Prevalence of vitamin A deficiency in South Asia: causes, outcomes, and possible remedies.

Vitamin A deficiency (VAD) has been recognized as a public-health issue in developing countries. Economic constraints, sociocultural limitations, insufficient dietary intake, and poor absorption leading to depleted vitamin A stores in the body have been regarded as potential determinants of the prevalence of VAD in South Asian developing countries. VAD is exacerbated by lack of education, poor sanitation, absence of new legislation and enforcement of existing food laws, and week monitoring and surveillance system. Several recent estimates confirmed higher morbidly and mortality rate among children and pregnant and non-pregnant women of childbearing age. Xerophthalmia is the leading cause of preventable childhood blindness with its earliest manifestations as night blindness and Bitot's spots, followed by blinding keratomalacia, all of which are the ocular manifestations of VAD. Children need additional vitamin A because they do not consume enough in their normal diet. There are three general ways for improving vitamin A status: supplementation, fortification, and dietary diversification. These approaches have not solved the problem in South Asian countries to the desired extent because of poor governmental support and supervision of vitamin A supplementation twice a year. An extensive review of the extant literature was carried out, and the data under various sections were identified by using a computerized bibliographic search via PubMed, Web of Science, and Google Scholar. All abstracts and full-text articles were examined, and the most relevant articles were selected for screening and inclusion in this review. Conclusively, high prevalence of VAD in South Asian developing countries leads to increased morbidity and mortality among infants, children, and pregnant women. Therefore, stem efforts are needed to address this issue of public-health significance at local and international level in lower- and middle-income countries of South Asia.

Epidemiology of vitamin A deficiency and xerophthalmia in at-risk populations.

Vitamin A deficiency (VAD) is an important public health problem worldwide that contributes significantly to the global burden of disease. Vitamin A deficiency disorders include xerophthalmia and increased risk of infectious diseases, both of which increase risk of mortality. Xerophthalmia is also a leading cause of preventable blindness. Areas with highly prevalent VAD often share common dietary and other environmental exposures, including poverty, infectious diseases, limited development and poor availability of vitamin A containing food. Globally, the prevalence of VAD has been declining, which may be due to widespread vitamin A supplementation in conjunction with measles immunisation in at-risk populations. Recent meta-analyses confirm that provision of vitamin A to children aged between 6 months and 5 years confers a significant mortality benefit. Further preventative measures for VAD comprise improving availability of vitamin A containing food, including foods biofortified with vitamin A. Ensuring vitamin A is available in any form in adequate quantities remains problematic, especially in areas affected by environmental catastrophes and conflict, and other areas where access to vitamin A containing foods and healthcare interventions is limited. Hence, it remains essential that maternal and child health workers remain vigilant for VAD in nutritionally vulnerable populations.

Child feeding and care behaviors are associated with xerophthalmia in rural Nepalese households.

The study examined caregiver-child interactions, intrahousehold food allocation and general child care behaviors and their effect on children's xerophthalmia status in the rural Terai region of Nepal. Seventy-eight households with a child having a history of xerophthalmia (cases) were matched with 78 households with a child of the same age having no history of xerophthalmia (controls). Seven day-long continuous monitoring observations were performed in each household (over 15 months) by trained Nepali observers, focusing on feeding and care of a focus child and his/her younger sibling. Nineteen different behavioral variables were operationalized, including serving method, second helpings, serving refusals, encouragement to eat, request intensity, meal serving order, food channeling, food sharing, positive social behaviors, negative social behaviors, and positive health behaviors. Automatic serving and request intensity were strongly negatively correlated, especially among younger siblings. Children who serve themselves receive less encouragement to eat. Those children who are refused in their requests for food tend to ask for food more frequently, for a longer time, and be less likely to self-serve. Children who eat from a shared plate are less likely to interact with a food server and more likely to self-serve. Negative social behavior towards children is associated with the child having to request food more frequently and a greater likelihood of being refused food. Children who receive positive health care from their caregivers are also more frequently asked if they would like food by the server and are encouraged to eat. Several caregiver child feeding behaviors were related to a child's risk of having past vitamin A deficiency. Controls were much more likely to be served food automatically. Cases were more likely to serve themselves food and have multiple servings of food. Cases were nearly two times more likely than controls to be treated with neglect or harshly, and much less likely than controls to have their health needs receive attention. Examining intrahousehold behavior is critical for understanding the causes of vitamin A deficiency in rural Nepalese children, and has great potential for identifying and improving interventions to improve children's diets and care.

Vitamin A deficiency and its consequences: a field guide to detection and control / Vitamin A deficiency and its consequences: a field guide to detection and control

Ocular manifestations of vitamin A deficiency, particularly night blindness, have been recognized since antiguity. Animal research and clinical observations early in the twentieth century indicated that vitamin A was important for numerous bodily functions: animals and humans deficient in vitamin A grew poorly, suffered more persistent or severe infections, and subsequently developed characteristic ocular problems termed "xerophthalmia" or "dry eye". By the early 1940s these readily apparent eye signs had been eliminated from wealthier countries through dietary interventions. In developing countries today, however, at least 5-10 million children developed xerophthalmia every year, of whom between a quarter and a half a million go blind

Recent data indicated that mortality rates are also increased amongh children with even mild vitamin A deficiency and that, in many areas, enhanced vitamin A intake can reduce the risk of mortality from childhood infections by up to 54 per cent. It is estimated that the deaths of al least one million children would be prevented each year if vitamin A status were improved...extension and further refinement of knowledge about the importance of vitamin A in child health and survival made it necessary to revised this manual. This greater understanding, combined with growing commitment by governments, enhances the feasibility of achieving the declared goal of eliminating vitamin A deficiency as a significant public health problema by the start of the next millennium

Depressed immune response to tetanus in children with vitamin A deficiency.

A randomized, double-masked, placebo-controlled clinical trial was conducted with 236 preschool children, age 3-6 y, in Indonesia to assess immune status in mild vitamin A deficiency. The immune response to tetanus immunization was used as a measure of immune competence. Clinically normal children (n = 118) and children with mild xerophthalmia (n = 118) were randomly assigned to receive oral vitamin A (60,000 micrograms retinol equivalent) or placebo treatment for a total of four study groups. Two weeks after treatment, children were immunized with diphtheria-pertussis-tetanus vaccine. The immunoglobulin G (IgG) responses to tetanus at baseline and 3 wk following immunization were measured by ELISA. After adjusting for previous tetanus immunization, clinically normal and xerophthalmic children receiving vitamin A had a significantly greater IgG response to tetanus than clinically normal and xerophthalmic children receiving placebo (P less than 0.05). These results suggest that children with mild vitamin A deficiency have a relative immune depression compared with children who have been supplemented to normal vitamin A levels.

Influence of diet on tear function.

The effect of diet on tear function is illustrated clearly by malnutrition-induced xerophthalmia. Dietary habits in well nourished North American society have been implicated as a cause of some tear dysfunction. A review of the ocular literature suggests that sufficient dietary protein, vitamins A, B6 and C, potassium, and zinc may be necessary for normal tear function. Excesses of dietary fats, salt, cholesterol, alcohol, protein, and sucrose have been associated with or suggested as causes of tear dysfunction. No unequivocal link has been established between diet and remission of dry eye states in a well nourished population.

Vitamin A activity of buriti (Mauritia vinifera Mart) and its effectiveness in the treatment and prevention of xerophthalmia.

The fruit of buriti, a palm tree that grows wild in some regions of Brazil, contains beta-carotene in its oily fraction in a concentration 10 times higher than that of red-palm oil. The effectiveness of buriti sweet in the treatment and prevention of xerophthalmia was tested in 44 children aged 43-144 mo through daily supplementation with an amount corresponding to 134 micrograms retinol equivalent over 20 d. The results demonstrated that this natural food source of vitamin A can reverse clinical xerophthalmia and restore liver reserves of the vitamin, suggesting its possible utilization in intervention programs to combat vitamin A deficiency in countries where the fruit is available or has the potential for cultivation.

Rehabilitation of xeropthalmic children. A follow-up study in southern India.

Two hundred and seventy-five children were admitted to the Nutrition Rehabilitation Centre (NRC), Madurai in 1975; 213 had xeropthalmia and 62 showed no eye signs. All were malnourished, the largest single group being less than half their expected weight for age. A follow-up study was made both by means of recall to the NRC and by means of house visits to children of Madurai town. Less than half the total, but 55% of town children were found. The distribution of eye signs on admission in those who were later followed-up, corresponded with that in the total. Weight improved while at the NRC and also after return home. All existing cases of corneal xerosis healed but conjunctival xerosis remained in some. Major corneal damage through ulceration, keratomalacia and scars was present in 94 children at admission, 34 of these were followed-up. Four were blind and five had severely limited vision in both eyes, but useful vision was present in one or both eyes of the other 25 (73%) children. For example, of 15 children found blind in one eye, 13 had good vision in their other. The mortality among xerophthalmic children children while at the NRC was 6.6%, and among those visited later at home was 20%. Almost all mothers questioned, said they gave their children green vegetables, but apart from this very important precept, few other dietary suggestions were followed.

Topical retinoic acid in the treatment of corneal xerophthalmia.

Eight children with corneal xerophthalmia (x2 or x3A) received standard high-protein diets and massive systemic vitamin A therapy. Retinoic acid, 0.1% in oil, was applied daily to one eye, and oil alone to the other. Topical retinoic acid proved safe and effective in speeding corneal healing, especially during the first critical days.

A nutrition rehabilitation centre for children with xerophthalmia.

A nutrition rehabilitation centre for treatment of children with xerophthalmia was established in Madurai, India. Treatment was based on provision of locally available food, rich in protein and beta-carotene and cheap enough for the families concerned to buy at home. This diet alone, with general medical treatment for other diseases, was sufficient to reverse conjunctival xerophthalmia and corneal xerosis. Children with more severe xerophthalmia received additional vitamin A. The records of 296 children followed up for between two months and three years were analysed. The results of treatment at the centre seemed as good as those produced by more expensive, and usually unobtainable, hospital treatment. Participation of the mother in buying, cooking, and sharing the food given to her child was of some educational value.

Manifestaciones oculares de la hipovitaminosis A / Ocular manifestations of hypovitaminosis A

The ocular manifestations of hypovitaminosis A -known as Nutriophthalmopathy A (NOA)- involve the anterior segment of the eye, mainly the conjunctiva and the cornea. The eyes are more vulnerable in pre-school age, 2-4 years, but are rarely affected in the first year and above the fourth year

In the course of the survey carried out by WHO in 1962-1963 (in 37 countries of Asia, Africa and America) 2,532 children were examined in Latin America; of these children 14.7 per cent were malnourished and 1.5 per cent had NOA in varying degrees, mostly as ulcers, or keratomalacia but this percentage rose to 14 per cent among the malnourished only. The lesions were noted more frequently during the rainy season, when there is always an increase in gastrointestinal infections in children and that may have to do with the seasonal variations observed in NOA

The author classifies the eye lesions observed in seven stages, according to their severity: night blindness, Bitot's spots, conjunctivocorneal xeroxis, interstitial corneal infiltration, corneal ulceration, keratomalacia, sequelae

The clinical picture observed in NOA lends itself to a prognosis not only in regard to the eye but also to a life expenctancy. The first six stages represent the active stage of the disease and stage VII is a stationary one and the final outcome. The first four of these stages are reversible, the changes being amenable to ...(AU)

Encuesta mundial sobre la xeroftalmia : La hipovitaminosis A : Epidemiologia y aspectos de salud publica / A global survey on xerophthalmia : Epidemiology and public health aspects o hypovitaminosis A

The purpose of this study was to review the problem of nutritional disorders of the eye; with that end in view, surveys were carried out between July 1962 and March 1963 in South and East Asia, in the Near East and Northern Africa, and in Mexico, Central America, and South America. The authors first examine the sources of information used, which included replies to specially prepared questionnaires; government statistics and hospital records; surveys (cases of xerophthalmia might be detected during the course of surveys of infectious diarrhea, especially shigellosis); vernacular names for this condition; and personal observations of the consultants. On analyzing the epidemiological aspects the authors point out that climatic conditions have less influence on the occurrence of xerophthalmia than might at first be thought; more important is the correct use of available foods. On the other hand, studies made in Vietnam showed that seasonal variations do have a significant influence, especially in places where changes in climate are more marked. Among the social and economic factors which play a role in the occurrence of xerophthalmia and other nutritional disorders of childhood, attitudes toward foods and especially their suitability for young children, mal-distribution of food in the family and the abandonment of breast feeding among the economically insecure have a profound effect. Etiologic