Vitamin B5: Pantothenic Acid

Pantothenic acid is composed of two molecules: pantoic acid and amino acid alanine.¹ Pantothenic acid is destroyed by heat and low pH levels but is stable in light and air.¹ Other than food sources, pantothenic acid can be synthesized by intestinal bacteria.¹ Pantothenic acid is known for being a part of the molecule coenzyme A (CoA) used in metabolic pathways such as the Krebs cycle.¹

Absorption/Circulation/Excretion: The majority of pantothenic acid (85%) is found as a part of coenzyme A within foods and is converted into pantotheine during digestion.¹ Pantotheine is then converted into pantothenic acid and is absorbed within the small intestine, specifically the jejunum, via a protein called the sodium-dependent multivitamin transporter (SMVT).¹ SMVT is responsible for biotin absorption.¹ Pantothenic acid is also absorbed via passive diffusion.¹

Once absorbed, pantothenic acid enters the portal vein. The liver, cardiac muscle, and skeletal muscle absorb pantothenic acid using a sodium-dependent, active process compared to the passive process in adipose cells, central nervous tissue, and renal tissue.¹ Red blood cells contain pantothenic acid in the form of coenzyme A.¹ Tissues in the heart, kidneys, liver, adrenal glands, and brain have a higher concentration of pantothenic acid due to their roles in metabolism.¹ Pantothenic acid is excreted in urine under renal regulation.¹

Functions: Pantothenic acid is used during the post-translation of certain proteins for stabilization and is part of the acyl carrier protein (ACP) that is found in the fatty acid synthase (FAS) enzyme complex.¹ ACP binds nascent fatty acids during synthesis.¹ Free radicals may be destroyed by pantothenic acid.¹

However, the main function of pantothenic acid is as coenzyme A in many metabolic molecules. Pantothenic acid is prepped to form coenzyme A in a series of reactions.¹ Coenzyme A  is used in glucose, protein, fat, and alcohol metabolism.¹ Examples of coenzyme A in metabolic molecules include:

Acetyl CoA: synthesized during oxidation of fatty acids, specific amino acids, pyruvate, and ethanol.¹ Acetyl CoA forms citrate, the first molecule of the Krebs cycle, when condensed with oxaloacetate.¹

Acetyl CoA is required for fatty acid and cholesterol synthesis, and fatty acids require CoA during b-oxidation and phospholipid attachment.¹

Propionyl CoA: derived when CoA activates propionic acid which is created during oxidation of odd-length fatty acids and amino acids methionine, leucine, and isoleucine.¹

Methylmalonyl CoA: an intermediate product derived from the conversion of propionyl CoA to succinyl CoA.¹

Succinyl CoA: an intermediate product derived when CoA activates succinic acid.¹

Dietary Reference Intake (DRI) - The Adequate Intake (AI) of pantothenic acid for males and females 14-70+ years old is 5 milligrams/day.²

Deficiency/Toxicity - Pantothenic acid deficiency is rare and can range from tingling of feet, impaired motor function, and GI distress to tachycardia, hypotension, and ulcerations as it develops.¹ No case of toxicity is known.¹

Dietary Sources of Pantothenic Acid 

The prefix pantos (derived from Greek) means “from everywhere” - pantothenic acid can be found in a variety of foods.¹ This includes animal meats (including organ meats), grains/nuts, dairy, and produce.¹ Pantothenic acid content may be reduced during cooking processes such as exposure to heat and acid. Examples of foods that contain pantothenic acid are: 

Meat -  beef liver, chicken, tuna, beef 

Grains/Nuts/Seeds - Oatmeal, breakfast cereals (fortified), sunflower seeds 

Dairy -  Greek yogurt, milk, cheese, yogurt 

Fruit/Vegetables - shitake mushrooms, avocados, potatoes, broccoli, clementines

Source(s):

1. Denise M Medeiros and Robert E.C. Wildman, Advanced Human Nutrition, 4th ed. (Burlington, MA: Jones & Bartlett, 2019).

2. https://ods.od.nih.gov/factsheets/PantothenicAcid-HealthProfessional/