Landholding, wealth and risk of blinding malnutrition in rural Bangladeshi households

Prevalence of ocular manifestations of vitamin A deficiency in children: A systematic review

OBJECTIVE

Identify the prevalence of ocular manifestations due to vitamin A in children.

METHODS

The systematic search was carried out in September 2022. Observational studies with populations between 0-18 years old, who had ocular manifestations due to vitamin A deficiency, were included. Studies with selected subjects with underlying diseases were excluded. The results were exported to the Rayyan tool for duplicate removal and paired reading. The methodological quality assessment of the included articles was carried out with the Agency for Healthcare Research and Quality Institute instrument.

RESULTS

79 studies published from 1972 to 2020 were included, carried out mainly in Asia 42 (53%) and Africa 28 (35.4%). In America, 4 studies were from Brazil; no research was found in Europe. The most reported ocular manifestations due to vitamin A were: xerophthalmia in 38.0% of the articles and night blindness in 69.6%, being more common in the general population (76.3%) and less in aborigines (1.9%). The diagnostic methods used were: surveys (82.3%), laboratory tests (32%), ocular evaluation by optometry or ophthalmologist (25.3%) and ocular examination by trained personnel (8.9%). The studies were carried out in the general population (79.7%), hospitals (15.2%), schools for the blind (2.5%), migrants in transit (1.3%) and aborigines (1.3%).

CONCLUSION

Ocular manifestations continue to represent a public health problem that affects children from 0 to 18 years of age on 4 continents, with greater emphasis on Asia and Africa. Additional studies are required to understand the impact of vitamin A deficiency in Latin America.

Increasing the production and consumption of vitamin A–rich fruits and vegetables: Lessons learned in taking the Bangladesh homestead gardening programme to a national scale

Micronutrient malnutrition affects more than 20 million children and women (at least 50% of this population) in Bangladesh. the diets of more than 85% of women and children in Bangladesh are inadequate in essential micronutrients such as vitamin A, largely because adequate amounts of foods containing these micronutrients are not available, or the household purchasing power for these foods is inadequate. in Bangladesh and many other developing countries, large-scale programmes are needed to make a significant impact on this overwhelming malnutrition problem. There has been limited experience and success in expanding small-scale pilot programmes into large-scale, community-based programmes. This paper describes the development and expansion of the Bangladesh homestead gardening programme, which has successfully increased the availability and consumption of vitamin A–rich foods. the programme, implemented by Helen Keller International through partnerships with local non-governmental organizations, encourages improvements in existing gardening practices, such as promotion of year-round gardening and increased varieties of fruits and vegetables. We present our experience with the targeted programme beneficiaries, but we have observed that neighbouring households also benefit from the programme. Although this spillover effect amplifies the benefit, it also makes an evaluation of the impact more difficult. the lessons learned during the development and expansion of this community-based programme are presented. There is a need for an innovative pilot programme, strong collaborative partnerships with local organizations, and continuous monitoring and evaluation of programme experiences. the expansion has occurred with a high degree of flexibility in programme implementation, which has helped to ensure the long-term sustainability of the programme. in addition to highlighting the success of this programme, useful insights about how to develop and scale up other food-based programmes as well as programmes in other development sectors are provided.

Human plasma lipocalins and serum albumin: Plasma alternative carriers?

Lipocalins are an evolutionarily conserved family of proteins that bind and transport a variety of exogenous and endogenous ligands. Lipocalins share a conserved eight anti-parallel β-sheet structure. Among the different lipocalins identified in humans, α-1-acid glycoprotein (AGP), apolipoprotein D (apoD), apolipoprotein M (apoM), α1-microglobulin (α1-m) and retinol-binding protein (RBP) are plasma proteins. In particular, AGP is the most important transporter for basic and neutral drugs, apoD, apoM, and RBP mainly bind endogenous molecules such as progesterone, pregnenolone, bilirubin, sphingosine-1-phosphate, and retinol, while α1-m binds the heme. Human serum albumin (HSA) is a monomeric all-α protein that binds endogenous and exogenous molecules like fatty acids, heme, and acidic drugs. Changes in the plasmatic levels of lipocalins and HSA are responsible for the onset of pathological conditions associated with an altered drug transport and delivery. This, however, does not necessary result in potential adverse effects in patients because many drugs can bind both HSA and lipocalins, and therefore mutual compensatory binding mechanisms can be hypothesized. Here, molecular and clinical aspects of ligand transport by plasma lipocalins and HSA are reviewed, with special attention to their role as alterative carriers in health and disease.

Recommendations for vitamin A supplementation

In all populations where vitamin A deficiency is an important public health problem, prophylactic vitamin A supplements should be given to all infants and young children (0-59 mo), pregnant women and postpartum women within 6 wk after delivery. The efficacy of vitamin A supplementation of young children is one of the best-proven, safest and most cost-effective interventions in international public health. The International Vitamin A Consultative Group (IVACG) also recommends that three 50,000-international unit (IU) doses of vitamin A should be given at the same time as infant vaccines during the first 6 mo of life. Recent kinetic studies have indicated that this regimen will be safe and is necessary to maintain the infant's vitamin A stores, even when the mother is also given 400,000 IU within the first 6 wk after delivery. IVACG will make a decision on whether to recommend prophylactic supplementation of all women of childbearing age when the results of two large trials in Ghana and Bangladesh are available. Active corneal xerophthalmia is always a medical emergency that should be treated with immediate high-dose vitamin A. High-dose vitamin A treatment is also recommended for infants and young children with xerophthalmia, severe malnutrition or measles. Low-dose vitamin A treatment is recommended for women with night blindness and/or Bitot's spots. Given the evidence of the cost-effectiveness of vitamin A supplementation, it is essential that effective vitamin A supplementation programs are made universally available to all populations where vitamin A deficiency is an important public health problem.

Synergistic effect of zinc and vitamin A on the biochemical indexes of vitamin A nutrition in children

BACKGROUND

Zinc deficiency limits the bioavailability of vitamin A. Because zinc and vitamin A deficiency often coexist in malnourished children, simultaneous zinc and vitamin A supplementation may improve the vitamin A deficiency in these children.

OBJECTIVE

A randomized, double-blind, placebo-controlled intervention trial was conducted to evaluate whether combining zinc and vitamin A supplementation would improve the biochemical indexes of vitamin A nutriture.

DESIGN

Children aged 12-35 mo were randomly assigned to 1 of 4 intervention groups: 20 mg Zn/d for 14 d (Z group), 60000 retinol equivalents (200000 IU) vitamin A on day 14 (A group), zinc plus vitamin A (ZA group), or placebo syrup and placebo capsule (placebo group). Venous blood was drawn at enrollment and on day 21.

RESULTS

Mean serum retinol concentrations were not significantly different between the A and ZA groups. Among vitamin A-deficient children, the proportion of children who remained vitamin A deficient (serum retinol <0.7 micromol/L) after supplementation was 40.6% in the Z group, 37.5% in the A group, and 47.0% in the placebo group; only 13.3% in the ZA group remained vitamin A deficient (P < 0.05 compared with the placebo group). The proportion of children whose retinol binding protein concentrations remained low was significantly lower in the ZA group than in the other groups (P < 0.05).

CONCLUSION

Combined zinc and vitamin A supplementation improves vitamin A nutriture in vitamin A-deficient children.

Home Gardening and Access to Animals in Households with Xerophthalmic Children in Rural Nepal

This case–control study compares the home garden and animal husbandry practices of households with and without xerophthalmic children in south-central Nepal, focusing on the relationship between these practices and household intake of vitamin A–rich foods. Eighty-one households with a child between the ages of one and six years diagnosed with xerophthalmia (cases) and 81 households with an age-matched, non-xerophthalmic child (controls) were studied. There was little difference between case and control households in the size of their gardens. However, case households were significantly less likely to plant carotenoid-rich vegetables from October to March than were control households (odds ratio, 0.39; 95% confidence interval, 0.16 to 0.96). The mean consumption of non-carotenoid-rich vegetables, but not of carotenoid-rich vegetables, increased linearly with garden size. Case households were significantly more likely than control households to rent domesticated animals from others (χ2 = 5.91; p < .05). Control households were more likely than case households to own chickens and pigeons (χ2 = 6.6–9.2; p < .05). During specific seasons, household meat consumption was significantly lower in case households, regardless of access to animals. Case households appeared to have significantly lower intakes of key vitamin A–rich foods, particularly green leaves and meat, regardless of their socio-economic level (as determined by ownership of material goods), access to animals, or availability of home gardens.

Serum vitamin A in relation to socio-economic, demographic and dietary characteristics in Bangladeshi children

The purpose of this study was to examine socio-economic conditions, demographic factors, use of vitamin A capsules and dietary practices in relation to the risk of low serum vitamin A. One hundred and twenty four night blind cases were identified by parents in a cross-sectional survey in Bangladesh in 1992. Age-, sex- and neighbourhood-matched controls were selected. Venous blood was collected from 87 cases and 97 controls for the determination of serum vitamin A. Information about socio-economic conditions, demographic factors, use of vitamin A capsules and dietary practices was obtained by interview. The level of serum vitamin A was strongly related to age and consumption of beta-carotene rich foods. The preschool years (2-6 years) are important risk periods for vitamin A deficiency among children. We conclude that long-term prevention of vitamin A deficiency should rely on efforts to improve local diet.

Sustainability of a nutrition education programme to prevent night-blindness in Bangladesh

Cross-sectional surveys were conducted to assess prevalence of night-blindness and dietary habits prior to intervention (in 1986), after 3 years of intervention (in 1989) and 3 years after the termination of active intervention (in 1992), in the northern part of Bangladesh. The prevalence of night-blindness per thousand children decreased from 1986 to 1989 (during intervention) and rose from 1989 to 1992, but remained significantly lower in 1992 than the 1986 prevalence. Household income declined from 1989 to 1992, and lower consumption of beta-carotene rich food, protein items and vitamin A capsules was registered in 1992 despite almost the same level of awareness relating to the prevention of night-blindness in the community during the period 1989-1992. The results indicate that the long-term impact of a health education programme to prevent night-blindness is uncertain. Improvement in socioeconomic conditions, in addition to relevant knowledge, is probably a precondition for maintaining a sustainable impact of health education.

A causal model of high rates of child mortality

The distribution of child mortality has often been misunderstood because of insufficient attention to its context. High rates of child mortality in developing countries have variously been attributed to child neglect, cultural traditions of child care, population pressure, low maternal educational levels, lack of medical care, and insufficient basic resources. The model proposed in this article organizes factors leading to high child mortality rates onto three tiers to contextualize the medical causes of death and the debate over traditions of child care. The proximate tier includes the immediate biomedical conditions that result in death, typically involving interactions of malnutrition and infection. The intermediate tier includes child care practices and other behavior that increase the exposure of children to causes of death on the proximate tier. The ultimate tier encompasses the broad social, economic, and cultural processes and structures that lead to the differential distribution of basic necessities, especially food, shelter, and sanitation. The ultimate tier thus forms the context of causes located on the other tiers. Research from rural Mexico, Central America, and Africa supports various parts of the model, particularly concerning traditional parental behavior, which has often been interpreted as child neglect but appears in many cases to result ultimately from economic scarcity. Links from tier to tier in the model especially warrant further attention from both researchers and policy makers.

Breast feeding and vitamin A deficiency among children attending a diarrhoea treatment centre in Bangladesh: a case-control study

OBJECTIVE

To determine the effect of breast feeding on the risk of xerophthalmia in children aged 6 months to 3 years attending a diarrhoea treatment centre in Bangladesh.

DESIGN

Case-control study based on stratified analysis (Mantel-Haenszel) and multivariate analysis (logistic regression) of data from a treatment centre based surveillance system.

SETTING

A large diarrhoea treatment centre in Dhaka, Bangladesh.

PATIENTS

2687 children aged 6 months to 3 years representing a 4% systematic sample of all children in this age group treated yearly at the centre over three consecutive years. 66 of the children were cases of xerophthalmia (that is, they had Bitot's spots or corneal lesions or night blindness or night blindness plus conjunctival xerosis or any combination of these) and the remaining 2621 did not have signs or symptoms of vitamin A deficiency. This second group served as controls.

MAIN OUTCOME MEASURE

Xerophthalmia and breast fed at onset of diarrhoea or presentation.

RESULTS

The odds ratio relating breast feeding to vitamin A deficiency after adjustment for a large number of confounding variables (0.26 (95% confidence interval 0.14 to 0.49); p less than 0.001) reflected a 74% reduction in the risk of vitamin A deficiency among breast fed children. The estimated reduction of risk did not decline with age, and some 49% of children aged 24-35 months were still being breast fed. The odds ratio relating breast feeding to xerophthalmia in the third year of life (0.35 (95% confidence interval 0.35 to 0.86) reflected a 65% reduced risk of vitamin A deficiency. Other important risk factors or prognostic indicators for xerophthalmia as identified by multivariate analysis were recent measles, prolonged diarrhoea, severe protein energy malnutrition, and poor socioeconomic state.

CONCLUSIONS

These results indicate that breast feeding was associated with a substantial reduction of the risk of vitamin A deficiency extending to the third year of life and support the recommendation that mothers in developing countries should be advised to breast feed for as long as possible.

Defective modernization and health in Mexico

This paper uses data gathered in a semi-arid, mountain region of the border state of Sonora, Mexico to illustrate that modernization and the importation of urban ideas and values can influence health status in unexpected ways. It traces the historic process of modernization in a rural municipio, relating this to social promises and economic cycles in Mexico. Modernization is seen to encompass life standard improvements and access to medical care; extension of road and transportation systems; and the widespread availability of information and education, as well as lifestyle changes required to incorporate these 'urban' influences. Reviewing the link between climate and health in arid lands, the paper notes that such modernization can be a well-meaning intrusion upon a set of cultural and social practices which had proved adaptive in dealing with climatic extremes. Initial modernization produces impressive declines in mortality and morbidity, as illustrated in an analysis of mortality figures and causes in relation to age cohorts and decades for the years 1955-1984. However, reductions in epidermic-related infant mortality are shown to be offset by increases in deaths due to trauma, chronic conditions and endemic disease. An analysis of morbidity for the year 1983-84 indicates that continuing high rates of infectious disease are related to conditions which result from increasingly defective modernization. To maintain technology, including water, electrical, and sewage systems, continual capital expenditure on both the public and private level is required. The economic crisis in Mexico is reducing available funds at a time when the community has adjusted its traditional lifestyle to incorporate technological improvements. In light of this, it is likely that inroads against infectious disease will not just continue to be stalemated, but could actually be reversed. This finding has implications for towns and villages on both sides of the Mexican-American border.