Vitamin A. Computer model of a molecule of vitamin A, or retinol (C20. H30. O). Atoms are represented as balls, joined by sticks representing atomic bonds. Vitamin A is essential for normal growth and development. It is needed for the production of bones and teeth, for protection against infection and for night vision. It is found in eggs, liver oils and dairy products. It can also be made in the body from the carotene found in many vegetables and fruits. Excessive intake can be harmful.