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.
In addition to treating deficiency syndromes, vitamin A has several potential preventive and therapeutic uses. Vitamin A is important medicine for the immune system. It keeps skin and mucous membrane cells healthy. When membranes are healthy they stay moist and resistant to cell damage. The moistness inhibits bacteria and viruses from putting down stakes and starting infectious diseases.