Vitamin A is a vitamin
that is needed by the retina of the eye in the form of a specific metabolite,
the light-absorbing molecule retinal, that is necessary for both low-light and
color vision
Vitamin A deficiency is a lack of vitamin A in humans. It is
common in developing countries but rarely seen in developed countries. Night
blindness is one of the first signs of vitamin A deficiency. Exophthalmia,
keratomalacia, and complete blindness can also occur since Vitamin A has a
major role in phototransduction. Approximately 250,000 to 500,000 malnourished
children in the developing world go blind each year from a deficiency of
vitamin A, approximately half of whom die within a year of becoming blind. The
United Nations Special Session on Children in 2002 set the elimination of
vitamin A deficiency by 2010. The prevalence of night blindness due to vitamin
A deficiency is also high among pregnant women in many developing countries.
Vitamin A deficiency also contributes to maternal mortality and other poor
outcomes in pregnancy and lactation
Vitamin A deficiency also
diminishes the ability to fight infections. In countries where children are not
immunized, infectious disease like measles have higher fatality rates. As
elucidated by Dr. Alfred Sommer, even mild, subclinical deficiency can also be
a problem, as it may increase children’s risk of developing respiratory and
diarrheal infections, decrease growth rate, slow bone development, and decrease
likelihood of survival from serious illness.Thank you for general knowledge.com.
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