What Is a Cyanocobalamin Injection?

Cyanocobalamin injection is vitamin B12. It is given supplementally to people who are vitamin B12 deficient. These may include strict vegetarians and people with impaired absorption due to an underlying clinical condition such as pernicious anemia, post-gastrectomy or gastric bypass and those with malabsorption disorders. It is usually given as an intramuscular or deep sub-cutaneous injection.

A deficiency of vitamin B12 can have serious adverse effects on the body. Vitamin B12 is involved in numerous functions, including normal cell reproduction and growth. It also plays an important role in the production of red blood cells or hematopoieisis.

Vitamin B12 is a water-soluble vitamin which is normally obtained through diet. Natural sources of the vitamin include organ meats, eggs, fish, meat, poultry and milk. It is for this reason that strict vegetarians or vegans may have vitamin B12 deficiency, and regular cyanocobalamin injections may be recommended for those who are deficient. Infants of vegan mothers may also require supplemental cyanocobalamin.

In order for vitamin B12 to be absorbed, it needs to be released from the protein in the stomach by hydrochloric acid and then combined with intrinsic factor. Some clinical conditions, such as pernicious anemia, cause a deficiency in the intrinsic factor and, therefore, decrease absorption of vitamin B12. The same may occur after gastric bypass surgery or post-gastrectomy, and cyanocobalamin injection may be given to counteract the resulting deficiency.

The dose and frequency of a cyanocobalamin injection will depend on the extent of the vitamin B12 deficiency. In the acute stage it may be given as often as alternate days, whereas in cases of mild deficiency, for maintenance or as prophylaxis it may be given monthly. Folic acid supplementation may be given at the same time but should not be started until at least 24 hours after the administration of the cyanocobalamin injection. Vitamin B12 supplementation should only be given under medical supervision and the recommended dose should not be exceeded.

As with any medication, cyanocobalamin may interact with other medications and be contraindicated in patients with some clinical conditions. Any other medicines, including homeopathic, complementary and over-the-counter medications or underlying medical conditions should be discussed with the health professional. Pregnancy, desired pregnancy and lactation should also be disclosed.

While rare, adverse effects or allergic reactions have occasionally been reported during administration of cyanocobalamin injection. Should any untoward side effects be experienced, medical attention should be obtained immediately.