Up to $500m a year could be put to better use by stopping ineffective and potentially harmful supplementation programmes in poorer countries, say JB Mason, CS Benn, and HPS Sachdev; but Keith P West ...Jr, Amanda C Palmer, and Alfred Sommer disagree, saying that such programmes have been proved to save millions of lives and should be withdrawn only when robust evidence permits
Biofortified maize, designed as an intervention strategy to prevent vitamin A deficiency, can provide upwards of 15 μg β-carotene per g dry weight. Some varieties also have elevated concentrations of ...other carotenoids. We conducted a cluster randomized, controlled feeding trial in rural Zambia to test the impact of daily consumption of biofortified maize over a 6-month period on vitamin A status. Serum concentrations of retinol and carotenoids were assessed by high-performance liquid chromatography. Data on circulating carotenoids by intervention group in 679 children are reported here. As previously shown, consumption of this β-carotene-rich maize significantly improved serum β-carotene concentrations (0.273 vs. 0.147 μmol/L, p < 0.001, in this subset of children). Here we show significant increases in α-carotene, β-cryptoxanthin, and zeaxanthin (p < 0.001). There was no impact on lutein or lycopene concentrations. Consumption of biofortified maize can have broader implications beyond the control of vitamin A deficiency (Trial registration: NCT01695148).
To estimate the burden of anemia attributable to malaria, inflammation, and deficiency of iron or vitamin A during low and high malaria seasons among Zambian children.
From a cohort of children ...(n = 820), 4-8 years of age participating in a randomized controlled trial of pro-vitamin A, we estimated attributable fractions for anemia (hemoglobin of <110 or 115 g/L, by age) owing to current malaria or inflammation (C-reactive protein of >5 mg/L, or α-1 acid glycoprotein of >1 g/L, or both), and current or prior iron deficiency (ID; defined as low ferritin <12 or 15 μg/L for age <5 or >5 years or functional ID soluble transferrin receptor of >8.3 mg/L or both) and vitamin A deficiency (retinol of <0.7 μmol/L), during low and high malaria seasons, using multivariate logistic regression. Serum ferritin, soluble transferrin receptor, and retinol were adjusted for inflammation.
The burden of anemia independently associated with current malaria, inflammation, ID, and vitamin A deficiency in the low malaria season were 12% (P < .001), 6% (P = .005), 14% (P = .001), and 2% (P = .07), respectively, and 32% (P < .001), 15% (P < .001), 10% (P = .06), and 2% (P = .06), respectively, in the high malaria season. In both seasons, functional ID was independently associated with more anemia (approximately 11%) than low ferritin (approximately 4%). Anemia and ID in the low malaria season, accounted for 20% (P < .001) and 4% (P = .095) of the anemia in the subsequent high malaria season.
Anemia in this population is strongly linked to malaria, inflammation, and functional ID, and to a lesser extent, low iron stores. Integrated control strategies are needed.
Background:
Industrial food fortification is a major strategy to improve dietary micronutrient intakes and prevent deficiencies. Zambia introduced mandatory sugar fortification with vitamin A, at a ...target of 10 mg/kg, in 1998. Representative surveys conducted since that time do not support marked improvement in vitamin A status.
Objective:
To describe vitamin A concentrations in retail sugar, as well as vendor practices, perceptions of fortified foods, and sugar use practices.
Methods:
We conducted a census of sugar vendors in one Zambian community, capturing information on vendors, available brands and packaging options, and storage conditions. We purchased all brands and package types of sugar available at each vendor. In a 15% subsample, we conducted semi-structured interviews with vendor–consumer pairs. We tested 50% of sugar samples at random for vitamin A using an iCheck portable fluorimeter.
Results:
The distribution of vitamin A in sugar in market samples was highly skewed, with a median of 3.1 mg/kg (25th-75th percentiles: 1.8-5.5) and a range from 0.2 to 29.9 mg/kg. Only 11.3% of samples met the 10 mg/kg statutory requirement. Sugar was primarily repackaged and sold in small quantities, with rapid turnover of stocks. Perceptions of fortification by vendors and consumers were generally positive.
Conclusions:
Vitamin A in fortified sugar fell well below statutory requirements. Our data point to challenges at regional depot and/or poor adherence to fortification standards at the factory level. A renewed commitment to monitoring and enforcement will be required for Zambia to benefit from a food fortification strategy.
Impairments in visual function have been well characterized in vitamin A deficiency. However, eye function may also be sensitive to other nutrient deficiencies.
We examined associations between ...visual function—characterized by pupillary threshold or pupillary responsiveness—and nutritional status in Zambian children.
We used digital pupillometry to measure visual responses to calibrated light stimuli (−2.9 to 0.1 log cd/m2) among dark-adapted children aged 4–8 y (n = 542). We defined pupillary threshold as the first light stimulus at which pupil diameter decreased by ≥10% and considered a pupillary threshold ≥−0.9 log cd/m2 as impaired. Pupillary responsiveness was defined by absolute percentage of change in pupil diameter from pre- to poststimulus. We tested associations between these measures and serum concentrations of retinol, β-carotene, ferritin, soluble transferrin receptor, and hemoglobin (Hb <11.0 or 11.5 g/dL were used to define anemia, depending on age), as well as anthropometric indexes, with the use multilevel mixed-effects models.
Pupillary threshold was correlated only with serum retinol (r = 0.12, P < 0.05). The strongest correlates of pupillary responsiveness were Hb (r = −0.16, P < 0.01), height-for-age z score (r = 0.14, P < 0.05), weight-for-age z score (r = 0.14, P < 0.05), and soluble transferrin receptor (r = 0.12, P < 0.05). In multivariate models, anemia was positively associated with pupillary responsiveness (β = 2.99; 95% CI: 1.26, 4.72).
In this marginally nourished population, we found positive correlations between vitamin A status, iron status, or anthropometric indexes and visual function. Hb was negatively associated with visual function, with greater pupillary responsiveness among anemic children. We posit that this may signal altered parasympathetic activity, possibly driven by infection. Future studies should consider a broader range of indicators to better characterize the relation between nutrition and visual function. This trial was registered at clinicaltrials.gov as NCT01695148.
A Changing Landscape for Vitamin A Programs Klemm, Rolf D. W.; Palmer, Amanda C.; Greig, Alison ...
Food and nutrition bulletin,
06/2016, Volume:
37, Issue:
2_suppl
Journal Article
Peer reviewed
Open access
Background:
Vitamin A deficiency (VAD) remains a widespread public health problem in the developing world, despite changes in under-5 mortality rates, morbidity patterns, and intervention options.
...Objective:
This article considers the implications of a changing epidemiologic and programmatic landscape for vitamin A (VA) programs.
Methods:
We review progress to prevent VAD and its health consequences, assess gaps in VA status and intervention coverage data, and assess data needed to guide decisions regarding the optimal mix, targeting, and dose of VA interventions to maximize benefit and minimize risk.
Results:
Vitamin A supplementation programs have contributed to the reduction in under-5 mortality rates, but alone, do not address the underlying problem of inadequate dietary VA intakes and VAD among preschool-aged children in the developing world. A combination of VA interventions (eg, supplementation, fortified foods, multiple micronutrient powders, and lipid-based nutrient supplements) will be required to achieve VA adequacy in most settings. Current efforts to measure the coverage of multiple VA interventions, as well as whether and how much VA children are receiving, are few and fragmented.
Conclusions:
Where intervention overlap exists, further effort is needed to monitor VA intakes, ensuring that targeted groups are consuming adequate amounts but not exceeding the tolerable upper intake level. Vitamin A status data will also be critical for navigating the changing landscape of VA programs. Data from these monitoring efforts will help to guide decisions on the optimal mix, targeting, and exposure to VA interventions to maximize public health benefit while minimizing any potential risk.
Background
In efforts to meet the Millennium Development Goal for mortality among children under 5 years of age, countries require strategies for covering hard-to-reach and older children who are ...often missed by routine, fixed-site health services.
Objective
To document the evolution of Child Health Days (CHDs), designed as regular events for the delivery of health and nutrition services to children under the age of five.
Methods
We extracted information on service delivery strategies and codelivered interventions for the period 1999 to 2010 from global monitoring databases for vitamin A and immunization.
Results
Our data illustrate a dramatic rise in CHDs over the decade: only two countries held CHDs in 1999; in 2010, 96 CHDs were conducted in 51 countries. Reliance on CHDs has been particularly marked in sub-Saharan Africa, where they are increasingly used to deliver five or more services per event. Whereas early CHDs were largely defined by codelivery of vitamin A, immunizations, and deworming, they have since evolved into diverse packages including services such as water purification tablets and screening for severe malnutrition.
Conclusions
The scale-up of CHDs is helping countries to achieve high and equitable coverage of essential health and nutrition services. Future research should consider whether the increasingly diverse services delivered via CHDs are guided by epidemiologic considerations, and whether the rising number of codelivered interventions is affecting coverage performance or service quality. Guidance is also needed to ensure that CHDs are implemented as part of systematic efforts to improve health systems.
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 for modulating QS signaling and either ameliorating or augmenting 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 and synthetic analogues. Accordingly, identifying AHL analogues with little or no activity toward 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 discernible 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 that are 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.
Higher iron stores, defined by serum ferritin (SF) concentration, may increase malaria risk.
We evaluated the association between SF assessed during low malaria season and the risk of malaria during ...high malaria season, controlling for inflammation.
Data for this prospective study were collected from children aged 4–8 y (n = 745) participating in a biofortified maize efficacy trial in rural Zambia. All malaria cases were treated at baseline (September 2012). We used baseline SF and malaria status indicated by positive microscopy at endline (March 2013) to define exposure and outcome, respectively. Iron status was defined as deficient (corrected or uncorrected SF <12 or <15 μg/L, depending on age <5 or ≥5 y, respectively), moderate (<75 μg/L, excluding deficient), or high (≥75 μg/L). We used a modified Poisson regression to model the risk of malaria in the high transmission seasons (endline) as a function of iron status assessed in the low malaria seasons (baseline).
We observed an age-dependent, positive dose-response association between ferritin in the low malaria season and malaria incidence during the high malaria season in younger children. In children aged <6 y (but not older children), we observed a relative increase in malaria risk in the moderate iron status incidence rate ratio (IRR) with SF: 1.56; 95% CI: 0.64, 3.86; IRR with inflammation-corrected SF: 1.92; 95% CI: 0.75, 4.93 and high iron status (IRR with SF: 2.66; 95% CI: 1.10, 6.43; or IRR with corrected SF: 2.93; 95% CI: 1.17, 7.33) categories compared with the deficient iron status category. The relative increase in malaria risk for children with high iron status was statistically significant only among those with a concurrently normal serum soluble transferrin receptor concentration (<8.3 mg/L; IRR: 1.97; 95% CI: 1.20, 7.37).
Iron adequacy in 4- to 8-y-old children in rural Zambia was associated with increased malaria risk. Our findings underscore the need to integrate iron interventions with malaria control programs. This trial was registered at clinicaltrials.gov as NCT01695148.
Background:
While considerable progress has been made in reducing undernutrition in Bangladesh, regional disparities are known to exist, and certain population subgroups may lag behind.
Objective:
To ...characterize nutritional status among school-age children in a historically marginalized population of Bangladesh.
Methods:
We conducted a cross-sectional assessment of children attending 14 nongovernmental organization-operated schools serving the tea estate population in Kulaura Upazila, Sylhet Division. We randomly selected 168 children from a population of 418 whose parents attended school-organized Parent–Teacher Association meetings. Parents provided consent and data on household food consumption in the past week, foods consumed by children in the past 24 hours, and household food insecurity. We drew venous blood from assenting children for the analysis of hemoglobin and plasma retinol, C-reactive protein, and α1-acid glycoprotein. Children were classified as stunted, underweight, or thin based on comparisons with the World Health Organization standards for height-for-age, weight-for-age, or body mass index-for-age, respectively.
Results:
Food insecurity was highly prevalent, with ∼85% of households affected. Roughly half of children had low dietary diversity. Prevalence estimates for stunting, underweight, and thinness were 32%, 50%, and 49%, respectively. Approximately 60% of children had a hemoglobin concentration <11 g/dL. The mean (±SD) plasma retinol concentration was 0.79 μmol/L (±0.23 μmol/L), with 34% deficient using a 0.70 μmol/L cutoff.
Conclusions:
A heightened focus on tracking progress in underserved populations and appropriately targeted programming will be critical as Bangladesh seeks to accelerate progress toward global development goals for nutrition.
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