Pantothenic acid, commonly called vitamin B5, is a water-soluble vitamin that participates in many central metabolic reactions. It is chemically related to the compound pantoate coupled with the amino acid beta-alanine. As an essential nutrient, pantothenic acid must be obtained from the diet; it is widely distributed in plant and animal foods.

Chemical nature and forms

Pantothenic acid exists in free form and as salts (pantothenates) and is a constituent of longer functional molecules. Its most important biological derivatives are coenzyme A (CoA) and the 4'-phosphopantetheine group of acyl carrier protein (ACP). These derivatives act as carriers of acyl groups and are central to metabolism of carbohydrates, fats and some amino acids.

Biological functions

Through CoA and ACP, pantothenic acid helps transfer chemical groups during energy-producing pathways and the synthesis and breakdown of fatty acids, cholesterol and certain neurotransmitters. It therefore supports cellular energy production, lipid metabolism and the building blocks needed for cellular repair and growth.

Dietary sources and deficiency

Pantothenic acid is found in a wide variety of foods, which explains its name derived from the Greek for "from everywhere." Common sources include meat, poultry, fish, eggs, dairy, whole grains, legumes and many vegetables. Because it is widespread in foods, deficiency in otherwise healthy people is uncommon. When it does occur, reported signs include fatigue, irritability, gastrointestinal upset and, in severe cases, neuropathic symptoms.

History, uses and safety

Identified in the early 20th century as a necessary nutrient, pantothenic acid later became recognized for its role in forming CoA. It is used in dietary supplements, fortified foods and animal feeds. Topical and cosmetic products sometimes include pantothenate derivatives for claimed skin or hair benefits, though evidence varies. As a water-soluble vitamin, excess amounts are generally excreted in urine and it has a low toxicity profile.

Notable distinctions and practical notes

  • Pantothenic acid is one of the B vitamin group: see general vitamin resources at B vitamins overview.
  • Because it is a building block of coenzyme A, its role is structural as well as catalytic in metabolism — see basic vitamin information at vitamin pages.
  • Supplementation may be recommended in specific clinical or dietary situations, but most people meet needs through a varied diet.

Pantothenic acid remains an essential, broadly available nutrient notable for its central biochemical role rather than for its scarcity in foods.