micronutrient fortification of foods — rationale, application and impact

Micronutrient Fortification of Foods- Rationale, Application and Impact M.G. V e n k a t e s h M a n n a r a n d R. S a n k a r

The Micronutrient Initiative, 250 Albert Street, Ottawa, Canada

Abstract. Deficiencies in intake of essential vitamins and minerals (commonly referred to as micronutrients) that are essential for efficient energy metabolism and other functions of the human body (commonly termed as micronutrients) are severe and widespread in many parts of the world. They cause an immeasurable burden on individuals, on health services, education systems and families caring for children who are disabled or mentally impaired. Studies by World Bank have shown that countries whose populations suffer from micronutrient deficiencies encounter economic losses as high as 5% of gross domestic product (GDP). The solution to control and prevent micronutrient deficiencies is available and affordable. At a national level, micronutrient malnutrition can be addressed by implementing programmes designed to educate people to diversify their diets (where appropriate foods are available), or by fortifying commonly eaten foods with the missing micronutrients or providing nutrient supplements through targeted distribution programmes. Food fortification is increasingly recognized as an effective means of delivering micronutrients. Fortification of foods can provide meaningful amounts of the nutrient at normal consumption of the food vehicle. Proper choice of fortificant and processing methods could ensure the stability and bioavailability of the nutrient. The level of fortification should take into account variations in food consumption to ensure safety for those at the higher end of the scale and impact for those at the lower end. Fortification needs to be supported by adequate food regulations and labeling, quality assurance and monitoring to ensure compliance and desired impact. In industrialized countries food fortification has played a major role in the substantial reduction and elimination of a number of micronutrient deficiencies. Although a growing number of large scale fortification programmes in different parts of the world are beginning to demonstrate impact at the biochemical level and are leading to the elimination of several nutrient deficiencies, food fortification remains an underutilized opportunity in many developing countries where micronutrient malnutrition remains a public health problem. [Indian J Pediatr 2004; 71 (11) : 997-1002] Email: [email protected]

Key words : Micronutrients; Malnutrition; Food fortification

Micronutrient deficiencies are a significant cause of malnutrition and associated ill health throughout the world. This is particularly true in the developing world. Solutions to control and prevent these deficiencies are available and affordable. At national level, micronutrient malnutr i t ion can be addressed by implementing programmes designed to educate people to diversify their diets (where appropriate foods are available), or by providing nutrient supplements to vulnerable groups (in the form of tablets, capsules and syrups) through targeted distr ibution programmes (Supplementation). Additionally, commonly eaten foods can be fortified with the missing micronutrients (Food fortification).

Food fortification has become a realistic and accessible option for developing countries. Fortification of common foods with vitamins and minerals is one of the most sustainable and cost-effective strategies to deliver key micronutrients to large populations. Examples of food that can be fortified include: flour, sugar, salt, margarine, cooking oil, and sauces. In the Indian context, the public

Correspondence and Reprint requests : Mr. M.G. Venkatesh Mannar, The Micronutrient Initiative, 250 Albert Street, Ottawa, K1R 7Z1, Ontario, Canada.

distribution system (PDS), the integrated child development scheme (ICDS) and mid-day meal are some of the programmes that offer a ready opportunity to reach the micronutrient interventions to the under-privileged populations.

MAGNITUDE OF VITAMIN AND MINERAL DEFICIENCY (VMD)

Vitamin and mineral deficiencies are preventing as many as a third of the world's people from reaching their physical and mental potential. Iodine deficiency is estimated to have lowered the intellectual capacity of most developing nations by as much as 10 to 15 percentage points. 1 Iron deficiency in the 6-24 month age group is impairing the mental development of approximately 40% to 60% of the developing world's children. 2 Vitamin A deficiency is compromising the immune systems of approximately 40% of the developing world 's under-fives and leading to the deaths of approximately i million young children each year. 3 Folate deficiency is responsible for approximately 250,000 severe birth defects each year? Also, there are other deficiencies

Indian Journal of Pediatrics, Volume 71--November, 2004 997

M.G. Venkatesh Mannar and R. Sankar

that are certainly widespread but far less well recognized. Rickets in young children, associated with calcium and vitamin D deficiency is probably widespread in China and possibly elsewhere. Dietary intake surveys and limited biochemical indicators show that zinc deficiency is likely as widespread as that of iron deficiency anemia? ,6 Selenium and as well as several other micronutrients (folate, vitamin E) may have major role in reducing risks on chronic disease (e.g. cancers, heart diseases). In several parts of the world, vitamin and mineral deficiencies overlap and interact. Half of deficient children in developing countries suffer from multiple deficiencies - adding up an immeasurable burden on individuals, on health services, education systems and families caring for children who are disabled or mentally impaired.

The major cause of micronutrient deficiencies is lack of adequate intake of bioavailable minerals and vitamins from the staple diets. 7~ This is exacerbated by the fact that commonly consumed foods and beverages (such as rice, wheat, maize, legumes, tea and coffee) are high in inhibitors and low in enhancers of micronutrient absorption?

FOOD FORTIFICATION FOR ELIMINATION OF VMD

In addressing micronutrient malnutrition in a country, a combination of interventions involving the promotion of breast feeding, dietary modification (e.g., increasing food availabili ty and consumption, and improving micronutrient bioavailability), food fortification and pharmaceutical supplementat ion will need to be emphasized and implemented in a complementary manner. Among these interventions, fortification could play a significant role - obviously as one part of a range of measures that influence the quality of food that include improved agricultural practices, improved food processing and storage and consumer education to adopt good food preparation practices.

Fortification of foods is aimed to provide meaningful levels of the nutrient (usually 30% to 50% of the daily adult requirements) at normal consumption of the food vehicle. The levels also need to take into account variations in food consumption so that the safety of those at the higher end of the scale and impact for those at the lower end are ensured. They should also consider prorated intakes by young children to ensure efficacious and safe dosages?

The First step for food fortification involves the identification of commonly eaten foods in a country or region that can act as vehicles for one or more micronutrients and lend themselves to centralized processing on an economical scale. Fortification when imposed on existing food patterns may not necessitate changes in the dietary habits and practices of the population and does not call for individual compliance. It could often be dovetailed into existing food production and distribution systems.

In a country where a universally consumed vehicle is not available, fortification of a multiple number of foods offers several key strategic advantages. When multiple foods are fortified, each with less than the RDI per single serving, the possibility of consuming excessive levels of a micronutrient through consumption of a single food becomes more remote.

The concept of nutrient fortification of staple foods was developed in the early part of the last century as a means of dealing with micronutrient and vitamin deficiency diseases that were prevalent in Europe and North America. Salt was iodized in Switzerland 11,12 and in the United States, 13 in the early part of the century. Margarine fortified with vitamin A was introduced in Denmark in 1918.14 During the 30s and 40s milk was fortified with vitamin A 15 and flour was fortified with iron and B vitamins in a number of European countries and in North America. 16

In the developing world, there has been a rapid growth in fortifying a wide range of foods and food fortification has become a more realistic and accessible option in many of these countries. The most successful global fortification experience is the fortification of salt with iodine. Fortification of other staple foods such as flour, oils, sugar, condiments, dairy products and a range of processed foods with other minerals and vitamins are also growing. In Latin America flour fortification is covering significant numbers of people and sugar fortification has taken hold in Central America. There is growing interest and action on food fortification in South and South East Asia. In Africa the fortification of wheat and maize flours with multiple nutrients has been made mandatory in South Africa and Nigeria.

SELECTION OF FOOD VEHICLES

The selection of a suitable vehicle and the micronutrient(s) (fortificant) in the right amounts to meet the need for entire population is extremely rare. Salt iodization is one example of successful large-scale fortification in the developing world--the primary reason being the simple and low-cost technology and the narrow band of salt consumption quantities within a given region or population. There exist several other opportunities for single and multiple fortification of several commonly eaten foods such as wheat and wheat products, corn, rice, milk and milk products, cooking oils, salt, sugar and condiments at the time of proceeding. As processed foods gain populari ty in the developing world, with an increasing market outreach, they offer new channels for micronutrient delivery.

Potential food vehicles could be visualised as a three- tiered pyramid as shown in Fig. 1. Staple foods such as cereals and grains, sugar, fats and oils form the base; basic foods such as breads and biscuits, packaged cereals and flours, and dairy products are in the middle; and value- added foods such as condiments, snacks, candies,

998 Indian Journal of Pediatrics, Volume 71--November, 2004

Micronutrient Fortification of F o o d s - Rationale, Application and Impact

V A L ~ O O D S e.g.)=on=,,,~, s, ?e,Rr=~... s

/ / .s,c ooos \ e.g. breeds, biscuits, ~ k ~

STAPLE FOODS e.g. whole grain & milled cereals,

oils & fats, sug~, salt

Fig. 1. Food Product Pyramid

convenience and ready-to-eat foods are at the top. Fortifying less expensive staple foods at the base of the pyramid results in broader dissemination of micronutrients throughout the population, particularly the poor. Also, since basic and value-added foods are processed from staple commodities, fortifying foods at the base of the pyramid results in fortifying products throughout the food chain.

In many countries a flexible approach utilizing a variety of vehicles each fortified to a specified proportion of RDI may offer an effective option. If consumption of a particular vehicle is consistent in some groups but only sporadic in others, fortifying several vehicles will likely provide complementary coverage. For example, in the Philippines a variety of vehicles including margarine, flour, noodles and sugar will offer protection from micronutr ient deficiencies for specific consumer segments. In Nigeria three foods are being fortified with vitamin A since 2003 (wheat flour, cooking oils and sugar). When considering a multifaceted approach, each food vehicle offers specific opportunities and constraints.

Cereals: Inexpensive staples such as rice, corn and wheat flour have the potential to reach large population. However, these foods are often eaten where they are grown and processed at the community level. This limits opportunities for fortification but also increases quality and safety challenges. Notwiths tanding this the fortification of whole grain cereals remains an intriguing and challenging possibility.

Fat and Oils: Cooking fats and oils may offer an option to deliver a portion of the RDA, of fat soluble vitamins such as vitamin A. They have an advantage in that they are often centrally refined and packed

Dairy Products: In areas where milk is processed in dairies and this may offer an option for fortification. Cost, distribution and other factors may limit accessibility among vulnerable populations in rural areas.

Condiments: Sugar, spices, starches and sauces are attractive carriers. Some are processed centrally and consumed in regular quantities and offer great potential.

Value -added Produc t s : The most vulnerable populations consume these higher priced products only sporadically. However, consumer awareness, technical

breakthroughs and marketing innovations often emerge from the development of fortified value-added products.

FORTIFICATION OF COMPLEMENTARY FOODS

Infants and children under the age of 24 months consume a different dietary pattern than the older individuals do. There are no major differences in consumption among children aged two years and older. Industrially produced fortified complementary foods are recommended by pediatricians worldwide as an essential part of a nutritionally adequate infant diet (beyond the age of 6 months) and as complementary to breast milk and home- prepared foods. This is essential in order to meet the micronutrient requirements of infants, especially for iron and zinc. Beyond the superior micronutrient content of industrially fortified complementary foods over home- prepared rice porridge and other traditional infant foods, they have also the advantages of delivering micronutrients of higher bioavailability, higher energy density and protein quality, not to mention the safety and convenience.

Where there are few centrally processed complementary foods and consumption of such foods is infrequent and rare, careful research is needed on the best ways to address micronutrient problems of infants. Where centralized fortification of complementary foods is not feasible alternative mechanisms are available to deliver micronutrient mixes in daily-dose sachets known as sprinkles. During infancy iron absorption from Sprinkles in a maize-based porridge met and surpassed iron needs for absorbed iron; and iron absorption is up- regulated in infants with iron deficiency anaemia. 1~

TARGETED FORTIFICATION THROUGH SUPERVISED PUBLIC PROGRAMMES

Fortification of foods that are targeted to vulnerable and low-income groups needs high priority. There are several opportunities in India, if taken advantage of and applied could make a vast difference to millions of people suffering from micronutrient deficiencies. This will be in line with the government's stated position that they aim not only at 'food security', but 'nutrition security'. This being pursued through the fortification of foods supplied through the Public Distribution System (PDS), Midday Meals Progammes in schools or through the Integrated Child Development Scheme (ICDS).

PDS with its coverage of nearly 330 million people through its network of 4.76 lakh fair price shops is probably the only way to reach this huge but needy population, e.g., atta flour fortified with iron and folic acid, edible oils or sugar fortified with vitamin A, iodized or double fortified salt. Several states in India already supplied iodised salt through PDS and fair price shops. There are states like Chhattisgarh and Gujarat that have provided significant subsidy to make available quality iodised salt at a much lower price than in the market for the population below poverty line.



ICDS can ensure that all food provided to children and to mothers in the programme is micronutrient-enriched. There is already considerable experience in supply of fortified food through the World Food Programme (WFP) and CARE. WFP has also supported the establishment of plants to produce blended foods that contain all essential micronutrients. Several States including Andhra Pradesh and Gujarat provide fortified ready-to-eat food from local p roce s s ing uni ts . A recen t s t u d y by MI in Gujara t revealed a significantly improved micronutrient status in blocks where children received fortified blended foods (unpublished report). Standards for these fortified foods need to be set to ensure that they contain 100% RDI of essential micronutrients . At a min imum special effort should be made to use fortified staple foods (flour, oil, sugar and salt) once they are available, in the food cooked at Anganwadi centers . W h e r e v e r cooked meals are p rov ide d th rough schools oppor tuni t ies exist to use fortified foods.

EFFECTIVENESS OF FOOD FORTIFICATION

Food fo r t i f i ca t ion has been an ef fec t ive nu t r i t i o n intervention used for over eight decades in industrialized countr ies and several s tudies have demons t ra ted its effectiveness in eliminating micronutrient deficiencies. The current low levels of iron deficiency in the USA are a t t r ibutable to for t i f ied sources. Almost 1 /4 of i ron intakes in the US diet come from fortified sources, much of that from flour products. 17, is Studies from the US show that women of reproductive age who consume fortified cereals get 40% of their total iron intakes f rom these foods. 19 In Denmark, Finland and Sweden 10 to 20 % of the iron consumed comes from fortified cereals. 19

In Canada, flour fortification with B vitamins began in Newfoundland in 1944. Within four years, deficiencies that were earlier found in nearly 20~ of the population had dropped to negligible levels. More recently folic acid fortification of flour increases maternal consumption of folic acid and has been shown to decrease the number of children born with birth defects in the USA and Canada by 19% and 48% respectively. 2~ 21 Over the last 50 years

i 27 26

I, |

40

1965 1977 1987 1995 1967 1996 1966 1988 1998 G U A T E M A L A H O N D U R A S EL S A L V A D O R

First Period Second Per iod (Effectiveness) (Effectiveness) (EI~c~cy) (Effectiveness)

iBefore fortification RAfter fortification iP lus supplementation U Source: Nutritional National Surveys

SA-SL-99-07

Fig. 2. Vitamin A status of Preschoolers) plasma retinol < 20 ~tg/dL)

food fortification has played a major role in the health of the populations at large in the developed countries and several nutritional deficiencies have been eliminated. In addition to the virtual elimination of VAD and IDD and the substantial reduction of IDA, diseases as varied as xerophthalmia, pellagra, beriberi, rickets, goitre and ariboflavinosis have essentially disappeared.

In the last decade considerable progress has been made in improving the availability and accessibility of quality iodised salt to the population across the world and this has contributed towards substantial reduction in IDD. In most nations where IDD was recognized as a public heal th p rob lem at the beg inn ing of this decade , an average of 60-70% of all salt is now iodized. Bolivia and Ecuador have been officially certified IDD-free. In African nations like Nigeria, Madagascar and Eritrea more than 80% of current production is iodized. In China nearly 89% of the salt at consumer level contains iodine within the specified range. In 27 out of 31 provinces 90% of the population has urinary iodine excretion rates above the cut-off value. Between 1995 and 1999 the total goiter rate in children 6-12 years has reduced from 20.4 % to 8.8%. Wor ldwide , an es t imated 12 mill ion cases of mental retardation have been prevented. In Asia cretinism has been cut in half. The stage is set for the elimination of Iodine Deficiency Disorders by the end of this decade. 22

Food fort if icat ion has also p layed a major role in substantially reducing vitamin A and iron deficiencies. In many Central and South American countries, in addition to the iodization of salt, wheat flour is fortified with iron, folic acid, n iacin and th iamine . A na t iona l sugar fortification in Guatemala for more than 10 years has virtually eliminated VAD as a public health problem. 23,24 Flour for t i f ica t ion in Chile and Venezue la are substantially improving iron status across all sectors of the population. 2s

In Venezuela in order to address the deter iorat ing nutritional status of the Venezuelan population following an economic crisis, the G o v e r n m e n t ins t i tu ted a manda tory programme of iron fortification in 1993 to enrich precooked corn flour with 50 m g / k g of iron as fe r rous fumara te , v i t amin A, th iamine , n iacin and riboflavin. Eight months later, fortification of wheat flour was started voluntar i ly including the same nutr ients except v i t amin A. The op t imal i ron for t i f icant was d e t e r m i n e d to be a mix of f e r rous fumara t e and electrolytic iron. Monitoring surveys in Caracas in school children of 7-15 years, showed that the prevalence of iron deficiency measured by serum ferritin concentration, dropped from 37% in 1992, to 16% in 1994, only one year af ter the i ron for t i f ica t ion p r o g r a m m e was started. P reva lence of anemia , m e a s u r e d by h e m o g l o b i n concentration, diminished from 19% to 10% In the same period, z~ Results from three other surveys carried out in 1997, 1998and 1999 on the same age and socio-economic groups that had been evaluated in 1990, 1992 and 1994, showed that after a dramatic reduct ion in 1994, there


Micronutrient Fortification of Foods - Rationale, Application and Impact

were no further reductions in either biochemical indicator. It is possible that viral infections, reduction in corn flour consumption along with an increase in wheat flour intake (with no vitamin A fortification), continuous deterioration on life quality and the change of iron compound, could be responsible for the return of anemia prevalence to the baseline values found in 1992. Finally, in spite of the fact that conditions in the country continue deteriorating, it may be concluded that this fortification programme has improved and maintained iron stores.

In Costa Rica after the addition of folic acid to flour the incidence of neural tube defects fell from a mean rate of 9.7/1000 live births in the period 1996-98 to 6.3/1000 live bir ths in the per iod 1999-2000. A nat ional survey of Guatemala in 1965 found 27% of children deficient in vitamin A. Sugar fortification was launched in 1974. In 1977, only 9% of children suffered low levels of vitamin A in their blood. Unfortunately, due to a number of reasons fortification stopped. VAD reappeared and by 1987, a general s tudy found a situation similar to that of 1965. Sugar fortification was reactivated in 1987 and by 1995, a national survey determined that the vitamin A deficiency was no longer a public health problem with less than 16% of children having low levels of serum retinol. Recently, mor e d rama t i c resul ts of sugar for t i f ica t ion were demonstrated in two other Central American countries. 26 In Honduras, children with low levels of vitamin A fell from 40% in 1967 to 13% in 1996. In E1 Salvador, 44% rate of VAD in 1966 d r o p p e d to less than 10% in 1998. However , in the latter case, the success could also be attributable to the combined effect of supplementation. Today in Latin America, Asia and Africa consumers of fortified products as varied as margarine, milk, noodles and corn starch are substantially protected from a range of micronutrient deficiencies.

In China soy sauce was selected as the food carrier, because about 70% of Chinese population consumes it on a regular basis. Sodium Iron EDTA (NaFeEDTA) was se lected as the i ron c o m p o u n d , because of its h igh bioavailability for people consuming plant food based diet. (The average rate of iron absorption of NaFeEDTA and FeSO4 in soy sauce in adult Chinese females was found to be 10.5% and 4.7%, respectively.) Soy sauce conta in ing 5 or 20 mg Fe, as NaFeEDTA was highly effective in the t reatment of anemic children within 3 months. A double blind controlled efficacy trial covered about 10,000 subjects in a high risk population with about 30% prevalence of anemia was started in September, 2000, using NaFeEDTA fortified soy sauce (4 mg/adul t /day) . The increase of blood hemoglobin level and reduction of anemia prevalence rate in all age groups in the intervened group after 6 months trial were highly significant, while no obvious change was observed in the control group. The trial will cont inue for 2 years. In add i t ion to b lood hemoglobin level, other variables measured in the study include: blood hematocrit, ferritin, Zn protoporphyrin and retinol; anthropometry; and food consumption (using

FFQ). The next step is to provide advice to the national regulatory authorit ies to promulgate regulations and s tandards for the control of NaFeEDTA fortified soy sauce, and also work with national soy sauce association to deve lop mechanisms of g radua l ly expand ing the production of NaFeEDTA fortified soy sauce. 27

CONCLUSION

Food for t i f ica t ion s tands out am o n g publ ic hea l th interventions as one of the most effective methods of preventing nutritional deficiencies. Food fortification has contr ibuted significantly to the virtual elimination of goiter, rickets, beriberi and pellagra in the Western world. Unfor tuna te ly , this appropr ia te t echnology remains gross ly u n d e r u t i l i z e d in the d e v e l o p i n g wor ld . Exper ience with salt iodiza t ion has shown that it is eminently possible to implement and sustain successful fortification programmes in developing countries.

Research and deve lopment efforts have enhanced effectiveness of fortification technology. Better refining procedures and packaging have significantly improved the stability of iodine compounds in salt. In the case of iron, stabilizers and absorpt ion enhancers are added along with the fortificant to retain it in an absorbable form or improve absorption. The structure of the iron or iron compounds has been modified to improve absorption. In the case of Vitamin A, work is ongoing to retard the loss of potency on storage through addition of anti-oxidants and other stabilizers 28. In all these cases there is scope for fu r the r i m p r o v e m e n t and r e f inemen t for be t te r p r o d u c t s tabi l i ty , abso rp t ion and lower cost and development efforts need to continue.

Food fortification campaigns in developing countries r equ i re careful p lann ing , p r o g r a m m i n g and communication. Strong development of a local food - processing industry, the commitment and support of local g o v e r n m e n t s t h r o u g h effect ive legis la t ion and monitoring, and a consumer culture that perceives gains from investing nominal amounts for personal health are key factors in the long- te rm success of for t i f icat ion programmes.

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micronutrient fortification of foods — rationale, application and impact

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