Sounds like 'SYE-an-oh-ko-BAL-a-min'

Easy-to-read medicine information about cyanocobalamin – what it is, how is it given and possible side effects.

Type of medicine Also called
  • Vitamin B supplement
  • Cytamen®
  • Vitamin B12
  • Cyanocobalamin (AFT)
  • Cobalamin

What is cyanocobalamin?

  • Cyanocobalamin is a synthetic (man-made) form of vitamin B12.
  • Vitamin B12 is needed to make new cells in the body such as red blood cells. A lack of vitamin B12 leads to anaemia, stomach problems and nerve damage.
  • Most people get enough vitamin B12 from their diet. It is is found in meat, fish, eggs, and milk — but not in fruit or vegetables. A normal balanced diet contains enough vitamin B12. 
  • A deficiency of vitamin B12 may occur in certain health conditions such as poor nutrition, stomach or intestinal problems (such as Crohn's disease), infection, and cancer. Also longterm strict vegetarian or vegan diets (no animal products) are associated with a higher risk of vitamin B12 deficiency.
  • Throughout pregnancy and breast feeding, higher dietary levels of vitamin B12 are required. Breastfed infants receive their daily intake of vitamin B12 through breast milk, dependent on the mother's intake. Breastfed infants receive their daily intake of vitamin B12 through breast milk, dependent on the mother's intake.
  • The level of vitamin B12 in the body can be measured by a blood test. If you have low levels of vitamin B12 your doctor may prescribe cyanocobalamin.
  • Cyanocobalamin is available as an injection. 

How is cyanocobalamin given?

  • Cyanocobalamin is given as an intramuscular injection, into the buttock muscle.
  • The usual dose of cyanocobalamin in people with pernicious anaemia is 1 milligram injected three times a week for two weeks, then once every two to three months.
  • For people with gastrointestinal disorders and older adults (over 50 years) who cannot obtain enough vitamin B12 in the diet, cyanocobalamin is given as twice yearly injections (every 6 months). This can be stopped when vitamin B12 levels have returned to normal and if the diet has improved.  

Possible side effects

Like all medicines, cyanocobalamin can cause unwanted side effects, although not everyone gets them. Often unwanted effects improve as your body gets used to the new medicine.  

Side effects What should I do?
  • Pain, redness or bruising at the injection site
  • This usually settles after a few days
  • Tell your doctor if troublesome
  • Signs of an allergic reaction such as skin rash, itches, swelling of the face, lips, mouth and tongue or problems breathing
  • Tell your doctor immediately or ring HealthLine 0800 611 116

Learn more

The following links provide further information on cyanocobalamin. Be aware that websites from other countries may contain information that differs from New Zealand recommendations.

Vitamin B12 deficiency and pernicious anaemia Patient Info, UK

Credits: Sandra Ponen, Pharmacist. Reviewed By: Dr J Bycroft. Health Navigator NZ Last reviewed: 03 Sep 2015