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Medical and Pharmacy Editor:

Brand Name: Vitamin B12, Nascobal, Athlete, Calomist, Cobalamin, Cobex, Crystamine, Prime, Rubramine PC, Vibisone, Eligen B12

Generic Name: Cyanocobalamin

Drug Class: B Vitamins; Vitamins, Water-Soluble

What Is Cyanocobalamin and How Does It Work?

Cyanocobalamin is a prescription and over-the-counter (OTC) man-made form of vitamin B12 used to prevent and treat low blood levels of vitamin B12. Most people get enough vitamin B12 from their diet. Vitamin B12 is important to maintain the health of your metabolism, blood cells and nerves. Serious vitamin B12 deficiency may result in a low number of red blood cells (anemia), stomach/intestine problems, and permanent nerve damage.

Vitamin B12 deficiency may occur in certain health conditions, such as intestinal/stomach problems, poor nutrition, cancer, HIV infection, pregnancy, old age, alcoholism. It may also occur in people who follow a strict vegetarian (vegan) diet.

Cyanocobalamin is available under the following different brand names: Vitamin B12, Nascobal, Athlete, Calomist, Cobalamin, Cobex, Crystamine, Prime, Rubramine PC, Vibisone, and Eligen B12.

Dosages of Cyanocobalamin:

Adult and pediatric dosages:


  • 100 mcg
  • 250 mcg
  • 500 mcg
  • 1,000 mcg

Tablet, extended release

  • 1,000 mcg

Tablet, sublingual

  • 2,500 mcg

Injectable solution

  • 1,000 mcg/ml

Nasal spray

  • 500 mcg/spray

Dosage Considerations – Should be Given as Follows:

Nutritional Supplementation


  • Adults over 19 years: 2.4 mcg
  • Pregnant women: 2.6 mcg
  • Breastfeeding women: 2.8 mcg
  • Dietary supplement: 50-6,000 mcg/day


  • Infants 0-6 months: 0.4 mcg
  • Infants 7-12 months: 0.5 mcg
  • Children 1-3 years: 0.9 mcg
  • Children 4-8 years: 1.2 mcg
  • Children 9-13 years: 1.8 mcg
  • Children over 14 years: 2.4 mcg

Pernicious Anemia

Adult Dosages

  • Manufacturer recommendation: 100 mcg intramuscularly or subcutaneously once daily for 6-7 days, then every other day for 7 doses, then 3-4 days for 2-3 weeks, then monthly
  • Alternative parenteral dosing: 1,000 mcg intramuscularly or subcutaneously once daily for 7 days, then weekly for 1 month, then monthly
  • Nasal spray: 500 mcg (1 spray in 1 nostril) weekly; if patient is taking hot meals, spray should be administered 1 hour before or after meal

Pediatric Dosages

  • 30-50 mcg intramuscularly or subcutaneously once daily for 2 weeks or more for total dose of 1,000 mcg to 5,000 mcg administer concomitantly with 1 mg/day of folic acid for 1 month
  • Maintenance: 100 mcg intramuscularly or subcutaneously monthly

B12 Deficiency

Adult Dosages

  • Initial: 30 mcg intramuscularly once daily for 5-10 days
  • Maintenance: 100-200 mcg intramuscularly monthly
  • Nasal dose: 500 mcg once weekly

Dosing considerations:

Pediatric Dosages

  • 0.2 mcg/kg for 2 days; follow by 1,000 mcg/day for 2-7 days; follow by 100 mcg/day for 2-7 days; then 100 mcg/week for 1 month
Medically Reviewed by a Doctor on 5/18/2017

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