Vitamin B5 (Pantothenic Acid) - Nutrition

What is Vitamin B5 (Pantothenic Acid)?

Vitamin B₅, also called pantothenic acid, is an essential water-soluble vitamin used in energy metabolism. Pantothenic acid is an integral component of coenzyme A, which is synthesised in animals by a series of steps that involve the initial phosphorylation to pantothenic acid 4' -phosphate catalysed by pantothenate kinase, the primary regulatory step of Coenzyme A (CoA) synthesis. Dietary pantothenic acid is widely distributed in many foods, and is normally found as a component of CoA, acyl-CoA synthetase, or acyl carrier proteins. All of these forms are hydrolysed to pantothenic acid within the intestinal lumen prior to being absorbed by carrier mediated transport across the mucosa. Pantothenic acid is then transported in blood bound to red blood cells to target tissues. Pantothenic acid is filtered by the renal tubules, with active reabsorption during periods of low intake.

Why is it Important?

Pantothenic acid is an integral component of Coenzyme A (CoA) which is a key substrate in energy metabolism and is also required for synthesis of certain proteins and fatty acids.

Roles in the Body

1. Energy Metabolism: Pantothenic acid as CoA forms acetyl-CoA, which condenses with oxaloacetate to form citrate in the tricarboxylic acid (TCA) cycle during oxidation of glucose and fatty acids
2. Synthesis Reactions: Acetyl-CoA is used to form succinyl-CoA for synthesis of the porphyrin ring in haemoglobin; CoA involved in the synthesis of acetylcholine, ketone bodies, fatty acids, cholesterol, and vitamin D.

Consequences of Pantothenic Acid Deficiency

Dogs:

Dogs and puppies fed pantothenic acid-deficient diets experienced poor food intake and can develop sudden prostration and coma, tachypnea and tachycardia, gastritis, enteritis, and intussusceptions; death can results if efficiency not corrected.

Cats:

There are no published reports of pantothenic acid deficiencies in adults, but kittens fed pantothenic acid deficient diets experience poor growth rates. Conditions associated with diuresis (e.g. chronic disease, such as renal disease or diabetes, or therapeutic intervention, such as intravenous fluids or increased water intake with management of lower urinary diseases) can result in increased loss of pantothenic acid and may increase daily requirements. Patient on chronic haemodialysis are at an increased risk for developing a deficiency.

Toxicity

There are no published reports of pantothenic acid toxicity in dogs and cats.

Dietary Sources

Variable amounts of pantothenic acid occur naturally in all foods, but is found in highest concentrations in muscle and organ meats, eggs, dairy, cereal grains, and pulses (i.e. legumes). Pantothenic acid is typically supplemented in commercially-prepared complete and balanced dog and cat foods. Pantothenic acid like other water-soluble vitamins is prone to degradation with heat processing, and manufacturers have to account for processing losses in their recipes.

Diagnosing Pantothenic Acid Deficiency

Diagnosis is also made on clinical signs consistent with deficiency and evaluation of diet (either direct measurement or computer evaluation for pantothenic acid).

References

• 6. Gershoff SN and Gottlieb LS. Pantothenic acid deficiency in cats. J Nutr 1964;82:135-138.