Vitamin A is a fat-soluble, group of organic compounds that can be separated into two groups: the retinoids and carotenoids. Retinoids, also known as preformed vitamin A, include retinol, retinoic acid and retinaldehyde. The major carotenoids, also known as pro-vitamin A, are pre-cursors to preformed vitamin A, and include α-, β-, γ-carotenes, and β-cryptoxanthin. Retinol and retinoic acids can be found only from animal sources such as meat, fish, dairy, eggs, and milk with a