To the north are the Chukchi and Beaufort seasâthe southern parts of the Arctic Ocean. The Pacific Ocean lies to the south and southwest. Alaska is the largest state in the United States by area, the 3rd least populous and the least densely populated of the 50 United States.
Vitamin A deficiency (VAD) is a lack of vitamin A in humans. It is common in poorer countries but rarely seen in more developed countries.Nyctalopia (night blindness) is one of the first signs of VAD.revalence of vitamin A deficiency. Vitamin A deficiency (VAD) is a lack of vitamin A in humans. It is common in poorer countries but rarely seen in more developed countries. Nyctalopia (night blindness) is one of the first signs of VAD.
Symptoms. An early symptom of vitamin A deficiency is night blindness, which is caused by a disorder of the retina. Soon thereafter, the whites (conjunctiva) and corneas of the eyes may become dry and thickâa condition called xerophthalmia.isorders that impair the intestineâs absorption of fats can reduce the absorption of vitamin A and increase the risk of vitamin A deficiency. These disorders include chronic diarrhea, celiac disease, cystic fibrosis, certain pancreatic disorders, and blockage of the bile ducts.