Vitamin B12 Deficiency & Self-Injection

Vitamin B12 (coblamin) is, according to the National Institute of Health’s Office of Dietary Supplements, “a nutrient that helps keep the body’s nerve and blood cells healthy and helps make DNA, the genetic material in all cells.” Also, it is an important nutrient in energy and can be depleted by common medications.

In order for the body to absorb vitamin B12, two steps are required:

  1. Acid in the stomach detaches vitamin B12 from the protein to which it is joined.
  2. Vitamin B12 combines with a protein called intrinsic factor and is absorbed by the body.

Many people eating an omnivorous diet absorb enough B12 through foods. Foods found to contain B12 include:

  • Beef liver and clams
  • Fish, meat, poultry, eggs, milk, and other dairy products
  • Some breakfast cereals, nutritional yeasts and other food products that are fortified

But, some people may not be able to gain adequate amounts of B12 from food.

Causes of Deficiency

Vitamin B12 deficiency has a number of possible causes, including:

  • Aging which results in decreased stomach acid
  • Thinning stomach lining (atrophic gastritis)
  • Surgical removal of part of the stomach or intestine, including weight loss surgeries
  • Pernicious anemia, a disease where the body doesn’t make intrinsic factor preventing absorption
  • Heavy drinking
  •  A vegan diet
  • A limited vegetarian diet lacking in eggs or dairy products
  • Crohn’s disease, celiac disease, irritable bowel disease
  • Immune system disorders
  • Long-term use of acid reducing drugs, such as Prilosec or Tums
  • Common medications

These are not the only causes and a person could very well have a deficiency without knowing it.

  • Genetic mutations such as Metformin- MTHFR.


Vitamin B12 deficiency can be dangerous, as it causes:

  • Insomnia
  • Fatigue
  • Megaloblastic anemia: blood disorder marked by the appearance of very large red blood cells
  • Nerve problems like numbness or tingling, muscle weakness, loss of balance and problems walking
  • Weakness or lightheadedness
  • Heart palpitations and shortness of breath
  • Mood disorders like depression or anxiety, memory changes such as memory loss, or behavioral changes

If you think you may have a deficiency, ask your doctor for a test. In fact, Harvard Medical Publications urges people who fall into the following categories to ask their doctor for a test:

  • over 50 years old
  • on a proton-pump inhibitor (such as Nexium or Prevacid) or H2 blocker (such as Pepcid or Zantac)
  • take metformin (a diabetes drug)


Many people respond well to vitamin B12 supplements, but some do not. In cases where absorption is hindered, intramuscular injections are a quick and effective source of vitamin B12 supplementation.

According to the Centers for Disease Control and Prevention (CDC), administering cyanocobalamin injections has been the “standard treatment protocol for decades.” This is because there are few side effects and patients’ acceptance is high. They also note: “Cobalamin replacement is effective because crystalline forms of B12 can be absorbed even when animal protein bound forms cannot be digested.” Higher doses can be administered intravenously (IV) or intramuscular (IM) as compared to oral doses.

If you are looking to boost your energy or combat a deficiency, consider vitamin B12 injections. Discuss available B12 treatment options with your physician.