CHAPTER 7: Novel Functions of Vitamin E Nicotinate

Vitamin E nicotinate is an ester of tocopherol (vitamin E) and niacin (vitamin B₃). While this ester can be chemically synthesized, whether vitamin E nicotinate is formed from vitamin E and niacin in the biological system is unclear. Our previous metabolomics analysis demonstrated that the heart tissue level of vitamin E nicotinate is 30-fold lower in heart failure. Since the rat diet used in these experiments contained vitamin E acetate and niacin separately, but not in the form of vitamin E nicotinate, these results revealed that vitamin E and niacin could be esterified to form vitamin E nicotinate in the biological system. Observations that the vitamin E nicotinate level gets altered in the disease state suggest clinical importance. While it was expected that oxidative stress occurring during heart failure decreases the levels of various antioxidants, only vitamin E nicotinate, but not other forms of vitamin E including α-tocopherol, was reduced. Hence, vitamin E nicotinate may function independently from simply serving as a source of active vitamin E. Consistent with this idea, we recently found that the intact vitamin E nicotinate structure could elicit cell signaling for the formation of anandamide. Exciting novel functions of vitamin E nicotinate are discussed.