Usual Adult Dose for Pernicious Anemia

Initial dose: 1000 mcg intramuscularly or deep subcutaneous once a day for 6 to 7 days
If clinical improvement and reticulocyte response is seen from the above dosing:

• 100 mcg every other day for 7 doses, then:
• 100 mcg every 3 to 4 days for 2 to 3 weeks, then:

• Administer concomitant folic acid if needed.
• Chronic treatment should be done with an oral preparation in patients with normal intestinal absorption.

Usual Adult Dose for B12 Nutritional Deficiency

25 to 2000 mcg orally daily

Usual Adult Dose for Schilling Test

1000 mcg intramuscularly is the flushing dose

Usual Pediatric Dose for B12 Nutritional Deficiency

0.5 to 3 mcg daily

Renal Dose Adjustments

Data not available

Liver Dose Adjustments

Data not available

Dialysis

Data not available

Other Comments

Administration advice:

• Avoid intravenous administration: almost all of the vitamin will be lost in the urine.
• Warm parenteral solution to body temperature before administration for patient comfort.

• Pernicious anemia: monitor serum potassium closely during the first 48 hours of treatment and replace potassium if needed.

• Patients with pernicious anemia will require B12 for the rest of their lives; failure to do so will cause anemia to return, which could lead to incapacitating and irreversible damage to the nerves and spinal cord.
• Taking folic acid instead of B12 may prevent anemia, but allow degeneration of the spinal cord.