This nutritional deficiency is widespread in developing countries, and the problem is exacerbated by a tendency by some to withhold vegetables from children for cultural or other reason.
Where it is the limiting nutrient, vitamin A deficiency causes anemia, growth retardation and xerophthalmia; increases the incidence and/or severity of infectious episodes.
Reduced survival is the most severe and potentially the most widespread consequence of vitamin A deficiency, and the one that has generated the most interest.
It is also common knowledge that an adequate levels of vitamin A is essential for animal vision and that prolonged low levels of vitamin A can lead to xerophthalmia and ultimately, blindness.
Vitamin A deficiency decreases resistance to infections and increases the severity, complications and risk of death from various diseases.
When vitamin A deficient, the epithelial cells of growth skin, oral cavities and respiratory, genitourinary and gastrointestinal tracts become dry and flat, hardening so that absorption of nutrients is reduced.
Moreover, vitamin A deficiency may increase the risk of bacteria colonization or delay recovery.
Deficiency of vitamin A