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Food fortification - the debate continues
Jack Bagriansky, France Bégin, Venkatesh Mannar, Peter Ranum
The Micronutrient Initiative, Canada
This article is in response to an earlier article at Science in Africa by Gary
Klugman on "Addressing Malnutrition in
South Africa" Science in Africa January 2002. Below, authors from the
Micronutrient Initiative in Canada address some issues raised in that article. The
debate on food fortification continues.
A Tragedy of Food Quality not just Food Quantity
Mr. Klugman says "Food, or the lack of it, is one of the factors
affecting the nutritional status of children in South Africa." While this
is correct, the alarming nutritional status of South African children is not
only due to the inadequate quantity of food but also deficient nutritional
density or quality. Many South African children, particularly the poor, rely
almost exclusively on maize porridge for their nutrition. The National Food
Consumption Survey (NFCS) indicates a median consumption of 500 g/day porridge
for children aged 7-9 year old and 410 g/day for those aged 1-3 year old. The
proposed fortification program focuses on improving the nutritional quality of
this vehicle by increasing the vitamin and mineral intake from maize porridge by
150-340% depending on amount consumed.
Fortification Restores the Vitamins and Minerals Lost in Processing
With few other foods supplying essential vitamins and minerals, young
children are disproportionately dependent on maize. Processed maize, while
providing much of the original calories and protein of the whole grain, delivers
only a fraction of the original nutrients. For example, de-germed maize offers
about 1/3rd of the iron or thiamin or about ¼ of the riboflavin or niacin found
in the original grain. Fortification generally restores the original nutrient
levels, and in some cases increases them. Fortification could also introduce
additional nutrients not present in the original food or present in very small
quantities (such as vitamin A in maize).
Can vitamin A RDA be achieved?
The NFCS indicates a median vitamin A intake of only 587 IU/day - about 44%
of RDA - for 1-3 year olds in South Africa. After accounting for 40% vitamin
losses and dilution in porridge of 2.5 times, an additional 630 IU/day in 410 g
of fortified porridge (or 164 g of dry maize) more than doubles this original
daily intake to more than 1200 IU/day (i.e., >90% of daily needs (1333 IU/day)
of this age group as shown in Table 1). For the poorest children, current daily
vitamin A intake of only 237 IU/day - which is about 20% of daily needs - would
increase by more than 365% providing about two thirds of RDA. While the role of
food fortification is not to provide 100% of RDA provided through consumption
through one single food, the fortified maize will go along way to achieve
vitamin A sufficiency, especially when combined with vitamin A from other
sources.
Selection of iron
It cannot be denied that iron deficiency and anaemia are widespread in South
Africa. In the light of the overwhelming need of South African children as well
as evidence of effectiveness of fortification programs in North and South
America, it would be unethical not to move forward. Recognizing the complexity
of the issue, the Department of Health (DOH) was thorough and scientific in its
approach to the selection of an iron compound and its level. Dr. Patrick
Macphail, a world renowned South African iron expert, was commissioned to
prepare a position paper comparing a variety of iron forms. In addition, CSIR
carefully assessed the organoleptic effects of various iron compounds. The
milling industry was regularly consulted to ensure the technical feasibility of
addition and product acceptability. The latest reports of international
consultations were taken into account. All of us recognize the difficulty in
identifying an iron source that is optimally bioavailable, stable and acceptable
to the consumer in the food to which it is added. Elemental iron powders are the
most common iron fortificant used worldwide because they are more stable in food
products and are relatively inexpensive. Among the different forms of elemental
iron, DOH specified the electrolytic grade because the state-of-the-art research
suggests this is the most bioavailable of the elemental iron powders . Mr.
Klugman erroneously states that "the choice of iron compound for the DOH
food fortification program is "Reduced Iron". The electrolytic form of
elemental iron is quite distinct and different from the reduced from.
Bioavailability of electrolytic iron
Mr. Klugman's analysis comparing dietary and absorbed iron needs is
misleading. He states that after accounting for absorption, fortified maize meal
will "still only deliver 0.074mg, as a contribution to the child's daily
needs of 10mg." In fact, the median absorbed iron needs for a child aged
2-3 year old is 0.56 mg/day , and not 10 mg/day as suggested by Mr. Klugman.
Mr. Klugman's assertion that the bioavailability of electrolytic iron, as
proposed by the DOH, is 0.2% is also misleading. A more useful yardstick for
comparison is the absorption of the iron compound relative to ferrous sulfate
(Relative Biological Value -RBV). In the review of elemental iron studies , the
data on electrolytic iron is the most consistent and estimated the relative
absorption (RBV) at about 50% of ferrous sulfate. In Hurrell's paper reviewing
the literature, iron absorption in human subjects from ferrous sulfate ranges
roughly from 1-9% (Table 2) . This means that absorption of electrolytic iron
would range between 0.5 - 4.5%. Given the proposed level of fortification (7.0
mg iron per 200 g dry maize meal) and level of consumption for children 1-3
years old and taking a bioavailability factor ranging between 0.5- 4.5%, a child
would absorb between 0.035 to 0.31 mg of iron, i.e. up to 56% its iron needs.
This can make quite a difference to a child's iron status!
Finally, Mr. Klugman also states that "use of Reduced Iron of smaller
particle sizes (from 45 microns) may offer an improvement". Actually,
electrolytic iron has a particle size averaging closer to 20 microns.
Additional Fortification and Health Strategies Needed
The nutritional status of South African children is so desperate that in too
many cases, they will need more than this tremendous boost of nutrients provided
by maize fortification. Other strategies such as sugar fortification,
supplementation and improved diet will also play a role if these children are to
achieve their full growth and development as students, workers and citizens of
South Africa. However, in the meantime, fortification delayed means nutrition
denied to millions of South African children.
Read responses to this article:
For Gary Klugman's response to this article:
For France Begin's reply:
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