5. Special needs of vulnerable groups
Certain vulnerable groups in the population have special nutritional needs. Measures to _ ensure adequate micronutrient availability and consumption by the population as a whole may be insufficient to meet the needs of these vulnerable groups. In some countries, the difficulty of meeting the needs of vulnerable groups through nutrient supplementation or dietary means may provide one of the strongest arguments for food fortification.
Because body stores of micronutrients are built up over time, the best strategy to assure healthy micronutrient status in pregnant and lactating women is to ensure adequate nutrient intake both before and during the reproductive period. Body stores of micronutrients may also be built up during feasts and seasons of abundant food supply.
In most cases, food-based approaches are the most appropriate means of ensuring adequate vitamin A intake by pregnant and lactating women. High-dose vitamin A supplementation is inappropriate if there is a possibility that a woman may be pregnant; high levels of retinol may be toxic to the foetus. Normal dietary levels of retinol and provitamin A are generally considered safe.
Assessment should determine the existence of food restrictions which may affect the micronutrient status of pregnant and lactating women. Consideration should be given to using communication strategies to change beliefs that may restrict dietary micronutrient intake. For example, messages may focus on increasing consumption of leafy vegetables, eating vitamin C-rich fruit after meals to enhance iron absorption and delaying the drinking of tea or coffee for a few hours after meals to avoid inhibiting iron absorption.
In most countries, the distribution of iron-folate tablets to pregnant women is good public health policy. When they receive the tablets, women should be advised about locally available, inexpensive food sources of these nutrients and about foods that enhance and inhibit iron absorption. These messages should be simple and location-specific.
Breast milk is an excellent source of vitamin A for all infants. If the vitamin A status of the infant's mother is healthy, breast milk is an adequate sole source of this nutrient for the first 6 months of life. Breast milk also contains iodine and thyroid hormones. However, if the mother is severely deficient in iodine, the infant will not receive an adequate supply of this nutrient through breastfeeding.
Colostrum, which is high in vitamin A, can make an important contribution to the infant's stores of this nutrient. In some countries, however, people believe that colostrum is harmful and throw it away. Recent experience suggests it is possible to counteract this belief in some countries. The Worldview International Foundation Comprehensive Nutrition and Blindness Prevention Programme in Bangladesh is a successful example of the strategy of encouraging women to initiate Breastfeeding earlier and to feed their children colostrum. (See Appendix 1 for contact information.)
Full-term babies have iron stores at birth; breast milk provides adequate iron until about 6 months, the age by which UNICEF and WHO recommend adding solid foods to the diet (UNICEF/WHO 1995). Breastfeeding helps to prevent diarrhoea and dehydration and provides useful levels of micronutrients to sick children. In children aged 6 months to 2 years, even small amounts of breast milk can be important.
Intensive Breastfeeding causes lactational amenorrhoea (a delay in the return of menstruation), which is beneficial to women with above-average menstrual blood loss, who are at greater risk for iron deficiency. Lactational amenorrhoea conserves iron stores for these women even after iron secreted into breast milk is deducted (Greiner 1991) and delays additional pregnancies. Though often lasting for about a year, lactational amenorrhoea for up to 18 months has been reported in some studies (Huffman et al. 1987).
It is well recognized that infant health is endangered when bottle feeding is practiced by those who cannot afford to buy adequate quantities of formula or who are unable to prepare it hygienically. Less well known, however. is the fact that most infants in poor regions are bottle-fed with improperly fortified formula or with milk powders and other fluids that lack key micronutrients. In most developing countries, women often breastfeed and bottle-feed their infants simultaneously. When Breastfeeding stops, vitamin A deficiency can very quickly cause blindness. Such cases have been recorded in Thailand, Brazil and India, where blindness has been seen to occur at 2-3 months of age (Underwood 1993).
Voluntary groups such as La Leche League International offer advice to women on breastfeeding. The World Alliance for Breastfeeding Action sponsors World Breastfeeding week each August to raise community awareness. The UNICEF BabyFriendly Hospital Initiative strives to improve hospital practices related to Breastfeeding at delivery. WHO and UNICEF offer training courses for health workers to effectively promote and sup port breastfeeding. (See Appendix 1 for contact information on these organizations.) Communication strategies have been devised to encourage breastfeeding (Green 1989). WHO has also designed indicators for assessing breastfeeding practices both in household surveys (WHO 1991) and in maternity facilities (WHO 1992a).
Around 6 months, most children require complementary foods to meet their energy and nutrient needs. Children's growth may begin to falter at about 6 months if they are not given complementary foods, if the foods are offered too rarely or if they are too bulky or diluted to meet nutrient needs. Instead of complementing breast milk, some mothers may replace it with foods that are low in micronutrients and/or too bulky. At six months, an infant's condition may already be weakened as a result of having been fed diluted or contaminated complementary foods during the early months of life.
Micronutrient deficiencies become increasingly likely as the amount of breast milk in the child's diet declines. Breast milk may be the only source of retinol in the child's diet; it is also a good source of fat, which is necessary for the absorption of beta-carotene. Some of the most serious deficiency states, particularly for vitamin A and iron, can occur in children between the ages of 6 months and 5 years. Childhood diseases and parasitism also contribute to micronutrient malnutrition in young children. Barriers to achieving adequate iron and vitamin A nutrition include lack of awareness of the high nutritional needs of pre-school-age children and a reduction in maternal attention to an older child when a new baby is born.
Animal milk provides excellent nutritional supplementation for young children. However, its excessive use can contribute to iron deficiency because it is low in iron and high in calcium. The latter can inhibit absorption of iron from other dietary sources. Before about 9 months of age, fresh cow's milk can cause occult intestinal blood loss. Ideally, animal milk should be given between meals. When animal milk is included in the diets of young children, extra attention should be paid to hygienic practices.
For poor families in many regions, green leafy vegetables are the major potential source of micronutrients. Yet many commonly eaten green leaves are too fibrous or bitter for young children to eat. Recent programmes in South Asia and elsewhere have successfully promoted consumption of green leaves among young children by encouraging mothers to choose soft, non-fibrous leaves that are not bitter and to boil, mash and strain the leaves and mix them with well-liked foods such as groundnut sauce and grated coconut (Greiner and Mitra 1995).
The ideal complement to breast milk is a diet which combines the local staple food with other locally produced foods, including vegetables, fruits, legumes, meat, fish, oils and fats (Gibbons and Griffiths 1984). Continued efforts are needed to devise effective programmes to assist mothers in providing complementary foods of adequate quantity, quality and safety. Education may be needed to remind mothers to feed these foods even when the child is sick or has a poor appetite. Techniques such as fermentation can be used to improve complementary foods to increase energy density and micronutrient content. Small amounts of green leaves and other micronutrient-rich foods can be added to porridge. Age-appropriate snack foods can increase meal frequency with minimal preparation time.
In Tanzania, programmes were focused on the production and promotion of foods well liked by children such as fruits, pumpkins and sweet potatoes in addition to dark green leafy vegetables. Guava is considered a children's food in Tanzania, thereby reducing adult competition for available food (TFNC 1991). In countries where mangoes grow, fibrous types of mango can be promoted. Since they have little market value, they are more likely to be left to children to eat.
It may be useful to incorporate messages about complementary foods into micronutrient communication programmes. Practical advice on complementary feeding of young children in developing countries is available from UNICEF and WHO. (See Appendix 1 for contact information.)
The special needs of young children present opportunities for food fortification. In Chile, a rice-based weaning cereal was fortified with iron. In China, tests have shown that rusks or teething biscuits fortified with iron improved children's iron status. It may be possible to fortify certain snack foods that are popular among children.
In some countries, a teaspoon of red palm oil a day or a tablespoon of leafprotein concentrate at each meal could improve both iron and vitamin A status. Previously in some industrialized countries, some micronutrient deficiencies were prevented largely by educating all mothers to give young children daily doses of tonics and mixtures such as cod or halibut liver oil.
Schoolchildren may be at increased risk of micronutrient deficiencies owing to increased energy expenditure combined with decreased meal frequency, reduced maternal attention, and parasitic infections. The severity of parasitic infections such as hookworm and schistosoma is highest in this age group.
Opportunities to target micronutrient programmes at school-age children have increased as developing countries move towards providing universal primary education. School feeding programmes can contribute to preventing micronutrient malnutrition among children. School gardens can provide micronutrient-rich foods. (See Section 2.1.2.)
Improving the micronutrient status of children will improve the costeffectiveness of investments in education. In most poor regions, a modest investment in the nutrition and health of schoolchildren will increase children's ability to learn more than will a comparable investment in teacher training, textbooks or improve meets to school facilities (Jamison and Leslie 1990). The efficacy of adding small amounts of low-cost, high-carotene foods to the diets of school-age children has been demonstrated (Wadhwa et al. 1994).
School curricula can be effectively used to communicate messages about nutrition. However, changing curricula requires time and careful planning. Including education sector representatives on micronutrient deficiency control planning committees can facilitate curriculum revisions and promote advocacy. (See Section 2.1.2, Schoolbased gardening programmes.)
Micronutrient deficiencies are common among refugees and famine-affected populations, who may not have access to a diet that is sufficient in either quality or quantity to provide adequate levels of micronutrients. Refugees and displaced persons may also lack protection from infections that increase nutrient requirements and impair absorption. Deficiencies of vitamin A, vitamin C (scurvy), thiamine (beriberi) and niacin (pellagra) have been documented in emergency situations where diet quality is poor (Toole 1992).
Micronutrient deficiencies may be avoided by encouraging refugees and displaced persons to trade donated foods and other supplies for fresh produce in local markets. Fortification of food aid commodities can increase intake of selected nutrients and is particularly important in prolonged feeding situations. (See Exhibit 5.1.)
Exhibit 5.1. Fortification of Food Aid to Prevent Micronutrient Deficiencies Among Refugees and Persons
Micronutrient deficiency problems are especially likely to occur in prolonged refugee feeding situations. Providing micronutrient-rich, locally available food is often not feasible in emergencies. Food aid provided by donors, which often consists of a limited variety of staple foods that can withstand long storage, may be the only food available.
The World Food Programme (WFP) is working with donor countries to improve the Micronutrient content of emergency food aid through fortification. WFP distributes iodised salt, vitamin A-fortified dried skimmed milk, edible oils and flours and blended foods fortified with a variety of vitamins and minerals.
The Opportunities for Micronutrient Interventions (OMNI) project recently completed a review of Micronutrient fortification and enrichment practices for U.S. emergency food aid that is provided through the Public Law 480 Title 2 program (OMNI 1994). The review offers recommendations for improvement of these practices.
Sometimes food aid reaches its destination or is distributed after long periods of transportation or storage in inadequate facilities. As a result, the level of micronutrients in the food may have greatly declined by the time the food is consumed. Food donors and organizations such as the World Food Programme, the United Nations High Commission for Refugees and other relief agencies are aware of these problems. Methods to improve Micronutrient content in the diets of refugees and displaced persons are being examined (Harrell-Bond et al. 1989, Henry and Seaman 1992). In long-term ("protracted") refugee situations, camps should arrange, whenever possible, for space for horticultural (fruits and vegetables) and small animal production. Such production will reduce refugee dependence on external donations.