Vitamin A is a fat soluble Vitamin. Vitamin A is also known as Retinol. It produces pigments in the retina of the Eye. The role of Vitamin A in the body is to promote good vision at night and low light. Vitamin A is important for normal vision, Immune System, and Reproduction. It regulates the formation and development of the Cells.
There are two types of Vitamin A :
Type 1 : This Vitamin A is found in meat , poultry , fish , and dairy products.
Type 2 : This type of Vitamin A is found in fruits , vegetables and other plant based products.

Normal level of Vitamin A in the body
Women should consume 800 mcg daily.
Men should consume 1000 mcg daily.

Requirement of Vitamin A per day :
3,000 IU ( male )
2,300 IU ( female )

Functions of Vitamin A in the body
Vitamin A regulates genes. It helps to regulate the rate of gene transcriptions. It is responsible for maintaining function of the cells. Vitamin A activates the production of White Blood cells and Red Blood Cells. Vitamin A regulates the Immune System. It is important for the development and reproduction of Embryonic cells. It is responsible for Cell division and differentiation.

Benefits of Vitamin A
Vitamin A stimulates the development and maintenance of the body tissues , Bones, Skin and Hair. It protects the Eyes from infection. Vitamin A helps in wrinkle reduction and treatment of Acne. It is essential in the production of White Blood cells which fight against infections in the Body. Vitamin A prevents Cataract and other Eye problems. Vitamin A reduces the risk of Heart diseases and Cancer. Vitamin A is important for the reproductive process for both males and females. In males, Vitamin A helps in the production of sperms. In females, Vitamin A is essential in Embryonic development. Vitamin A is a strong Anti oxidant. It fights against impurities that causes Cancer. Vitamin A produces calcium phosphate that prevents the formation of Kidney stones in the Body.

Effects of deficiency of Vitamin A in the body
Vitamin A deficiency means lack of vitamin A in the body. First sign of Vitamin A deficiency is night blindness. Its deficiency reduces the ability of the body to fight infections. Vitamin A deficiency may cause the risk of death in infants. Its deficiency causes Eye inflammation and Corneal inflammation. Skin becomes rough and dry because of deficiency of Vitamin A. Vitamin A deficiency leads to maternal mortality.

Symptoms of Vitamin A deficiency
Xerophthalmia
Cornea becomes dry, wrinkled, lusterless, hazy and pigmented.
Skin changes
Dry and scaly skin with itching
Change in the Eye
Burning and inflammation of the eye
Epithelial Changes
Degeneration and hardening of epithelium
Lowered Resistance to Infection
Unable to perform protective functions
Changes in the Respiratory Tract
Respiratory organs become dry and rough
Changes in the Skeletal System
Irregular development of the skeleton , skull and vertebral column

Deficiency of Vitamin A in the Body may cause
Night Blindness
Poor Dental health
Weak Immune System
Reduced Reproductive capabilities
Dry and hard Epithelial surfaces

Effects of excess Vitamin A in the body
Smokers who take high doses of Vitamin A ( supplements ) have an increased risk of Lung Cancer.
Mega doses of Vitamin A may lead to toxicity. Increased amounts Vitamin A may turn the skin yellow or orange. The skin color will return to normal once you reduce intake of Vitamin A. Over consumption of Vitamin A in women lowers the bone mass and increases the risk of Hip fractures.