Vitamin B-12 (Cyanocobalamin) (By mouth)

Cyanocobalamin (sye-an-oh-koe-BAL-a-min)

Supplies your body with vitamin B12. You might need a vitamin B12 supplement if your body has trouble using the vitamin B12 in the food you eat. You also might need vitamin B12 if you are a vegetarian, if you have had part of your stomach removed, or for other reasons. Prevents pernicious anemia, a blood problem caused by a lack of vitamin B12. Cyanocobalamin is another name for vitamin B12.

Brand Name(s):

B-12-SL, Mason Natural B-12, Nature's Blend B12, Sundown Naturals B12, Twelve Resin-K, Vitamist B12-500

There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

You should not use this medicine if you have had an allergic reaction to vitamin B12 (cyanocobalamin), hydroxycobalamin, or cobalt (a metal).

How to Use This Medicine:

Capsule, Tablet, Long Acting Tablet, Lozenge, Dissolving Tablet, Liquid, Spray

  • Your doctor will tell you how much medicine to use. Do not use more than directed.
  • Carefully follow your doctor's instructions about any special diet.
  • Follow the instructions on the medicine label if you are using this medicine without a prescription.
  • Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup. You might need to shake the liquid just before you use it. You may mix the oral liquid in some juice if you prefer.
  • Place the lozenge in your mouth or under your tongue and let it melt. Some brands of lozenges can also be swallowed. You might need to hold the medicine in your mouth for 30 seconds before you swallow it. Follow the directions on the medicine label.
  • Place the sublingual tablet under your tongue and let it melt. Some brands can also be swallowed. You might need to hold the medicine in your mouth for at least 30 seconds before you swallow. Follow the directions on the medicine label.
  • Spray the mouth spray on the inside of your cheek. Hold the medicine in your mouth for about 30 sections, then swallow.
  • Swallow the extended-release tablet whole. Do not crush, break, or chew it.

If a dose is missed:

  • Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

How to Store and Dispose of This Medicine:

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Make sure your doctor knows if you are also using folic acid (folate) supplements.

Warnings While Using This Medicine:

  • Make sure your doctor knows if you are pregnant or breast feeding, or if you have liver disease, kidney disease, or Leber's disease (an eye disease). Tell your doctor if you have low levels of iron in your blood.
  • Your doctor might need to check your blood at regular visits while you are using this medicine. Be sure to keep all appointments.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

If you notice these less serious side effects, talk with your doctor:

  • Diarrhea.
  • Mild skin itching.

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 11/6/2020

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