<unk>  is common in developing countries but rarely seen in developed countries. Approximately 250,000 to 500,000 malnourished children in the developing world go blind each year from a deficiency of vitamin A. Night blindness is one of the first signs of<unk> .<unk>  contributes to blindness by making the cornea very dry and damaging the retina and cornea.<unk>  also diminishes the ability to fight infections. In countries where children are not immunized, infectious disease like measles have relatively 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.
In addition to dietary problems, there are other causes of<unk> . Iron deficiency can affect vitamin A uptake. Excess alcohol consumption can deplete vitamin A, and a stressed liver may be more susceptible to vitamin A toxicity. People who consume large amounts of alcohol should seek medical advice before taking vitamin A supplements.
Treatment of<unk>  can be undertaken with both oral and injectable forms, generally as vitamin A palmitate.
Vitamin A deficiency
Vitamin B12 deficiency
Biotin deficiency
Chromium deficiency
Iodine deficiency
Child abuse
Zinc deficiency
Folate deficiency