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Vitamin B5

Acidum pantothenicum

For medical students2 min readUpdated 2026-10-10

Pantothenic acid (Acidum pantothenicum) is an essential nutrient whose deficiency leads to systemic metabolic and organ function disorders. Due to its ubiquitous presence in food, a deficiency of this vitamin is extremely rare.

DeficiencyAn extremely rare phenomenon due to the abundance of the vitamin in foods.
Nervous SystemParesthesias, neuritis, paralysis, sleep disturbances, and headaches.
Heart and GI TractMyocardial dystrophy, anorexia, and digestive disorders.
ToxicityNone. Excess is safe, and cases of poisoning are unknown.

Causes and Epidemiology of Deficiency

In medical practice, hypovitaminosis of Acidum pantothenicum is diagnosed extremely rarely. The primary and virtually sole etiological cause of this pathological state is an alimentary factor, meaning a permanent deficiency of the nutrient in the daily diet.

Because this chemical compound is found in almost all common food products, developing a pronounced deficiency on a standard diet is virtually impossible.

Pathogenesis and Metabolic Disruption

When pantothenic acid deficiency develops, critical biochemical processes in the body are impaired:

Clinical Manifestations by Organ System

Generalized pantothenic acid deficiency causes multi-organ pathology:

  1. Nervous System: Sleep disorders, chronic fatigue, persistent headaches, unpleasant paresthesias, nerve inflammation (neuritis), and even paralysis occur.
  2. Endocrine Status: Irreversible degenerative changes develop in the adrenal cortex, triggering the clinical picture of hypocorticism.
  3. Cardiovascular System: Dystrophic changes are recorded in the myocardium, accompanied by cardiac arrhythmias.
  4. Gastrointestinal Tract: Patients lose their appetite (anorexia) and suffer from disorders of luminal and membrane-bound digestion.
  5. Immune System: Against the background of profound immunosuppression, susceptibility to severe inflammatory and infectious diseases sharply increases. Specific impairments in renal function are also noted.

Safety and Toxicity

An important feature of pantothenic acid is its complete atoxicity. Even very high doses of this substance entering the body do not lead to negative consequences. Modern medical literature does not describe a single case of intoxication or overdose with this vitamin.

Mnemonic

Pantothenic acid is everywhere (from Greek pantos meaning 'from everywhere'): it is always present in food, and its deficiency hits the nerves, adrenals, and heart!

Frequently asked questions

Which essential coenzymes include pantothenic acid?

Pantothenic acid is the precursor vitamin for the synthesis of the essential acylation coenzyme — Coenzyme A.

  • Coenzyme A (CoA / HS-CoA) is a complex compound whose active form contains an adenylyl nucleotide, a thioethanolamine residue, and pantothenic acid (in the form of pantetheine).

The synthesis of this coenzyme in the body involves the phosphorylation of pantothenic acid using ATP, the addition of cysteine to form 4'-phosphopantetheine, and subsequent adenylylation.

What is the average daily requirement of an adult for pantothenic acid?

The average daily requirement of the body for pantothenic acid is about 10 mg.

The vitamin is ubiquitous in nature and is present in sufficient quantities in almost all food products (yeast, liver, egg yolk, fish, milk, meat, legumes, green plant parts). In addition, part of the required amount of the vitamin is synthesized by the normal intestinal microflora. This is why pathological conditions associated with pantothenic acid deficiency are very rare.

In which metabolic reactions does the active form of Vitamin B5 participate?

The active form of Vitamin B5 (Coenzyme A) participates in enzymatic reactions that catalyze the activation and transfer of acyl and acetyl groups.

Key metabolic reactions:

  • Formation of active forms of fatty acids.
  • Activation of acetate (acetic acid) with the formation of a high-energy bond in the acetyl-CoA molecule.
  • Oxidative decarboxylation of $\alpha$-keto acids (pyruvic and $\alpha$-ketoglutaric) as part of their respective multienzyme dehydrogenase complexes.
Why is Vitamin B5 deficiency so rare?

Pantothenic acid deficiency is practically non-existent in clinical practice because this vitamin is found in almost all food products.

What endocrine changes are caused by a lack of Vitamin B5?

The deficiency causes degenerative changes in the adrenal cortex, leading to hypocorticism and decreased synthesis of glucocorticoids.

Is an excess of pantothenic acid dangerous in overdose?

No, excess Vitamin B5 is completely non-toxic even at high doses; cases of intoxication have not been described in medical practice.

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