What is this medication?

Vitamin B12 (VAHY tuh min B12) prevents and treats low vitamin B12 levels in your body. It is used in people who do not get enough vitamin B12 from their diet or when their digestive tract does not absorb enough. Vitamin B12 plays an important role in maintaining the health of your nervous system and red blood cells.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

COMMON BRAND NAME(S): B-12 Compliance Kit, B-12 Injection Kit, Cyomin, Dodex, LA-12, Nutri-Twelve, Physicians EZ Use B-12, Primabalt

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

  • Kidney disease
  • Leber's disease
  • Megaloblastic anemia
  • An unusual or allergic reaction to cyanocobalamin, cobalt, other medications, foods, dyes, or preservatives
  • Pregnant or trying to get pregnant
  • Breast-feeding

How should I use this medication?

This medication is injected into a muscle or deeply under the skin. It is usually given in a clinic or care team's office. However, your care team may teach you how to inject yourself. Follow all instructions.

Talk to your care team about the use of this medication in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you are given your dose at a clinic or care team's office, call to reschedule your appointment. If you give your own injections, and you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medication?

  • Colchicine
  • Heavy alcohol intake

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medication?

Visit your care team regularly. You may need blood work done while you are taking this medication.

You may need to follow a special diet. Talk to your care team. Limit your alcohol intake and avoid smoking to get the best benefit.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

  • Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
  • Swelling of the ankles, hands, or feet
  • Trouble breathing

Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):

  • Diarrhea

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medication?

Keep out of the reach of children.

Store at room temperature between 15 and 30 degrees C (59 and 85 degrees F). Protect from light. Throw away any unused medication after the expiration date.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

Copyright ©2023 Elsevier Inc. All Rights Reserved. Terms of Use.

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy