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Vitamin B12
From WikEM
Contents
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
