Nicotinamide adenine dinucleotide (NAD) and the phosphate derivative, NADP, are two coenzymes that are regularly utilized in the body for electron-transfer biochemical reactions as carriers of hydrogen ions. NADH (the reduced form of NAD) is the active coenzyme form of vitamin B-3 and is necessary for the production of cellular energy and integral in the development of essential neurotransmitters.

View a second image of nicotinamide adenine dinucleotide.

View a third image of nicotinamide adenine dinucleotide.

When the nucleotide adenosine (A) is coupled to a nicotinamide analog nucleotide, NAD and NADP are produced. Nicotinamide adenine dinucleotide phosphate (NADP) is simply NAD with a third phosphate group attached, and is very important in the energy transformation process of photosynthesis. While the oxidized form is represented as NAD+, the reduced form is recognized as NADH. Several investigators have speculated that NAD and vitamin B-12 might be evolutionary remnants of the original RNA-based metabolism that predates the current genetic code. Nicotinamide adenine dinucleotide is also available as pharmaceutical and reagent-grade synthesized white crystals.

Deficiencies in vitamin B-3 occur with alcoholics and result in NADH deficiencies. Therapies for chronic fatigue syndrome, Alzheimer's disease, congestive heart failure, and Parkinson's disease are based on administering doses of nicotinamide adenine dinucleotide. Natural sources for NAD dietary intake are the muscle tissue of fish, poultry, and cattle, as well as yeasty foods such as breads and ale. NADH acts as an antioxidant and enzyme facilitator. Lower levels of the coenzyme are associated with aging and may explain a general lack of energy in deficient individuals. NADH as a supplement may aid in the treatment of migraine headaches, diabetes, depression, and some respiratory problems. In the brain, medical research indicates that nicotinamide adenine dinucleotide improves alertness and concentration, and helps balance moods and emotions by allowing the proper functioning of the enzyme monoamine oxidase.