There are basically two forms of this vitamin -- retinoids and carotenoids -- and they have different jobs in your body.
Retinol is in animal products, including milk, liver, and certain fortified foods. Beta-carotene is what gives orange vegetables and some fruits -- sweet potatoes, carrots, cantaloupe, papaya -- their hue. Spinach and other dark-green, leafy veggies also have a lot.