Ask Your Pharmacist

March 24, 2022

I have been having a difficult time getting to the doctor for my monthly B12 injections. Are there other options?


Vitamin B12, also known as cobalamin, is an important water-soluble vitamin involved in red blood cell production, keeping a healthy brain, and in cell growth.

Vitamin B12 deficiency is present in five out of 100 Canadians. The main cause of B12 deficiency in Canada is lack of a special factor known as intrinsic factor, in people diagnosed with Pernicious Anemia. Pernicious Anemia occurs in about two out of 100 Canadians. People with specific diet requirements (i.e., vegan diet) may also be deficient in vitamin B12.

Vitamin B12 is found in most of our diets, contained in meat, seafood, dairy products and eggs.  The recommended daily allowance of cobalamin is 2.4 mcg, except in pregnancy it is 3.5 mcg.  The human body stores approximately two to five milligrams of vitamin B12, and in most people it takes up to five years to deplete these stores.

Signs and symptoms of vitamin B12 deficiency include nerve damage, numbness and tingling, worsening coordination, abnormal uncontrolled movements, memory lapses, impairment in thinking related to aging, and digestive problems. The risk of B12 deficiency rises with age.

Historically, people with vitamin B12 deficiency have been treated by intramuscular injection by a health care professional. The continual visits to the doctor’s office for monthly injections can be logistically difficult, and inconvenient. This can be a particular challenge in rural areas of the province given the shortages of primary care providers. There is always risk of injection site infection with any kind of injection, the injections can leave your arm sore, and some people do not like needles. 

New Brunswick pharmacists who are certified injectors can administer B12 intramuscular injections. There is a fee of $15 to $20 associated with the administration of this injection because it is currently not covered by Medicare when it is administered by a pharmacist.

Scientists compared the effectiveness of oral tablets versus intramuscular injection for boosting vitamin B12. Results of these studies showed that in terms of resolution of B12 deficiency signs and symptoms, and improved in blood work, oral B12 replacement worked as well as intramuscular injections.

If you are getting B12 replacement by injection, it is worth discussion with your doctor or nurse practitioner to see if oral B12 replacement is an option for you. 

Oral vitamin B12 is available over the counter without a prescription. The oral formulations are available as cyanocobalamin or methylcobalamin. Cyanocobalamin is a synthetic form of vitamin B12 found only in supplements, while methylcobalamin is a naturally occurring form that you can get through either food sources or supplements. Both types are effective and both types are converted in the body to cobalamin. 

Multiple dosage forms and brands of vitamin B12 supplements are available. The cost is approximately $15 for 90 capsules of cyanocobalamin 1000 mcg. Generally, the recommended oral dosing of vitamin B12 is 1000 mcg to 2000 mcg daily initially, and then 1000 mcg daily, thereafter weekly and then monthly. Talk to your pharmacist to help you with your specific dosage regimen. She/he will also help you choose an appropriate over-the-counter product. If you do choose oral vitamin B12 supplementation, it is important to remember to take the dose daily or as prescribed.

If you are receiving a vitamin B12 injection at the pharmacy, it is best practice to get a prescription from a doctor or nurse practitioner first so that they can order bloodwork and arrange follow-up monitoring to make sure your symptoms are improving and that your blood levels are at target. Yearly blood tests to measure your complete blood count and vitamin B12 levels are recommended. Patients with Pernicious Anemia require lifelong therapy, while patients with food-malabsorption require treatment until the underlying condition or diet is corrected.

Continuing vitamin B12 injections or oral supplementation can lead to very high levels of vitamin B12 in the blood. Although generally this is not unsafe, it is unnecessary and is not a good use of your hard-earned money or our precious health care resources.

Dr. Kevin Duplisea (PharmD BSc. Pharm, BSc. ACPR) is a pharmacist at Sharp’s Corner Drugstore in Sussex, New Brunswick. His opinions expressed in this newspaper are published for educational and informational purposes only, and are not intended as a diagnosis, treatment or as a substitute for professional medical advice, diagnosis or treatment. Send your questions to