Carotenoids are an important vitamin like substance that is beneficial to the human body. Carotenoids include beta carotene and lutein. About half of the body's carotenoids are converted to vitamin A. Foods rich in carotenoids include orange juice, zucchini, other types of squash, broccoli, spinach, kale, orange pepper, grapes, kiwi fruit, and broccoli. Whole grains can also provide carotenoids in the human diet. Carotenoids can be made in the laboratory as well.

Carotenoids, especially lutein, are used to decrease the chances of developing cataracts, retinitis pigmentosa, and age-related macular degeneration. They also are related to eye health. Lutein is a color pigment in the human eye located within the macula and the retina.

It is believed that lutein helps filter light and protects the tissues of the eye from damage caused by the sun. Beta carotene has been used to help with alcoholism, depression, headaches, heartburn, epilepsy, and to improve fertility. Some people also take carotenoids to help decrease the chances of diabetes and heart disease.