B12 Uses

The body needs vitamin B12 for blood cell reproduction as well as the formation and functioning of nerve and brain cells. A deficiency of this vitamin can lead to severe megaloblastic anemia, a type of anemia characterized by abnormally large red blood cells. This type of anemia can also occur in people with folic acid deficiency.

Signs and symptoms of B12 deficiency include glossitis (inflammation of the tongue), pale skin, fatigue, palpitations, weight loss, infertility, dementia, and numbness and tingling.

The following may receive cyanocobalamin injections to treat and prevent B12 deficiency:

People with pernicious anemia, a type of anemia in which there is lack of intrinsic factor, a natural substance that is required to absorb B12 from the intestines.

Individuals with certain diseases, such as Crohn’s disease or small intestinal  bacterial overgrowth (SIBO), which can interfere with the normal intestinal absorption of B12.

People who eat a strictly vegan or vegetarian diet that lacks natural food sources of B12 such as meat, fish, poultry, eggs, dairy, or fortified foods like breakfast cereals and nutritional yeast.

Parenteral administration of B12 (by injection under the skin or into a muscle) can be used to supplement B12 in people who have problems with oral absorption. Intravenous administration of vitamin B 12 can likewise bypass the digestive system.

There may be other uses of B12 (cyanocobalamin injections). Your health care professional or pharmacist can give you further B12 information.

B12 Mechanism of Action

B 12 (cyanocobalamin) is a man-made form of vitamin B12, which is found in certain foods. This vitamin is needed for DNA formation in the cells of the body. It is needed to maintain red blood cells, nerve cells, and brain cells.

B12 Doses

The dose of vitamin B 12 depends on the condition being treated and the severity of the deficiency. The usual dose of a cyanocobalamin injection is 100 mcg. The injection is given by a healthcare professional. You will receive injections regularly, initially once daily for about a week, then less frequently, and ultimately once every month. If you have pernicious anemia, you may need to take a cyanocobalamin injection monthly lifelong. 

Keep in mind that most people who eat a balanced healthy diet do not need oral B 12 supplementation. This vitamin is present in foods of animal origin, such as meat, fish, poultry, eggs, dairy, as well as fortified foods like breakfast cereals and nutritional yeast. People who eat a strict vegetarian diet may need to take B12 supplements.

According to the National Institutes of Health (NIH), the recommended daily allowance of B12 is as follows:

• Birth to 6 months: 0.4 mcg
• 7 to 12 months: 0.5 mcg 
• 1-3 years: 0.9 mcg
• 4-8 years: 1.2 mcg
• 9-13 years: 1.8 mcg
• 14+ years: 2.4 mcg
• Pregnancy: 2.6 mcg
• Lactation: 2.8 mcg

Source: National Institutes of Health