be bioavailable, could substantially reduce the prevalence of inadequate zinc intake by children and women in Bangladesh.

Reasons for raising the maximum acceptable daily intake of EDTA and the benefits for iron fortification of foods for children 6-24 months of age

The current maximum acceptable daily intake (ADI) of ethylenediaminetetraacetic acid (EDTA) of 1.9 mg day(-1) per kilogram bodyweight (mg day(-1)  kgbw(-1) ) limits the daily intake of iron as iron EDTA [ferric sodium EDTA; sodium iron(III) EDTA] to approximately 2-2.5 mg day(-1) for children 6-24 months of age. This limit was defined by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1973 based on data from an animal-feed study published in 1963. Other animal studies indicate that this limit can be raised to 4.4 or possibly up to 21.7 mg day(-1)  kgbw(-1) , which is 2.3-11.4 times higher than the current value. For nearly 50 years, iron EDTA has been used in France in medicinal syrup for infants 1-6 months of age. The maximum recommended dosage of this drug is 37 times higher than the maximum ADI of EDTA. No adverse health effects have been reported as a result of this medicinal consumption of iron EDTA. Raising the maximum ADI of EDTA to only 4.4 mg day(-1)  kgbw(-1) would enable iron EDTA, an iron fortificant with proven bioavailability in phytate-rich meals, to be added in adequate amounts to cereal-based meals for children 6-24 months of age, who are at risk of iron deficiency.

Evaluating the cost-effectiveness of preventive zinc supplementation

BACKGROUND

Even though the WHO currently recommends zinc for diarrhea management, no consensus has been reached with respect to routine distribution of zinc for preventive reasons. We reviewed the health impact of preventive zinc interventions, and evaluated the relative cost effectiveness of currently feasible interventions.

METHODS

Using the latest relative risk estimates reported in the literature, we parameterized a health impact model, and calculated the expected benefits of zinc supplementation in a representative low-income country. We then computed the cost and cost-effectiveness for three delivery mechanisms: the direct distribution of zinc supplements, the distribution of micronutrient biscuits including zinc, and the distribution of zinc through water filtration systems.

RESULTS

Combining all health outcomes and impact estimates, we find that systematic zinc supplementation among children of ages one to five would avert 1.423 DALYs per 100 households and year in least developed countries. The estimated cost per DALY is US$ 606 for pill supplementation, US$ 1211 for micronutrient biscuits, and US$ 879 per DALY saved for water filtration systems.

CONCLUSIONS

Preventive zinc supplementation to children of ages 1-5 appears to be a highly cost-effective intervention in typical developing country settings. More research will be needed to determine the most effective mechanism to deliver zinc to this target population.

Zinc supplementation for preventing mortality, morbidity, and growth failure in children aged 6 months to 12 years of age

BACKGROUND

Zinc deficiency is prevalent in low- and middle-income countries, and contributes to significant diarrhoea-, pneumonia-, and malaria-related morbidity and mortality among young children. Zinc deficiency also impairs growth.

OBJECTIVES

To assess the effects of zinc supplementation for preventing mortality and morbidity, and for promoting growth, in children aged six months to 12 years of age.

SEARCH METHODS

Between December 2012 and January 2013, we searched CENTRAL, MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, Embase, African Index Medicus, Conference Proceedings Citation Index, Dissertation Abstracts, Global Health, IndMED, LILACS, WHOLIS, metaRegister of Controlled Trials, and WHO ICTRP.

SELECTION CRITERIA

Randomised controlled trials of preventive zinc supplementation in children aged six months to 12 years compared with no intervention, a placebo, or a waiting list control. We excluded hospitalised children and children with chronic diseases or conditions. We excluded food fortification or intake, sprinkles, and therapeutic interventions.

DATA COLLECTION AND ANALYSIS

Two authors screened studies, extracted data, and assessed risk of bias. We contacted trial authors for missing information.

MAIN RESULTS

We included 80 randomised controlled trials with 205,401 eligible participants. We did not consider that the evidence for the key analyses of morbidity and mortality outcomes were affected by risk of bias. The risk ratio (RR) for all-cause mortality was compatible with a reduction and a small increased risk of death with zinc supplementation (RR 0.95, 95% confidence interval (CI) 0.86 to 1.05, 14 studies, high-quality evidence), and also for cause-specific mortality due to diarrhoea (RR 0.95, 95% CI 0.69 to 1.31, four studies, moderate-quality evidence), lower respiratory tract infection (LRTI) (RR 0.86, 95% CI 0.64 to 1.15, three studies, moderate-quality evidence), or malaria (RR 0.90, 95% CI 0.77 to 1.06, two studies, moderate-quality evidence).Supplementation reduced diarrhoea morbidity, including the incidence of all-cause diarrhoea (RR 0.87, 95% CI 0.85 to 0.89, 26 studies, moderate-quality evidence), but the results for LRTI and malaria were imprecise: LRTI (RR 1, 95% CI 0.94 to 1.07, 12 studies, moderate-quality evidence); malaria (RR 1.05, 95% 0.95 to 1.15, four studies, moderate-quality evidence).There was moderate-quality evidence of a very small improvement in height with supplementation (standardised mean difference (SMD) -0.09, 95% CI -0.13 to -0.06; 50 studies), but the size of this effect might not be clinically important. There was a medium to large positive effect on zinc status.Supplementation was associated with an increase in the number of participants with at least one vomiting episode (RR 1.29, 95% CI 1.14 to 1.46, five studies, high-quality evidence). We found no clear evidence of benefit or harm of supplementation with regard to haemoglobin or iron status. Supplementation had a negative effect on copper status.

AUTHORS' CONCLUSIONS

In our opinion, the benefits of preventive zinc supplementation outweigh the harms in areas where the risk of zinc deficiency is relatively high. Further research should determine optimal intervention characteristics such as supplement dose.

Effect of supplementation with a lipid-based nutrient supplement on the micronutrient status of children aged 6-18 months living in the rural region of Intibucá, Honduras

BACKGROUND

Lipid-based nutrient supplements (LNS) have been effective in the treatment of acute malnutrition among children. We evaluated the use of LNS supplementation for improving the micronutrient status of young children.

METHODS

A 12-month randomised controlled trial was conducted among children aged 6-18 months living in Intibucá, Honduras. Communities (n = 18) were randomised into clusters matched by poverty indicators (9 intervention, n = 160 and 9 controls, n = 140). Intervention participants received LNS. All children received food vouchers and nutrition education. Primary outcomes included measures of micronutrient status: at baseline, 6 and 12 months' blood were collected for assessment of folate, iron, zinc, riboflavin, and vitamin B12 status; haemoglobin was measured every 3 months; and dietary and anthropometry collected monthly. Longitudinal analyses were based on intent to treat and LNS adherence. Generalised estimating equations were used in the estimation of generalised linear regression models specified for the data.

RESULTS

At 6-month follow-up, children in the intervention group had a lower proportion classified as deficient for B12 (43.6%) compared with the control (67.7%; P = 0.03). The intervention group had a higher mean concentration for folate at 6 months (P = 0.06), and improvements continued through 12 months for folate (P = 0.002) and vitamin A deficiency (P = 0.03). This pattern of results, with improved significance, remained in subanalysis based on LNS adherence.

CONCLUSION

These data demonstrate that LNS improved select micronutrient status in young non-malnourished Honduran children.

Differences in energy and micronutrient intakes among Central Texas WIC infants and toddlers after the package change

OBJECTIVE

To assess nutrient intakes after the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) package changes within an at-risk, majority Hispanic population of WIC infants and toddlers in Central Texas.

METHODS

For this cross-sectional observational study, Nutrition Data System for Research was used to collect 24-hour recalls of infants and toddlers from a sample of caregivers in 2009 and 2011. Usual nutrient intakes were estimated and compared with Dietary Reference Intakes using the National Cancer Institute method. Mean single-day nutrient intakes were compared using Mann-Whitney tests.

RESULTS

Subjects were children ages 4-24 months (2009, n = 84; 2011, n = 120). After the package change, usual energy intakes exceeded recommended levels for infants (79% in excess of Estimated Energy Requirement), but fell below recommended levels for toddlers (88% below Estimated Energy Requirement). Also after the package change, mean usual intake of vitamin D was below the Estimated Average Requirement for toddlers (6.54 vs 10 μg), and mean usual intakes of vitamin A and zinc exceeded the Tolerable Upper Intake Level for all groups.

CONCLUSIONS AND IMPLICATIONS

Whereas lower energy intake may reduce obesity risk, in toddlers, lower energy intake increases risk for micronutrient deficiencies. Recommendations include culturally appropriate education and reinstatement of previous milk allotment in the toddler package.

Establishing desirable fortificant levels for calcium, iron and zinc in foods for infant and young child feeding: examples from three Asian countries

We used the World Health Organization's recommended procedures to establish desirable fortificant levels for three problem micronutrients in children's diets, based on dietary data collected earlier from Filipino (n = 1374; 6-36 months), Mongolian (n = 179; 12-36 months) and Cambodian (n = 177; 12-36 months) children. Prevalence of inadequate and excessive intakes of calcium and zinc (via cut-point method) and iron (via full-probability approach) was assessed after adjusting usual intake distributions with pc-side using internal or external within-person variances from Filipino (calcium and iron) and US National Health And Nutrition Examination Survey III (zinc) national surveys. Fortificant levels were determined by repositioning usual intake distributions so that the 2.5th percentile of the targeted populations equalled the estimated average requirement (calcium, zinc) or so that full-probability prevalence was no larger than 2.5% (iron). Prevalence of inadequate intakes was ≥70% for calcium and iron, except Filipino infants (30% for Ca) and Cambodian toddlers (41% for Fe); but <1% for zinc for toddlers in Mongolia and 20% in Cambodia. Prevalence of excessive intakes was <1% for zinc, calcium and iron, except for Mongolian toddlers (11% for Zn). Desirable fortificant levels, although apparently negligible for zinc, were 530-783 mg for calcium and 10.8-22.8 mg for iron (per 100 g). Fortificant levels can be estimated from 24-h recalls, preferably by applying internal within-person variances. Fortification with calcium and iron was necessary, but seemingly not for zinc, despite a high prevalence of low serum zinc, suggesting the need for better defined cut-offs for population risk of zinc deficiency based on dietary zinc intake and/or serum zinc.

Comparison of the estimated cost-effectiveness of preventive and therapeutic zinc supplementation strategies for reducing child morbidity and mortality in sub-Saharan Africa

BACKGROUND

Zinc supplementation of young children in lower-income countries reduces morbidity from diarrhea and pneumonia and all-cause mortality, but the most cost-effective approach for distributing zinc supplements is unknown.

OBJECTIVE

To examine the potential impact of four possible strategies for delivering zinc supplements on disease prevention and deaths averted among children 6 to 59 months of age in sub-Saharan Africa.

METHODS

We analyzed different zinc supplementation strategies to assess their likely impact on morbidity and mortality of preschool children in sub-Saharan Africa and to estimate their possible costs.

RESULTS

Preventive zinc supplementation reduces diarrhea incidence by 27% among children 12 to 59 months of age, pneumonia incidence by 21% among children 6 to 59 months of age, and all-cause mortality by 18% among children 12 to 59 months of age. The likely average total program costs of zinc supplementation programs were estimated from the outlays of existing service delivery platforms, such as child health days, community-based nutrition programs, and clinic-based treatment of diarrhea, assuming different levels of coverage and target age ranges of children.

CONCLUSIONS

We found that the average total costs per life saved ranged from approximately US$462 to US$3,111, and the most cost-effective interventions were weekly or intermittent preventive zinc supplementation, because of the possibility of high coverage and fewer supplements required. Empirical data from zinc supplementation programs will be needed to confirm these estimates.

Micronutrient fortification of food and its impact on woman and child health: a systematic review

BACKGROUND

Vitamins and minerals are essential for growth and metabolism. The World Health Organization estimates that more than 2 billion people are deficient in key vitamins and minerals. Groups most vulnerable to these micronutrient deficiencies are pregnant and lactating women and young children, given their increased demands. Food fortification is one of the strategies that has been used safely and effectively to prevent vitamin and mineral deficiencies.

METHODS

A comprehensive search was done to identify all available evidence for the impact of fortification interventions. Studies were included if food was fortified with a single, dual or multiple micronutrients and impact of fortification was analyzed on the health outcomes and relevant biochemical indicators of women and children. We performed a meta-analysis of outcomes using Review Manager Software version 5.1.

RESULTS

Our systematic review identified 201 studies that we reviewed for outcomes of relevance. Fortification for children showed significant impacts on increasing serum micronutrient concentrations. Hematologic markers also improved, including hemoglobin concentrations, which showed a significant rise when food was fortified with vitamin A, iron and multiple micronutrients. Fortification with zinc had no significant adverse impact on hemoglobin levels. Multiple micronutrient fortification showed non-significant impacts on height for age, weight for age and weight for height Z-scores, although they showed positive trends. The results for fortification in women showed that calcium and vitamin D fortification had significant impacts in the post-menopausal age group. Iron fortification led to a significant increase in serum ferritin and hemoglobin levels in women of reproductive age and pregnant women. Folate fortification significantly reduced the incidence of congenital abnormalities like neural tube defects without increasing the incidence of twinning. The number of studies pooled for zinc and multiple micronutrients for women were few, though the evidence suggested benefit. There was a dearth of evidence for the impact of fortification strategies on morbidity and mortality outcomes in women and children.

CONCLUSION

Fortification is potentially an effective strategy but evidence from the developing world is scarce. Programs need to assess the direct impact of fortification on morbidity and mortality.

Extruded rice grains fortified with zinc, iron, and vitamin A increase zinc status of Thai school children when incorporated into a school lunch program

Iron (Fe), zinc (Zn), and vitamin A (VA) deficiencies are common among children in developing countries and often occur in the same individual. Rice is widely consumed in the developing countries of Asia and the low phytate in polished rice makes it ideal for Zn and Fe fortification. Triple-fortified rice grains with Zn, Fe, and VA were produced using hot extrusion technology. The main objective of the present study was to determine the impact of triple-fortified extruded rice on Zn status in school children in Southern Thailand. Although serum zinc was the main outcome indicator, Fe and VA status were also assessed. School children with low serum zinc (n = 203) were randomized to receive either triple-fortified rice (n = 101) or natural control rice (n = 102) as a component of school lunch meals for 5 mo. Serum Zn, hemoglobin, serum ferritin, serum retinol, and C-reactive protein were measured at baseline and at the end of the study. After the intervention, serum Zn increased (P < 0.05) in both the fortification (11.3 ± 1.3 μmol/L) and control (10.6 ± 1.4 μmol/L) groups, most likely due to the proper implementation of the school lunch and school milk programs, with the increase greater in the group receiving the triple-fortified rice (P < 0.05). Because the children were not Fe or VA deficient at baseline, there was no change in Fe or VA status. We conclude that Zn fortification of extruded rice grains is efficacious and can be used to improve Zn status in school children.

A historical review of progress in the assessment of dietary zinc intake as an indicator of population zinc status

Dietary components influencing zinc (Zn) bioavailability were implicated in the first cases of human Zn deficiency in the Middle East in the 1960s. It was not until the 1980s that isotope tracer studies in humans quantified the effects of the type and/or quantity of Zn, protein, iron, and phytate (myo-inositol hexaphosphate) on Zn absorption in humans and confirmed the dose-dependent inhibitory effect of phytate on Zn absorption. This led to further analysis of the Zn and phytate content of foods. The use of phytate-to-Zn molar ratios as likely estimates of absorbable dietary Zn followed together with an assessment of their relationship with Zn biomarkers in low-income countries (LIC). In the 1990s, increasing knowledge of factors governing Zn-absorption diets led to refinements of Zn requirements and algorithms to estimate dietary Zn bioavailability. Their use highlighted that inadequate Zn intake from plant-based diets were a major etiological factor in morbidity and stunting in LIC, prompting the need to identify indicators of the population's Zn status. Major advances in analyses of dietary data pioneered by Beaton in 1980s led to the endorsement in 2007 of a dietary Zn indicator based on the prevalence of the population with usual Zn intake below the estimated average requirement for Zn. Risk of Zn deficiency is a public health concern when the prevalence of inadequate Zn intake is >25%. Recent findings that Zn bioavailability from high-phytate, whole-day diets is lower than previous estimates suggest that revision of Zn estimated average requirement for LIC may be warranted.

Effects of micronutrient fortified milk and cereal food for infants and children: a systematic review

BACKGROUND

Micronutrient deficiency is a common public health problem in developing countries, especially for infants and children in the first two years of life. As this is an important time window for child development, micronutrient fortified complementary feeding after 6 months of age, for example with milk or cereals products, in combination with continued breastfeeding, is recommended. The overall effect of this approach is unclear.

METHODS

We performed a Systematic Review and Meta-analysis to assess the impact of micronutrient fortified milk and cereal food on the health of infants and little children (aged 6 months to 5 years) compared to non-fortified food. We reviewed randomized controlled trials using electronic databases (MEDLINE and Cochrane library searches through FEB 2011), reference list screening and hand searches. Three reviewers assessed 1153 studies for eligibility and extracted data. One reviewer assessed risk of bias using predefined forms.

RESULTS

We included 18 trials in our analysis (n = 5'468 children; range of mean hemoglobin values: 9.0 to 12.6 g/dl). Iron plus multi micronutrient fortification is more effective than single iron fortification for hematologic outcomes. Compared to non-fortified food, iron multi micronutrient fortification increases hemoglobin levels by 0.87 g/dl (95%-CI: 0.57 to 1.16; 8 studies) and reduces risk of anemia by 57% (relative risk 0.43; 95%-CI 0.26 to 0.71; absolute risk reduction 22%; number needed to treat 5 [95%-CI: 4 to 6]; 6 Studies). Compared to non-fortified food, fortification increases serum levels of vitamin A but not of zinc. Information about functional health outcomes (e.g. weight gain) and morbidity was scarce and evidence is inconclusive. Risk of bias is unclear due to underreporting, but high quality studies lead to similar results in a sensitivity analysis.

CONCLUSIONS

Multi micronutrient fortified milk and cereal products can be an effective option to reduce anemia of children up to three years of age in developing countries. On the basis of our data the evidence for functional health outcomes is still inconclusive.

Short-term evaluation of the impact of a food program on the micronutrient nutritional status of Argentinean children under the age of six

This study was undertaken to evaluate the impact of Plan Más Vida (PMV) on the micronutrient nutritional condition of children aged 1 to 6 years 1 year after PMV implementation. The food program was intended for low-income families from the province of Buenos Aires, Argentina and provided supplementary diets. A prospective, nonexperimental study was carried out. Children (472 at baseline and 474 after 1 year) were divided into two groups (1-2 and 2-6 years of age). Biochemical tests (hemogram, ferritin, zinc, vitamin A, and folic acid), anthropometric assessments (weight and height), and dietary surveys (24-h recall) were performed. Chronic growth retardation (-2 height/age Z-score) was present in 2.8% and 8.7% of 1-2- and 2-6-year-old children, respectively; 14.4% in the former and 8.8% in the latter group had overweight/obesity. No significant changes were recorded 1 year after PMV implementation. Whereas anemia values decreased (55.3% to 39.1%, p = 0.003) and serum zinc values increased in 1-2-year-old children, the risk for vitamin A deficiency decreased significantly in both age groups. The evaluation of the early impact of PMV actions provided important nutritional data that should be used by provincial health authorities to conduct future evaluations.