Risk Factors for Vitamin A Deficiency

Vitamin A deficiency is more common among poor families in developing countries, and along with poverty are many associated risk factors such as low maternal and paternal education, lack of land, crowding, poor hygiene, increased infectious disease morbidity, geographic isolation, lack of a home garden, and inadequate intake of vitamin A. Infants, preschool, and primary school-aged children are at higher risk for vitamin A deficiency, Fig. 17. Risk factors for vitamin A deficiency. Fig. 17....

Xerophthalmia and Keratomalacia

Keratomalacia Children

The WHO classification of xerophthalmia is shown in Table 3. This classification was first adopted in 1976 (126), with minor modification in 1982 (247). The ocular signs are Fig. 5. Night blindness in a public health poster from Indonesia. Fig. 5. Night blindness in a public health poster from Indonesia. classified in order of severity from night blindness (XN) to corneal ulceration and kera-tomalacia that involves one-third of the cornea or greater (X3B). A corneal scar (XS) is not a sign of...

Dietary Sources and Metabolism of Vitamin A 321 Food Sources of Vitamin A

Vitamin A is available in dietary sources as either preformed vitamin A or as provitamin A carotenoids. Rich dietary sources of preformed vitamin A include egg yolk, liver, butter, cheese, whole milk, and cod-liver oil. In animal foods, vitamin A is mostly in the form of retinyl esters, such as retinyl palmitate. In many developing countries, the consumption of foods containing preformed vitamin A is limited, and provitamin A carotenoids often comprise the major dietary source of vitamin A...