Vitamin A 3,000 mcg (10,000 IU) From Fish Liver Oil Among the essential vitamins, few have a more important role than Vitamin A. It is at the core of cell development itself. Thats because Vitamin A plays an important role in the normal DNA transcription into RNA, ensuring genes are expressed properly, and cells develop normally. Supports Eye Health and Healthy Immune Function* Vitamin A is essential for maintaining the tissues that line the internal and external surfaces of the body, including the eyes, skin, respiratory, GI and urinary tracts.