which condition is caused by a deficiency of vitamin A
Vitamin A deficiency is the leading cause of preventable childhood blindness and is critical to achieving Millennium Development Goal 4:2 to reduce child mortality.itamin 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.