Vitamin A-rich Foods Research Articles

Intra-class correlation estimates for assessment of vitamin A intake in children.

In many community-based surveys, multi-level sampling is inherent in the design. In the design of these studies, especially to calculate the appropriate sample size, investigators need good estimates of intra-class correlation coefficient (ICC), along with the cluster size, to adjust for variation inflation due to clustering at each level. The present study used data on the assessment of clinical vitamin A deficiency and intake of vitamin A-rich food in children in a district in India. For the survey, 16 households were sampled from 200 villages nested within eight randomly-selected blocks of the district. ICCs and components of variances were estimated from a three-level hierarchical random effects analysis of variance model. Estimates of ICCs and variance components were obtained at village and block levels. Between-cluster variation was evident at each level of clustering. In these estimates, ICCs were inversely related to cluster size, but the design effect could be substantial for large clusters. At the block level, most ICC estimates were below 0.07. At the village level, many ICC estimates ranged from 0.014 to 0.45. These estimates may provide useful information for the design of epidemiological studies in which the sampled (or allocated) units range in size from households to large administrative zones.

Donated Fortified Cereal Blends Improve the Nutrient Density of Traditional Complementary Foods in Haiti, but Iron and Zinc Gaps Remain for Infants

This research assesses whether fortified cereal blends such as corn-soy blend (CSB) or wheat-soy (WSB) blend can significantly contribute to improving the quality of the diet of infants and young children 6 to 23 months of age. A series of participatory recipe trials was conducted to assess current complementary feeding practices in the Central Plateau of Haiti and to develop new, improved recipes by using a combination of locally available ingredients and foods and donated fortified cereal blends. Our findings show that it is feasible to improve the nutritional quality of complementary foods in poor rural areas of Haiti, using locally available ingredients and fortified cereal blends. Significant improvements in the concentrations of vitamin A could be obtained by including acceptable and affordable amounts of locally available vitamin A-rich foods such as pumpkin or eggs. Only preparations using CSB, however, could achieve the recommended concentrations of iron and zinc in complementary foods, and even this was achievable only for 12- to 23-month-old children. For infants, and especially those between 6 and 8 months of age, the high requirements of 7.7 mg of iron and 1.6 mg of zinc per 100 kcal of complementary foods could not be met, even with a combination of fortified CSB and other locally available, acceptable, and affordable foods. The same was true for the zinc density of complementary foods among 9- to 11-month-old children, which could not be achieved even with fortified CSB. Thus, in this population, fortified cereal blends were key to achieving the recommended iron and zinc densities of complementary foods for children 12 to 23 months of age, but they were not sufficient for infants. Complementary approaches, such as improving the availability, access, and intake of animal-source foods or the use of home fortification techniques (using spreads, sprinkles, or dispersible tablets), are needed to ensure adequate iron and zinc density of complementary foods for infants younger than 12 months in resource-constrained environments such as rural Haiti.

Children aged 6 to 60 months in Nepal may require a vitamin A supplement regardless of dietary intake from plant an animal food sources.

The purpose of this survey was to explore the relationship between the prevalence of the health indicators of malnutrition, diarrhea, and acute respiratory infection and the consumption of vitamin A-rich food and the supplementation status of three groups of children in Nepal (supplemented, supplemented only once, and never supplemented). A trained female community health worker interviewed mothers about vitamin A-rich food feeding practices to children aged 6 to 60 months using a standardized questionnaire and then estimated the nutritional status of the children using mid-upper-arm circumference measurements and recording the incidence of diarrhea and acute respiratory infection from mothers' interviews. Regardless of the amount of vitamin A-rich foods consumed, children who were regularly supplemented with high doses of vitamin A were protected against malnutrition, diarrhea, and acute respiratory infection at a higher rate than children who were supplemented only once or were never supplemented. Regularly providing a high-dose (200,000 IU) capsule of vitamin A to children aged 6 to 60 months, including those who eat vitamin A-rich foods, may be effective in decreasing the prevalence of morbidity from malnutrition, diarrhea, and acute respiratory infection.

Risk factors for nightblindness among women of childbearing age in Cambodia.

To characterize risk factors for nightblindness among nonpregnant women of childbearing age, a group recently recognized to be at high risk of vitamin A deficiency in some developing countries. Case-control study. The study included >15 000 households in National Micronutrient Survey of Cambodia conducted in 2000. The prevalence of nightblindness among 13 358 nonpregnant women was 2.0%. A total of 328 nonpregnant women with nightblindness were matched by province with 1009 nonpregnant women without nightblindness. Univariate and multivariate logistic regression models were used to estimate odds ratios (ORs) as estimates of the relative risk of factors associated with nightblindness. In a final model, materials in the wall of the house (OR 1.4, 95% confidence interval (CI) 0.9-2.0), land ownership < or =0.5 hectares (OR 1.4, 95% CI 1.0-1.9), nightblindness in last pregnancy (OR 44.5, 95% CI 29.2-67.8), parity >3 (OR 1.5, 95% CI 1.0-2.1), diarrhea within the last 2 weeks (OR 1.9, 95% CI 1.3-2.8), maternal body mass index <18.5 (OR 1.8, 95% CI 1.2-2.7), and lack of consumption of vitamin A-rich animal foods in the last 24 h (1-60 retinol equivalents (RE) OR 1.1, 95% CI 0.7-1.6; > or =60 RE, OR 0.7, 95% CI 0.4-1.0) were associated with nightblindness among nonpregnant women. Women of childbearing age in Cambodia with low socioeconomic status, low consumption of vitamin A-rich animal foods, a history of nightblindness during the previous pregnancy, parity >3, malnutrition, and diarrhea have a higher risk of nightblindness. United States Agency for International Development (442-G-00-95-00515-00).

Provitamin A carotenoid content of different cultivars of edible pandanus fruit

As part of an overall study to identify vitamin A-rich foods, a study was carried out in the Federated States of Micronesia (FSM) to provide information on production, acquisition, consumption and cultural acceptability of edible pandanus cultivars, Pandanus tectorius, and to identify their carotenoid content. Samples of five pandanus cultivars were collected and analyzed for α- and β-carotene by HPLC. The results showed that the two cultivars with yellow fruit coloration contained low levels of carotenoids, while the orange fruits, which were also well liked as a food in the community, contained higher levels at maxima of 190 μg/100 g and 393 μg/100 g for α- and β-carotene, respectively. Common patterns of intake when the fruit is available show that pandanus can provide a large proportion of estimated requirements of retinol equivalents. Local people were generally unaware that pandanus had health benefits, although the food was very popular. Nevertheless, key informants report that production had greatly decreased in recent years. To reverse this trend, those acceptable cultivars high in carotenoid content should be promoted both for their general enjoyment and their health benefits.

Control of Vitamin A Deficiency in Vietnam: Achievements and Future Orientation

Vitamin A deficiency is one of the major nutritional deficiencies in Vietnam. The first survey, conducted in 1985-1988 showed that the prevalence of severe xerophthalmia was seven times higher than the cutoff point established by the World Health Organization (WHO) to define vitamin A deficiency as a public health problem. The result of this survey strongly convinced the government to launch a program to control vitamin A deficiency, which started in 1988. The program strategies included nutrition education, universal distribution of high-dose vitamin A capsules to children aged 6 to 36 months in combination with national immunization days, and promotion of production and consumption of vitamin A-rich foods at the family level. The implementation network was set up based on the existing preventive health structure at all administrative levels. Organizations such as the women's union and other social sectors have participated actively in the program. Surveys conducted in 1994 and 1998 showed that the prevalence of clinical xerophthalmia was significantly lower than that identified in the baseline survey and below the WHO criteria for a public health problem. The achievements of our program have demonstrated that an effective vitamin A supplementation program can be implemented successfully by the preventive health network with active community participation. In the coming years, it will be important for our program to develop approaches other than vitamin A supplementation in order to maintain the past achievements.

Vitamin A Supplementation and the Control of Vitamin A Deficiency: Conclusions

It was the consensus among all meeting participants that their conclusions concerning vitamin A supplementation should be understood as applying to populations in countries or areas where vitamin A deficiency is a public health problem including HIV-infected populations. Additionally it was strongly emphasized that for success a multipronged approach to the elimination of vitamin A deficiency is needed. Food fortification and dietary diversification including an increased consumption of vitamin A-rich foods are key components in any strategy to control vitamin A deficiency. Efforts to promote these strategies should be pursued while implementing supplementation activities. (excerpt)

Vitamin A in pregnancy: requirements and safety limits

Most of the functions of vitamin A are mediated through the binding of retinoic acid to specific nuclear receptors that regulate genomic expression. Recent experimental work in transgenic mice showed clearly that normal embryonic development depends on the correct spatial and temporal expression of the receptors in the differentiating cells and on the binding of specific forms of retinoic acid. This implies that the parent compound, vitamin A, is available in adequate forms and quantities. Excessive dietary intake of vitamin A has been associated with teratogenicity in humans in <20 reported cases over 30 y. However, caution must be exercised to avoid unnecessary supplementation of women of childbearing age. Hypovitaminosis A affects millions of women and children worldwide. The main consequence of a poor vitamin A supply during pregnancy is a low vitamin A status at birth and in the next few months. Vitamin A deficiency is strongly associated with depressed immune function and higher morbidity and mortality due to infectious diseases such as diarrhea, measles, and respiratory infections. Vitamin A deficiency is often associated with an increased mother-to-child transmission of HIV-1. The initiation of vitamin A supplementation should be carefully examined in each case according to the risk-to-benefit ratio. The final decision should take into account the estimated vitamin A status of the woman, the availability of vitamin A-rich foods in her diet, and whether supplementation can be supervised.

Retinol and beta carotene content of indigenous raw and home-prepared foods in Northeast Thailand

Retinol and β-carotene contents of raw and home-prepared indigenous foods in Northeast Thailand were studied. The criteria used to select the vitamin A-rich foods were high retinol or β-carotene contents of the individual food items, the amount and frequency of consumption, preference of consumption and food availability. Items selected were chicken liver, chicken egg, ivy gourd, amaranth, swamp cabbage (Chinese), Chinese cabbage, pumpkin, yellow sweet potato and two traditional menu items, kang-nho-mai and om-kruang-nai-kai. Raw food items were purchased from the local market; the traditional cooking procedures of the community were duplicated in the laboratory. Retinol and β-carotene contents were determined prior to and following cooking using HPLC methodology. The results indicated that boiling intact chicken liver resulted in 5% loss of retinol; boiling with cutting into small pieces and grilling resulted in losses of 8 and 16%, respectively. Greater losses (43%) were observed for egg omelet compared to hard-boiled egg (11%). For vegetables, blanching resulted in 7–11% loss of β-carotene, while steaming, frying and boiling showed losses of 15, 18 and 43%, respectively. Traditional foods such as bambooshoot soup (Kang-nho-mai) and chicken organ soup (Om-kruang-nai-kai) exhibited β-carotene losses ranging from 6–21%.

Culture, environment and food to prevent vitamin A deficiency

National nutrition programmes are frequently designed to the exclusion of existing local dietary culture. Sometimes, they simply do not take account of the widely varying diet culture in different parts of the country. A rapid assessment method for obtaining such information at the local level is a useful tool for managers at district and sub-district level, who need to fine-tune the tenets of national programmes to their local context. This book describes the methods and results from pre-testing of a focused ethnographic study (FES) instrument, a simple tool for obtaining the answers to the basic issues pertinent to consumption of locally available vitamin A-rich foods. It establishes an important premise up front: that you cannot prescribe change without knowledge and understanding of the current situation. The FES method is applied to vitamin A nutrition to elicit the list of vitamin A foods that can be promoted, and for formulating the appropriate messages about them. This is described in simple language that is easy to read and understand, and which makes it a ready-to-use tool for programme managers. Successful application of the FES method in the diverse cultures covered in the five studies is a good indication of its flexibility. In the studies described, the FES was applied to small, culturally well-defined population groups. Whilst this was done in the pre-test, it is important to understand that it is not required to conduct the FES for all the cultural and ecological sub-groups in a country before a programme of action can be articulated. Several ingredients for its successful application are noted. Most important are the non-issues, such as that a health and nutrition or social science background is not a prerequisite. The following are important: initial training of the team using the FES manual, local composition of the team, local adaptation of the instrument and its application in different seasons if the seasonal variation in food ecology is marked. All of these prerequisites are available at least at the district level of the health system in most countries. The study in China provides a clear example of the merits of the FES instrument over traditional population survey instruments. In one example, the in-depth interviews provided insight into the politico-economic reasons why carrot production/consumption is no longer practised by the people of Doumen. This is information that would be vital to any initiative to promote carrots as part of a vitamin A programme, but which could not have been captured in a population survey of what people eat. Pile sorting particularly is good for determining the position of foods in terms of their attributes (positive or negative) which is important knowledge for any programmes that seek to promote these foods. It is interesting to note the remarkable cross-cultural consistency in food beliefs, and of the vitamin A deficiency name meanings, e.g. chicken eyes for xerophthalmia, and the basis of treatment. The indication here for programme managers is that if dietary inter-ventions have been possible in other settings, there is always the potential for them in their own settings. The crucial issue becomes the knowledge basis for developing the intervention. This book is recommended reading for national programme managers; but more importantly for local managers who must necessarily contribute to the development of national plans, and who in any case carry the responsibility for translating these plans into programmes on the ground.

Nutrition Promotion in Mali: Highlights of a Rural Integrated Nutrition Communication Program (1989–1995)

Between 1989 and 1995, the U.S. Agency for International Development funded the Nutrition Communication Project (NCP). NCP collaborated with the Government of Mali, UNICEF, and 10 nongovernmental organizations (NGOs) in a community-based program to improve women's and children's nutritional status. Increasing consumption of vitamin A-rich foods was stressed. Three southern regions of the country, with approximately 750,000 of Mali's 9 million people, were involved.Village-based health staff and volunteers were trained to use stories and drama to introduce new concepts and model desired behavior, as well as to negotiate individual behavior changes. This article focuses on the project's design and implementation, highlighting the qualitative data and processes used to develop the communication strategy. A final evaluation demonstrated that NCP was associated with positive changes in maternal diet and child feeding behaviors. NCP continues in Mali under the auspices of the government, UNICEF, and the NGO consortium.

Infant feeding practices reflect antecedent risk of xerophthalmia in Nepali children.

To determine the relationship between infant feeding history and risk of xerophthalmia due to vitamin A deficiency (VAD) in early childhood. A case-control study of previously xerophthalmic and non-xerophthalmic children. Rural lowland region of Nepal. One hundred and fifty-six children (aged 1-6 y old), half of whom previously had xerophthalmia due to vitamin A-deficiency, the other half matched by locale, age and the presence and age of a younger sibling (n = 102). Xerophthalmia was determined by trained ophthalmic assistants on the basic of current Bitot's spots, corneal xerosis or report of night blindness. Infant feeding history was collected through a diet history method obtained from the mother of the focus child. Exploratory factor analysis was conducted to determine the presence of underlying patterns in infant feeding practices. Conditional logistic regression was used to estimate odds ratios. Mothers of control children tended to have a higher level of education (P < 0.10) and to have fewer children who had died (P < 0.10) than mothers of case children. Feeding of meat (OR = 0.09, CI = 0.01-0.70) or fish (OR = 0.41, CI = 0.17-0.99) with liver, eggs (OR = 0.11, CI = 0.01-0.88) and mango (OR = 0.28, CI = 0.13-0.60) were protective in association with xerophthalmia in early childhood. Factor analysis uncovered several distinct patterns in infant feeding, which varied by age of the infant. Only the 'animal flesh' feeding pattern (factor), practiced in the second year of life, proved significantly protective from xerophthalmia (OR = 0.43, CI = 0.20-0.94). Feeding patterns of younger children closely paralleled those of their older siblings with and without VAD. The study supports the hypothesis that infant dietary practices can influence subsequent risk for VAD. Our findings emphasize the importance of introducing vitamin A-rich foods during weaning to reduce the risk of VAD-associated xerophthalmia in the later preschool years.

Chronic low intakes of vitamin A-rich foods in households with xerophthalmic children: a case-control study in Nepal

Dietary patterns in 81 rural Nepali households with a 1-6-y-old child with a history of xerophthalmia were compared with dietary patterns of 81 households with an age-matched nonxerophthalmic control subject. Weekly food-frequency questionnaires were collected from case and control "focus" children, a younger sibling (if present), and the household 1-2 y after recruitment and treatment of cases. Control households and children were more likely than case households and children to consume vitamin A-rich foods during the monsoon (July-September) and major rice harvesting (October-December) seasons. Cases were less likely to consume preformed vitamin A-rich foods throughout the year [odds ratio (OR) = 1.2-4.5] with the strongest differences observed from October to December (OR = 2.0-4.2). Dietary risks were generally shared by younger siblings of cases, suggesting that infrequent intake of beta-carotene and preformed vitamin-A rich foods begins early in life and clusters among siblings within households, a pattern that is consistent with their higher risk of xerophthalmia and mortality. In developing countries where vitamin A deficiency is endemic, dietary counseling for children with xerophthalmia should be extended to their younger siblings. Moreover, dietary intake of preformed vitamin A may be as, or more, important as carotenoid-containing food consumption in protecting children and other members of households from vitamin A deficiency.

Increasing Vitamin a Consumption in Young Children

Nongovernmental organizations (NGOs) working in indigenous Mayan areas in Guatemala have included among their program goals increased consumption of vitamin A-rich foods by infants and small children. The application of international infant and child feeding recommendations at the community level is often problematic, however, and questions arise regarding the most appropriate recommendations to promote among particular social groups. The answers can depend upon the specific vitamin A-rich foods available, accessible, and acceptable to mothers and children, and on customary caring and feeding behaviors.

Maternal vitamin A status and its importance in infancy and early childhood

Early fetal vitamin A supplies must be regulated to avoid teratogenic consequences from too little or too much. Late in gestation, adequate maternal vitamin A status is important for newborn reserves and for sustaining adequate breast-milk concentrations. Vitamin A supplements are not needed for most pregnant women in Western countries who consume the recommended dietary allowance during their reproductive years. Increased consumption of vitamin A-rich foods can meet increased needs during lactation. Women in developing countries whose habitual intakes are near basal needs should receive an additional 100 micrograms retinol equivalents (RE) during pregnancy and 300 micrograms RE during lactation. Supplements not above 3000 micrograms RE (10,000 IU) daily are safe for fertile women where circumstances preclude obtaining the needed increment through diet. The first postpartum month is the only safe period during which to provide deficient lactating women with a single high-dose supplement to benefit the mother and breast-feeding infant for several months.

Antioxidant micronutrients and breast cancer.

We reviewed epidemiologic evidence on the relationship between four antioxidant micronutrients (vitamin A, vitamin C, vitamin E, and selenium) and breast cancer risk. Available data support a modest protective effect of vitamin A, although more studies are needed to examine further this association and to assess the relative contributions of preformed vitamin A (retinol) and carotenoids. In addition, the possibility that some other component of vitamin A-rich foods may account for this observed association should be explored. Data on the relationship between vitamins C and E and breast cancer risk are limited and inconsistent, and further information is necessary. A substantial body of evidence indicates a lack of any appreciable effect of selenium intake on breast cancer risk, at least within the range of human diets. Future observational studies should ideally be prospective in design, as prospective studies are less prone to selection and recall bias than are case-control studies, and should address methodologic issues such as confounding by other micronutrients and appropriate storage conditions of blood specimens. Although hypotheses relating micronutrient intake to risk of breast cancer should be tested in randomized trials, ethical and logistical constraints make these studies difficult to perform.

Risk factors for developing mild nutritional blindness in urban Bangladesh.

Mild vitamin A deficiency may be associated with increased morbidity and mortality among children in developing countries. A community-based case-control study was performed to determine risk factors for mild ophthalmologic manifestations of vitamin A deficiency in urban Bangladeshi children. Cases were identified in children less than 14 years of age with night blindness with or without other signs of mild xerophthalmia detected in a house-to-house survey. Controls were randomly selected neighbors who lacked subjective and objective ophthalmologic evidence of vitamin A deficiency. Demographic characteristics that were independently associated with vitamin A deficiency in a logistic model included male gender, greater age (mean, 6.1 years in children with cases and 2.8 years in controls), and a greater number of children living with the family. After controlling for these demographic characteristics, poor intake of locally available vitamin A-rich foods, cessation of breast-feeding, and a recent history of protracted diarrhea remained associated with vitamin A deficiency. Maternal ignorance of prevention and control of vitamin A deficiency was also associated with increased risk. The results support programs that educate mothers to breast-feed and to provide appropriate food supplements and suggest that clinicians caring for children with chronic diarrhea should initiate vitamin A supplementation.