Which of the following diseases correspond to the deficiency of vitamin A in humans? P. Xerosis cornea Q. Bitot’s spots R. Angular stomatitis S. Folicullar hyperkeratosis

In humans, the important deficiency states due to the lack of vitamin A in the diet are: i. Night Blindness: In the early stages of vitamin A deficiency, the individual cannot see well in dim light. In advanced deficiency, the subject cannot see objects in dim light. ii. Xerosis Conjunctiva: The conjunctiva is dry, thickened, wrinkled and pigmented. The pigmentation gives conjunctiva a smoky appearance. iii. Xerosis Cornea: When dryness spreads to cornea, it takes on a hazy, lusterless appearance. iv. Bitot’s Spots: Greyish glistening white plaques, formed of desquamated thickened conjuctival epithelium, usually triangular in shape and firmly adhering to the conjuctiva. v. Keratomalacia: When xerosis of the conjuctiva and cornea is not treated, it may develop into a condition known as keratomalacia. vi. Folicullar Hyperkeratosis: The skin becomes rough and dry. The lesions at the angles of the mouth are termed as angular stomatitis and this disease is caused by the lack of vitamin B2 or riboflavin.