Night blindness is an early symptom.
Blindness can eventually develop.
The eyes, skin, and other tissues become dry and damaged, and infections develop more often.
The diagnosis is based on symptoms and blood tests.
Animal and fish liver
Orange, yellow, and dark green vegetables and yellow and orange fruits
Eggs
Fortified milk products
diarrhea, celiac disease, cystic fibrosis, certain pancreatic disorders, and blockage of the bile ducts. Surgery on the intestine or pancreas can have the same effect.
retina. Soon thereafter, the whites (conjunctiva) and corneas of the eyes may become dry and thick—a condition called xerophthalmia
The skin becomes dry and scaly, and the lining of the lungs, intestine, and urinary tract thicken and stiffen.
The immune system does not function normally, making infections more likely, particularly in infants and children.
A doctor's evaluation
Blood tests
If people have problems seeing in the dark, eye tests, such as electroretinography
