Why are vitamin A and vitamin C essential to us? Give their important sources.

Answer

Vitamin `A` is essential to us because its deficiency causes xerophthalmia (hardening of cornea of eye) and night blindness.
Sources : Fish liver oil, carrots, butter and milk.
Vitamin C . Vitamin C is essential to us because its deficiency causes scurvy (bleeding gums) and pyorrhea (loosening and bleeding of teeth)
Sources : Citrous fruits ; arnia, green leafy vegetables.