Vitamins & CofactorsMarch 19, 20262 min read

5-second rule for Pantothenic acid

Quick-hit shareable content for Pantothenic acid. Include visual/mnemonic device + one-liner explanation. System: Biochemistry.

5-second rule for Pantothenic acid (Vitamin B5)

If you can say this in 5 seconds, you’ll never miss a B5 question again:

“Pantothenic acid (B5) makes CoA (and fatty acid synthase), so deficiency = dermatitis, enteritis, alopecia, plus neuropathy and fatigue.”

The 5-second rule (memorize this)

B5 → CoA → Acyl transfers (FA metabolism) → “DEA + tired nerves”

  • Dermatitis
  • Enteritis (GI inflammation/diarrhea)
  • Alopecia
  • + fatigue, irritability
  • + peripheral neuropathy (classically “burning feet”)

Visual mnemonic (quick mental picture)

“PANTO = PANTS + COA”

Picture someone wearing pants with a big tag that says “CoA”.

  • When the pants (PANTO) are missing:
    • Skin looks rash-y (dermatitis)
    • Gut is angry (enteritis/diarrhea)
    • Hair is falling out (alopecia)
    • Feet feel like they’re burning (neuropathy)

One-liner explanation (why this happens)

Pantothenic acid is a core component of CoA, so low B5 impairs acyl-group transfer reactions used in fatty acid metabolism and energy production—leading to skin/GI issues and neuropathy.

High-yield USMLE facts (Step 1 + Step 2)

What B5 does

  • Pantothenic acid (Vitamin B5) is required to form:
    • Coenzyme A (CoA) → acyl-group transfer (e.g., acetyl-CoA, succinyl-CoA derivatives)
    • Acyl carrier protein (ACP) in fatty acid synthase

Where it shows up in biochem pathways

Know that CoA derivatives are everywhere:

  • Fatty acid synthesis and β-oxidation
  • TCA entry via acetyl-CoA
  • Synthesis of:
    • Cholesterol/steroid hormones
    • Ketone bodies
    • Acetylcholine (acetyl-CoA donor)

Deficiency

  • Rare (widely available in diet)
  • Classically associated with severe malnutrition (boards may frame as a broad vitamin deficiency picture)
  • Key symptoms to recognize:
    • Dermatitis, enteritis, alopecia
    • Peripheral neuropathy (may be described as burning feet)
    • Fatigue/irritability

Don’t confuse with other B vitamins

  • B3 (niacin): dermatitis + diarrhea + dementia (± death)
  • B2 (riboflavin): cheilosis, corneal vascularization
  • B7 (biotin): dermatitis, alopecia, enteritis (often from raw egg whites)
  • B5 (pantothenate): DEA + neuropathy/fatigue, tied to CoA
💡

Test-taking tip: If the vignette emphasizes CoA/acyl transfer (fat metabolism, acetyl-CoA) + skin/GI + neuropathy, think B5.

Lightning review (shareable)

Pantothenic acid (B5) = “PANTO wears COA pants.”
Deficiency (rare): Dermatitis, Enteritis, Alopecia + neuropathy/fatigue (burning feet).

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