The undiscovered problems of vitamin ' A ' are: 1. The normal growth of the body is disrupted. 2. There are obstacles to keep the eyes healthy and to preserve the vision. 3. Immunity is reduced , often becomes ill. 4. Digestive capacity is reduced , often stomach ailments occur and diarrhea is chronic. 5. The skin is rough. . The hair is reddish and falls out easily. . Night blindness is a disease that can be easily treated by taking vitamin A capsules , which , if left untreated, can lead to visual impairment and permanent blindness. . The normal growth of children is hindered.