NAIROBI - Vitamin A deficiency has been getting a lot of media attention in recent months. According to data from the World Health Organisation (WHO), young children and pregnant women in low-income countries of Africa and South-East Asia are particularly at risk.
This is not to say, however, that adults are not at risk. WHO estimates that 250 million pre-school children are vitamin A deficient, and it is likely that in vitamin A deficient areas, a significant proportion of pregnant women are also affected.
The main cause for concern is that, besides reversible symptoms such as dry skin, vitamin A is a crucial micronutrient for eye health and, as such, causes dry eyes, inflammation of the cornea (the transparent front part of the eye ball) and blindness in an estimated 250,000 to 500,000 children every year in Africa and south-east Asia.
Combative initiatives
A number of global agencies have therefore established initiatives, in partnership with ministries of health in these regions, with a view to combat vitamin A deficiency.
Besides direct supplementation with vitamin A tablets or injection, the two other approaches taken are (1) food fortification, where certain foods such as margarine, sugar, milk powder may be fortified with vitamin A, and (2) dietary diversification, where plant sources of vitamin A, namely fruit and green leafy vegetables, are ingested in addition to animal sources of vitamin A such as liver, oily fish and dairy products (milk, cheese yoghurt).
Breast milk provides an adequate source of vitamin A for newborns, so long as the mother is not vitamin A deficient.
Beta-carotene, which gives orange vegetables their colour, is a precursor of vitamin A. Any orange vegetables such as carrots and orange peppers are therefore a good indirect vitamin A source.
Maize, originally from Mesoamerica, is reported to be the third most important cereal crop in the world. In Kenya, it may be the most important, as dictated by the demand and supply.
One of the criticisms of white maize, however, particularly if eaten regularly as a staple food, is its limited nutritional value, particularly if consumed as processed flour (ugali or porridge) whereby the most nutritious component of the maize seed, the endosperm, is discarded during the process.
Given the large numbers of people globally who regularly consume maize, bearing in mind that we live in an era where food security is a pressing concern; and given the increasing global population and decreasing arable land, HarvestPlus, an organisation that uses biofortification to breed higher levels of micronutrients directly into key staple foods, has produced orange maize which contains beta-carotene.
Biofortification is conducted through traditional breeding methods, as opposed to genetic engineering, to produce a genetically modified organism (GMO).
A recently published study in the American Journal of Clinical Nutrition found that beta-carotene from orange maize was converted at a rate that was almost twice as high as previously assumed for maize, and even higher than from vegetables. And, from a recent interview transmitted by the BBC World Service, a pilot study in communities in Zambia has shown acceptance of the orange maize.
This is in stark contrast to the 'golden rice' developed through a collaboration between Swiss and German scientists, where genetical manipulation of rice was conducted so that the rice plant may synthesise beta-carotene in the endosperm, which is the part of rice that we eat, as opposed to the leaves.
However, despite this apparent humanitarian action, it has been met with much resistance, particularly by environmentalists, due to the production of a genetically modified food.
A word of caution: vitamin A in excessive amounts is toxic as it is a fat-soluble vitamin. Therefore, if you regularly eat a well balanced diet, you do not need vitamin A supplementation.
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