D-Ribose supplies a supplemental source of D-Ribose, a naturally occurring five-carbon sugar found in all living cells. D-Ribose is essential to life, and has been shown to support healthy cardiac function. It is an essential component of RNA and DNA, as well as an essential ingredient in the production of ATP. It is found in high amounts in organs and tissues of high-energy output, including the heart, liver, adrenals, brain, muscles, endocrine glands and the gastrointestinal tract. Although ribose can be made in vivo from glucose, and is not considered an essential nutrient, it may become conditionally essential in times of high-energy output. In the production of ATP, ribose is an essential part of both the de novo pathway, and what is termed the “salvage pathway.” In the salvage pathway, ribose is “salvaged” from ATP metabolites, which in turn is utilized to form new ATP molecules.