All trans-Retinal is one of the major derivatives of vitamin A group. A variety of food serves as a source of vitamin A. It is predominant in liver and among the brightly colored vegetables.;Product Description:All trans-Retinal is one of the major derivatives of vitamin A group. A variety of food serves as a source of vitamin A. It is predominant in liver and among the brightly colored vegetables.An oxidized form of retinol that is a corotenoid component of the visual pigments.