Vitamin B12

Administration

  • Type: Vitamin
  • Dosage Forms:
  • Routes of Administration: IV/IM, oral, nasal, sublingual
  • Also known as cobalamin, cyanocobalamin

Adult Dosing

  • Normal absorption: 1000 mcg/day PO
  • Malabsorption: 100-1000 mcg IV/IM or deep SC injection daily for 6 or 7 days
  • Nasal spray: 500 mcg intranasally in one nostril weekly

Pediatric Dosing

  • 30-50mcg IM daily (preferred) OR 1000 mcg/day PO

Special Populations

  • Pregnancy Rating: C
  • Lactation risk: Infant risk cannot be ruled out
  • Renal dosing: increased dose/frequency may be required
  • Hepatic dosing: increased dose/frequency may be required

Contraindications

  • Allergy to class/drug

Adverse Reactions

Serious

  • CHF, pulmonary edema
  • Anaphylaxis, angioedema
  • Peripheral vascular disease

Common

  • Injection site pain
  • Arthralgia
  • Dizziness, headache
  • Nasopharyngitis

Pharmacology

  • Half-life:
  • Metabolism: biliary; enterohepatic cycling
  • Excretion: mostly renal

Mechanism of Action

  • Vital to cell reproduction, growth, and synthesis of myelin and nucleoprotein, as well as energy metabolism

Comments

See Also

References

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