Carotenoids are orange, yellow, and red pigments which organisms such as plants, algae, and several species of bacteria and fungi produce. Carotenoids are responsible for the orange color of carrots and pumpkins, as well as the coloration of tomatoes, corn, and daffodils. Carotenoids can be manufactured from basic metabolic building blocks such as fats.

In humans, absorbtion of carotenoids is aided when consumption of high-fat means is increased. Cooking vegetables which contain carotenoids in oil increases bioavailability of these compounds.

Carotenoids are an important part of the brown pigment melanin, which is found in eyes, hair and skin. Melanin absorbs high-energy light and protect tissues from cellular damage.