Pantothenic acid
Essential B vitamin required for coenzyme A synthesis.
Pantothenic acid, also known as vitamin B5, is a water-soluble B vitamin and an essential nutrient. It is required by all animals for the synthesis of coenzyme A (CoA), which is critical for cellular energy production and the metabolism of proteins, carbohydrates, and fats. Its name derives from the Greek word πάντοθεν (pantothen), meaning 'from everywhere,' because it is found in small amounts in almost all foods.
- field
- Nutrition, Biochemistry
- known_for
- Essential precursor to coenzyme A (CoA); water-soluble B vitamin
- chemical_form
- Combination of pantoic acid and β-alanine
- common_supplement_form
- Calcium pantothenate
- adequate_intake_adults
- 5 mg/day (US and EU)
Lore & Background
Pantothenic acid is synthesized from the amino acid β-alanine and pantoic acid. Unlike some vitamins that occur in multiple forms (vitamers), pantothenic acid is a single chemical compound. It serves as the starting compound for the five-step biosynthesis of coenzyme A, which requires pantothenic acid, cysteine, and four equivalents of ATP. The first committed step is phosphorylation by pantothenate kinase, and the pathway is suppressed by end-product inhibition, where CoA competitively inhibits that enzyme. Dietary sources include animal-sourced foods, dairy, eggs, potatoes, tomato products, oat-cereals, sunflower seeds, avocado, mushrooms, and whole grains. Milling grains to produce white rice or white flour removes much of the pantothenic acid. Deficiency is very rare in humans. In supplements, the stable form calcium pantothenate is often used, and pantothenol (panthenol) is also common as a shelf-stable analog that converts to pantothenic acid after consumption. Absorption requires conversion of food-bound CoA and acyl carrier protein into free pantothenic acid via enzymatic hydrolysis in the intestine. Free pantothenic acid is absorbed via a saturable, sodium-dependent active transport system, with passive diffusion occurring at high intakes. Excretion occurs in urine, with typical daily urinary output around 2.6 mg/day.
Reader's Guide
Pantothenic acid is a foundational nutrient because it is indispensable for the synthesis of coenzyme A, a cofactor central to the citric acid cycle, fatty acid synthesis, and numerous acetylation and acylation reactions. Without it, cells cannot efficiently produce energy or metabolize macronutrients. Its rarity of deficiency in humans reflects its widespread presence in foods, and no countries require fortification with it. Dietary reference intakes are set as Adequate Intakes (AIs) rather than Recommended Dietary Allowances due to insufficient data for EARs; the US AI for adults is 5 mg/day, matching the European Food Safety Authority's value. No tolerable upper intake level has been established because no adverse effects from high doses have been documented in humans. A related compound, pantethine (two pantothenic acid molecules linked by a disulfide bridge), may lower LDL cholesterol, but pantothenic acid itself does not share this effect. The compound's role in CoA synthesis connects it to other B vitamins, including thiamin and folic acid.
Did You Know?
- Pantothenic acid's name comes from the Greek 'pantothen,' meaning 'from everywhere,' because it is found in almost all foods.
- Deficiency of pantothenic acid is very rare in humans.
- Calcium pantothenate is used in supplements because it is more stable than sodium pantothenate or free pantothenic acid.
- No countries require foods to be fortified with pantothenic acid due to the rarity of deficiency.
Frequently Asked Questions
Who is Pantothenic acid?
Pantothenic acid, commonly called vitamin B5, is a water-soluble B vitamin that every animal needs to build coenzyme A, the molecule that powers cellular energy and drives the breakdown of proteins, carbs, and fats. Its name comes from the Greek 'pantothen,' meaning 'from everywhere,' a nod to how widely it appears across the food supply.
What are Pantothenic acid's powers/role?
Its signature role is serving as the essential precursor to coenzyme A (CoA), without which cells cannot generate energy or metabolize macronutrients. Chemically it is a combination of pantoic acid and β-alanine, and in supplement form it most often appears as calcium pantothenate.
How does Pantothenic acid's story end?
Because it is water-soluble, the body cannot store meaningful reserves, so any excess is simply flushed out in urine and the nutrient must be 'recast' daily through diet. The recommended adequate intake for adults in the US and EU sits at just 5 mg per day, and true deficiency is exceedingly rare in well-fed populations.
Why is Pantothenic acid important?
Without it, the synthesis of coenzyme A halts, which would stall virtually every energy-producing pathway in the cell. It is therefore classified as an essential nutrient, meaning the body cannot manufacture it and must obtain it from food or supplementation.
Where can fans find Pantothenic acid in the canon?
Staying true to its 'from everywhere' name, it is present in trace amounts in nearly all whole foods, from meats and eggs to grains and vegetables. For those seeking a concentrated dose, calcium pantothenate is the most common supplement form on the market.
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