Benefits of Vitamin A
Retinoids (such as retinol) are types of vitamin A that come from animal sources. They are the most readily usable forms of the vitamin. Carotenoids (such as beta-carotene) are types of vitamin A from plant sources. The body uses carotenoids to make retinol. Vitamin A is stored in the liver, and the liver helps maintain the proper blood levels of the vitamin.
Vitamin A is necessary for cell growth and differentiation (the process that makes stem cells into different types of cells), bone growth, reproduction, good vision, and a healthy immune system. It is important for maintaining the health of the lining of the respiratory, urinary, and intestinal tracts. It also helps control the genes for numerous different structural proteins, such as certain important proteins in the skin.
Most importantly, vitamin A is used for the transduction of light into nerve signals that are essential for vision.
Vitamin A is safe for children when taken in amounts that do not exceed the recommended dosage. High doses are not safe for children, except in the case of a documented vitamin A deficiency.