Vitamin A deficiency

Disease resulting from low Vitamin A concentrations in the body

Vitamin A deficiency (VAD) or hypovitaminosis A is a lack of vitamin A in blood and tissues. It is common in poorer countries, especially among children and women of reproductive age, but is rarely seen in more developed countries. Nyctalopia is one of the first signs of VAD, as the vitamin has a major role in phototransduction; but it is also the first symptom that is reversed when vitamin A is consumed again. Xerophthalmia, keratomalacia, and complete blindness can follow if the deficiency is more severe.

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