Coenzyme Q10 (or ubiquinone) is an important rate- limiting nutrient that is a cofactor in the mitochondrial electron transport chain, the biochemical pathway in cellular respiration from which adenosine triphosphate (ATP) and metabolic energy is derived. Since nearly all cellular activities are dependent upon energy, coenzyme Q10 is essential for the health of all human tissues and organs. Coenzyme Q10 is a naturally-occurring antioxidant nutrient which retards free radical formation in biological systems. Coenzyme Q10 resembles vitamin E and vitamin K in chemical structure. Biochemically, it functions much like vitamin E in that it participates in certain antioxidant and free radical reactions. Healthy humans who consume a well-balanced diet have the ability to synthesize coenzyme Q10. Unhealthy individuals, those on lipid lowering drugs and those consuming an inadequate diet may not synthesize coenzyme Q10 in sufficient quantity. According to Dr. Karl Folkers and other experts, humans can biosynthesize coenzyme Q10 from tyrosine or phenylalanine and mevalonic acid, which are small molecules abundant in the body. This is a complex biochemical process that requires 15 separate steps and many enzymes, coenzymes, vitamins and minerals. Only by such a process can the respiratory chain receive proper levels of coenzyme Q10. Thus, the biosynthesis of coenzyme Q10 in the human body requires a good diet – one that is high in vitamins, minerals, and other nutrient factors. It has been shown by the NHANES studies that many Americans do not have an adequate diet. Rather, their intake of most water soluble vitamins, vitamin A and some minerals and trace elements is insufficient. Many of these nutrients are essential for the biosynthesis of coenzyme Q10. In addition, it has been shown that in disease states, nutrients from food sources may not necessarily be absorbed or available. According to some experts, coenzyme Q10 should be considered an essential nutrient, as it is well established that coenzyme Q10 is essential for the health of every cell in the human body. Numerous studies indicate coenzyme Q10 also plays an important role in the maintenance of the entire cardiovascular system. Supplementation with coenzyme Q10 in patients has shown to be useful for the maintenance of already healthy blood pressure. Coenzyme Q10 is also important for the maintenance of blood vessels and heart muscle function. In addition, people taking statin drugs can develop deficiencies in coenzyme Q10 and may require supplementation.