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Factors influencing vitamin A intake and programmes to improve vitamin A status

T. Johns, S. L. Booth, and H. V. Kuhnlein

Programmes to increase the consumption of natural food sources of vitamin A and provitamin A

Several reviews of programmes designed to eradicate vitamin A deficiency are available [90-95], including summaries of the activities being implemented or proposed by major international agencies and non-governmental organizations.

While the long-term goal of bringing about sustained dietary change to improve vitamin A intake is proposed for most programmes, few such programmes have been implemented [96]. Programmes that have published evaluations have demonstrated varying levels of success. However, programme strategies and summaries are difficult to obtain, and the operational details rarely appear in publicly accessible literature. Therefore, the programmes described in this section should not be interpreted as an exhaustive list of all of those designed to increase the consumption of natural food sources of vitamin A and provitamin A. Instead, a selection of programmes is used to illustrate the problems encountered. In particular, the gardening and nutrition education approaches to improving dietary intake of provitamin A are stressed, as are alternative approaches that show promise in achieving the goal of sustained dietary change.

Promoting gardening activity

The promotion of community, school, and household gardens, and especially the cultivation of foods rich in provitamin A activity, is currently one of the more common strategies to promote dietary change. This strategy has been reviewed by Brownrigg [97]. It has been one component of current or proposed programmes supported by the ministries of health in Guatemala [98], Brazil [99], and Mali [27], and elsewhere. In most countries, programmes are collaborative with other ministries, international agencies, and local institutions [92]. In Bella Coola, British Columbia, Canada, a traditional plant food garden as a source of vitamin A and several other nutrients was successfully promoted [100]. In Guatemala, promotion of local foods rich in vitamin A activity has involved collaboration at the national and international levels, including the ministries of Health and Education, the United Nations Children's Fund (UNICEF), the International Eye Foundation, the US Agency for International Development (USAID), the Institute of Nutrition of Central America and Panama (INCAP), the National Committee for the Blind and Deaf, and the University of San Carlos, among others [98]. Before regional planning and implementation of the garden projects were undertaken, nutrition and anthropological surveys were conducted at the household and community levels to identify local food sources, food habits relating to provitamin A-rich foods, and marketing behaviours [101].

The collection of preliminary data on dietary intake and attitudes towards health, food, and vitamin A deficiency has been given more importance by certain agencies, and this may help to reverse an otherwise poor record of success among gardening projects [97]. The International Vitamin A Consultative Group (IVACG), for example, has published a simplified approach to the assessment of dietary intake of provitamin A and preformed vitamin A to identify high-risk groups or regions, to identify culturally acceptable foods, and to evaluate programmes designed to increase the intake of foods rich in vitamin A activity [ 1 02]

A recent evaluation of food beliefs, food habits, and attitudes towards health in Macina. Mali. confirmed the value of multidisciplinary collaboration in projects designed to eradicate vitamin A deficiency [27]. The evaluation demonstrated that villages in which CARE had gardening and nutrition education projects had a greater comprehension of and receptivity to the concept of preventing vitamin A deficiency by using provitamin A and preformed vitamin A-rich foods. Recommendations were presented for nutrition education, including specific dietary behaviour targeted for change and recommendations for mass media strategies. For example, older women had more time available for gardening, so it was recommended that programmes promoting this activity be directed towards this group.

Factors limiting the success of the gardening approach to increasing the intake of provitamin A include limited access to water, attack by pests, consumption of plants by domestic animals, limited availability of seeds and gardening equipment, and the promotion of inappropriate food items [27, 92, 95]. Shrimpton [99] argues that, in Brazil, the promotion of introduced vegetables that are lower in provitamin A activity than local species has diverted resources, including seeds, fertilizer, and water, from the indigenous foods. With projected increases in the percentage of functionally landless people and those living in poverty, access to land for gardening will also become increasingly difficult [92].

Nutrition education

Nutrition education is often incorporated into gardening projects and is provided at health centres in conjunction with the distribution of vitamin A supplements. In some regions, when a woman becomes pregnant, her previous child who has been being breast-fed is abruptly weaned to a diet devoid of vitamin A [103]. Indonesian mothers may not give their children green leafy vegetables for numerous reasons, including a lack of knowledge of cooking methods. Cases such as these suggest that nutrition education is necessary for the promotion of foods rich in provitamin A.

Using data on maternal attitudes on infant feeding, a rapid education workshop was used in rural Egypt to demonstrate methods of meal selection and preparation (W. Mousa, personal communication). This was a general education project that included some vitamin A-rich foods. While the CARE programme in Mali, previously mentioned. has been favourably evaluated, it was found that a number of constraints, including money, time, and market availability of promoted foods, limited the capacity of women to incorporate their knowledge into meal preparation to increase the use of vitamin A-rich foods [27]. At a nutrition rehabilitation centre in south India, mothers could recite the recommended diet to increase vitamin A intake at the centre during nutrition education sessions; however, few actually incorporated the dietary guidelines into family meal preparation [104].

In contrast, reports from a five-year programme to improve vitamin A status implemented by the Tanzania Food and Nutrition Centre stated that nutrition education through the media was successful [57]. However, funding was limited and active promotion at the community and household levels was not attempted [105]. Local nutrient analyses of indigenous leafy green vegetables, palm oil, and commercial baby formula were incorporated into the programme. Analyses of freshwater fish revealed no traces of contamination with pesticides and heavy metals, and the fish were found to have high levels of preformed vitamin A [106]. Future goals of the programme include expansion of the data base on nutrient values for locally analysed food items, and the introduction of improved techniques for the extraction of red palm oil. These were incorporated into programmes to increase the production and consumption of red palm oil and green leafy vegetables [105].

The promotion of a wide variety of indigenous foods resulted in increased intake of these foods, many of which are rich in preformed vitamin A and provitamin A, and improved serum retinol levels among Canadian Nuxalk women, men, and teenaged girls and boys [100, 107].

Social marketing

Current trends in nutrition communication include the use of social marketing. Social marketing techniques are used to influence the acceptability of social action and to create programmes that elicit desired behaviours [108]. Behavioural changes perceived by the community as beneficial are the target for this approach [109]. Social marketing requires the active involvement of community members and a mixture of communication strategies.

Programmes using social marketing techniques to promote vitamin A intake are being conducted by Helen Keller International in Bangladesh, Indonesia, and the Philippines. The programme in Bangladesh was preceded by an evaluation of factors creating hypovitaminosis A in the region, and the results challenged many of the assumptions found in earlier literature [7, 110]. In an informative review of causality, Rizvi [7] argues that Bangladesh does not have abundant sources of provitamin A, because fruits such as papayas and mangoes are too prohibitive in price and availability for most families. The situation is further hampered by the belief that infants cannot digest greens. It is argued that successful promotion of provitamin A sources should focus on alternative food items that are affordable for poorer sectors of the population, are widely available, and are not prohibited by dietary proscription. Underwood [95] suggested that social marketing techniques that attempt to improve the prestige of local provitamin A sources may be more effective in creating dietary change than promoting horticultural activities.

In the Indonesian project, the use of social marketing techniques through inter-personal and mass-media interaction has had mixed success to date [8]. Although success in reaching the target population through posters, radio, and health personnel was demonstrated, there was poor recall of the messages promoting the consumption of provitamin A-rich foods. However, a preliminary report indicates that consumption of greens has increased among pregnant women and children. This has also been documented in a project in the Philippines, which included a component to increase the use of oil when preparing greens [5].

Social marketing using a decentralized approach has also demonstrated success in promoting the production and intake of the vitamin A-rich ivy gourd grown in household gardens [108]. Most problems encountered within the three-year programme were resolved through cooperation at all levels. When individuals involved in the local programme requested auxiliary information on pest control, fertilizers, and construction of trellises, an expanded education component evolved from the coordination between the agricultural and health sectors of the programme. When agricultural advisers failed to control pests, a local treatment using extracts of leaves was added to the commercial solution and eradicated the infestation. All these auxiliary efforts substantially enhanced the programme's success.

Summary

1. The few programmes promoting dietary change that have been implemented and evaluated to date indicate that the potential for applying community-based research to the vitamin A deficiency problem is substantial.
2. Preliminary collection of locally relevant data on dietary intake and attitudes towards health, food, and vitamin A deficiency appears to improve the success of gardening and nutrition education programmes.
3. Social marketing is a recently introduced concept in nutrition communication that has the potential to create programmes for increasing the intake of natural foods rich in vitamin A activity that are appropriate to the local context.

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