Coenzyme Q10 is also known as Coenzyme Q10, ubiquinone-50, ubiquinol-10, and ubidecarerone. It belongs to a class of molecules known as ubiquinones. The different coenzyme molecules consist of a head and a tail, each responsible for specific actions. There are 12 different coenzymes. The number of units on the tail designates the number of a given coenzyme.
Coenzyme Q10 is an essential cofactor involved in the electron transport chain, accepting electrons in both Complex I and Complex II. Without Coenzyme Q10, ATP (energy), could not be made. Coenzyme Q10 is also a potent antioxidant, primarily affecting the mitochondria and cell membranes. Like Vitamin E and Vitamin A, CoQ10 is also a lipid soluble anti-oxidant. This ubiquinone protects the cell membrane and other components of the cell against lipid peroxidation.
Coenzymes occur in the majority of aerobic (oxygen using) bacteria, plants, and animals. Coenzyme Q10 is the most prominent form in humans. It is biosynthesized by the human body in the liver. Interestingly, the pathway used to create Coenzyme Q10 is also the pathway used to make cholesterol.
Coenzyme Q10 is absorbed in the small intestine. Only 40% of ingested Coenzyme Q10 is absorbed and used by the human body. Once it enters the blood the different cholesterol molecules, LDL, HDL, and VLDL, provide carriers for its movement throughout the body. Because it is bound to cholesterol, any unabsorbed Coenzyme Q10 is excreted in the bile.
Coenzyme Q10 is believed to be cardioprotective, cytoprotective, and neuroprotective. It is an anti-oxidant and an important metabolic cofactor for the production of energy. 
The main sources of supplemental Coenzyme Q10 are tobacco leaf extracts, and fermented beet and sugar cane.  There are no therapeutic dosages of Coenzyme Q10 available from any food source. Additionally, tthe amount of Coenzyme Q10 made by the human body does not meet the dosages for therapeutic value in the treatments of chronic disease.
Coenzyme Q10 is an effective adjunct treatment for various conditions of the cardiovascular system. Its most well recognized and studied uses lie within the conditions of congestive heart failure, hypertension, and angina.
- For individuals with congestive heart failure, Coenzyme Q10 has been shown to increase the quality of life. In study, CoQ10 has yielded improvements in the common symptoms of congestive heart failure such as; cyanosis, edema, breathing abnormalities, enlarged liver, shortness of breath, heart palpitations, sweating, insomnia, vertigo, and arrhythmias.  Coenzyme Q10 was also able to increase the exercise capacity in individuals with heart failure. 
- Coenzyme Q10 may improves symptoms in patients with high blood pressure, mitral valve prolapse, and angina. Studies have documented reduction in the amounts of medications needed by individuals with those conditions. 
- Coenzyme Q10 is also protective against the development of atherosclerosis, by inhibiting the oxidation of LDL  and by increasing HDL levels.  Coenzyme Q10 has also been shown to reduce the number of cardiac events following a heart attack, including the development of atherosclerosis. 
- Coenzyme Q10 may be an effective addition to any cancer treatment protocol. Numerous studies have highlighted its ability to decrease the cardiac toxicity of a popular anti-cancer drug, doxorubicin; also known as Adriamycin.  Doxorubicin is an anthracycline antibiotic that is commonly used for leukemia and lymphoma, but is very toxic to heart tissue.
- There are also reports that Coenzyme Q10 may be a useful adjunctive treatment for individuals with breast cancer. However, more studies are needed to confirm this preliminary finding. Coenzyme Q10 can reduce oxidative stress via its anti-oxidant action. It is theorized that by reducing oxidative stress, CoQ10 can protect against cardiovascular and neurological disease; among the many other conditions that may be related to free radical damage and oxidative stress. 
- Coenzyme Q10 can be helpful for individuals with early onset Parkinson's disease. It may slow the progression of disease and deterioration of cognitive function.  In one particular controlled study, individuals taking Coenzyme Q10 had less disability over time than those not taking Coenzyme Q10. Supplemental CoQ10 was well tolerated with few side effects in very high doses.
- Individuals with Type II diabetes may benefit from taking Coenzyme Q10 as well. Marked improvements in glycemic control caused by CoQ10’s ability to positively affecting Hemoglobin A1C levels have been noted. It has also been effective at lowering the blood pressure]] of individuals with Type II diabetes.  However, CoQ10 is not thought to be effective in controlling the glycemic response of those people with Type I diabetes.
- Coenzyme Q10 can effectively lower blood pressure in both essential hypertension (not caused by another disease) and secondary hypertension (caused by another disease). 
- Coenzyme Q10 may improve exercise performance and recovery.  It may be helpful for individuals with high endurance sports activities such as swimming, marathon runners, and cyclists.
- Topical Coenzyme Q10 can be an effective treatment alone, or in combination with non-surgical therapy for peridontitis. It has been shown to improve symptoms of the disease and reduce the progression.  Topical CoQ10 creams are also becoming popular in many cosmetic formulations.
Coenzyme Q10 can be taken in various dosages, ranging from 5 - 300 milligrams per day. The most common dosage used in clinical studies is 100 - 200 mg per day. Although doses as high as 1200 mg per day have been administered for the treatment of serious conditions. 
Coenzyme Q10 is best taken with food, as its absorption increases with fat intake. Levels of Coenzyme Q10 will reach maximal values in the blood after 3 weeks of taking a regular, daily dose.  Typically, the beneficial effects of Coenzyme Q10 will not be observed until taking the dose for 3 weeks; again, the time needed to reach maximal value in blood.
There are no reported toxicities with intakes of Coenzyme Q10 up to 1200 mg per day. Mild side effects due to the oral administration of Coenzyme Q10 include nausea, diarrhea, and epigastric distress. 
Pregnant and nursing women should not take Coenzyme Q10 due to the lack of information on the effects in these populations.
Coenzyme Q10 is depleted by statin drugs (lovastatin, simvastatin, pravastatin). The common metabolic pathway that is shared between cholesterol and Coenzyme Q10. Individuals who are taking statin drugs should also be taking Coenzyme Q10 to avoid a potential deficiency.
There is one published case study of Coenzyme Q10 decreasing the effectiveness of warfarin, an anti-coagulant medication. Individuals taking warfarin should inform their physician and may need to have their mediation dosage adjusted.
Individuals with Type II diabetes may also have to adjust their dosage of medications due to Coenzyme Q10’s ability to improve glycemic control.
Beta-blockers may decrease the metabolic activity of Coenzyme Q10. In addition, piperine, from black pepper, may increase the levels of Coenzyme Q10 in the blood.
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