Micronutrient malnutrition, also known as hidden hunger, reduces learning and cognitive ability, impairs growth, reduces immunity, decreases working capacity, causes several pregnancy complications, blindness, goitre, and raises the risk of mortality.
The populations most at risk of such deficiencies are infants and children, women of reproductive age, pregnant women, and the elderly. Lack of dietary diversity (monotonous diets), poor mineral bioavailability in plant foods, incidence of illness and disease, and increased physiological demands are the main contributors to micronutrient deficiencies.
Of global concern are deficiencies in iron, vitamin A, zinc, folate, and iodine. The World Health Organization (WHO) reported that over two billion people are at risk of vitamin A, iodine, and/or iron deficiency, with the most severe problems found in developing countries.
Short-, intermediate-, and long-term sustainable solutions that are based on scientific evidence of both efficacy and effectiveness must be pursued to alleviate micronutrient malnutrition in developing countries. Although several approaches are practiced to address micronutrient malnutrition, micronutrient deficiencies remain a global challenge, which suggests that gaps remain to be filled at both research and public health levels.
The most conventional and widely practiced strategies used to address micronutrient malnutrition are supplementation and food fortification. These strategies do not, however, address the primary cause of poor micronutrient status—inadequate dietary intake because of food insecurity—and may not be the most acceptable, accessible, or appropriate strategies for rural and/or ultra- poor households.
Complementary strategies are needed in these contexts that support culturally appropriate dietary modification and community- and agriculture-based interventions, with simultaneous efforts to improve capacity and reach of supplementation and fortification.
Nicholas Noyes, New York, US
Provision of large doses of micronutrients in highly absorbable form normally provides the fastest amelioration of the micronutrient status of individuals or targeted populations. Examples of such provisions include supplementation programs targeting anaemia through iron supplementation; folic acid supplementation in pregnant women; and vitamin A supplementation in children younger than five years.
Analysis of available supplementation programs show that provision of micronutrient supplementation is most effective when combined with other maternal and child health interventions through primary health care systems or health care delivery systems.
Vitamin A Supplementation
Integrated approaches are not only more effective, but also cheaper than stand-alone supplementation programs. In Bangladesh, children aged 9–11 months receive vitamin A capsules at the time of measles vaccination, and children aged 12–59 months receive a massive-dose capsule every six months. In 2007, 88 percent of children had received a vitamin A capsule during the last six months, but the coverage of postpartum vitamin A supplementation to mothers was only 20 percent.
In Nepal, vitamin A supplements are provided through community health workers, who also provide nutrition education, contraceptives, oral rehydration solution, and information on health and family planning (80–90 percent coverage is achieved in areas where the community health worker program is running).
According to the 2005–2006 National Family Health Survey in India, only 20.2 percent of children had received a vitamin A capsule in the previous six months. In an attempt to improve coverage, the Bihar State in India successfully introduced community health workers to increase the coverage of vitamin A supplementation beyond the levels achieved through routine contact with the health system.
This was made possible through the political decisions to assign human and program resources. According to UNICEF, vitamin A supplementation coverage rates have shown dramatic increases over the past few years, and in 2008, 71 percent of 6-59 months old children in developing countries had received two doses of vitamin A.
The delivery system is the major cost of vitamin A supplementation programs, not the supplement itself.
Supplementation is the fastest way to control micronutrient deficiencies in individuals or population groups. It is, however, a temporary solution and does not address the underlying cause of nutrient deficiency. To achieve population impact and be most cost effective, micronutrient supplements should be distributed through the primary health care system.
Major barriers to effective iron supplementation programs are inadequate counselling and distribution, difficulty of access, and poor utilisation of health care services.
Food fortification is potentially an effective strategy to address micronutrient malnutrition. In some cases, fortification is targeted toward foods that are eaten by specific population groups.
In school children, for example, studies have showed beneficial effects of MMN-fortified foods (beverages, milk products, biscuits, seasoning powder) on child growth and cognitive domains related to memory and reduced morbidity from diarrhoea and respiratory infections.
With mass fortification at a national level, the focus is on foods that are widely consumed in constant and sufficient amounts by the majority of the target population.
Examples of fortified foods in developing countries are salt (with iodine) and wheat or maize flour (with several micronutrients). Iodisation of salt has been shown to significantly decrease the incidence of hypothyroidism, while folic acid-fortified flour has been shown to significantly reduce neural-tube defects and other congenital abnormalities.
Traditional condiments and seasonings (such as soy and fish sauces or curry powder) have been proposed as fortification vehicles, mainly in countries where they are widely consumed. In Vietnamese women, for example, consumption of fortified fish oil was shown to improve iron status and reduce the prevalence of anaemia.
Programs using iodised salt to prevent iodine deficiency are recognised as a major global public- health success. In 2011, an excessive intake of iodine was observed in 11 countries, highlighting the importance of regular monitoring of iodine status to detect both low and excessive intake of iodine.
Challenges in salt iodisation programs are, reaching economically disadvantaged groups living in remote areas, and convincing the food industry and small-scale producers to iodise their salt.
The choice of fortification vehicle affects the impact of food fortification on iron outcome indicators. The selection of a vehicle food for a fortification program requires consideration of the matrix of the food, as this could affect the fortificant bioavailability, the dietary habits of the target population and the cost of the intervention.
The vehicle food must be commonly consumed in constant, but sufficient amounts by a large proportion of the target population, accessible and available, considered feasible for the addition of bioavailable fortificants, and be produced in a few centralised sites.
Mass fortification of staple foods is generally designed for the adult population, which is expected to consume a larger amount of flour-processed products than children. Because infants and small children consume relatively small amounts of food, mass flour fortification has little impact in this age group.
The importance of the vehicle food is further illustrated in data from Guatemala, which showed that the consumption of fortified wheat flour was about 15 times higher among non-poor than among extremely poor families because rural indigenous populations in the highlands tend to consume corn rather than wheat.
The vehicle food may also affect the cost of the fortification. For example, a vitamin A compound needed for fortification of dry matrices (such as flour) is at least four times more expensive than the oily forms. Data from Uganda suggest that fortifying vegetable oil with vitamin A is 4.6 times more cost effective than fortifying sugar with vitamin A.
Fortification costs constitute approximately 80 percent of total fortification program cost. Successful food fortification programs require high bioavailability of micronutrient compounds to be used in fortified products.
Furthermore, the fortificant must be stable, e a long shelf life, and should not alter the colour, taste or appearance of the food. For nutrients such as iron, bioavailability in fortified foods is of critical importance. The iron compound used for fortification may, in fact, affect the iron outcome indicators.
In Brazil, for example, mandatory flour fortification was shown to be ineffective in reducing the prevalence of anaemia in children, probably because of the low bioavailability of the fortificant used.
Barriers for a positive impact of fortification programs were the use of non-recommended, low-cost, low-bioavailability fortificants, low fortification levels and low coverage.
Effective fortification programs usually require legislation that mandates the private sector to comply with the fortification guidelines. Governments play a critical role in quality assurance, monitoring, and enforcement of fortification regulations.
camknows, Washington, US
Home (point of use) fortification represents a novel and innovative approach for fortifying foods at the household level using three types of food supplements: 1) foodlets, which are crushable or water-soluble micronutrient tablets; 2) sprinkles, which are single-dose packets containing multiple vitamins and minerals in powder form (MNP) that can be sprinkled onto any semisolid food; and 3) lipid-based nutrient supplements, which are micronutrient-fortified lipid-based spreads/pastes providing energy, protein, and essential fatty acids in addition to vitamins and minerals.
A foodlet providing daily multiple micronutrients was shown to be efficacious for controlling anaemia and iron deficiency. Micronutrient powders/sprinkles were also shown to be efficacious in reducing anaemia and iron deficiency in infants and children under two, and seem to be as efficacious as the commonly used daily iron supplementation. Home-fortified complementary foods did not, however, exert any benefit on child growth and were associated with increased incidence of diarrhoea.
Products used for home fortification are usually unfamiliar to the target population. Before large-scale implementation, assessing acceptance of these products within a given sociocultural context and gathering of information on the type of information that needs to be provided to improve adherence is important, as this may improve compliance.
Thorough training of staff, social marketing, community mobilisation, continued monitoring, and prompt management of adverse events are important. Although the risk of toxicity because of excessive intake is low, packing the product in single-dose sachets, rather than larger containers, could be beneficial. Labelling is important to ensure correct use by the target population.
Scaling up requires a reliable high-quality supply of the product and sustainable distribution systems that are able to reach the most vulnerable populations. Data from a pilot study in India showed that it is feasible to distribute sprinkles through an existing program.
For market-based community distribution, continued promotion and monitoring are essential. Home fortification strategies use home-prepared food as a vehicle; it is therefore important to cover topics on hygienic preparation of complementary foods and hand washing in the behavioural and communication campaigns that promote appropriate use of MNP.
In general, it is strongly recommended to use food- based approaches in conjunction with public health interventions such as promotion and support of breastfeeding, control of infectious and parasitic diseases, education, and sanitation.
In summary, food fortification can reach a large sector of the population through existing food delivery systems, but the impact will depend on the fortification vehicle and the fortificant used.
Home fortification is an innovative approach, but further investigation is required to evaluate its impact on health outcomes, as well as the way to deliver this intervention effectively in public health programs.
Food fortification programs continue to face structural hurdles, as they require political support and long-term commercial commitment. Fortification strategies further require appropriate technical capacity, social marketing, community mobilisation, private- sector awareness, partnerships, coordination, and continued monitoring.