Lutein is a yellow dihydroxylated carotenoid which is found to be a common constituent in many dietary supplements.

Lutein may be used as a reference standard for the determination of lutein in processed foods and supplements, in tomato juice, in human plasma and in leafy vegetables by high performance liquid chromatography-photodiode array detection (HPLC-PDA) and in fish eggs by HPLC coupled with electrospray ionisation (ESI) and tandem mass spectrometry (MS/MS)

Dietary carotenoid with no vitamin A potency. Increases macular pigment concentration in the eye and may improve visual function.