a.Performed vitamin A
b.Pro vitamin A Performed vitamin A is also known as retioids and it is usually used in retina formation of eyes.this all is due to retina that we are able to see things.Pro vitamin A also known as carotids. They usually work work as antioxidant.Performed vitamin A is immediately available for body as it is taken.Pro vitamin A is not available. In-fact body changes carotenoids to vitamin a after intake.
Sources:We can get Performed vitamin A through fish,animal meat(liver),eggs and dairy etc. We can get Pro vitamin A through fruits and vegetables.
Harmful effect:Vitamins are not harmful but when they are taken in large quantity they can be toxic.Excessive use of vitamin a can cause liver problems as well as effect our bones. Function:Its vital for fertility.It boosts immune system.It protects us from certain cancers.It plays an important role in eye health and fetal development.
Deficiency:Its deficiency may cause death due to infections, aniema, hair loss and headache etc
Source: Iram Khan