vitamin b12
Vitamin B12 (cyanocobalamin) is a dietary supplement used to treat low blood vitamin B12 levels (vitamin B12 deficiency). It's available as a pill and liquid that's typically taken by mouth once per day. But depending on your specific situation, your provider might have you take a different dosage. Vitamin B12 (cyanocobalamin) is generally well tolerated and doesn't have many side effects.
What is Vitamin B12 (cyanocobalamin)?
What is Vitamin B12 (cyanocobalamin) used for?
- Vitamin B12 deficiency in adults
How Vitamin B12 (cyanocobalamin) works
Vitamin B12 (cyanocobalamin) is a dietary supplement. Your body needs vitamin B12 (cyanocobalamin) for several processes, such as promoting red blood cell growth, maintaining nerve cell health, and making DNA (genetic material).
Drug facts
More on Vitamin B12 (cyanocobalamin) essentials
Side effects of Vitamin B12 (cyanocobalamin)
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
Side effects aren't common.
Vitamin B12 (cyanocobalamin) serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Serious allergic reaction: rash; trouble breathing; swelling of the lips, tongue, or face; vomiting
The following Vitamin B12 (cyanocobalamin) side effects have also been reported
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
Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):
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Pros and cons of Vitamin B12 (cyanocobalamin)
Pros
- Can help restore vitamin B12 levels if you're not getting enough from your diet
- Taken by mouth once per day
- Available over the counter in many different forms (e.g., pill, gummy, liquid)
Cons
- Not labeled for use in children younger than 18 years of age
- Many different dosages available, which can be confusing
- Some forms (e.g., liquids, gummies) contain sugar
Pharmacist tips for Vitamin B12 (cyanocobalamin)
- Discuss with your provider whether you're getting enough vitamin B12 from your diet or if you should take a vitamin B12 (cyanocobalamin) supplement.
- For the fast-dissolvable tablets, make sure your hands are dry before handling the medication. Place the tablet on the tongue to let it dissolve, and swallow with saliva. Don't swallow the fast-dissolving tablets whole. You don't need to drink water when taking a fast-dissolving tablet.
- For the liquid, use the measuring device that's included in the packaging to measure your dose of vitamin B12 (cyanocobalamin). This can sometimes be a dropper, medication dose cup, or an oral syringe. Ask your pharmacy to provide you with one if the product doesn't include it in its packaging or if you lose it. Don't use household spoons because they might not be accurate and might cause you to take the wrong dose. Follow the directions on the product labeling or your provider's instructions.
- You can take vitamin B12 (cyanocobalamin) with or without food. Check your product's labeling or with your provider for specific recommendations.
- Vitamin B12 (cyanocobalamin) is found in many other multivitamins and supplements. Make sure to read labels carefully on all of the dietary supplements you're taking to see if it contains vitamin B12 (cyanocobalamin).
- If you're taking metformin, a proton pump inhibitor (PPI) like omeprazole (Prilosec), or an H2 antagonist like famotidine (Pepcid AC), ask your provider whether you need to also take a vitamin B12 (cyanocobalamin) supplement. These medications can lower your blood vitamin B12 (cyanocobalamin) levels.
- Keep vitamin B12 (cyanocobalamin) out of reach of children so that they don't accidentally take it. If your child accidentally took vitamin B12 (cyanocobalamin), call your local Poison Control Center right away at 1-800-222-1222.
More on Vitamin B12 (cyanocobalamin) tips
Common questions about Vitamin B12 (cyanocobalamin)
Vitamin B12 (cyanocobalamin) has three major roles in the body. It helps your body make red blood cells to help prevent a condition called anemia. Vitamin B12 (cyanocobalamin) also keeps nerve cells healthy so that they work well. In addition, this vitamin is needed for your body to make DNA. Let your provider know if you have symptoms like headaches, dizziness, changes in vision, tingling in the arms or legs, and problems with balance. These can be symptoms of low vitamin B12 levels. Your provider can check your vitamin B12 levels and discuss with you whether you need vitamin B12 (cyanocobalamin) supplementation.
The recommended amount of vitamin B12 (cyanocobalamin) that you need per day differs based on your age and whether you're pregnant or breastfeeding. But in general, the recommended daily intake of vitamin B12 for adults is 2.4 mcg to 2.8 mcg per day. Most people can get enough vitamin B12 (cyanocobalamin) from their diet, but some people might need help to do so by taking supplements. Vitamin B12 (cyanocobalamin) supplements can contain amounts much higher than your body typically needs, like 1,000 mcg per day. But your body only absorbs a small portion of this amount. Depending on your specific situation (e.g., your vitamin B12 level, medical history), your provider might have you take a different dosage of vitamin B12 (cyanocobalamin).
It's usually not really a concern if you take too much vitamin B12 (cyanocobalamin). This is because it's a water-soluble vitamin. If you take too much vitamin B12 (cyanocobalamin) and your body doesn't need it, it'll typically get removed from your body through your urine. But to be safe from possible side effects, contact a poison control center at 1-800-222-1222 for help if you're worried that you or a loved one has taken too much vitamin B12 (cyanocobalamin).
Vitamin B12 (cyanocobalamin) is found in several types of foods, such as beef, seafood, poultry, and dairy products. It's also found in foods that are fortified with vitamin B12, such as nutritional yeasts and some breakfast cereals. In terms of manufactured forms of vitamin B12, it's often found in different types of vitamins and dietary supplements. Check the manufacturer's label of any dietary supplement or vitamin you're taking to see how much vitamin B12 (cyanocobalamin) you're getting.
You can take vitamin B12 (cyanocobalamin) supplements at any time of the day and with or without food. Take vitamin B12 (cyanocobalamin) whenever is most convenient for you when you won't forget to take any doses.
Methylcobalamin is simply the active form of vitamin B12. When you take vitamin B12 (cyanocobalamin), it gets changed into methylcobalamin in the body. When compared to one another, both forms of vitamin B12 appear to work similarly for most people. Talk with your provider about which form of vitamin B12 is best for you.
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Risks and warnings for Vitamin B12 (cyanocobalamin)
Vitamin B12 (cyanocobalamin) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Allergic reactions
Allergic reactions to vitamin B12 (cyanocobalamin) are possible, including life-threatening reactions like facial swelling, shock, and anaphylaxis (e.g., closing of the throat). If you notice difficulty breathing, a choking sensation, swelling around your eyes, swelling of the lips or tongue, dizziness, or nausea after using vitamin B12 (cyanocobalamin), get medical attention right away.
Not recommended for people with Leber’s disease (a rare genetic eye condition)
People with a rare, inherited eye condition called Leber's disease who received vitamin B12 developed severe eye damage. Vitamin B12 (cyanocobalamin) products isn't recommended in people with Leber's disease. If you have Leber's disease, speak with your provider about alternatives for vitamin B12 supplementation.
Close monitoring needed for people with severe pernicious anemia
If you have pernicious anemia, discuss with your provider whether vitamin B12 (cyanocobalamin) supplements that are taken by mouth are right for you. Sometimes, treating severe pernicious anemia with vitamin B12 can cause serious problems, like low potassium and high platelet levels. If you do, your provider will follow up with you more often. They'll track your potassium and platelet levels through bloodwork during treatment with vitamin B12 (cyanocobalamin). Contact your provider if you notice headache, confusion, shortness of breath, heart palpitations (chest pounding), muscle weakness or cramps, or unusual bleeding. These can be symptoms of electrolyte or platelet problems.
Potential to hide anemia due to low folic acid
- Risk factors: Taking more than 10 mcg of vitamin B12 daily
Taking vitamin B12 can sometimes mask anemia due to low folic acid levels). This means that vitamin B12 might help raise your red blood cell count without affecting your folic acid (folate) levels (so your folic acid levels will still be low). Your provider will check your folic acid levels through bloodwork before you start vitamin B12 (cyanocobalamin) to make sure you receive appropriate treatment for all your nutrient deficiencies.
Vitamin B12 (cyanocobalamin) dosage
How much does Vitamin B12 (cyanocobalamin) cost?
$3.30
What are alternatives to Vitamin B12 (cyanocobalamin)?
