Abstract:
This study provides a comprehensive review on the fat-soluble
micronutrient vitamin A, changes in its status among vulnerable groups
of different populations and the results of experience with different
strategies/interventions designed to improve its status. Vitamin A can
be derived from animal sources (preformed in liver, milk, eggs, fatty
fish) or plant sources (in fruits and vegetables as provitamin A). The
vitamin is required for normal growth and development, playing a part
in reproduction, differentiation of cellular epithelium, regulation of
cell division, genetic regulation and enhancement of immune responses.
Retinol (its basic molecule) is metabolised into a number of biologically
active retinoid compounds, such as retinal (active element of visual pigment)
and retinoic acid, an intracellular messenger that modulates cell differentiation.
Uneven distribution of natural sources of vitamin A, low dietary intake
of animal products, the traditional technological transformation/processing
of foods, low absorption and limited bioconversion of carotenoids may
impact negatively on vitamin A activity. Vitamin A deficiency (VAD), a
major public health nutritional problem in many developing countries,
results in a range of developmental and pathological states with consequences
ranging from potentially blinding xerophthalmia to increased risks of
infection and mortality. All alternatives employed towards eradicating
VAD (nutrition education, dietary diversification, dietary supplementation
and food fortification) have provided a high return on investment in terms
of disability-adjusted-life years gained. Key options for action, as well
as important areas of research are being discussed. Control of VAD will
lead to a substantial improvement in childhood survival and prevent the
scandal of irreversible blindness. It is suggested that early introduction
of children to abundant natural sources of vitamin A (like red palm oil-prepared
meals) be encouraged.