What It Is
Coenzyme Q10 (CoQ10) is a vitamin-like substance that's manufactured by the body. Also called "ubiquinone" (or, ubiquitous—meaning "everywhere present"—quinone), CoQ10 is found in every living cell. It was first discovered in 1957 by Dr. Frederick Crane, who isolated the compound from a beef heart. Further research showed that CoQ10 occurs naturally in the tissues of almost all plants and animals, including humans.

What It Does
CoQ10 is critical for the production of energy necessary to keep cells, tissues and organs functioning properly. It's found in the mitochondria ("power plants") of cells, where it helps produce adenosine triphosphate (ATP)—the body's main energy source. ATP must be produced constantly to support every cell in the body. CoQ10 is found in high concentration in the heart, liver, kidneys and pancreas—all of which require greater levels of energy for proper function.

CoQ10 is also known to be a powerful antioxidant. It helps protect the proteins, lipids, and DNA of cell mitochondria from the damaging effects of free radicals.

Why You Should Take It
Levels of CoQ10 in the body decrease with age. They're known to peak at age 20, but a steady decline begins in the mid-thirties. By age 70, you're functioning on less than one third of the supply you had in your youth.

Some scientists believe the decline of energy production within cells is the main cause of cell death and dysfunction that occurs with aging. Low levels of CoQ10 in the body may cause less-efficient functioning of organs and lead to a number of diminished states of health, possibly playing a part in degenerative illnesses.

Those with chronic conditions such as heart disease, muscular dystrophies, Parkinson's disease, cancer, diabetes and HIV/AIDS have lower CoQ10 levels than healthy individuals. And people taking prescription drugs for lowering cholesterol, known as statins, may also have depleted levels of CoQ10.

What Amount Is Right For You
The general recommended supplementation dose for healthy adults is between 30 mg and 90 mg per day. Individuals with particular health concerns may choose to supplement with higher levels, basing the amount on study results published in medical and scientific journals. The above dosages are based on research, though they have not been approved as treatment by the U.S. Food and Drug Administration.