Most abundant form of pro-vitamin A is:-

Carotenoids are provitamins of vitamin A which are present in plants. Most impoant carotenoid is beta carotene , which consists of two molecules of retinal joined end to end. ADDITIONAL READING ON VITAMIN A: There are three biologically active forms of Vitamin A: Retinol: necessary for reproductive system Retinal: involved in vision Retinoic acid: involved in growth and cellular differentiation Retinoids are all-natural/ synthetic compounds with Vitamin A like activity.