A quarter of century has passed since FRI published its first comprehensive review on vitamin A deficiency (VAD) and its prevention. At the time, the major impetus to prevent VAD was to reduce ...xerophthalmia in preschool children. Today, we have a broader understanding of the public health implications of VAD, with disorders including xerophthalmia, mortality, severe infection, and anemia in preschool children and pregnant women. While deficiency affects most developing countries, nearly half of all deficient children and women live in Southern Asia. Prevention has made substantial strides. High potency vitamin A supplementation (with 200,000 IU) remains a prophylactic mainstay, delivered through fixed facilities, enhanced outreach activities, and national child health day campaigns twice annually. Surprisingly, the costs of semi-annual delivery of vitamin A have changed little over the years, with new cost estimates remaining comparable to earlier figures of US ∼$0.50 per child per year. Emerging is the potential to reduce infant mortality by ∼20% in Southern Asia by giving a single, oral, 50,000 IU dose of vitamin A to newborns. While ∼500 million vitamin A capsules are routinely distributed worldwide each year to achieve effective control, progress has been slower with efforts to improve diet on a purposeful global public health scale. Future advances through effective dietary diversification and various means of food fortification will be required before periodic supplementation can be phased down as a major population strategy for controlling vitamin A deficiency.
Abstract only Large‐scale food fortification is a major strategy to improve dietary vitamin A (VA) intakes and control VA deficiency. Zambia introduced mandatory sugar fortification with VA, at a ...target of 10 mg/kg, in 1998; however, there are conflicting reports as to the program's impact on VA status. Our objective was to assess the current state of the program from the policy level to the household. We conducted key informant interviews with stakeholders regarding the program's history, implementation, impact, and perceived challenges. In one district, we mapped formal and informal sugar vendors and recorded coverage of available brands and packaging options. In a random sample, we conducted a Knowledge, Attitudes, and Practices survey of both vendors and consumers. We obtained 50 g samples of sugar from vendors for quantitative VA analysis using an iCheck portable fluorimeter and, in an ongoing surveillance cohort in this community, collected ~1 g samples for qualitative analysis. Key informant interviews revealed a strong commitment to sugar fortification in Zambia, but also several concerns: potential for excess VA intake, poisoning or infertility, cost of fortificant, and limited resources available for monitoring and evaluation of program impact. Market assessments revealed a variety of sources for fortified sugar. The distribution of VA in sugar in market samples was highly skewed, with a median of 2.4 mg/kg (25 th percentile, 75 th percentile: 1.5, 5.6) and a range from 0.6 mg/kg to 18.0 mg/kg. VA levels in sugar varied by source. Overall, the commitment of stakeholders to VA fortification of sugar is promising for the program's ability to adjust course, as needed, and for its long‐term sustainability. While limited to one area of the country, our data suggest wide variability in VA content, with median levels falling below the 10 mg/kg target. Given observed differences in VA content, it is possible that this is related to varied storage and packaging—a challenge that could be addressed by targeted messages to vendors. Additional research is needed to better understand patterns of sugar consumption at the household level, both to inform the contribution of fortified sugar to overall dietary VA intakes, but also as a baseline in a country that is experiencing a nutrition transition. Support or Funding Information Funded by Sight & Life, with support from CBM Internationa
Animal source foods are rich in multiple nutrients. Regular egg consumption may improve infant growth in low- and middle-income countries.
To assess the impact of daily egg consumption on linear ...growth among 6-2-mo olds in rural Bangladesh.
We conducted a 2 × 4 factorial cluster-randomized controlled trial allocating clusters (n = 566) to treatment for enteric pathogens or placebo and a daily egg, protein supplement, isocaloric supplement, or control. All arms received nutrition education. Here, we compare the effect of the egg intervention compared with control on linear growth, a prespecified aim of the trial. Infants were enrolled at 3 mo. We measured length and weight at 6 and 12 mo and visited households weekly to distribute eggs and monitor compliance. We used linear regression models to compare 12-mo mean length, weight, and z-scores for length-for-age (LAZ), weight-for-length, and weight-for-age (WAZ), and log-binomial or robust Poisson regression to compare prevalence of stunting, wasting, and underweight between arms. We used generalized estimating equations to account for clustering and adjusted models for baseline measures of outcomes.
We enrolled 3051 infants (n = 283 clusters) across arms, with complete 6 and 12 mo anthropometry data from 1228 infants (n = 142 clusters) in the egg arm and 1109 infants (n = 141 clusters) in the control. At baseline, 18.5%, 6.0%, and 16.4% were stunted, wasted, and underweight, respectively. The intervention did not have a statistically significant effect on mean LAZ (β: 0.05, 95% confidence interval CI: -0.01, 0.10 or stunting prevalence (β: 0.98, 95% CI: 0.89, 1.13) at 12 mo. Mean weight (β: 0.07 kg, 95% CI: 0.02, 0.11) and WAZ (β: 0.06, 95% CI: 0.02, 0.11) were significantly higher in the egg compared with control arms.
Provision of a daily egg for 6 mo to infants in rural Bangladesh improved ponderal but not linear growth.
NCT03683667, https://clinicaltrials.gov/ct2/show/NCT03683667.
PASQUALINO et al Pasqualino, Monica M; Shaikh, Saijuddin; Islam, Md Tanvir ...
Maternal and child nutrition,
07/2023, Volume:
19, Issue:
3
Journal Article
Peer reviewed
Open access
Context-specific research is needed on the relationship between household animal production and nutrition outcomes to inform programmes intervening in small-scale animal production. We examined ...associations between household animal/fishpond ownership and animal source food (ASF) consumption among 6- to 12-month-old infants enroled in the control arm of a cluster-randomised controlled trial in rural Bangladesh. We measured ASF consumption using a 7-day food frequency questionnaire at 6, 9 and 12 months and assessed household animal/fishpond ownership at 12 months. We developed negative binomial regression models with random intercepts for infant and cluster, controlling for infant age and sex, maternal age, socioeconomic status and season. Models were stratified by a dichotomised maternal decision-making score. Compared with infants in households without each animal type, those with 4–10 and ≥11 poultry consumed eggs 1.3 (95% confidence interval CI: 1.1, 1.6) and 1.6 (95% CI: 1.3, 2.0) times more, respectively; 2–3 and ≥4 dairy-producing animals consumed dairy 1.9 (95% CI: 1.3, 2.7) and 2.0 (95% CI: 1.3, 3.1) times more, respectively; and ≥12 meat-producing animals consumed meat 1.4 (95% CI: 1.0, 1.8) times more. It was unclear whether there was an association between fishpond ownership and fish consumption. Our results did not suggest that maternal decision-making power was a modifier in the relationship between animal/fishpond ownership and ASF consumption. In this South Asian context, strategies intervening in household animal production may increase infant consumption of eggs, dairy and meat, but not necessarily fish. Research is needed on the role of market access and other dimensions of women's empowerment.
Bacteria regulate a variety of phenotypes in response to their population density using quorum sensing (QS). This phenomenon is regulated by small molecule or peptide signals, the best characterized ...of which are the
N
-acyl L-homoserine lactones (AHLs) utilized by Gram-negative bacteria. As many QS-controlled phenotypes, notably pathogenicity and symbiosis, can profoundly impact host eukaryotes, there is significant interest in developing methods to modulate QS signaling and either ameliorate or augment these phenotypes. One strategy has been the use of non-native AHL analogues to agonize or antagonize specific AHL receptors. This approach is complicated, however, by the potential for prospective hosts to respond to both native AHLs as well as synthetic analogues. Accordingly, identifying AHL analogues with little or no activity towards eukaryotes is important in developing QS modulation as a strategy for the regulation of prokaryotic behaviors. Herein, we utilize the model plant
Arabidopsis thaliana
to characterize eukaryotic responses to a variety of synthetic AHL analogues to identify structural elements of existing scaffolds that may elicit responses in prospective hosts. Our results indicate that, while many of these compounds have no discernable effect on
A. thaliana
, some elicit strong phenotypes similar to those produced by auxin, a hormone involved in almost all aspects of plant development. We outline concentrations and chemical scaffolds ideal for deployment on plant hosts for the regulation of QS. This approach should be exportable to other eukaryotes for the selection of optimal AHL tools for the study of QS at the host-microbe interface.
A growing body of evidence highlights the importance of a mother’s nutrition from preconception through lactation in programming the emerging organ systems and homeostatic pathways of her offspring. ...The developing immune system may be particularly vulnerable. Indeed, examples of nutrition-mediated immune programming can be found in the literature on intra-uterine growth retardation, maternal micronutrient deficiencies, and infant feeding. Current models of immune ontogeny depict a “layered” expansion of increasingly complex defenses, which may be permanently altered by maternal malnutrition. One programming mechanism involves activation of the maternal hypothalamic-pituitary-adrenal axis in response to nutritional stress. Fetal or neonatal exposure to elevated stress hormones is linked in animal studies to permanent changes in neuroendocrine-immune interactions, with diverse manifestations such as an attenuated inflammatory response or reduced resistance to tumor colonization. Maternal malnutrition may also have a direct influence, as evidenced by nutrient-driven epigenetic changes to developing T regulatory cells and subsequent risk of allergy or asthma. A 3rd programming pathway involves placental or breast milk transfer of maternal immune factors with immunomodulatory functions (e.g. cytokines). Maternal malnutrition can directly affect transfer mechanisms or influence the quality or quantity of transferred factors. The public health implications of nutrition-mediated immune programming are of particular importance in the developing world, where prevalent maternal undernutrition is coupled with persistent infectious challenges. However, early alterations to the immune system, resulting from either nutritional deficiencies or excesses, have broad relevance for immune-mediated diseases, such as asthma, and chronic inflammatory conditions like cardiovascular disease.
Background: Provitamin A carotenoid–biofortified maize is a conventionally bred staple crop designed to help prevent vitamin A deficiency. Lactating women are a potential target group, because ...regularly eating biofortified maize may increase vitamin A in breast milk—a critical source of vitamin A for breastfeeding infants.
Objective: We assessed whether daily consumption of biofortified orange maize would increase the retinol concentration in the breast milk of Zambian women.
Methods: Lactating women (n = 149) were randomly assigned to receive orange maize delivering 600 μg retinol equivalents (REs)/d as carotenoid plus placebo (OM), low-carotenoid white maize plus 600 μg REs/d as retinyl palmitate (VA), or white maize plus placebo (WM). Boiled maize (287 g dry weight/d) was served as 2 meals/d, 6 d/wk for 3 wk. We measured initial and final breast milk plasma retinol and β-carotene concentrations, and plasma inflammatory protein concentrations.
Results: Groups were comparable at enrollment, with an overall geometric mean milk retinol concentration of 0.95 μmol/L (95% CI: 0.86, 1.05 μmol/L); 56% of samples had milk retinol <1.05 μmol/L. Median capsule and maize intake was 97% and 258 g dry weight/d, respectively. Final milk β-carotene did not vary across groups (P = 0.76). Geometric mean (95% CI) milk retinol concentration tended to be higher in the OM 1.15 μmol/L (0.96, 1.39 μmol/L) and VA 1.17 μmol/L (0.99, 1.38 μmol/L) groups than in the WM group 0.91 μmol/L (0.72, 1.14 μmol/L); P = 0.13, and the proportion of women with milk retinol <1.05 μmol/L was 52.1%, 42.9%, and 36.7% in the WM, OM, and VA groups, respectively (P-trend = 0.16).
Conclusions: Daily biofortified maize consumption did not increase mean milk retinol concentration in lactating Zambian women; however, there was a plausible downward trend in the risk of low milk retinol across intervention groups. This trial was registered at clinicaltrials.gov as NCT01922713.
Background: Impaired dark adaptation is an early functional indicator of vitamin A deficiency that may be prevented by regular dietary intake of foods containing provitamin A carotenoids.
Objective: ...We tested the impact of provitamin A carotenoid–biofortified maize consumption (∼15 μg β-carotene/g) on dark adaptation in Zambian children.
Methods: We used a cluster-randomized trial of children aged 4–8 y (n = 1024) in Mkushi District, Zambia, and compared the regular consumption (2 meals/d, 6 d/wk for 6 mo) of biofortified orange maize (OM) to white maize (WM). The primary outcome was the serum retinol response. In a random sample (n = 542), we used a digital pupillometer to test pre- and postintervention responses to graded light stimuli (−2.9 to 0.1 log cd/m2) in a dark-adapted state.
Results: At baseline, 11.7% of the children had serum retinol <0.7 μmol/L, 14.4% had impaired dark adaptation (pupillary threshold ≥ −1.11 log cd/m2), and 2.3% had night blindness. The mean ± SD pupillary responsiveness to light stimuli was poorer at baseline in the OM group (16.1% ± 6.6%) than the WM group (18.1% ± 6.4%) (P = 0.02) but did not differ at follow-up (OM: 17.6% ± 6.5%; WM: 18.3% ± 6.5%). Among children with serum retinol <1.05 μmol/L at baseline, there was greater improvement in pupillary responsiveness in the OM group (2.2%; 95% CI: 0.1%, 4.3%) than the WM group (0.2%; 95% CI: −1.1%, 1.5%; P = 0.01), but there were no differences in children with adequate baseline status. We found no effect of treatment on pupillary threshold or night blindness.
Conclusions: The regular consumption of provitamin A carotenoid–biofortified maize increased pupillary responsiveness among children with marginal or deficient vitamin A status, providing evidence of a functional benefit to consuming this biofortified crop. This trial was registered at clinicaltrials.gov as NCT01695148.
This laboratory experiment is designed to allow undergraduate students to gain experience in polymer synthesis and characterization. Polystyrene quantitatively end-labeled with fluorene is produced ...via atom transfer radical polymerization run under a nitrogen atmosphere, using unpurified reagents and solvents. Molecular weight characterization of the polymers is performed using UV–vis spectroscopy, eliminating the need for specialized equipment such as gel permeation chromatography. Number average molecular weight values are obtained using Beer–Lambert's law, which is used to determine the molarity of fluorene-labeled polymers in THF solutions. These calculated values consistently agreed within 11% of molecular weights obtained using calibrated gel permeation chromatography systems, demonstrating the accuracy of the results. This laboratory exercise is suitable for undergraduate students in an organic or polymer chemistry course and requires no previous experience in polymer synthesis or characterization.
Vitamin A deficiency remains a nutritional concern in sub-Saharan Africa. Conventionally bred maize hybrids with high provitamin A carotenoid concentrations may have the potential to improve vitamin ...A status in maize-consuming populations. We evaluated the efficacy of regular provitamin A carotenoid-biofortified "orange" maizemeal (~15 μg β-carotene/g) consumption in improving vitamin A status and reducing vitamin A deficiency in children. This was a cluster-randomized controlled trial in the rural farming district of Mkushi, Zambia. All 4- to 8-y-old children in an ~400-km2 area were identified and grouped by proximity into clusters of ~15-25 children. We randomly assigned clusters to 1) orange maizemeal (n = 25), 2) white maizemeal (n = 25), or 3) a parallel, nonintervention group (n = 14). Children in intervention clusters (n = 1024) received 200 g maizemeal for 6 d/wk over 6 mo; the maizemeal was prepared according to standardized recipes and served in cluster-level kitchens. Staff recorded attendance and leftovers. We collected venous blood before and after the intervention to measure serum retinol, β-carotene, C-reactive protein, and a1-acid glycoprotein. Intervention groups were comparable at baseline, and vitamin A status was better than anticipated (12.1% deficient on the basis of serum retinol <0.7 μmol/L). Although attendance at meals did not differ (85%), median daily maize intake was higher in white (154 g/d) than in orange (142 g/d) maizemeal clusters. At follow-up, mean serum β-carotene was 0.14 μmol/L (95% CI: 0.09, 0.20 μmol/L) higher in orange maizemeal clusters (P < 0.001), but mean serum retinol (1.00 ± 0.33 μmol/L overall) and deficiency prevalence (17.1% overall) did not differ between arms. In this marginally nourished population, regular biofortified maizemeal consumption increased serum β-carotene concentrations but did not improve serum retinol.
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