Daily Zinc but Not Multivitamin Supplementation Reduces Diarrhea and Upper Respiratory Infections in Tanzanian Infants: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Zinc for prevention and treatment of the common cold

BACKGROUND

The common cold is an acute, self-limiting viral respiratory illness. Symptoms include nasal congestion and mucus discharge, sneezing, sore throat, cough, and general malaise. Given the frequency of colds, they are a public health burden and a significant cause of lost work productivity and school absenteeism. There are no established interventions to prevent colds or shorten their duration. However, zinc supplements are commonly recommended and taken for this purpose.

OBJECTIVES

To assess the effectiveness and safety of zinc for the prevention and treatment of the common cold.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, and LILACS to 22 May 2023, and searched Web of Science Core Collection and two trials registries to 14 June 2023. We also used reference checking, citation searching, and contact with study authors to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in children or adults that tested any form of zinc against placebo to prevent or treat the common cold or upper respiratory infection (URTI). We excluded zinc interventions in which zinc was combined with other minerals, vitamins, or herbs (e.g. a multivitamin, or mineral supplement containing zinc).

DATA COLLECTION AND ANALYSIS

We used the Cochrane risk of bias tool to assess risks of bias, and GRADE to assess the certainty of the evidence. We independently extracted data. When necessary, we contacted study authors for additional information. We assessed zinc (type and route) with placebo in the prevention and treatment of the common cold. Primary outcomes included the proportion of participants developing colds (for analyses of prevention trials only), duration of cold (measured in days from start to resolution of the cold), adverse events potentially due to zinc supplements (e.g. unpleasant taste, loss of smell, vomiting, stomach cramps, and diarrhoea), and adverse events considered to be potential complications of the common cold (e.g. respiratory bacterial infections).

MAIN RESULTS

We included 34 studies (15 prevention, 19 treatment) involving 8526 participants. Twenty-two studies were conducted on adults and 12 studies were conducted on children. Most trials were conducted in the USA (n = 18), followed by India, Indonesia, Iran, and Turkey (two studies each), and Australia, Burkina Faso, Colombia, Denmark, Finland, Tanzania, Thailand, and the UK (one study each). The 15 prevention studies identified the condition as either common cold (n = 8) or URTI (n = 7). However, almost all therapeutic studies (17/19) focused on the common cold. Most studies (17/34) evaluated the effectiveness of zinc administered as lozenges (3 prevention; 14 treatment) in acetate, gluconate, and orotate forms; gluconate lozenges were the most common (9/17). Zinc gluconate was given at doses between 45 and 276 mg/day for between 4.5 and 21 days. Five (5/17) lozenge studies gave acetate lozenges and two (2/17) gave both acetate and gluconate lozenges. One (1/17) lozenge study administered intranasal (gluconate) and lozenge (orotate) zinc in tandem for cold treatment. Of the 17/34 studies that did not use lozenges, 1/17 gave capsules, 3/17 administered dissolved powders, 5/17 gave tablets, 4/17 used syrups, and 4/17 used intranasal administration. Most studies were at unclear or high risk of bias in at least one domain. There may be little or no reduction in the risk of developing a cold with zinc compared to placebo (risk ratio (RR) 0.93, 95% CI 0.85 to 1.01; I2 = 20%; 9 studies, 1449 participants; low-certainty evidence). There may be little or no reduction in the mean number of colds that occur over five to 18 months of follow-up (mean difference (MD) -0.90, 95% CI -1.93 to 0.12; I2 = 96%; 2 studies, 1284 participants; low-certainty evidence). When colds occur, there is probably little or no difference in the duration of colds in days (MD -0.63, 95% CI -1.29 to 0.04; I² = 77%; 3 studies, 740 participants; moderate-certainty evidence), and there may be little or no difference in global symptom severity (standardised mean difference (SMD) 0.04, 95% CI -0.35 to 0.43; I² = 0%; 2 studies, 101 participants; low-certainty evidence). When zinc is used for cold treatment, there may be a reduction in the mean duration of the cold in days (MD -2.37, 95% CI -4.21 to -0.53; I² = 97%; 8 studies, 972 participants; low-certainty evidence), although it is uncertain whether there is a reduction in the risk of having an ongoing cold at the end of follow-up (RR 0.52, 95% CI 0.21 to 1.27; I² = 65%; 5 studies, 357 participants; very low-certainty evidence), or global symptom severity (SMD -0.03, 95% CI -0.56 to 0.50; I² = 78%; 2 studies, 261 participants; very low-certainty evidence), and there may be little or no difference in the risk of a change in global symptom severity (RR 1.02, 95% CI 0.85 to 1.23; 1 study, 114 participants; low-certainty evidence). Thirty-one studies reported non-serious adverse events (2422 participants). It is uncertain whether there is a difference in the risk of adverse events with zinc used for cold prevention (RR 1.11, 95% CI 0.84 to 1.47; I2 = 0%; 7 studies, 1517 participants; very low-certainty evidence) or an increase in the risk of serious adverse events (RR 1.67, 95% CI 0.78 to 3.57; I2 = 0%; 3 studies, 1563 participants; low-certainty evidence). There is probably an increase in the risk of non-serious adverse events when zinc is used for cold treatment (RR 1.34, 95% CI 1.15 to 1.55; I2 = 44%; 2084 participants, 16 studies; moderate-certainty evidence); no treatment study provided information on serious adverse events. No study provided clear information about adverse events considered to be potential complications of the common cold.

AUTHORS' CONCLUSIONS

The findings suggest that zinc supplementation may have little or no effect on the prevention of colds but may reduce the duration of ongoing colds, with an increase in non-serious adverse events. Overall, there was wide variation in interventions (including concomitant therapy) and outcomes across the studies, as well as incomplete reporting of several domains, which should be considered when making conclusions about the efficacy of zinc for the common cold.

Zinc Supplementation in Very Low Birth Weight Infants: A Randomized Controlled Trial

OBJECTIVE

 Preterm infants have high zinc (Zn) requirements and are generally believed to be in a negative Zn balance in the early period of life. In this study, we aimed to investigate the effect of high-dose Zn supplementation in very low birth weight (VLBW: infants with birth weight < 1.5 kg) infants on feeding intolerance and development of mortality and/or morbidities including necrotizing enterocolitis (NEC) and late-onset sepsis (LOS).

STUDY DESIGN

 This is a prospective randomized trial. VLBW preterm infants with gestational age of <32 weeks were randomly allocated on the seventh day of life to receive extra amount of supplemental Zn along with the enteral feedings (9 + 3 mg), besides regular low-dose supplementation (3 mg), from enrollment until discharge. Outcome measures were feeding intolerance, NEC (stage ≥ 2), LOS, and mortality.

RESULTS

 A total of 195 infants (97 from study group and 98 from control group) were analyzed. A total of 46 (47.4%) infants in the study group and 64 (65.3%) infants in the control group ended up with feeding intolerance (p = 0.012). NEC was observed in 11 infants (11.2%) in the control group and only 1 infant (1%) in the study group (p = 0.003). There was a negative correlation between high-dose Zn supplementation and number of culture-proven LOS episodes (p = 0.041). This significance was also present for clinical sepsis, being higher in the control group (p = 0.029). No relationship between high-dose Zn supplementation and mortality and other morbidities (hemodynamically significant patent ductus arteriosus, bronchopulmonary dysplasia, retinopathy of prematurity, and severe intraventricular hemorrhage) was observed.

CONCLUSION

 Zn supplementation for VLBW infants is found to be effective to decrease feeding intolerance, NEC, and LOS episodes in this vulnerable population. Current data support the supplementation of VLBW infants with higher than regular dose of Zn.

KEY POINTS

· Higher dose of Zn supplementation is shown to be a beneficial intervention in VLBW infants.. · Zn may decrease feeding intolerance, sepsis or NEC.. · Higher than regular dose of Zn seems to be safe..

Effects of Zinc Supplementation on Metabolomic Profiles in Tanzanian Infants: A Randomized Trial

BACKGROUND

Provision of zinc supplementation to young children has been associated with reduced infectious morbidity and better growth outcomes. However, the metabolic pathways underlying these outcomes are unclear, and metabolomic data from humans undergoing zinc supplementation, particularly infants, are generally lacking.

OBJECTIVES

This study aimed to examine the effect of zinc supplementation on metabolic profiles in Tanzanian infants aged 6 wk and 6 mo.

METHODS

Blood samples were collected at age 6 wk and 6 mo from 50 Tanzanian infants who were enrolled in a randomized placebo-controlled trial of zinc supplementation (5 mg oral daily). Metabolomic analysis using an ultrahigh-performance liquid chromatography/tandem mass spectroscopy platform was performed to identify potential metabolomic profiles and biomarkers associated with zinc supplementation. Principal component analysis (PCA) was used to summarize metabolomic data from all samples. Two-way repeated measures analysis of variance with compound symmetry covariance structures were used to compare metabolome levels over time between infants in the 2 treatment arms.

RESULTS

In PCA, the samples tended to be more separated by child age (6 wk compared with 6 mo) than by zinc supplementation status. We found that zinc supplementation affected a variety of metabolites associated with amino acid, lipid, nucleotide, and xenobiotic metabolism, including indoleacetate in the tryptophan metabolism pathway; 3-methoxytrosine and 4-hydrxoyphenylphruvate in the tyrosine pathway; eicosanedioate, 2-aminooctanoate, and N-acetyl-2-aminooctanoate in the fatty acid pathway; and N6-succinyladenosine in the purine metabolism pathway. Compared to the relatively small number of metabolites associated with zinc supplements, many infant metabolites changed significantly from age 6 wk to 6 mo.

CONCLUSIONS

Zinc supplementation, despite having overall clinical benefits, appears to induce limited metabolomic changes in blood metabolites in young infants. Future larger studies may be warranted to further examine metabolic pathways associated with zinc supplementation. The parent trial was registered at clinicaltrials.gov as NCT00421668.

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.

Acknowledging the gap: a systematic review of micronutrient supplementation in infants under six months of age

Background: Micronutrient deficiencies remain common worldwide, but the consequences to growth and development in early infancy (under six months of age) are not fully understood. We present a systematic review of micronutrient interventions in term infants under six months of age, with a specific focus on iron supplementation. Methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and Embase (Ovid) from January 1980 through December 2019. Interventions included iron or multiple micronutrients (MMNs). Results: Of 11,109 records identified, 33 publications from 24 trials were included (19 iron and five MMN supplementation trials). All but one trial (evaluating only morbidity and mortality) evaluated the effect of supplementation on biochemical outcomes, ten reported on growth, 15 on morbidity and/or mortality and six on neuro-behavioural development. Low- and middle- income countries made up 88% (22/25) of the total trial locations. Meta-analysis was not possible due to extensive heterogeneity in both exposure and outcome measures.  However, these trials indicated that infants less than six months of age benefit biochemically from early supplementation with iron, but the effect of additional nutrients or MMNs, along with the impacts on growth, morbidity and/or mortality, and neuro-behavioural outcomes remain unclear. Conclusions: Infants less than six months of age appear to benefit biochemically from micronutrient supplementation. However, well-powered randomised controlled trials are required to determine whether routine supplementation with iron or MMNs containing iron should commence before six months of life in exclusively breast-fed infants in low-resource settings.

Acknowledging the gap: a systematic review of micronutrient supplementation in infants under six months of age

Background: Micronutrient deficiencies remain common worldwide, but the consequences to growth and development in early infancy (under six months of age) are not fully understood. We present a systematic review of micronutrient interventions in term infants under six months of age, with a specific focus on iron supplementation. Methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and Embase (Ovid) from January 1980 through December 2019. Interventions included iron or multiple micronutrients (MMNs). Results: Of 11,109 records identified, 32 publications from 23 trials were included (18 iron and five MMN supplementation trials). All 23 trials evaluated the effect of supplementation on biochemical outcomes, ten reported on growth, 14 on morbidity and/or mortality and six on neuro-behavioural development. Low- and middle- income countries made up 88% (21/24) of the total trial locations. Meta-analysis was not possible due to extensive heterogeneity in both exposure and outcome measures.  However, these trials indicated that infants less than six months of age benefit biochemically from early supplementation with iron, but the effect of additional nutrients or MMNs, along with the impacts on growth, morbidity and/or mortality, and neuro-behavioural outcomes remain unclear. Conclusions: Infants less than six months of age appear to benefit biochemically from micronutrient supplementation. However, well-powered randomised controlled trials are required to determine whether routine supplementation with iron or MMNs containing iron should commence before six months of life in exclusively breast-fed infants in low-resource settings.

Enteral Multiple Micronutrient Supplementation in Preterm and Low Birth Weight Infants: A Systematic Review and Meta-analysis

OBJECTIVES

To assess effects of supplementation with 3 or more micronutrients (multiple micronutrients; MMN) compared to no MMN in human milk-fed preterm and low birth weight (LBW) infants.

RESULTS

Data on a subgroup of 414 preterm or LBW infants from 2 randomized controlled trials (4 reports) were included. The certainty of evidence ranged from low to very low. For growth outcomes in the MMN compared to the non-MMN group, there was a small increase in weight-for-age (2 trials, 383 participants) and height-for-age z-scores (2 trials, 372 participants); a small decrease in wasting (2 trials, 398 participants); small increases in stunting (2 trials, 399 participants); and an increase in underweight (2 trials, 396 participants). For neurodevelopment outcomes at 78 weeks, we found small increases in Bayley Scales of Infant Development, Version III (BISD-III), scores (cognition, receptive language, expressive language, fine motor, gross motor) in the MMN compared to the non-MMN group (1 trial, 27 participants). There were no studies examining dose or timing of supplementation.

CONCLUSIONS

Evidence is insufficient to determine whether enteral MMN supplementation to preterm or LBW infants who are fed mother's own milk is associated with benefit or harm. More trials are needed to generate evidence on mortality, morbidity, growth, and neurodevelopment.

Enteral Zinc Supplementation in Preterm or Low Birth Weight Infants: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Evidence on the effect of zinc supplementation on health outcomes in preterm or low birth weight (LBW) infants is unclear. We estimated the effect of enteral zinc versus no zinc supplementation in human milk fed preterm or LBW infants on mortality, growth, morbidities, and neurodevelopment.

METHODS

Data sources include PubMed, Cochrane Central and Embase databases through March 24, 2021. Study selection was randomized or quazi-experimental trials. Two reviewers independently screened, extracted data, and assessed quality. We reported pooled relative risks (RR) for categorical outcomes, and mean differences (MD) for continuous outcomes.

RESULTS

Fourteen trials with 9940 preterm or LBW infants were included. Moderate to low certainty evidence showed that enteral zinc supplementation had little or no effect on mortality (risk ratio 0.73, 95% confidence interval [CI] 0.46 to 1.16), but increased weight (MD 378.57, 95% CI 275.26 to 481.88), length (MD 2.92, 95% CI 1.53 to 4.31), head growth (MD 0.56, 95% CI 0.23 to 0.90), and decreased diarrhea (RR 0.81; 95% CI 0.68 to 0.97). There was no effect on acute respiratory infections, bacterial sepsis, and psychomotor development scores. The effect of zinc supplementation on mental development scores is inconclusive. There was no evidence of serious adverse events. Eight trials had some concerns or high risk of bias, small-sized studies, and high heterogeneity between trials led to moderate to very low certainty of evidence.

CONCLUSIONS

Zinc supplementation in preterm or LBW infants have benefits on growth and diarrhea prevention. Further research is needed to generate better quality evidence.

Nutrient supplementation for prevention of viral respiratory tract infections in healthy subjects: A systematic review and meta-analysis

It remains uncertain as to whether nutrient supplementation for the general population considered healthy could be useful in the prevention of RTIs, such as COVID-19. In this systematic review and meta-analysis, the evidence was evaluated for primary prevention of any viral respiratory tract infection (RTI) such as SARS-CoV-2, through supplementation of nutrients with a recognized role in immune function: multiple micronutrients, vitamin A, folic acid, vitamin B12, C, D, E, beta-carotene, zinc, iron and long-chain polyunsaturated fatty acids. The search produced 15,163 records of which 93 papers (based on 115 studies) met the inclusion criteria, resulting in 199,055 subjects (191,636 children and 7,419 adults) from 37 countries. Sixty-three studies were included in the meta-analyses, which was performed for children and adults separately. By stratifying the meta-analysis by world regions, only studies performed in Asia showed a significant but heterogeneous protective effect of zinc supplementation on RTIs (RR 0.86, 95% CI 0.7-0.96, I²  = 79.1%, p = .000). Vitamin D supplementation in adults significantly decreased the incidence of RTI (RR 0.89, 95% CI 0.79-0.99, p = .272), particularly in North America (RR 0.82 95% CI 0.68-0.97), but not in Europe or Oceania. Supplementation of nutrients in the general population has either no or at most a very limited effect on prevention of RTIs. Zinc supplementation appears protective for children in Asia, whilst vitamin D may protect adults in the USA and Canada. In 10/115 (8.7%) studies post-hoc analyses based on stratification for nutritional status was performed. In only one study zinc supplementation was found to be more effective in children with low zinc serum as compared to children with normal zinc serum levels.

Childhood stunting and micronutrient status unaffected by RCT of micronutrient fortified drink

Micronutrient supplementation is widely used to prevent stunting in children under 5 years in low‐ and middle‐income countries (LMIC), but the impact of treatment has been disappointing, possibly due to non‐compliance. Our aim was to deliver long‐term micronutrient supplementation via a novel, culturally acceptable liquid food to improve linear growth in a high stunting prevalence region.

In a randomised control trial, 971 children aged 6–72 months received either ‘Chispuditos®’ (n = 681), a hot drink (atole) fortified with micronutrients (atole + MN) (9 mg/zinc, 12.5 mg/iron), or lactose‐free milk (n = 290) for 18 months. Primary outcomes were changes in length/height‐for‐age (HAZ) score and the prevalence of stunting at 18‐month follow‐up. Adherence was monitored monthly, and 73% children in atole + MN group consumed at least half their daily zinc and iron requirement. At 18 months, there was no difference between the treatments in growth [mean change in HAZ −0.02 (95% CI −0.12, 0.08)] or stunting [atole + MN 41%, milk 41%; RR 0.99 (95% CI 0.84, 1.19)]. There were no differences in haemoglobin (HB), ferritin or zinc. No children had iron deficiency anaemia (IDA) at outcome, but zinc deficiency remained equally prevalent in both groups: atole + MN 35%, milk 35% [RR 1.02 (95% CI 0.83, 1.24)]. There was no difference in morbidity between the groups, and micronutrient status was unrelated to HAZ. Long‐term micronutrient supplementation via a culturally acceptable food had no impact on stunting or morbidity, raising the question of whether large‐scale micronutrient supplementation is worthwhile.

Effects of prenatal and postnatal maternal multiple micronutrient supplementation on child growth and morbidity in Tanzania: a double-blind, randomized-controlled trial

BACKGROUND

Maternal micronutrient status is critical for child growth and nutrition. It is unclear whether maternal multiple micronutrient supplementation (MMS) during pregnancy and lactation improves child growth and prevents child morbidity.

METHODS

This study aimed to determine the effects of prenatal and postnatal maternal MMS on child growth and morbidity. In this double-blind, randomized-controlled trial, 8428 HIV-negative pregnant women were enrolled from Dar es Salaam, Tanzania, between 2001 and 2004. From pregnancy (12-27 weeks of gestation) through to 6 weeks postpartum, participants were randomized to receive daily oral MMS or placebo. All women received daily iron and folic acid during pregnancy. From 6 weeks postpartum through to 18 months postpartum, 3100 women were re-randomized to MMS or placebo. Child-growth measures, haemoglobin concentrations and infectious morbidities were assessed longitudinally from birth to ≤18 months.

RESULTS

Prenatal MMS led to modest increases in weight-for-age z-scores (mean difference: 0.050; 95% confidence interval: 0.002, 0.099; p = 0.04) and length-for-age z-score (mean difference: 0.062; 95% confidence interval: 0.013, 0.111; p = 0.01) during the first 6 months of life but not thereafter. Prenatal or postnatal MMS did not have benefits for other child outcomes.

CONCLUSIONS

Whereas maternal MMS is a proven strategy to prevent adverse birth outcomes, other approaches may also need to be considered to curb the high burdens of child morbidity and growth faltering.

Effect of zinc supplementation on mortality in under 5-year children: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Several clinical trials evaluated the effect of zinc supplementation on mortality in children, but the results were inconsistent. We aimed to conduct a systematic review and meta-analysis on the impact of zinc supplementation on mortality in under 5-year children.

METHODS

A comprehensive search was conducted using the electronic (PubMed, Scopus, Web of Science) databases, and Google Scholar, up to June 2020. Randomized clinical trials (RCTs) that reported the effect of zinc supplementation on death incidence in under 5-year children were included in the analysis. Screening was performed based on title/abstract and full-text. A random effects model was applied to calculate the summary relative risk (SRR). Risk of Bias 2.0 tool was used to rate the quality of trials. The body of evidence was assessed by the GRADE approach.

RESULTS

Combining 30 RRs from 28 RCTs including 237,068 participants revealed that zinc supplementation has significantly reduced the risk of all-causes mortality by 16% in children (SRR: 0.84, 95% CI: 0.74, 0.96). A follow-up duration of less than 1 year after supplementation resulted in 54% reduced risk of mortality (0.46; 0.33, 0.63) with no heterogeneity between investigations. Subgroup analysis by zinc dosage showed that assigning ≥ 10 mg/d zinc to under five children and duration of less than 11 months of intervention decreased the risk of all-cause mortality by 44% (0.56; 0.42, 0.75) and 48% (0.52; 0.38, 0.72), respectively. In low birth weight (LBW) infants, zinc supplementation was reduced all-cause mortality by 52% (0.48; 0.23, 1.00). Zinc supplementation significantly reduced the risk of death from pneumonia (0.70: 0.64, 0.98) and infection (0.54; 0.39, 0.76), also changed the risk of mortality from diarrhea by 15% (0.85; 0.70, 1.03) and sepsis by 57% (0.43; 0.18, 1.02).

CONCLUSION

This meta-analysis on RCTs revealed that zinc supplementation in under 5-year children has significantly reduced the risk of all-cause mortality. Notable decreases were found in trials with a dose of 10 mg/d or more zinc supplementation, a maximum of 11 months of supplementation, a follow-up less than one year and especially in LBW infants.

Effects of therapeutic zinc supplementation for diarrhea and two preventive zinc supplementation regimens on the incidence and duration of diarrhea and acute respiratory tract infections in rural Laotian children: A randomized controlled trial

Background

Diarrhea and respiratory tract infections are leading causes of childhood morbidity and mortality. This individually randomized, double-blind placebo-controlled trial was designed to evaluate the effects of different zinc supplementation regimens on the incidence and duration of diarrhea and acute lower (ALRI) and upper (AURI) respiratory tract infections among rural Laotian children. The study included 3407 children, 6-23 months at enrollment.

Methods

Children were randomized to one of four study groups: therapeutic zinc supplements for diarrhea treatment (20 mg/d for 10 days with each episode; TZ), daily preventive zinc tablets (7 mg/d; PZ), daily multiple micronutrient powder (10 mg/d zinc, 6 mg/d iron and 13 other micronutrients; MNP), or daily placebo powder for 9 months. Incidence and duration of diarrhea (≥3 liquid stools/24 hours), ALRI (persistent cough with wheezing, stridor or chest in-drawing) and AURI (purulent nasal discharge with cough) were assessed by parental report during weekly home visits and analyzed using negative binomial models.

Results

Baseline mean age was 14.2 ± 5.1 months, and 71% had low plasma zinc (<65 μg/dL). Overall diarrhea incidence (0.61 ± 0.01 episodes/100 days at risk) and duration (2.12 ± 0.03 days/episode) did not differ by study group. Age modified the impact of the interventions on diarrhea incidence (P = 0.06) and duration (P = 0.01). In children >18 months, TZ reduced diarrhea incidence by 24% vs MNP (P = 0.035), and 36% vs Control (P = 0.004), but there was no difference with PZ. This patterned remained when analyses were restricted to diarrhea episode occurring after the first treatment with TZ. Also, in children >18 months, TZ reduced diarrhea duration by 15% vs PZ (P = 0.03), and 16% vs Control (P = 0.03), but there was no difference with MNP. There were no overall effects of study group on incidence of ALRI (overall mean 0.005 ± 0.001 episodes/100 days, P = 0.14) or AURI (overall mean 0.09 ± 0.01 episodes/100 days, P = 0.72).

Conclusions

There was no overall impact of TZ, PZ or MNP on diarrhea, ALRI and AURI. However, in children >18 months, TZ significantly reduced both the duration of diarrhea episodes and the incidence of future diarrhea episodes compared with placebo.

Trial registration

ClinicalTrials.gov: NCT02428647.

Role and effects of zinc supplementation in HIV-infected patients with immunovirological discordance: A randomized, double blind, case control study

INTRODUCTION

It has been estimated that between 15% and 18% of patients who start antiretroviral therapy (ART) do not achieve a successful immune recovery despite complete virological suppression. In the literature this phenomenom is known as poor immune recovery or immunovirological discordance (IVD). Zinc has an immunomodulatory role associated with T lymphocytes and its supplementation could enhance immune recovery.

OBJECTIVE

To determine if zinc supplementation on IVD patients prevents immune failure after 12 months of supplementation. Secondary objectives were to determine serum zinc levels in HIV patients with and without IVD and the frequency of hypozincemia in discordant patients.

METHOD

We reviewed the historical record of patients under care at Arriarán Foundation. Following inclusion criteria were defined: 1) age ≥ 18 years, 2) standard ART (three effective drugs) for at least 18 months, 3) virologically suppressed for 12 months, 3) persistence of CD4 count ≤200 cells/mm3 and/or increase ≤ 80 cells/mm3 after one year of viral undetectability. A control group was assigned paired 1:1 by sex, age (± 2 years) that did achieved an increase of CD4> 350 cells/ mm3. In both groups plasma zinc levels were determined. In a later phase, patients with IVD were randomized to receive zinc (15 mg daily) versus placebo. Patients were followed for 12 months with CD4 count, viral load and zinc levels determinations every 4-6 months.

RESULTS

A total of 80 patients, 40 patients with IVD criteria and 40 controls were included. 92.5% were men, and age average was 47.5 years. The median baseline CD4 was 189 cells/mm3 (71-258) in the cases vs. 552.5 cells/ mm3 (317-400) in the control group with a median increase at the end of the study of 39 cell/mm3 and 19 cell/mm3 respectively. There was no difference in baseline plasma zinc levels between both groups (81.7 + 18.1 in cases versus 86.2 + 11.0 in controls). In the 40 patients with IVD, the median absolute increase in CD4 after annual zinc supplementation was 31.5 cells/mm3 in the treated group versus 50 cells/mm3 in the placebo group, this difference being statistically not significant (p = 0.382).

CONCLUSIONS

Patients with IVD have plasma zinc levels similar to those who achieve adequate immune recovery. Zinc supplementation in IVD patients showed a statistically non-significant difference in in CD4 levels between cases and controls. The results warrant a comparative study with a larger number of patients.

The Associated Regulatory Mechanisms of Zinc Lactate in Redox Balance and Mitochondrial Function of Intestinal Porcine Epithelial Cells

Zinc lactate (ZnLA) is a new organic zinc salt which has antioxidant properties in mammals and can improve intestinal function. This study explored the effects of ZnLA and ZnSO₄ on cell proliferation, Zn transport, antioxidant capacity, mitochondrial function, and their underlying molecular mechanisms in intestinal porcine epithelial cells (IPEC-J2). The results showed that addition of ZnLA promoted cell proliferation, inhibited cell apoptosis and IL-6 secretion, and upregulated the mRNA expression and concentration of MT-2B, ZNT-1, and CRIP, as well as affected the gene expression and activity of oxidation or antioxidant enzymes (e.g., CuZnSOD, CAT, and Gpx1, GSH-PX, LDH, and MDA), compared to ZnSO₄ or control. Compared with the control, ZnLA treatment had no significant effect on mitochondrial membrane potential, whereas it markedly increased the mitochondrial basal OCR, nonmitochondrial respiratory capacity, and mitochondrial proton leakage and reduced spare respiratory capacity and mitochondrial reactive oxygen (ROS) production in IPEC-J2 cells. Furthermore, ZnLA treatment increased the protein expression of Nrf2 and phosphorylated AMPK, but reduced Keap1 and p62 protein expression and autophagy-related genes LC3B-1 and Beclin mRNA abundance. Under H₂O₂-induced oxidative stress conditions, ZnLA supplementation markedly reduced cell apoptosis and mitochondrial ROS levels in IPEC-J2 cells. Moreover, ZnLA administration increased the protein expression of Nrf2 and decreased the protein expression of caspase-3, Keap1, and p62 in H₂O₂-induced IPEC-J2 cells. In addition, when the activity of AMPK was inhibited by Compound C, ZnLA supplementation did not increase the protein expression of nuclear Nrf2, but when Compound C was removed, the activities of AMPK and Nfr2 were both increased by ZnLA treatment. Our results indicated that ZnLA could improve the antioxidant capacity and mitochondrial function in IPEC-J2 cells by activating the AMPK-Nrf2-p62 pathway under normal or oxidative stress conditions. Our novel finding also suggested that ZnLA, as a new feed additive for piglets, has the potential to be an alternative for ZnSO₄.

Identifying Infants and Young Children at Risk of Unplanned Hospital Admissions and Clinic Visits in Dar es Salaam, Tanzania

BACKGROUND

Pediatric inpatient mortality rates are as high as 11% in parts of sub-Saharan Africa. Unscheduled clinic visits also burden children in sub-Saharan Africa. Our objective was to identify factors associated with hospital admissions and unscheduled clinic visits among Tanzanian children < 24 months of age.

METHODS

We conducted a secondary analysis of 2 trials conducted in Dar es Salaam, Tanzania. We performed univariate and Poisson multivariable regression analyses to identify factors associated with hospital admissions and unscheduled clinic visits.

RESULTS

Of 4784 children < 24 months of age, 293 (6.1%) were hospitalized at least once and 1308 (27.3%) had ≥ 1 unscheduled clinic visit. Infants and children who were exposed to but HIV-negative had increased risk of hospital admission [adjusted risk ratios (aRR): 3.67; 95% CI: 2.45-5.50; P < 0.001] compared with HIV-unexposed children. Those who were HIV-positive had even higher risk of hospital admission compared with those not exposed to HIV (aRR: 10.87; 95% CI: 7.01-16.89; P < 0.001). Birth weight and breast-feeding status were not associated with increased risk of hospital admission. Children with Apgar scores < 7 (aRR: 1.32; 95% CI: 1.03-1.69; P = 0.001), not exclusively breast-fed up to 6 months of age (aRR: 1.34; 95% CI: 1.12-1.60; P = 0.001), and who were HIV-exposed and HIV-negative (aRR: 2.35; 95% CI: 2.08-2.66; P < 0.001) or HIV-positive (aRR: 3.02; 95% CI: 2.52-3.61; P < 0.001) had higher risk of unscheduled clinic visits.

CONCLUSIONS

Exposure to HIV and being HIV-positive were associated with the greatest risk for hospital admission and unplanned clinic visits among infants and children in Tanzania. Targeting these vulnerable populations in interventional studies may reduce morbidity.

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.

Risk factors for mortality among Tanzanian infants and children

BACKGROUND

During the era of the Millennium Development Goals, under 5 mortality rates decreased significantly worldwide; however, reductions were not equally distributed. Children in sub-Saharan Africa still account for more than 50% of the world's annual childhood deaths among children under 5 years of age. Understanding upstream risk factors for mortality among children may reduce the large burden of childhood mortality in sub-Saharan Africa. Our objective was to identify risk factors for mortality among infants and children in Tanzania.

METHODS

We conducted a secondary analysis of data pooled from two randomized-controlled micronutrient supplementation trials. A total of 4787 infants were enrolled in the two trials (n = 2387 HIV-exposed and n = 2400 HIV-unexposed). Predictors of mortality were assessed using unadjusted and adjusted hazard ratios (aHRs).

RESULTS

There were 307 total deaths, 262 (11%) among children who were HIV-exposed and 45 (2%) among children who were HIV-unexposed (P < 0.001). The most common cause of death was respiratory diseases (n = 109, 35.5%). Causes of death did not significantly differ between HIV-exposed and HIV-unexposed children. In adjusted regression analyses, children with birth weight <2500 g (aHR 1.75, 95% CI 1.21-2.54), Apgar score of ≤7 at 5 min (aHR 2.16, 95% CI 1.29-3.62), or who were HIV-exposed but not infected (aHR 3.35, 95% CI 2.12-5.28) or HIV-infected (aHR 27.56, 95% CI 17.43-43.58) had greater risk of mortality.

CONCLUSIONS

Infection with HIV, low birthweight, or low Apgar scores were associated with higher mortality risk. Early identification and modification of determinants of mortality among infants and children may be the first step to reducing such deaths.

Respiratory Syncytial Virus-Induced Oxidative Stress Leads to an Increase in Labile Zinc Pools in Lung Epithelial Cells

Zinc supplementation in cell culture has been shown to inhibit various viruses, like herpes simplex virus, rotavirus, severe acute respiratory syndrome (SARS) coronavirus, rhinovirus, and respiratory syncytial virus (RSV). However, whether zinc plays a direct antiviral role in viral infections and whether viruses have adopted strategies to modulate zinc homeostasis have not been investigated. Results from clinical trials of zinc supplementation in infections indicate that zinc supplementation may be beneficial in a pathogen- or disease-specific manner, further underscoring the importance of understanding the interaction between zinc homeostasis and virus infections at the molecular level. We investigated the effect of RSV infection on zinc homeostasis and show that RSV infection in lung epithelial cells leads to modulation of zinc homeostasis. The intracellular labile zinc pool increases upon RSV infection in a multiplicity of infection (MOI)-dependent fashion. Small interfering RNA (siRNA)-mediated knockdown of the ubiquitous zinc uptake transporter ZIP1 suggests that labile zinc levels are increased due to the increased uptake by RSV-infected cells as an antiviral response. Adding zinc to culture medium after RSV infection led to significant inhibition of RSV titers, whereas depletion of zinc by a zinc chelator, N,N,N',N'-tetrakis(2-pyridinylmethyl)-1,2-ethanediamine (TPEN) led to an increase in RSV titers. The inhibitory effect of zinc was specific, as other divalent cations had no effect on RSV titers. Both RSV infection and zinc chelation by TPEN led to reactive oxygen species (ROS) induction, whereas addition of zinc blocked ROS induction. These results suggest a molecular link between RSV infection, zinc homeostasis, and oxidative-stress pathways and provide new insights for developing strategies to counter RSV infection.IMPORTANCE Zinc deficiency rates in developing countries range from 20 to 30%, and zinc supplementation trials have been shown to correct clinical manifestations attributed to zinc deficiency, but the outcomes in the case of respiratory infections have been inconsistent. We aimed at understanding the role of zinc homeostasis in respiratory syncytial virus (RSV) infection. Infection of lung epithelial cell lines or primary small-airway epithelial cells led to an increase in labile zinc pools, which was due to increased uptake of zinc. Zinc supplementation inhibited RSV replication, whereas zinc chelation had an opposing effect, leading to increases in RSV titers. Increases in labile zinc in RSV-infected cells coincided with induction of reactive oxygen species (ROS). Both zinc depletion and addition of exogenous ROS led to enhanced RSV infection, whereas addition of the antioxidant inhibited RSV, suggesting that zinc is part of an interplay between RSV-induced oxidative stress and the host response to maintain redox balance.

Zinc supplementation for the promotion of growth and prevention of infections in infants less than six months of age

BACKGROUND

Zinc is a vital micronutrient for humans and is essential for protein synthesis, cell growth, and differentiation. Severe zinc deficiency can lead to slower physical, cognitive and sexual growth, cause skin disorders, decrease immunity, increase incidence of acute illnesses in infants and children and contribute to childhood stunting. By estimation, 17.3% of the world population is at risk of inadequate zinc intake. Such nutritional impairment increases the risk of diarrhoea and pneumonia by 20%, as well as leads to a global loss of more than 16 million disability-adjusted life years in children less than five years of age. Not only does zinc deficiency affect lives, it adds to the considerable financial burden on depleted resources in countries that are most affected. By preventing or curing this deficiency, we can improve childhood mortality, morbidity and growth.

OBJECTIVES

To assess the effectiveness of zinc supplementation for the promotion of growth, reduction in mortality, and the prevention of infections in infants less than six months of age.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2018, Issue 4), MEDLINE via PubMed (1966 to 18 May 2018), Embase (1980 to 18 May 2018), and CINAHL (1982 to 18 May 2018). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. An updated search from 1 January 2018 to 29 January 2020 was run in the following databases: CENTRAL via CRS Web, MEDLINE via Ovid, and CINAHL via EBSCOhost.

SELECTION CRITERIA

All randomised controlled (individual and cluster randomised) and quasi-randomised trials of zinc supplementation in healthy, term infants, less than six months of age comparing infant mortality, incidence of diarrhoea or respiratory illnesses, growth and/or serum zinc levels were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors screened search results (title and abstracts) and relevant full texts. Studies fulfilling prespecified inclusion criteria were included with any disagreements resolved by consensus. Extraction and analysis were then conducted. We used the GRADE approach to assess the quality of evidence as indicated by certainty in effect estimates.

MAIN RESULTS

Eight studies (with 85,629 infants) were included and five studies were meta-analysed, out of which four studies compared zinc with placebo, and one compared zinc plus riboflavin versus riboflavin. Certain growth outcomes after six months of intervention (Weight for Age Z-scores (WAZ) (standardised mean difference) (SMD) 0.16, 95% CI 0.03 to 0.29; three studies, n = 955; fixed-effect; heterogeneity Chi² P = 0.96); I² = 0%); change in WAZ (SMD 0.16, 95% CI 0.07 to 0.25; one study, n = 386; fixed-effect); (Weight-for-Length Z-score (WLZ) (SMD 0.15, 95% CI 0.02 to 0.28; three studies, n = 955; fixed-effect; heterogeneity: Chi² P = 0.81); I² = 0%); (change in WLZ (SMD 0.17, 95% CI 0.06 to 0.28; one study, n = 386; fixed-effect)) were positively affected by zinc supplementation compared to placebo. A single study reported no difference in the incidence of diarrhoea and lower respiratory tract infection with zinc supplementation. Zinc had no effect on mortality in children younger than 12 months. When zinc plus riboflavin was compared to riboflavin only, significant improvement was observed in the incidence of wasting at 24 months (risk ratio (RR) 0.59, 95% CI 0.37 to 0.96; one study, n = 296; fixed-effect), but significant worsening of incidence of stunting was present at 21 months (RR 1.53, 95% CI 1.09 to 2.16; one study, n = 298; fixed-effect).

AUTHORS' CONCLUSIONS

There was a significant positive impact of zinc supplementation on WAZ and WLZ after six months of intervention in infants compared to placebo. When a combined supplement of zinc and riboflavin was compared to riboflavin, there was a significant reduction in wasting at 24 months, but stunting at 21 months was negatively affected. Although included trials were of good-to-moderate quality, evidence that could be meta-analysed was based on a few studies which affected the overall quality of results. Regardless, there is a need for strong trials conducted in infants younger than six months before a strong recommendation can be made supporting zinc supplementation in this age group.

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.

Markers of Systemic Inflammation and Environmental Enteric Dysfunction Are Not Reduced by Zinc or Multivitamins in Tanzanian Infants: A Randomized, Placebo-Controlled Trial

OBJECTIVE

To examine whether daily zinc and/or multivitamin supplementation reduce biomarkers of environmental enteric dysfunction (EED), systemic inflammation, or markers of growth in a sample of infants from Dar es Salaam, Tanzania.

STUDY DESIGN

Subgroup analysis of infants participating in a randomized, double-blind, placebo-controlled trial received daily oral supplementation of zinc, multivitamins, zinc + multivitamins, or placebo for 18 months starting at 6 weeks of age. EED (anti-flagellin and anti-lipopolysaccharide immunoglobulins), systemic inflammation (C-reactive protein and alpha-1-acid glycoprotein), and growth biomarkers (insulin-like growth factor-1 and insulin-like growth factor binding protein-3) were measured via enzyme-linked immunosorbent assay in a subsample of 590 infants at 6 weeks and 6 months of age. EED biomarkers also were measured in 162 infants at 12 months of age.

RESULTS

With the exception of anti-lipopolysaccharide IgG concentrations, which were significantly greater in infants who received multivitamins compared with those who did not (1.41 ± 0.61 vs 1.26 ± 0.65, P = .006), and insulin-like growth factor binding protein-3 concentrations, which were significantly lower in children who received zinc compared with those who did not (981.13 ± 297.59 vs 1019.10 ± 333.01, P = .03), at 6 months of age, we did not observe any significant treatment effects of zinc or multivitamins on EED, systemic inflammation, or growth biomarkers.

CONCLUSIONS

Neither zinc nor multivitamin supplementation ameliorated markers of EED or systemic inflammation during infancy. Other interventions should be prioritized for future trials.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT00421668.

Nutritional, Socioeconomic, and Delivery Characteristics Are Associated with Neurodevelopment in Tanzanian Children

OBJECTIVES

To evaluate the hypothesis that various maternal, socioeconomic, delivery, and infant nutritional characteristics are associated with early childhood development in young Tanzanian children.

STUDY DESIGN

We performed a prospective cohort study among 206 HIV-exposed, uninfected and 247 HIV-unexposed Tanzanian infants who had been enrolled in 2 separate micronutrient trials (NCT00197730 and NCT00421668). Trained nurses administered culturally modified Bayley Scales of Infant and Toddler Development, 3rd edition (BSID-III), to evaluate cognitive, motor, and language development at 15 months of age. This analysis explored predictors of BSID-III z-scores using multivariable linear regression.

RESULTS

Among maternal determinants, we found that low maternal height predicted all BSID-III domains in HIV-unexposed children; low maternal education predicted lower cognitive (standardized mean difference, -0.41; 95% CI, -0.74 to -0.08) and lower gross motor scores (standardized mean difference, -0.32; 95% CI, -0.61 to -0.04) in HIV-exposed children. Among delivery characteristics, facility delivery predicted higher cognitive scores (standardized mean difference, 1.36; 95% CI, 0.26-2.46); and oxytocin administration predicted lower fine motor scores (standardized mean difference, -0.48; 95% CI, -0.87 to -0.09) in HIV-exposed children. Higher length-for-age z-scores at 6 weeks of age predicted better cognitive (standardized mean difference, 0.15; 95% CI, 0.01-0.29) and expressive language scores (standardized mean difference, 0.16; 95% CI, 0.02-0.29) at 15 months in HIV-exposed infants.

CONCLUSIONS

This hypothesis-generating study found significant associations between nutritional status and health of the mother and child, and maternal educational attainment, with direct measures of early childhood development at 15 months of age. In addition, several aspects of delivery (facility birth and oxytocin administration) were associated with early childhood development. Future intervention trials should focus on modifiable maternal, infant, and obstetric factors to strengthen the evidence base concerning early childhood development.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00197730 and NCT00421668.

Effect of antenatal and infant micronutrient supplementation on middle childhood and early adolescent development outcomes in Tanzania

Background:

There is growing evidence that nutritional interventions in the first 1,000 days of life may influence long-term health and development outcomes. Few studies have examined the effect of maternal and infant micronutrient supplementation on development outcomes in sub-Saharan Africa.

Methods:

We conducted a follow-up study of two randomized trials of antenatal and infant micronutrient supplementation conducted in Dar es Salaam, Tanzania. We assessed the effect of maternal multiple micronutrient (MMN) supplementation in pregnancy on development of children at 11–14 years of age. We also examined the effect of infant zinc and MMN supplementation on development at 6–8 years of age. We use generalized linear models to assess standardized mean differences (SMDs) in general intelligence, executive function and mental health scores.

Results:

We followed-up 446 children whose mothers were enrolled in the maternal MMN supplementation trial and 365 children who were enrolled in the infant zinc and MMN supplementation trial. We found no effect of maternal MMN supplementation on general intelligence (SMD: −0.03; 95% CI: −0.15, 0.09), executive function (SMD: 0.00; 95% CI: −0.11, 0.11) and mental health scores (SMD: 0.06; 95% CI: −0.10, 0.22). We also found no effect of either infant zinc or MMN supplementation on any of the three development domains (p-values >0.05).

Conclusions:

We found that antenatal MMN supplementation and infant zinc and MMN supplementation did not have a large effect on development outcomes in middle childhood and early adolescence in Tanzania.

How cellular Zn2+ signaling drives physiological functions

Zinc is an essential micronutrient affecting many aspects of human health. Cellular Zn²⁺ homeostasis is critical for cell function and survival. Zn²⁺, acting as a first or second messenger, triggers signaling pathways that mediate the physiological roles of Zn²⁺. Transient changes in Zn²⁺ concentrations within the cell or in the extracellular region occur following its release from Zn²⁺ binding metallothioneins, its transport across membranes by the ZnT or ZIP transporters, or release of vesicular Zn²⁺. These transients activate a distinct Zn²⁺ sensing receptor, ZnR/GPR39, or modulate numerous proteins and signaling pathways. Importantly, Zn²⁺ signaling regulates cellular physiological functions such as: proliferation, differentiation, ion transport and secretion. Indeed, novel therapeutic approaches aimed to maintain Zn²⁺ homeostasis and signaling are evolving. This review focuses on recent findings describing roles of Zn²⁺ and its transporters in regulating physiological or pathological processes.

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.

Markers of Environmental Enteric Dysfunction Are Associated With Neurodevelopmental Outcomes in Tanzanian Children

BACKGROUND

Chronic exposure to enteropathogens may result in environmental enteric dysfunction (EED), a subclinical condition associated with poor child growth. Growth faltering is strongly associated with poor neurodevelopment, and occurs during sensitive periods of postnatal brain development. We investigated the role of novel EED biomarkers, systemic inflammation, and micronutrient status on neurodevelopment in Tanzanian children.

METHODS

Non-stunted subjects with 6-week and 6-month blood samples and neurodevelopmental measures (n = 107) were included in this study. Samples were tested for biomarkers of gastrointestinal function (citrulline, antibodies to lipopolysaccharide, and flagellin), micronutrient status (iron, retinol binding protein [RBP], and vitamin D), systemic inflammation (C-reactive protein [CRP] and alpha-1-acid glycoprotein), and growth (insulin-like growth factor and insulin-like growth factor binding protein 3).

RESULTS

Cognitive scores at 15 months were associated with higher concentrations of 6-month anti-lipopolysaccharide IgG (β = 1.95, P = 0.02), anti-flagellin IgA (β = 2.41, P = 0.04), and IgG (β = 2.99, P = 0.009). Higher receptive language scores were positively associated with anti-flagellin IgG (β = 0.95, P = 0.05), and receptive language and gross motor scores were positively associated with citrulline at 6 months (β = 0.09, P = 0.02; β = 0.10, P = 0.03, respectively). Gross motor scores were positively associated with RBP at 6 months (β = 1.70, P = 0.03). Markers of systemic inflammation were not significantly associated with neurodevelopment.

CONCLUSIONS

Plasma citrulline, a marker of gastrointestinal mucosal surface area, and vitamin A status were associated with higher gross motor development scores. Novel markers for EED, but not inflammation, were positively associated with cognitive scores, suggesting a possible mechanistic pathway involving immune response and neuroprotection.

Self-Care for Common Colds: The Pivotal Role of Vitamin D, Vitamin C, Zinc, and Echinacea in Three Main Immune Interactive Clusters (Physical Barriers, Innate and Adaptive Immunity) Involved during an Episode of Common Colds-Practical Advice on Dosages and on the Time to Take These Nutrients/Botanicals in order to Prevent or Treat Common Colds

Maintaining a normal healthy immune defense system lowers the incidence and/or the severity of symptoms and/or the duration of common cold (CC). Physical barriers and innate and adaptive immunity have been involved during a CC episode. Vitamins C and D, zinc, and Echinacea have evidence-based efficacy on these immune system barriers. This review includes 82 eligible studies to consider the preventive role of these nutrients in immune clusters and in CC to provide advice on dosage and assumption of these nutrients. Regarding vitamin C, regular supplementation (1 to 2 g/day) has shown that vitamin C reduces the duration (in adults by 8%, in children by 14%) and the severity of CC. Considering zinc, the supplementation may shorten the duration of colds by approximately 33%. CC patients may be instructed to try zinc within 24 hours of onset of symptoms. As for vitamin D, the supplementation protected against CC overall, considering baseline levels and age. Patients with vitamin D deficiency and those not receiving bolus doses experienced the most benefit. Regarding Echinacea, prophylactic treatment with this extract (2400 mg/day) over 4 months appeared to be beneficial for preventing/treating CC. In conclusion, the current evidence of efficacy for zinc, vitamins D and C, and Echinacea is so interesting that CC patients may be encouraged to try them for preventing/treating their colds, although further studies are needed on this topic.

Does early vitamin B12 supplementation improve neurodevelopment and cognitive function in childhood and into school age: a study protocol for extended follow-ups from randomised controlled trials in India and Tanzania

INTRODUCTION

As many as 250 million children under the age of 5 may not be reaching their full developmental potential partly due to poor nutrition during pregnancy and the first 2 years of life. Micronutrients, including vitamin B₁₂, are important for the development of brain structure and function; however, the timing, duration and severity of deficiencies may alter the impact on functional development outcomes. Consequently, to fully explore the effect of vitamin B₁₂ on cognitive function, it is crucial to measure neurodevelopment at different ages, in different populations and with vitamin B₁₂ supplementation at different times during the critical periods of neurodevelopment.

METHODS AND ANALYSIS

In this project, we follow up children from four recently completed randomised placebo-controlled trials of oral vitamin B₁₂ supplementation, two in India and two in Tanzania, to explore the long-term effects on neurodevelopmental outcomes and growth. All the included trials provided at least two recommended dietary allowances of oral vitamin B₁₂ daily for at least 6 months. Vitamin B₁₂ was supplemented either during pregnancy, early infancy or early childhood. Primary outcomes are neurodevelopmental status, cognitive function and growth later in childhood. We apply validated and culturally appropriate instruments to identify relevant developmental outcomes. All statistical analyses will be done according to intention-to-treat principles. The project provides an excellent opportunity to examine the effect of vitamin B₁₂ supplementation in different periods during early life and measure the outcomes later in childhood.

ETHICS AND DISSEMINATION

The study has received ethical approvals from all relevant authorities in Norway, USA, Tanzania and India and complies fully with ethical principles for medical research. Results will be presented at national and international research and policy meetings and published in peer-reviewed scientific journals, preferably open access.

TRIAL REGISTRATION NUMBER

NCT00641862 (Bangalore); NCT00717730, updated CTRI/2016/11/007494 (Delhi); NCT00197548 and NCT00421668 (Dar es Salaam).

Zinc and multivitamin supplementation have contrasting effects on infant iron status: a randomized, double-blind, placebo-controlled clinical trial

BACKGROUND/OBJECTIVES

Zinc (Zn) supplementation adversely affects iron status in animal and adult human studies, but few trials have included young infants. The objective of this study was to determine the effects of Zn and multivitamin (MV) supplementation on infant hematologic and iron status.

SUBJECTS/METHODS

In a double-blind RCT, Tanzanian infants were randomized to daily, oral Zn, MV, Zn and MV or placebo treatment arms at the age of 6 weeks of life. Hemoglobin concentration (Hb) and red blood cell indices were measured at baseline and at 6, 12 and 18 months of age. Plasma samples from 589 infants were examined for iron deficiency (ID) at 6 months.

RESULTS

In logistic regression models, Zn treatment was associated with greater odds of ID (odds ratio (OR) 1.8 (95% confidence interval (CI) 1.0-3.3)) and MV treatment was associated with lower odds (OR 0.49 (95% CI 0.3-0.9)). In Cox models, MV was associated with a 28% reduction in risk of severe anemia (hazard ratio (HR)=0.72 (95% CI 0.56-0.94)) and a 26% reduction in the risk of severe microcytic anemia (HR=0.74 (0.56-0.96)) through 18 months. No effects of Zn on risk of anemia were seen. Infants treated with MV alone had higher mean Hb (9.9 g/dl (95% CI 9.7-10.1)) than those given placebo (9.6 g/dl (9.4-9.8)) or Zn alone (9.6 g/dl (9.4-9.7)).

CONCLUSIONS

MV treatment improved iron status in infancy, whereas Zn worsened iron status but without an associated increase in risk for anemia. Infants in long-term Zn supplementation programs at risk for ID may benefit from screening and/or the addition of a MV supplement.

Neonatal and Infant Mortality Risk Associated with Preterm and Small for Gestational Age Births in Tanzania: Individual Level Pooled Analysis Using the Intergrowth Standard

OBJECTIVES

To evaluate the risk of newborn and infant mortality associated with preterm, small for gestational age (SGA), and low birth weight (LBW) stratified by maternal HIV status and the location of birth.

STUDY DESIGN

We created a prospective cohort by pooling 5 individually randomized trials. We used Cox proportional hazard models to estimate the risk of mortality for SGA defined using the recently published Intergrowth standard, preterm, LBW, and gestational age and size for gestational age categories (preterm- appropriate for gestational age [AGA], term-SGA, and preterm-SGA). Effect modification by maternal HIV status and place of residence was assessed using the likelihood ratio test.

RESULTS

Of the 31 988 infants, 15.3% were preterm, 16.6% were SGA, and 7.3% were LBW. The proportion of preterm and SGA births was higher among the HIV-infected cohort than in the uninfected cohort. Compared with term-AGA groups, infants born both preterm and SGA had a greater risk of neonatal mortality (hazard ratio [HR] 5.43, 95% CI 2.01-14.63) than preterm-AGA infants (HR 2.40, 95% CI 1.89-3.05) and term-SGA infants (HR 2.56, 95% CI 1.96-3.34). Maternal HIV infection modified the risk of infant mortality associated with being born preterm or LBW, with a higher relative risk among those born to HIV-uninfected women. Rural residence significantly modified the risk of neonatal mortality associated with being LBW (P for interaction = .005).

CONCLUSIONS

Preterm and SGA newborns had an increased risk of mortality during the first year of life. Interventions targeting these conditions, especially in HIV-exposed and rural populations, should be integrated into existing maternal and child health programs.

Delayed Breastfeeding Initiation Is Associated with Infant Morbidity

OBJECTIVE

To assess the relationship between breastfeeding initiation time and postneonatal mortality, morbidity, and growth through 24 months in a cohort of Tanzanian infants.

STUDY DESIGN

We included 4203 infants from 2 trials of micronutrient supplementation. We used Cox proportional hazards models or general estimating equations to estimate relative risks.

RESULTS

A total of 13% of infants initiated breastfeeding >1 hour after birth (n = 536). There was no association between breastfeeding initiation time and risk of all-cause or cause-specific mortality, nor infant growth failure, from 6 weeks to 2 years of age. However, delayed breastfeeding was associated with an increased risk of several common infectious morbidities in early infancy, including upper respiratory infection symptoms and vomiting. Compared with those who initiated breastfeeding within the first hour of birth, delayed breastfeeding initiation was associated with an 11% increased risk of cough (relative risk 1.11, 95% CI 1.02-1.21) and a 48% increased risk of difficulty breathing (relative risk 1.48, 95% CI 1.09-2.01) during the first 6 months. Delayed initiation was associated with a greater risk of difficulty breathing from 6 to 12 months of age, but it was not associated with risk of any other morbidity during this time, nor any morbidity between 12 and 24 months.

CONCLUSION

Delayed breastfeeding initiation is associated with an increased risk of infant morbidity during the first 6 months of life. Early breastfeeding initiation, along with exclusive and prolonged breastfeeding, should be prioritized and promoted in efforts to improve child health.

Vitamin D Deficiency Is Not Associated With Growth or the Incidence of Common Morbidities Among Tanzanian Infants

OBJECTIVE

The objective of this study was to examine risk factors for vitamin D deficiency and determine the association of vitamin D status with child growth and incidence of common morbidities among Tanzanian infants.

METHODS

A prospective cohort of 581 Tanzanian infants born to human immunodeficiency virus (HIV)-uninfected mothers had serum 25-hydroxyvitamin D assessed at 6 weeks and 6 months of age. Infants were seen at monthly clinic visits for growth monitoring until 18 months of age. Physicians examined infants every 3 months or when an illness was noted to document morbidities.

RESULTS

The prevalence of vitamin D deficiency (<20 ng/mL) declined from 76.4% at 6 weeks of age to 21.2% at 6 months. Infants who were exclusively breastfed at 6 weeks of age had 2.05 (95% confidence interval 1.11-3.79; P = 0.02) times the risk of vitamin D deficiency as compared formula-fed infants. After multivariate adjustment, there was no association of vitamin D status at 6 weeks or 6 months with the incidence of stunting, wasting, or underweight. There was also no association of low vitamin D with the incidence of diarrhea, upper respiratory infection, acute lower respiratory tract infection, or malaria.

CONCLUSIONS

Vitamin D deficiency is common during early infancy, particularly among exclusively breastfed infants; however, these observational data suggest it may not be an important contributor to morbidity and growth among the general population of Tanzanian infants. Future studies of vitamin D among high-risk infants, including those with low birthweight and exposed to HIV, may be warranted.

Infant Nutritional Status and Markers of Environmental Enteric Dysfunction are Associated with Midchildhood Anthropometry and Blood Pressure in Tanzania

OBJECTIVE

To assess whether growth and biomarkers of environmental enteric dysfunction in infancy are related to health outcomes in midchildhood in Tanzania.

STUDY DESIGN

Children who participated in 2 randomized trials of micronutrient supplements in infancy were followed up in midchildhood (4.6-9.8 years of age). Anthropometry was measured at age 6 and 52 weeks in both trials, and blood samples were available from children at 6 weeks and 6 months from 1 trial. Linear regression was used for height-for-age z-score, body mass index-for-age z-score, and weight for age z-score, and blood pressure analyses; log-binomial models were used to estimate risk of overweight, obesity, and stunting in midchildhood.

RESULTS

One hundred thirteen children were followed-up. Length-for-age z-score at 6 weeks and delta length-for-age z-score from 6 to 52 weeks were associated independently and positively with height-for-age z-score and inversely associated with stunting in midchildhood. Delta weight-for-length and weight-for-age z-score were also positively associated with midchildhood height-for-age z-score. The 6-week and delta weight-for-length z-scores were associated independently and positively with midchildhood body mass index-for-age z-score and overweight, as was the 6-week and delta weight-for-age z-score. Delta length-for-age z-score was also associated with an increased risk of overweight in midchildhood. Body mass index-for-age z-score in midchildhood was associated positively with systolic blood pressure. Serum anti-flagellin IgA concentration at 6 weeks was also associated with increased blood pressure in midchildhood.

CONCLUSIONS

Anthropometry at 6 weeks and growth in infancy independently predict size in midchildhood, while anti-flagellin IgA, a biomarker of environmental enteric dysfunction, in early infancy is associated with increased blood pressure in midchildhood. Interventions in early life should focus on optimizing linear growth while minimizing excess weight gain and environmental enteric dysfunction.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00197730 and NCT00421668.

The effect of daily zinc and/or multivitamin supplements on early childhood development in Tanzania: results from a randomized controlled trial

Impaired childhood development has lifelong consequences for educational attainment and wage-earning potential. Micronutrient supplements have the potential to improve development. The objective of this study was to determine the effect of daily zinc and/or multivitamin (vitamins C, E and B-complex) supplements on development among Tanzanian infants. In this randomized, 2 × 2 factorial, double-blind trial, 2400 infants were randomized to zinc (Zn), multivitamins (MV), zinc and multivitamins (Zn + MV) or placebo at 6 weeks of age. At approximately 15 months, a sub-sample of 247 children underwent developmental assessment using the cognitive, language (receptive and expressive) and motor (fine and gross) scales of the Bayley Scales of Infant and Toddler Development Third Edition (BSID-III). Mean BSID-III scores were compared using univariate and multivariate linear regression models adjusted for child's sex, post-conceptual age and test administrator. Logistic regressions were used to assess odds of low developmental scores. We did not detect a significant difference in mean BSID-III scores in any of the five domains in univariate or multivariate models comparing each of the four treatment groups. We also did not detect a significant difference in mean BSID-III scores when comparing children who received zinc supplements versus those who did not, or in comparisons of children who received multivitamin supplements versus those who did not. There was no significant difference in odds of a low BSID-III score in any of the five domains in treatment arms either. Because neither daily zinc nor multivitamin (vitamins B-complex, C and E) supplementation led to improvements in any of the developmental domains assessed using the BSID-III, we recommend pursuing alternative interventions to promote early childhood development in vulnerable populations. © 2016 John Wiley & Sons Ltd.

High Burden of Morbidity and Mortality but Not Growth Failure in Infants Exposed to but Uninfected with Human Immunodeficiency Virus in Tanzania

OBJECTIVE

To compare health and growth outcomes in children infected with HIV, children exposed to but uninfected with HIV, and children unexposed to HIV.

STUDY DESIGN

Our cohort included 3554 Tanzanian children enrolled in 2 trials of micronutrient supplementation. Among infants born to mothers infected with HIV, 264 were infected with HIV and 2088 were exposed to but uninfected at 6 weeks of age. An additional 1202 infants were unexposed to HIV. Infants were followed until 18 months of age, death, or loss to follow-up. Morbidity and growth were assessed at monthly nurse visits.

RESULTS

Compared with unexposed infants, hazard ratios (95% CI) for all-cause mortality in infants infected with HIV and infants who were exposed to but uninfected with HIV were 28.99 (14.83-56.66) and 2.79 (1.41-5.53), respectively, after adjusting for demographic and nutritional covariates. Compared with infants unexposed to HIV, infants infected with HIV also had a significantly greater risk of all measured morbidities, while infants who were exposed to but uninfected with HIV were significantly more likely to suffer from cough, fever, unscheduled outpatient visits, and hospitalizations. Infants infected with HIV also were more likely to experience stunting, wasting, and underweight at baseline and during follow-up. Infants exposed to but uninfected with HIV were more likely to be underweight at baseline (adjusted relative risk, 2.05; 95% CI, 1.45-2.89), but on average, experienced slower declines in height-for-age z-score, weight-for-age z-score, and weight-for-height z-score as well as a lower rate of stunting over follow-up, compared with unexposed infants.

CONCLUSION

In addition to preventing and treating HIV infection in infants, prevention-of-mother-to-child-transmission of HIV and child health services should also target children exposed to but uninfected with HIV to improve health outcomes in this vulnerable population.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT00197730 and NCT00421668.

Etiology of Diarrhea, Nutritional Outcomes, and Novel Intestinal Biomarkers in Tanzanian Infants

OBJECTIVE

Diarrheal diseases are a leading cause of morbidity and mortality worldwide, but the etiology of diarrhea and its relation to nutritional outcomes in resource-limited settings is poorly defined. We sought to determine the etiology of community-acquired diarrhea in Tanzanian infants and to assess the association with anthropometrics and novel intestinal biomarkers.

METHODS

A convenience sample of infants in a trial of zinc and/or multivitamin supplementation in Tanzania was selected. Subjects were enrolled at age 6 weeks and studied for 18 months. Stool samples were obtained from children with acute diarrhea. A novel, polymerase chain reaction-based TaqMan array was used to screen stool for 15 enteropathogens. A subset of subjects had serum gastrointestinal biomarkers measured.

RESULTS

One hundred twenty-three subjects with diarrhea were enrolled. The mean ± SD age at stool sample collection was 12.4 ± 3.9 months. Thirty-five enteropathogens were identified in 34 (27.6%) subjects: 11 rotavirus, 9 Cryptosporidium spp, 7 Shigella spp, 3 Campylobacter jejuni/coli, 3 heat stable-enterotoxigenic Escherichia coli, and 2 enteropathogenic E coli. Subjects with any identified enteropathogen had significantly lower weight-for-length z scores (-0.55 ± 1.10 vs 0.03 ± 1.30, P = 0.03) at the final clinic visit than those without an identified pathogen. Fifty of the 123 subjects (40.7%) had serum analyzed for antibodies to lipopolysaccharide (LPS) and flagellin. Subjects with any identified enteropathogen had lower immunoglobulin (IgA) antibodies to LPS (0.75 ± 0.27 vs 1.13 ± 0.77, P = 0.01) and flagellin (0.52 ± 0.16 vs 0.73 ± 0.47, P = 0.02) than those without an identified pathogen.

CONCLUSIONS

This quantitative polymerase chain reaction method may allow identification of enteropathogens that place children at higher risk for suboptimal growth. IgA anti-LPS and flagellin antibodies hold promise as emerging intestinal biomarkers.

Zinc supplementation for the prevention of pneumonia in children aged 2 months to 59 months

BACKGROUND

Pneumonia is a leading cause of morbidity and mortality in children younger than five years of age. Most deaths occur during infancy and in low-income countries. Daily zinc supplements have been reported to prevent acute lower respiratory tract infection (LRTI) and reduce child mortality. This is an update of a review first published in 2010.

OBJECTIVES

To evaluate the effectiveness of zinc supplementation in the prevention of pneumonia in children aged two to 59 months.

SEARCH METHODS

We searched CENTRAL (Issue 21 October 2016), MEDLINE (1966 to October 2016), Embase (1974 to October 2016), LILACS (1982 to October 2016), CINAHL (1981 to October 2016), Web of Science (1985 to October 2016) and IMSEAR (1980 to October 2016).

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating zinc supplementation for the prevention of pneumonia in children aged from 2 months to 59 months.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

We did not identify any new studies for inclusion in this update. We included six studies that involved 5193 participants.Analysis showed that zinc supplementation reduced the incidence of pneumonia by 13% (fixed-effect risk ratio (RR) 0.87; 95% confidence interval (CI) 0.81 to 0.94, six studies, low-quality evidence) and prevalence of pneumonia by 41% (random-effects RR 0.59; 95% CI 0.35 to 0.99, one study, n = 609, low-quality evidence). On subgroup analysis, we found that zinc reduced the incidence of pneumonia defined by specific clinical criteria by 21% (i.e. confirmation by chest examination or chest radiograph) (fixed-effect RR 0.79; 95% CI 0.0.71 to 0.88, four studies, n = 3261), but had no effect on lower specificity pneumonia case definition (i.e. age-specific fast breathing with or without lower chest indrawing) (fixed-effect RR 0.95; 95% CI 0.86 to 1.06, four studies, n = 1932).

AUTHORS' CONCLUSIONS

Zinc supplementation in children is associated with a reduction in the incidence and prevalence of pneumonia.

Randomised clinical trial: a Lactobacillus GG and micronutrient-containing mixture is effective in reducing nosocomial infections in children, vs. placebo

BACKGROUND

Nosocomial infections are a major public health issue and preventative strategies using probiotics and micronutrients are being evaluated.

AIM

To investigate the efficacy of a mixture of Lactobacillus GG and micronutrients in preventing nosocomial infections in children.

METHODS

A randomised, double-blind, placebo-controlled trial was conducted in hospitalised children. Children (6 months to 5 years of age) received Lactobacillus GG (6 × 10(9) CFU/day) together with vitamins B and C and zinc or placebo, for 15 days, starting on the first day of hospitalisation. The incidence of gastrointestinal and respiratory nosocomial infections after discharge was determined by follow-up telephone call at 7 days. After 3 months, another telephone call estimated the incidence of further infections during follow-up.

RESULTS

Ninety children completed the follow-up. Of 19/90 children with a nosocomial infection (20%), 4/45 children (9%) were in the treatment group and 15/45 (33%) in the placebo group (P = 0.016). Specifically, 2/45 (4%) children in the treatment group vs. 11/45 (24%) children in the placebo group (P = 0.007) presented with diarrhoea. The duration of hospitalisation was significantly shorter in the treatment group (3.9 days ± 1.7 vs. 4.9 ± 1.2; P = 0.003). At the follow-up, a total of 11/45 (24.4%) children in the treatment group had at least one episode of infection compared to 22/45 (48.9%) in the placebo group (P = 0.016).

CONCLUSION

A mixture containing Lactobacillus GG and micronutrients may reduce the incidence of nosocomial infections, supporting the hypothesis that this may represent a valid strategy to prevent nosocomial infections.

Dietary supplements and disease prevention - a global overview

Dietary supplements are widely used and offer the potential to improve health if appropriately targeted to those in need. Inadequate nutrition and micronutrient deficiencies are prevalent conditions that adversely affect global health. Although improvements in diet quality are essential to address these issues, dietary supplements and/or food fortification could help meet requirements for individuals at risk of deficiencies. For example, supplementation with vitamin A and iron in developing countries, where women of reproductive age, infants and children often have deficiencies; with folic acid among women of reproductive age and during pregnancy; with vitamin D among infants and children; and with calcium and vitamin D to ensure bone health among adults aged ≥65 years. Intense debate surrounds the benefits of individual high-dose micronutrient supplementation among well-nourished individuals because the alleged beneficial effects on chronic diseases are not consistently supported. Daily low-dose multivitamin supplementation has been linked to reductions in the incidence of cancer and cataracts, especially among men. Baseline nutrition is an important consideration in supplementation that is likely to modify its effects. Here, we provide a detailed summary of dietary supplements and health outcomes in both developing and developed countries to help guide decisions about dietary supplement recommendations.

Elevations in serum anti-flagellin and anti-LPS Igs are related to growth faltering in young Tanzanian children

BACKGROUND

Antibodies to LPS and flagellin have been described as indirect measures of increased gastrointestinal permeability and may be markers of environmental enteric dysfunction (EED), which is a condition associated with poor child growth.

OBJECTIVE

We assessed whether LPS- and flagellin-specific immunoglobulin (Ig) concentrations were associated with poor growth in young Tanzanian children at risk of EED.

DESIGN

Blood samples were obtained from 590 children at 6 wk, 6 mo, and 12 mo of age. Serum LPS- and flagellin-specific Ig concentrations (IgA and IgG) were measured with the use of an ELISA. Growth was measured on a monthly basis for 18 mo.

RESULTS

Anti-LPS and anti-flagellin IgA and IgG concentrations increased over the first year of life and were higher than concentrations (measured at 9 mo of age) in healthy controls. Children with anti-flagellin IgA, anti-LPS IgA, anti-flagellin IgG, and anti-LPS IgG concentrations in the highest quartile at 6 wk of age were 2.02 (95% CI: 1.11, 3.67), 1.84 (95% CI: 1.03, 3.27), 1.94 (95% CI: 1.04, 3.62), and 2.31 (95% CI: 1.25, 4.27) times, respectively, more likely to become underweight (weight-for-age z score <-2) after adjustment for covariates (P-trend < 0.05) than were children with Ig concentrations in the lowest quartile. Children with increased concentrations of anti-flagellin IgA were also more likely to become wasted; however, there was no association between any of the markers and subsequent stunting.

CONCLUSION

Serologic measures of increased intestinal permeability to bacterial components are associated with subsequent poor growth and could help identify children who may benefit most from preventive interventions. This trial was registered at clinicaltrials.gov as NCT00421668.

Effect of zinc and multivitamin supplementation on the growth of Tanzanian children aged 6-84 wk: a randomized, placebo-controlled, double-blind trial

BACKGROUND

Poor child growth increases risks of mortality and morbidity. Micronutrient supplements have the potential to improve child growth.

OBJECTIVE

We assessed the effect of daily zinc, multivitamin (vitamins C, E, and B-complex), and zinc and multivitamin (Zn+MV) supplementation on growth in infants in Tanzania.

DESIGN

In this randomized, 2 × 2 factorial, double-blind trial, 2400 infants were randomly assigned to receive zinc, multivitamins, Zn+MVs, or a placebo at 6 wk of age and were followed up for 18 mo with monthly growth measurements. Mixed-effects models with restricted cubic splines for the mean change in anthropometric z scores were fit for each group. Likelihood ratio tests were used to compare the effect of supplements on growth trajectories. Cox proportional hazards models were used to compare incidences of stunting, wasting, and underweight.

RESULTS

Children in all groups experienced growth faltering. At 19 mo of age, prevalences of stunting, wasting, and underweight were 19.8%, 6.0%, and 10.8%, respectively. Changes in weight-for-age z scores (WAZs) and weight-for-height z scores (WHZs) were significantly different across the 4 groups (P < 0.001 for both). The mean ± SE decline in the WAZ from baseline to the end of follow-up in the Zn+MV group was significantly less than in the placebo group (-0.36 ± 0.04 compared with -0.50 ± 0.04; P = 0.020), whereas the decline in the WHZ was significantly greater in the zinc-only group than in the placebo group (-0.57 ± 0.07 compared with -0.35 ± 0.07; P = 0.021). Supplements did not have a significant effect on mean change in the height-for-age z score or on rates of stunting, wasting, or underweight.

CONCLUSIONS

Although there were small but significant improvements in the WAZ in the Zn+MV group, daily zinc supplementation alone, multivitamin supplementation alone, and the combined Zn+MV did not reduce the incidences of underweight, stunting, or wasting in Tanzanian infants. Alternative approaches to prevent growth faltering should be pursued. This trial was registered at clinicaltrials.gov as NCT00421668.

Zinc in Early Life: A Key Element in the Fetus and Preterm Neonate

Zinc is a key element for growth and development. In this narrative review, we focus on the role of dietary zinc in early life (including embryo, fetus and preterm neonate), analyzing consequences of zinc deficiency and adequacy of current recommendations on dietary zinc. We performed a systematic search of articles on the role of zinc in early life. We selected and analyzed 81 studies. Results of this analysis showed that preservation of zinc balance is of critical importance for the avoidance of possible consequences of low zinc levels on pre- and post-natal life. Insufficient quantities of zinc during embryogenesis may influence the final phenotype of all organs. Maternal zinc restriction during pregnancy influences fetal growth, while adequate zinc supplementation during pregnancy may result in a reduction of the risk of preterm birth. Preterm neonates are at particular risk to develop zinc deficiency due to a combination of different factors: (i) low body stores due to reduced time for placental transfer of zinc; (ii) increased endogenous losses; and (iii) marginal intake. Early diagnosis of zinc deficiency, through the measurement of serum zinc concentrations, may be essential to avoid severe prenatal and postnatal consequences in these patients. Typical clinical manifestations of zinc deficiency are growth impairment and dermatitis. Increasing data suggest that moderate zinc deficiency may have significant subclinical effects, increasing the risk of several complications typical of preterm neonates (i.e., necrotizing enterocolitis, chronic lung disease, and retinopathy), and that current recommended intakes should be revised to meet zinc requirements of extremely preterm neonates. Future studies evaluating the adequacy of current recommendations are advocated.