Lutein is a member of the carotenoid family. Carotenoids are naturally occurring fat-soluble pigments found in a few plants, such as algae and certain plant bacteria. They serve as accessory light-gathering pigments and are used protect against the toxic effects of ultra-violet radiation and oxidation. Lutein appears to have the ability to protect humans against phototoxic damage as well. Lutein is found in the macula of the human retina as well as in the human crystalline lens and is thought to play a role in protection against age-related macular degeneration (ARMD) and age-related cataract formation and may protect against certain forms of cancer.

Food sources of lutein include corn, egg yolks, and green vegetables and fruits such as broccoli, green beans, green peas, brussels sprouts, cabbage, kale, collard greens, spinach, lettuce, kiwi, and honeydew. Lutein is also found in herbs such as nettles, algae, and the petals of many yellow flowers. Many of the marketed lutein nutritional supplements contain lutein esters which are derived from the dried petals of marigold flowers.

Dosage and Administration

Lutein is available as a non-esterified and esterified forms and as single ingredient or in combination with other nutritional supplements. Many times zeaxanthin (a similar carotenoid with similar effects) is also found along side lutein in smaller concentrations; however supplements that deliver higher amounts of zeaxanthin are being developed.

The optimal dosage for lutein supplementation is unknown. It has been suggested that dietary intake of lutein of 6 to 12 milligrams per day has been associated with a decreased risk of age-related macular degeneration.