💊 B12 Deficiency Symptom Timeline Simulator

B12 Store Depletion Begins

Liver B12 reserves start to fall when intake or absorption is inadequate.

• 2–5 mg: Typical liver reserve (placeholder reference value)
• Month 0: Depletion onset (placeholder timepoint)
• None: Symptom presence (placeholder status)
• Low intake: Common cause (placeholder example)

Placeholder heading for store depletion mechanism

Placeholder: reserves shrink slowly before any lab or symptom changes appear.

Subclinical Deficiency — No Symptoms Yet

Stores are low but compensatory mechanisms still mask any symptoms.

• ~20%: Store level (placeholder threshold)
• Borderline: Serum B12 (placeholder lab flag)
• Delayed: Symptom onset (placeholder note)
• Labs only: Detectability (placeholder note)

Placeholder heading for subclinical phase

Placeholder: lab markers may shift before any clinical symptom is noticeable.

Hematologic Symptoms — Macrocytic Anemia

Red blood cells enlarge as impaired DNA synthesis disrupts normal division.

• Elevated: MCV (placeholder lab trend)
• ~Month 6–12: Onset window (placeholder timepoint)
• Common: Fatigue (placeholder symptom)
• High: Reversibility (placeholder outlook)

Placeholder heading for macrocytic anemia

Placeholder: enlarged, fragile red cells reduce oxygen-carrying capacity over time.

Neurologic Symptoms — Paresthesia

Peripheral nerve myelin degrades, producing tingling and numbness.

• ~Month 12–24: Onset window (placeholder timepoint)
• Hands/feet: Common site (placeholder location)
• Myelin loss: Mechanism (placeholder note)
• Moderate: Reversibility (placeholder outlook)

Placeholder heading for paresthesia onset

Placeholder: demyelination of peripheral nerves produces early tingling sensations.

Advanced Neurologic Damage — Ataxia

Prolonged deficiency damages spinal cord pathways, impairing coordination.

• ~Month 24–36: Onset window (placeholder timepoint)
• Gait ataxia: Key sign (placeholder symptom)
• Cord damage: Mechanism (placeholder note)
• Low: Reversibility (placeholder outlook)

Placeholder heading for advanced neurologic damage

Placeholder: prolonged deficiency risks irreversible spinal cord degeneration.

Placeholder callout: early treatment before this stage improves recovery odds.