The pigment gives the unique red-orange color to many marine species such as salmon, trout, and crustaceans (shrimp, crab, and crayfish) and other animals, such as flamingos. This fat-soluble phytonutrient likely has antioxidant and anti-inflammatory properties that may protect cells against oxidative stress and inflammation if consumed through the diet.

Astaxanthin is a pure antioxidant, meaning it does not cause cell damage at high doses, and it neutralizes free radicals more effectively than other antioxidants. Since humans and animals generally cannot produce carotenoids de novo (self-production in the body), astaxanthin must be consumed through the diet.

Please note that astaxanthin is not an essential nutrient but belongs to the group of phytonutrients that can provide additional health benefits if consumed in the diet. The most common source of astaxanthin in nature is the freshwater microalga Haematococcus pluvialis, and it can be found in aquatic environments and freshwater accumulations worldwide.