Neither a zinc supplement nor phytate-reduced maize nor their combination enhance growth of 6- to 12-month-old Guatemalan infants

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.

Birth length is the strongest predictor of linear growth status and stunting in the first 2 years of life after a preconception maternal nutrition intervention: the children of the Women First trial

BACKGROUND

The multicountry Women First trial demonstrated that nutritional supplementation initiated prior to conception (arm 1) or early pregnancy (arm 2) and continued until delivery resulted in significantly greater length at birth and 6 mo compared with infants in the control arm (arm 3).

OBJECTIVES

We evaluated intervention effects on infants' longitudinal growth trajectory from birth through 24 mo and identified predictors of length status and stunting at 24 mo.

METHODS

Infants' anthropometry was obtained at 6, 12, 18, and 24 mo after the Women First trial (registered at clinicaltrials.gov as NCT01883193), which was conducted in low-resource settings: Democratic Republic of Congo, Guatemala, India, and Pakistan. Longitudinal models evaluated intervention effects on infants' growth trajectory from birth to 24 mo, with additional modeling used to identify adjusted predictors for growth trajectories and outcomes at 24 mo.

RESULTS

Data for 2337 (95% of original live births) infants were evaluated. At 24 mo, stunting rates were 62.8%, 64.8%, and 66.3% for arms 1, 2, and 3, respectively (NS). For the length-for-age z-score (LAZ) trajectory, treatment arm was a significant predictor, with adjusted mean differences of 0.19 SD (95% CI: 0.08, 0.30; P < 0.001) and 0.17 SD (95% CI: 0.07, 0.27; P < 0.001) for arms 1 and 2, respectively. The strongest predictors of LAZ at 24 mo were birth LAZ <-2 and <-1 to ≥-2, with adjusted mean differences of -0.76 SD (95% CI: -0.93, -0.58; P < 0.001) and -0.47 SD (95% CI: -0.56, -0.38; P < 0.001), respectively. For infants with ultrasound-determined gestational age (n = 1329), the strongest predictors of stunting were birth LAZ <-2 and <-1 to ≥- 2: adjusted relative risk of 1.62 (95% CI: 1.39, 1.88; P < 0.001) and 1.46 (95% CI: 1.31, 1.62; P < 0.001), respectively.

CONCLUSIONS

Substantial improvements in postnatal growth are likely to depend on improved intrauterine growth, especially during early pregnancy.

Micronutrient Supplementation and Fortification Interventions on Health and Development Outcomes among Children Under-Five in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis

Micronutrient deficiencies continue to be widespread among children under-five in low- and middle-income countries (LMICs), despite the fact that several effective strategies now exist to prevent them. This kind of malnutrition can have several immediate and long-term consequences, including stunted growth, a higher risk of acquiring infections, and poor development outcomes, all of which may lead to a child not achieving his or her full potential. This review systematically synthesizes the available evidence on the strategies used to prevent micronutrient malnutrition among children under-five in LMICs, including single and multiple micronutrient (MMN) supplementation, lipid-based nutrient supplementation (LNS), targeted and large-scale fortification, and point-of-use-fortification with micronutrient powders (MNPs). We searched relevant databases and grey literature, retrieving 35,924 papers. After application of eligibility criteria, we included 197 unique studies. Of note, we examined the efficacy and effectiveness of interventions. We found that certain outcomes, such as anemia, responded to several intervention types. The risk of anemia was reduced with iron alone, iron-folic acid, MMN supplementation, MNPs, targeted fortification, and large-scale fortification. Stunting and underweight, however, were improved only among children who were provided with LNS, though MMN supplementation also slightly increased length-for-age z-scores. Vitamin A supplementation likely reduced all-cause mortality, while zinc supplementation decreased the incidence of diarrhea. Importantly, many effects of LNS and MNPs held when pooling data from effectiveness studies. Taken together, this evidence further supports the importance of these strategies for reducing the burden of micronutrient malnutrition in children. Population and context should be considered when selecting one or more appropriate interventions for programming.

Advancing child nutrition science in the scaling up nutrition era: a systematic scoping review of stunting research in Guatemala

INTRODUCTION

Ever since the 1960s, Guatemala has been a principle site for global academic research on child growth and nutrition. Nevertheless, Guatemala still has one of the highest rates of child stunting in the world. Since 2012, Guatemala has had a comprehensive national policy on stunting, calling for a renewed investment in innovative, multilevel nutrition interventions and implementation science. Our objective was to perform a systematic search and scoping review of the literature on stunting in Guatemala to identify gaps in research and opportunities for responding to this unique policy opportunity.

METHODS

We conducted a systematic search and scoping review on stunting in Guatemala, searching the PubMed, Web of Science and PsycINFO databases. Eligible articles were of any design or format, published in English and Spanish from 2000 to 2018. Articles were thematically grouped by those published before (2000-2011) and after (2012-2018) the new national policy initiatives.

RESULTS

We identified a total of 1934 articles through database searches. After full-text review, 104 were included in the synthesis. The volume of published articles on stunting increased from a mean of 3.2 to 9.4 articles/year before and after 2012. There was a shift toward articles generating new data on priority populations, including rural indigenous Maya populations (34% vs 61%, χ² test, p=0.01). However, the proportion of studies conducting implementation evaluations or testing new interventions was low and did not change significantly (34% vs 18%, χ² test, p=0.07). Among 17 identified intervention studies, only 4 tested multilevel interventions, and there were no published interventions incorporating nutrition-sensitive interventions.

CONCLUSIONS

A systematic search and scoping review of the literature on child stunting in Guatemala identified critical opportunities for new research in multilevel interventions, nutrition-sensitive interventions and implementation science.

Reducing stunting by improving maternal, infant and young child nutrition in regions such as South Asia: evidence, challenges and opportunities

Meeting the high nutrient needs of pregnant and lactating women and their young children in regions such as South Asia is challenging because diets are dominated by staple foods with low nutrient density and poor mineral bioavailability. Gaps in nutritional adequacy in such populations probably date back to the agricultural revolution ~10 000 years ago. Options for improving diets during the first 1000 days include dietary diversification and increased intake of nutrient‐rich foods, improved complementary feeding practices, micronutrient supplements and fortified foods or products specifically designed for these target groups. Evidence from intervention trials indicates that several of these strategies, both prenatal and post‐natal, can have a positive impact on child growth, but results are mixed and a growth response is not always observed. Nutrition interventions, by themselves, may not result in the desired impact if the target population suffers from frequent infection, both clinical and subclinical. Further research is needed to understand the mechanisms underlying both prenatal and post‐natal growth restriction. In the meantime, implementation and rigorous evaluation of integrated interventions that address the multiple causes of stunting is a high priority. These intervention packages should ideally include improved nutrition during both pregnancy and the post‐natal period, prevention and control of prenatal and post‐natal infection and subclinical conditions that restrict growth, care for women and children and stimulation of early child development. In regions such as South Asia, such strategies hold great promise for reducing stunting and enhancing human capital formation.

Upregulation of Zinc Absorption Matches Increases in Physiologic Requirements for Zinc in Women Consuming High- or Moderate-Phytate Diets during Late Pregnancy and Early Lactation

Background: Estimated physiologic requirements (PRs) for zinc increase in late pregnancy and early lactation, but the effect on dietary zinc requirements is uncertain.Objective: The aim of this study was to determine changes in daily fractional absorbed zinc and total absorbed zinc (TAZ) from ad libitum diets of differing phytate contents in relation to physiologic zinc requirements during pregnancy and lactation.Methods: This was a prospective observational study of zinc absorption at 8 (phase 1) and 34 (phase 2) wk of gestation and 2 (phase 3) and 6 (phase 4) mo of lactation. Participants were indigenous Guatemalan women of childbearing age whose major food staple was maize and who had been randomly assigned in a larger study to either of 2 ad libitum feeding groups: low-phytate maize (LP; 1.6 mg/g; n = 14) or control maize (C; 7.1 mg/g; n = 8). Total dietary zinc (milligrams per day, TDZ) and phytate (milligrams per day) were determined from duplicate diets and fractional absorption (FAZ) by dual isotope ratio technique (TAZ = TDZ × FAZ). All variables were examined longitudinally and by group and compared with PRs. TAZ values at later phases were compared with phase 1. Measured TAZ was compared with predicted TAZ for nonpregnant, nonlactating (NPNL) women.Results: TAZ was greater in the LP group than in the C group at all phases. All variables increased from phase 1 to phases 2 and 3 and declined at phase 4. TAZ increased by 1.25 mg/d (P = 0.045) in the C group and by 0.81 mg/d (P = 0.058) in the LP group at phase 2. At phase 3, the increases were 2.66 mg/d (P = 0.002) in the C group and 2.28 mg/d (P = 0.0004) in the LP group, compared with a 1.37-mg/d increase in PR. Measured TAZ was greater than predicted values in phases 2-4.Conclusions: Upregulation of zinc absorption in late pregnancy and early lactation matches increases in PRs of pregnant and lactating women, regardless of dietary phytate, which has implications for dietary zinc requirements of pregnant and lactating women.

Oral zinc for treating diarrhoea in children

BACKGROUND

In developing countries, diarrhoea causes around 500,000 child deaths annually. Zinc supplementation during acute diarrhoea is currently recommended by the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF).

OBJECTIVES

To evaluate oral zinc supplementation for treating children with acute or persistent diarrhoea.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (the Cochrane Library 2016, Issue 5), MEDLINE, Embase, LILACS, CINAHL, mRCT, and reference lists up to 30 September 2016. We also contacted researchers.

SELECTION CRITERIA

Randomized controlled trials (RCTs) that compared oral zinc supplementation with placebo in children aged one month to five years with acute or persistent diarrhoea, including dysentery.

DATA COLLECTION AND ANALYSIS

Both review authors assessed trial eligibility and risk of bias, extracted and analysed data, and drafted the review. The primary outcomes were diarrhoea duration and severity. We summarized dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses (using either a fixed-effect or random-effects model) and assessed heterogeneity.We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

Thirty-three trials that included 10,841 children met our inclusion criteria. Most included trials were conducted in Asian countries that were at high risk of zinc deficiency. Acute diarrhoeaThere is currently not enough evidence from well-conducted RCTs to be able to say whether zinc supplementation during acute diarrhoea reduces death or number of children hospitalized (very low certainty evidence).In children older than six months of age, zinc supplementation may shorten the average duration of diarrhoea by around half a day (MD -11.46 hours, 95% CI -19.72 to -3.19; 2581 children, 9 trials, low certainty evidence), and probably reduces the number of children whose diarrhoea persists until day seven (RR 0.73, 95% CI 0.61 to 0.88; 3865 children, 6 trials, moderate certainty evidence). In children with signs of malnutrition the effect appears greater, reducing the duration of diarrhoea by around a day (MD -26.39 hours, 95% CI -36.54 to -16.23; 419 children, 5 trials, high certainty evidence).Conversely, in children younger than six months of age, the available evidence suggests zinc supplementation may have no effect on the mean duration of diarrhoea (MD 5.23 hours, 95% CI -4.00 to 14.45; 1334 children, 2 trials, moderate certainty evidence), or the number of children who still have diarrhoea on day seven (RR 1.24, 95% CI 0.99 to 1.54; 1074 children, 1 trial, moderate certainty evidence).None of the included trials reported serious adverse events. However, zinc supplementation increased the risk of vomiting in both age groups (children greater than six months of age: RR 1.57, 95% CI 1.32 to 1.86; 2605 children, 6 trials, moderate certainty evidence; children less than six months of age: RR 1.54, 95% CI 1.05 to 2.24; 1334 children, 2 trials, moderate certainty evidence). Persistent diarrhoeaIn children with persistent diarrhoea, zinc supplementation probably shortens the average duration of diarrhoea by around 16 hours (MD -15.84 hours, 95% CI -25.43 to -6.24; 529 children, 5 trials, moderate certainty evidence).

AUTHORS' CONCLUSIONS

In areas where the prevalence of zinc deficiency or the prevalence of malnutrition is high, zinc may be of benefit in children aged six months or more. The current evidence does not support the use of zinc supplementation in children less six months of age, in well-nourished children, and in settings where children are at low risk of zinc deficiency.

The Effect of Low Dose Iron and Zinc Intake on Child Micronutrient Status and Development during the First 1000 Days of Life: A Systematic Review and Meta-Analysis

Adequate supply of micronutrients during the first 1000 days is essential for normal development and healthy life. We aimed to investigate if interventions administering dietary doses up to the recommended nutrient intake (RNI) of iron and zinc within the window from conception to age 2 years have the potential to influence nutritional status and development of children. To address this objective, a systematic review and meta-analysis of randomized and quasi-randomized fortification, biofortification, and supplementation trials in women (pregnant and lactating) and children (6–23 months) delivering iron or zinc in doses up to the recommended nutrient intake (RNI) levels was conducted. Supplying iron or zinc during pregnancy had no effects on birth outcomes. There were limited or no data on the effects of iron/zinc during pregnancy and lactation on child iron/zinc status, growth, morbidity, and psychomotor and mental development. Delivering up to 15 mg iron/day during infancy increased mean hemoglobin by 4 g/L (p < 0.001) and mean serum ferritin concentration by 17.6 µg/L (p < 0.001) and reduced the risk for anemia by 41% (p < 0.001), iron deficiency by 78% (ID; p < 0.001) and iron deficiency anemia by 80% (IDA; p < 0.001), but had no effect on growth or psychomotor development. Providing up to 10 mg of additional zinc during infancy increased plasma zinc concentration by 2.03 µmol/L (p < 0.001) and reduced the risk of zinc deficiency by 47% (p < 0.001). Further, we observed positive effects on child weight for age z-score (WAZ) (p < 0.05), weight for height z-score (WHZ) (p < 0.05), but not on height for age z-score (HAZ) or the risk for stunting, wasting, and underweight. There are no studies covering the full 1000 days window and the effects of iron and zinc delivered during pregnancy and lactation on child outcomes are ambiguous, but low dose daily iron and zinc use during 6–23 months of age has a positive effect on child iron and zinc status.

Zinc bioavailability in rats fed a plant-based diet: a study of fermentation and zinc supplementation

BACKGROUND

Zinc deficiency is a significant problem, in developing countries and in vegetarians, which can be caused by plant-based diets. Thus, dietary strategies, such as fermentation, to improve zinc bioavailability of diets should be investigated.

OBJECTIVE

To improve zinc bioavailability in a plant-based diet by the inclusion of fermented food.

DESIGN

Cassava tubers were fermented and made to replace the unfermented cassava in a basal plant-based diet, and compared with plant-based diets with and without zinc supplement. The zinc bioavailability of the diets was evaluated in Wistar rats that were fed these diets for 28 days. The evaluation was for zinc apparent absorption (ZnAA), serum zinc levels, and zinc deposits in liver and femur; in addition, the feed efficiency ratio (FER) of the diets and femur weight (FW) of the rats were evaluated.

RESULTS

During the cassava fermentation, lactic acid increased and pH decreased (from 6.8 to 3.9), which is favorable for native phytase activity, resulting in a 90.2% reduction of phytate content in cassava. The diet containing fermented cassava showed significantly higher levels of ZnAA, FER, and FW (p<0.001). Moreover, the zinc levels in serum and femur were significantly higher (p<0.001) compared with the results of the diet with unfermented cassava. The results clearly show a higher zinc bioavailability in the diet containing fermented cassava and are comparable with the results obtained with the plant-based diet with zinc supplement.

CONCLUSIONS

In conclusion, the fermentation of cassava reduces the phytate content. The diet containing the fermented cassava represents a better nutritional alternative than the diet with unfermented cassava and is comparable with the zinc-supplemented diets.

The Global Network for Women's and Children's Health Research: A model of capacity-building research

In response to the global effort to accelerate progress towards the Millennium Development Goals 4 and 5, a partnership was created between the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and the Bill and Melinda Gates Foundation to establish the Global Network for Women's and Children's Health Research (Global Network) in 2000. The Global Network was developed with a goal of building local maternal and child health research capacity in resource-poor settings. The objective of the network was to conduct research focused on several high-need areas, such as preventing life-threatening obstetric complications, improving birth weight and infant growth, and improving childbirth practices in order to reduce mortality. Scientists from developing countries, together with peers in the USA, lead research teams that identify and address population needs through randomized clinical trials and other research studies. Global Network projects develop and test cost-effective, sustainable interventions for pregnant women and newborns and provide guidance for national policy and for the practice of evidence-based medicine. This article reviews the results of the Global Network's research, the impact on policy and practice, and highlights the capacity-building efforts and collaborations developed since its inception.

Zinc Absorption Is Not Related to Dietary Phytate Intake in Infants and Young Children Based on Modeling Combined Data from Multiple Studies

BACKGROUND

It is widely understood that the 2 primary factors affecting dietary zinc absorption in adults are the quantities of zinc and phytate in the diet. Although a similar association of absorption to dietary zinc and phytate is presumed to exist in children, to our knowledge, no large-scale examination of the relation of zinc absorption to dietary and growth factors has been conducted.

OBJECTIVE

The goal was to apply an adult absorption model and related models to data from zinc absorption studies of infants and children in order to determine the nature of the relation of zinc absorption to dietary zinc and phytate, age, body size, and zinc homeostatic variables.

METHODS

Data from 236 children between 8 and 50 mo of age were obtained from stable-isotope studies of zinc absorption. Statistical and mechanistic models were fit to the data using linear and nonlinear regression analysis.

RESULTS

The effect of dietary phytate on zinc absorption when controlling for dietary zinc was very small and not statistically discernable (P = 0.29). A 500-mg/d increase in dietary phytate reduced absorbed zinc by <0.04 mg/d. Absorption was observed to vary with age, weight, and height (P < 0.0001) when controlling for dietary zinc. For example, absorption from 6 mg/d of dietary zinc increased by as much as 0.2 mg/d with a 12-mo increase in age. Absorption varied with weight and exchangeable zinc pool size (0.01 < P < 0.05) when controlling for dietary zinc and age.

CONCLUSIONS

The absence of a detectable phytate effect on zinc absorption raises caution about use of dietary phytate:zinc molar ratios to predict zinc bioavailability and does not support phytate reduction as a strategy to improve zinc status of young children. The effect of age on zinc absorption and the absence of a phytate effect should facilitate estimations of dietary zinc needs in young children.

Participatory women's groups and counselling through home visits to improve child growth in rural eastern India: protocol for a cluster randomised controlled trial

BACKGROUND

Child stunting (low height-for-age) is a marker of chronic undernutrition and predicts children's subsequent physical and cognitive development. Around one third of the world's stunted children live in India. Our study aims to assess the impact, cost-effectiveness, and scalability of a community intervention with a government-proposed community-based worker to improve growth in children under two in rural India.

METHODS

The study is a cluster randomised controlled trial in two rural districts of Jharkhand and Odisha (eastern India). The intervention tested involves a community-based worker carrying out two activities: (a) one home visit to all pregnant women in the third trimester, followed by subsequent monthly home visits to all infants aged 0-24 months to support appropriate feeding, infection control, and care-giving; (b) a monthly women's group meeting using participatory learning and action to catalyse individual and community action for maternal and child health and nutrition. Both intervention and control clusters also receive an intervention to strengthen Village Health Sanitation and Nutrition Committees. The unit of randomisation is a purposively selected cluster of approximately 1000 population. A total of 120 geographical clusters covering an estimated population of 121,531 were randomised to two trial arms: 60 clusters in the intervention arm receive home visits, group meetings, and support to Village Health Sanitation and Nutrition Committees; 60 clusters in the control arm receive support to Committees only. The study participants are pregnant women identified in the third trimester of pregnancy and their children (n = 2520). Mothers and their children are followed up at seven time points: during pregnancy, within 72 hours of delivery, and at 3, 6, 9, 12 and 18 months after birth. The trial's primary outcome is children's mean length-for-age Z scores at 18 months. Secondary outcomes include wasting and underweight at all time points, birth weight, growth velocity, feeding, infection control, and care-giving practices. Additional qualitative and quantitative data are collected for process and economic evaluations.

DISCUSSION

This trial will contribute to evidence on effective strategies to improve children's growth in India.

TRIAL REGISTRATION

ISRCTN register 51505201 ; Clinical Trials Registry of India number 2014/06/004664.

Food Based Complementary Feeding Strategies for Breastfed Infants: What's the Evidence that it Matters?

The period of complementary feeding represents a major portion of the 1000 day critical window and thus impacts a period of substantial and dynamic infant development. This review highlights and synthesizes findings of several recent studies conducted to evaluate food based strategies on outcomes related to micronutrient status, growth and neurocognitive development. Particular emphasis is placed on interventions using meat or fortified products to impact iron and zinc intakes, due to the dependence of breastfed infants on complementary food choices to meet requirements for these two critical micronutrients. Regular consumption of modest amounts of meat or fortified cereals provides adequate absorbed zinc to meet estimated physiologic requirements, whereas homeostatic adaptation to lower zinc intake from unfortified cereal/plant staples is inadequate to meet requirements. Iron fortification of cereals may be somewhat more effective than meat to improve iron status, but neither prevents iron deficiency in breastfed infants, even in westernized settings. Improvements in the quality of complementary foods have had very modest effects on linear growth in settings where stunting is prevalent. Maternal education is strongly associated with both linear growth and with child neurodevelopment. The determinants of early growth faltering are more complex and intractable than 'simple' dietary deficiencies of micronutrients. Solutions to growth faltering in young children most likely need to be multi-factorial, and almost certainly will need to start earlier than the complementary feeding period.

Preventive zinc supplementation for children, and the effect of additional iron: a systematic review and meta-analysis

OBJECTIVE

Zinc deficiency is widespread, and preventive supplementation may have benefits in young children. Effects for children over 5 years of age, and effects when coadministered with other micronutrients are uncertain. These are obstacles to scale-up. This review seeks to determine if preventive supplementation reduces mortality and morbidity for children aged 6 months to 12 years.

DESIGN

Systematic review conducted with the Cochrane Developmental, Psychosocial and Learning Problems Group. Two reviewers independently assessed studies. Meta-analyses were performed for mortality, illness and side effects.

DATA SOURCES

We searched multiple databases, including CENTRAL and MEDLINE in January 2013. Authors were contacted for missing information.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised trials of preventive zinc supplementation. Hospitalised children and children with chronic diseases were excluded.

RESULTS

80 randomised trials with 205 401 participants were included. There was a small but non-significant effect on all-cause mortality (risk ratio (RR) 0.95 (95% CI 0.86 to 1.05)). Supplementation may reduce incidence of all-cause diarrhoea (RR 0.87 (0.85 to 0.89)), but there was evidence of reporting bias. There was no evidence of an effect of incidence or prevalence of respiratory infections or malaria. There was moderate quality evidence of a very small effect on linear growth (standardised mean difference 0.09 (0.06 to 0.13)) and an increase in vomiting (RR 1.29 (1.14 to 1.46)). There was no evidence of an effect on iron status. Comparing zinc with and without iron cosupplementation and direct comparisons of zinc plus iron versus zinc administered alone favoured cointervention for some outcomes and zinc alone for other outcomes. Effects may be larger for children over 1 year of age, but most differences were not significant.

CONCLUSIONS

Benefits of preventive zinc supplementation may outweigh any potentially adverse effects in areas where risk of zinc deficiency is high. Further research should determine optimal intervention characteristics and delivery strategies.

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.

Newborn length predicts early infant linear growth retardation and disproportionately high weight gain in a low-income population

BACKGROUND

Stunting is prevalent by the age of 6 months in the indigenous population of the Western Highlands of Guatemala.

AIM

The objective of this study was to determine the time course and predictors of linear growth failure and weight-for-age in early infancy.

STUDY DESIGN AND SUBJECTS

One hundred and forty eight term newborns had measurements of length and weight in their homes, repeated at 3 and 6 months. Maternal measurements were also obtained.

RESULTS

Mean ± SD length-for-age Z-score (LAZ) declined from newborn -1.0 ± 1.01 to -2.20 ± 1.05 and -2.26 ± 1.01 at 3 and 6 months respectively. Stunting rates for newborn, 3 and 6 months were 47%, 53% and 56% respectively. A multiple regression model (R(2) = 0.64) demonstrated that the major predictor of LAZ at 3 months was newborn LAZ with the other predictors being newborn weight-for-age Z-score (WAZ), gender and maternal education∗maternal age interaction. Because WAZ remained essentially constant and LAZ declined during the same period, weight-for-length Z-score (WLZ) increased from -0.44 to +1.28 from birth to 3 months. The more severe the linear growth failure, the greater WAZ was in proportion to the LAZ.

CONCLUSION

The primary conclusion is that impaired fetal linear growth is the major predictor of early infant linear growth failure indicating that prevention needs to start with maternal interventions.

The World Health Organization's global target for reducing childhood stunting by 2025: rationale and proposed actions

In 2012, the World Health Organization adopted a resolution on maternal, infant and young child nutrition that included a global target to reduce by 40% the number of stunted under-five children by 2025. The target was based on analyses of time series data from 148 countries and national success stories in tackling undernutrition. The global target translates to a 3.9% reduction per year and implies decreasing the number of stunted children from 171 million in 2010 to about 100 million in 2025. However, at current rates of progress, there will be 127 million stunted children by 2025, that is, 27 million more than the target or a reduction of only 26%. The translation of the global target into national targets needs to consider nutrition profiles, risk factor trends, demographic changes, experience with developing and implementing nutrition policies, and health system development. This paper presents a methodology to set individual country targets, without precluding the use of others. Any method applied will be influenced by country-specific population growth rates. A key question is what countries should do to meet the target. Nutrition interventions alone are almost certainly insufficient, hence the importance of ongoing efforts to foster nutrition-sensitive development and encourage development of evidence-based, multisectoral plans to address stunting at national scale, combining direct nutrition interventions with strategies concerning health, family planning, water and sanitation, and other factors that affect the risk of stunting. In addition, an accountability framework needs to be developed and surveillance systems strengthened to monitor the achievement of commitments and targets.

Effect of zinc intake on serum/plasma zinc status in infants: a meta-analysis

A systematic review and meta-analysis of available randomised controlled trials (RCTs) was conducted to evaluate the effect of zinc (Zn) intake on serum/plasma Zn status in infants. Out of 5500 studies identified through electronic searches and reference lists, 13 RCTs were selected after applying the exclusion/inclusion criteria. The influence of Zn intake on serum/plasma Zn concentration was considered in the overall meta-analysis. Other variables were also taken into account as possible effect modifiers: doses of Zn intake, intervention duration, nutritional status and risk of bias. The pooled β of status was 0.09 [confidence interval (CI) 0.05 to 0.12]. However, a substantial heterogeneity was present in the analyses (I(2) = 98%; P = 0.00001). When we performed a meta-regression, the effect of Zn intake on serum/plasma Zn status changed depending on the duration of the intervention, the dose of supplementation and the nutritional situation (P ANCOVA = 0.054; <0.001 and <0.007, respectively). After stratifying the sample according to the effect modifiers, the results by duration of intervention showed a positive effect when Zn intake was provided during medium and long periods of time (4-20 weeks and >20 weeks). A positive effect was also seen when doses ranged from 8.1 to 12 mg day(-1). In all cases, the pooled β showed high evidence of heterogeneity. Zn supplementation increases serum/plasma Zn status in infants, although high evidence of heterogeneity was found. Further standardised research is urgently needed to reach evidence-based conclusions to clarify the role of Zn supplementation upon infant serum/plasma Zn status, particularly in Europe.

Specially formulated foods for treating children with moderate acute malnutrition in low- and middle-income countries

BACKGROUND

Moderate acute malnutrition, also called moderate wasting, affects around 10% of children under five years of age in low- and middle-income countries. There are different approaches to addressing malnutrition with prepared foods in these settings; for example, providing lipid-based nutrient supplements or blended foods, either a full daily dose or in a low dose as a complement to the usual diet. There is no definitive consensus on the most effective way to treat children with moderate acute malnutrition.

OBJECTIVES

To evaluate the safety and effectiveness of different types of specially formulated foods for children with moderate acute malnutrition in low- and middle-income countries, and to assess whether foods complying or not complying with specific nutritional compositions, such as the WHO technical specifications, are safe and effective.

SEARCH METHODS

In October 2012, we searched CENTRAL, MEDLINE, LILACS, CINAHL, BIBLIOMAP, POPLINE, ZETOC, ICTRP, mRCT, and ClinicalTrials.gov. In August 2012, we searched Embase. We also searched the reference lists of relevant papers and contacted nutrition-related organisations and researchers in this field.    

SELECTION CRITERIA

We planned to included any relevant randomised controlled trials (RCTs), controlled clinical trials (CCTs), controlled before-and-after studies (CBAs), and interrupted time series (ITS) that evaluated specially formulated foods for the treatment of moderate acute malnutrition in children aged between six months and five years in low- and middle-income countries.

DATA COLLECTION AND ANALYSIS

Two authors assessed trial eligibility and risk of bias, and extracted and analysed the data. We summarised dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses using the random-effects model and assessed heterogeneity. The quality of evidence was assessed using GRADE methods.

MAIN RESULTS

Eight randomised controlled trials, enrolling 10,037 children, met our inclusion criteria. Seven of the trials were conducted in Africa. In general, the included studies were at a low risk of bias. There may have been a risk of performance bias as trial participants were aware which intervention group they were in, but we did not consider this likely to have biased the outcome measurement. We were unable to assess the risk of reporting bias in half of the trials and two trials were at high risk of attrition bias. Any specially formulated food versus standard care - the provision of food increased the recovery rate by 29% (RR 1.29, 95% CI 1.20 to 1.38; 2152 children, two trials; moderate quality evidence), decreased the number dropping out by 70% (RR 0.30, 95% CI 0.22 to 0.39; 1974 children, one trial; moderate quality evidence), and improved weight-for-height (MD 0.20 z-score, 95% CI 0.03 to 0.37; 1546 children, two trials; moderate quality evidence). The reduction in mortality did not reach statistical significance (RR 0.44; 95% CI 0.14 to 1.36; 1974 children, one trial; low quality evidence). Lipid-based nutrient supplements versus any blended foods (dry food mixtures, without high lipid content), at full doses - there was no significant difference in mortality (RR 0.93, 95% CI 0.54 to 1.62; 6367 children, five trials; moderate quality evidence), progression to severe malnutrition (RR 0.88, 95% CI 0.72 to 1.07; 4537 children, three trials; high quality evidence), or the number of dropouts from the nutritional programme (RR 1.14, 95% CI 0.62 to 2.11; 5107 children, four trials; moderate quality evidence). However, lipid-based nutrient supplements significantly increased the number of children recovered (RR 1.10, 95% CI 1.04 to 1.16; 6367 children, five trials; moderate quality evidence), and decreased the number of non-recovering children (RR 0.53, 95% CI 0.40 to 0.69; 4537 children, three trials; high quality evidence). LNS also improved weight gain, weight-for-height, and mid-upper arm circumference, although for these outcomes, the improvement was modest (moderate quality evidence). One trial observed more children with vomiting in the lipid-based nutrient supplements group compared to those receiving blended food (RR 1.43, 95% CI 1.11 to 1.85; 2712 children, one trial; low quality evidence). Foods at complementary doses - no firm conclusion could be drawn on the comparisons between LNS at complementary dose and blended foods at complementary or full dose (low quality evidence). Lipid-based nutrient supplements versus specific types of blended foods - a recently developed enriched blended food (CSB++) resulted in similar outcomes to LNS (4758 children, three trials; moderate to high quality evidence). Different types of blended foods - in one trial, CSB++ did not show any significant benefit over locally made blended food, for example, Misola, in number who recovered, number who died, or weight gain (moderate to high quality evidence). Improved adequacy of home diet - no study evaluated the impact of improving adequacy of local diet, such as local foods prepared at home according to a given recipe or of home processing of local foods (soaking, germination, malting, fermentation) in order to increase their nutritional content.

AUTHORS' CONCLUSIONS

In conclusion, there is moderate to high quality evidence that both lipid-based nutrient supplements and blended foods are effective in treating children with MAM. Although lipid-based nutrient supplements (LNS) led to a clinically significant benefit in the number of children recovered in comparison with blended foods, LNS did not reduce mortality, the risk of default or progression to SAM. It also induced more vomiting. Blended foods such as CSB++ may be equally effective and cheaper than LNS. Most of the research so far has focused on industrialised foods, and on short-term outcomes of MAM. There are no studies evaluating interventions to improve the quality of the home diet, an approach that should be evaluated in settings where food is available, and nutritional education and habits are the main determinants of malnutrition. There are no studies from Asia, where moderate acute malnutrition is most prevalent.

Oral zinc for treating diarrhoea in children

BACKGROUND

In developing countries, diarrhoea causes around two million child deaths annually. Zinc supplementation during acute diarrhoea is currently recommended by the World Health Organization and UNICEF.

OBJECTIVES

To evaluate oral zinc supplementation for treating children with acute or persistent diarrhoea.

SEARCH METHODS

In February 2012, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2011, Issue 11), MEDLINE, EMBASE, LILACS, CINAHL, mRCT, and reference lists. We also contacted researchers.

SELECTION CRITERIA

Randomized controlled trials comparing oral zinc supplementation with placebo in children aged one month to five years with acute or persistent diarrhoea, including dysentery.

DATA COLLECTION AND ANALYSIS

Both authors assessed trial eligibility and risk of bias, extracted and analysed data, and drafted the review. Diarrhoea duration and severity were the primary outcomes. We summarized dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses (using the fixed- or random-effects model) and assessed heterogeneity.The quality of evidence has been assessed using the GRADE methods

MAIN RESULTS

Twenty-four trials, enrolling 9128 children, met our inclusion criteria. The majority of the data is from Asia, from countries at high risk of zinc deficiency, and may not be applicable elsewhere. Acute diarrhoea. There is currently not enough evidence from well conducted randomized controlled trials to be able to say whether zinc supplementation during acute diarrhoea reduces death or hospitalization (very low quality evidence).In children aged greater than six months with acute diarrhoea, zinc supplementation may shorten the duration of diarrhoea by around 10 hours (MD -10.44 hours, 95% CI -21.13 to 0.25; 2175 children, six trials, low quality evidence), and probably reduces the number of children whose diarrhoea persists until day seven (RR 0.73, 95% CI 0.61 to 0.88; 3865 children, six trials, moderate quality evidence). In children with signs of moderate malnutrition the effect appears greater, reducing the duration of diarrhoea by around 27 hours (MD -26.98 hours, 95% CI -14.62 to -39.34; 336 children, three trials, high quality evidence).Conversely, In children aged less than six months, the available evidence suggests zinc supplementation may have no effect on mean diarrhoea duration (MD 5.23 hours, 95% CI -4.00 to 14.45; 1334 children, two trials, low quality evidence), and may even increase the proportion of children whose diarrhoea persists until day seven (RR 1.24, 95% CI 0.99 to 1.54; 1074 children, one trial, moderate quality evidence).No trials reported serious adverse events, but zinc supplementation during acute diarrhoea causes vomiting in both age groups (RR 1.59, 95% 1.27 to 1.99; 5189 children, 10 trials, high quality evidence). Persistent diarrhoea. In children with persistent diarrhoea, zinc supplementation probably shortens the duration of diarrhoea by around 16 hours (MD -15.84 hours, 95% CI -25.43 to -6.24; 529 children, five trials, moderate quality evidence).

AUTHORS' CONCLUSIONS

In areas where the prevalence of zinc deficiency or the prevalence of moderate malnutrition is high, zinc may be of benefit in children aged six months or more.The current evidence does not support the use of zinc supplementation in children below six months of age.

Randomized controlled trial of meat compared with multimicronutrient-fortified cereal in infants and toddlers with high stunting rates in diverse settings

BACKGROUND

Improved complementary feeding is cited as a critical factor for reducing stunting. Consumption of meats has been advocated, but its efficacy in low-resource settings has not been tested.

OBJECTIVE

The objective was to test the hypothesis that daily intake of 30 to 45 g meat from 6 to 18 mo of age would result in greater linear growth velocity and improved micronutrient status in comparison with an equicaloric multimicronutrient-fortified cereal.

DESIGN

This was a cluster randomized efficacy trial conducted in the Democratic Republic of Congo, Zambia, Guatemala, and Pakistan. Individual daily portions of study foods and education messages to enhance complementary feeding were delivered to participants. Blood tests were obtained at trial completion.

RESULTS

A total of 532 (86.1%) and 530 (85.8%) participants from the meat and cereal arms, respectively, completed the study. Linear growth velocity did not differ between treatment groups: 1.00 (95% CI: 0.99, 1.02) and 1.02 (95% CI: 1.00, 1.04) cm/mo for the meat and cereal groups, respectively (P = 0.39). From baseline to 18 mo, stunting [length-for-age z score (LAZ) <-2.0] rates increased from ~33% to nearly 50%. Years of maternal education and maternal height were positively associated with linear growth velocity (P = 0.0006 and 0.003, respectively); LAZ at 6 mo was negatively associated (P < 0.0001). Anemia rates did not differ by group; iron deficiency was significantly lower in the cereal group.

CONCLUSION

The high rate of stunting at baseline and the lack of effect of either the meat or multiple micronutrient-fortified cereal intervention to reverse its progression argue for multifaceted interventions beginning in the pre- and early postnatal periods.

Oral zinc for treating diarrhoea in children

BACKGROUND

In developing countries, diarrhoea causes around two million child deaths annually. Zinc supplementation during acute diarrhoea is currently recommended by the World Health Organization and UNICEF.

OBJECTIVES

To evaluate oral zinc supplementation for treating children with acute or persistent diarrhoea.

SEARCH METHODS

In February 2012, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2011, Issue 11), MEDLINE, EMBASE, LILACS, CINAHL, mRCT, and reference lists. We also contacted researchers.

SELECTION CRITERIA

Randomized controlled trials comparing oral zinc supplementation with placebo in children aged one month to five years with acute or persistent diarrhoea, including dysentery.

DATA COLLECTION AND ANALYSIS

Both authors assessed trial eligibility and risk of bias, extracted and analysed data, and drafted the review. Diarrhoea duration and severity were the primary outcomes. We summarized dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses (using the fixed- or random-effects model) and assessed heterogeneity.The quality of evidence has been assessed using the GRADE methods

MAIN RESULTS

Twenty-four trials, enrolling 9128 children, met our inclusion criteria. The majority of the data is from Asia, from countries at high risk of zinc deficiency, and may not be applicable elsewhere.Acute diarrhoeaThere is currently not enough evidence from well conducted randomized controlled trials to be able to say whether zinc supplementation during acute diarrhoea reduces death or hospitalization (very low quality evidence).In children aged greater than six months with acute diarrhoea, zinc supplementation may shorten the duration of diarrhoea by around 10 hours (MD -10.44 hours, 95% CI -21.13 to 0.25; 2091 children, five trials, low quality evidence), and probably reduces the number of children whose diarrhoea persists until day seven (RR 0.73, 95% CI 0.61 to 0.88; 3865 children, six trials, moderate quality evidence). In children with signs of moderate malnutrition the effect appears greater, reducing the duration of diarrhoea by around 27 hours (MD -26.98 hours, 95% CI -14.62 to -39.34; 336 children, three trials, high quality evidence).Conversely, In children aged less than six months, the available evidence suggests zinc supplementation may have no effect on mean diarrhoea duration (MD 5.23 hours, 95% CI -4.00 to 14.45; 1334 children, two trials, low quality evidence), and may even increase the proportion of children whose diarrhoea persists until day seven (RR 1.24, 95% CI 0.99 to 1.54; 1074 children, one trial, moderate quality evidence).No trials reported serious adverse events, but zinc supplementation during acute diarrhoea causes vomiting in both age groups (RR 1.59, 95% 1.27 to 1.99; 5189 children, 10 trials, high quality evidence).Persistent diarrhoeaIn children with persistent diarrhoea, zinc supplementation probably shortens the duration of diarrhoea by around 16 hours (MD -15.84 hours, 95% CI -25.43 to -6.24; 529 children, five trials, moderate quality evidence).

AUTHORS' CONCLUSIONS

In areas where the prevalence of zinc deficiency or the prevalence of moderate malnutrition is high, zinc may be of benefit in children aged six months or more.The current evidence does not support the use of zinc supplementation in children below six months of age.

Relationship between the nutritional status of breastfeeding Mayan mothers and their infants in Guatemala

A case-control study was conducted to determine the association between maternal height and infant length-for-age, and to evaluate how this association is modified by either maternal or infant nutritional status. We hypothesised that maternal excess caloric intake [measured as body mass index (BMI)] would increase the association, while infant nutrition (measured in main meals consumed in addition to breastfeeding) will diminish the effect. Mother and infant pairs in Chimaltenango, Guatemala, were measured for anthropometric values and nutritional status, and mothers were interviewed to elicit nutritional and socio-economic information. Infant length was converted into z-scores based on the World Health Organization's (WHO) standards. Odds ratios (ORs), associated 95% confidence intervals (CIs) and the relative excess risk due to interaction (RERI) were calculated. Cases were infants below 2 z-scores of the WHO's length-for-age, while controls were infants within the -2 to 2 z-score range. Cases (n = 84) had an increased odds (OR: 3.00, 95% CI: 1.57-5.74) of being born to a stunted mother (below 145 cm) when compared with controls (n = 85). When adjusted for potential confounders, the OR decreased to 2.55 (95% CI: 1.30-5.02). Negative RERI values were produced for the joint exposure of maternal BMI ≥ 25 and maternal stuntedness (RERI: -0.96), as well as for the joint exposure of maternal stuntedness and infant nutrition (RERI: -2.27). Our results confirm that maternal stuntedness is a significant contributor to infant stuntedness; however, this association is modified negligibly by maternal nutritional status and significantly by infant nutritional status, each in a protective manner.

Infant stunting is associated with short maternal stature

The objectives were to determine the range of maternal height associated with growth velocity of older infants and the magnitude of this association in an indigent population. Maternal height and infant length-for-age z scores (LAZ) were positively correlated at both 6 (n = 412, r = 0.324) and 12 (n = 388, r = 0.335) months (P < 0.0001) and for maternal heights from 131 to 164  cm. Maternal height is independently associated with infant LAZ and stunting (LAZ <-2) at both 6 and 12 months (P < 0.001) and with linear growth velocity from 6 to 12 months (P = 0.0023).

Short-term zinc supplementation with dispersible tablets or zinc sulfate solution yields similar positive effects on plasma zinc concentration of young children in Burkina Faso: a randomized controlled trial

OBJECTIVE

To assess zinc absorption from dispersible tablets by investigating the effects of short-term zinc supplementation, provided either as zinc (Zn) sulfate dispersible tablets or solution, on changes in plasma Zn concentration in young children.

STUDY DESIGN

We conducted a randomized, partially-masked, placebo-controlled trial in 451 children 6 to 23 months of age in Burkina Faso, randomly assigned to receive a dispersible tablet containing 5 mg Zn, a Zn solution containing 5 mg Zn/5 mL, or a placebo solution, daily for 3 weeks. The main outcome measure was change in plasma zinc concentration after supplementation compared with baseline.

RESULTS

The mean plus or minus SD change in plasma Zn concentration (μg/dL) was significantly greater in both Zn supplemented groups (tablets: 16.9±13.1μg/dL, liquid: 16.6±14.2 μg/dL), compared with the placebo group (0.2±10.9 μg/dL; P<.001, ANOVA). In both Zn supplemented groups, but not in the placebo group, change in plasma Zn concentration was progressively less with increasing age in months (-0.79 μg/dL/mo and -1.15 μg/dL/mo, respectively; P<.001); this effect did not differ in the Zn supplemented groups (P=.18).

CONCLUSIONS

Short-term supplementation results in a large increase in plasma Zn concentration, regardless of whether the additional Zn is provided as a dispersible tablet or solution.

Infant stunting is associated with short maternal stature

The objectives were to determine the range of maternal height associated with growth velocity of older infants and the magnitude of this association in an indigent population. Maternal height and infant length-for-age z scores (LAZ) were positively correlated at both 6 (n = 412, r = 0.324) and 12 (n = 388, r = 0.335) months (P < 0.0001) and for maternal heights from 131 to 164  cm. Maternal height is independently associated with infant LAZ and stunting (LAZ <-2) at both 6 and 12 months (P < 0.001) and with linear growth velocity from 6 to 12 months (P = 0.0023).

Zinc absorption from low phytic acid genotypes of maize (Zea mays L.), Barley (Hordeum vulgare L.), and Rice (Oryza sativa L.) assessed in a suckling rat pup model

Dietary phytic acid is a major causative factor for low Zn bioavailability in many cereal- and legume-based diets. The bioavailability of Zn in seed of low phytic acid (lpa) variants of maize ( Zea mays L.), rice ( Oryza sativa L.), and barley ( Hordeum vulgare L.) was evaluated using a suckling rat pup model. Suckling rat pups (14 days old, n = 6-8/treatment) were fasted for 6 h and intubated with (65)Zn-radiolabeled suspensions prepared using seed produced by either wild-type (normal phytic acid) or lpa genotypes of each cereal. Test solutions were radiolabeled overnight (all genotypes) or immediately prior to intubation (barley genotypes). Pups were killed 6 h postintubation and tissues removed and counted in a gamma counter. Zn absorption was low from wild-type genotypes of maize (21, 33%) and rice (26%), and phytic acid reduction resulted in significantly higher Zn absorption, 47-52 and 35-52%, respectively. Zn absorption from wild-type barley incubated overnight was high (86-91%), and phytate reduction did not improve Zn absorption (84-90%), which is likely due to endogenous phytase activity. When the wild-type barley solutions were prepared immediately before intubation, Zn absorption was significantly lower (63, 78%) than from the lpa cultivars (92, 96%). Variation in seed or flour phenolic acid levels did not affect Zn absorption. Differences in seed Zn levels did not substantially affect Zn absorption. Thus, when phytic acid is abundant in a diet, it has a larger effect on Zn absorption than the level of Zn. Therefore, reducing the phytic acid content of staple cereal grains may contribute to enhancing Zn nutrition of populations consuming these staple foods.

Oral zinc for treating diarrhoea in children

BACKGROUND

Diarrhoea causes around two million child deaths annually. Zinc supplementation could help reduce the duration and severity of diarrhoea, and is recommended by the World Health Organization and UNICEF.

OBJECTIVES

To evaluate oral zinc supplementation for treating children with acute or persistent diarrhoea.

SEARCH STRATEGY

In November 2007, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2007, Issue 4), MEDLINE, EMBASE, LILACS, CINAHL, mRCT, and reference lists. We also contacted researchers.

SELECTION CRITERIA

Randomized controlled trials comparing oral zinc supplementation (>/= 5 mg/day for any duration) with placebo in children aged one month to five years with acute or persistent diarrhoea, including dysentery.

DATA COLLECTION AND ANALYSIS

Both authors assessed trial eligibility and methodological quality, extracted and analysed data, and drafted the review. Diarrhoea duration and severity were the primary outcomes. We summarized dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses (using the fixed- or random-effects model) and assessed heterogeneity.

MAIN RESULTS

Eighteen trials enrolling 6165 participants met our inclusion criteria. In acute diarrhoea, zinc resulted in a shorter diarrhoea duration (MD -12.27 h, 95% CI -23.02 to -1.52 h; 2741 children, 9 trials), and less diarrhoea at day three (RR 0.69, 95% CI 0.59 to 0.81; 1073 children, 2 trials), day five (RR 0.55, 95% CI 0.32 to 0.95; 346 children, 2 trials), and day seven (RR 0.71, 95% CI 0.52 to 0.98; 4087 children, 7 trials). The four trials (1458 children) that reported on diarrhoea severity used different units and time points, and the effect of zinc was less clear. Subgroup analyses by age (trials with only children aged less than six months) showed no benefit with zinc. Subgroup analyses by nutritional status, geographical region, background zinc deficiency, zinc type, and study setting did not affect the results' significance. Zinc also reduced the duration of persistent diarrhoea (MD -15.84 h, 95% CI -25.43 to -6.24 h; 529 children, 5 trials). Few trials reported on severity, and results were inconsistent. No trial reported serious adverse events, but vomiting was more common in zinc-treated children with acute diarrhoea (RR 1.71, 95% 1.27 to 2.30; 4727 children, 8 trials).

AUTHORS' CONCLUSIONS

In areas where diarrhoea is an important cause of child mortality, research evidence shows zinc is clearly of benefit in children aged six months or more.