Cyanocobalamin with Ascorbic Acid Interaction Details

Brand Names Associated with Cyanocobalamin

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated Nov 15, 2023

Interaction Effect

Reduced amounts of cyanocobalamin available for serum and body stores

Interaction Summary

Ascorbic acid in doses as low as 250 mg may destroy up to 81% of the cyanocobalamin in a moderate vitamin B12-containing meal, and up to 25% in a high vitamin B12-containing meal. The degree of destruction appears to be dependent on the various other ingredients in the meal, such as iron in moderate amounts and nitrates, which may counteract ascorbic acid's effect on cyanocobalamin. To diminish the possibility and magnitude of such destruction, it is suggested that ascorbic acid be taken two or more hours after meals. While ascorbic acid may still destroy a substantial amount of the normally excreted vitamin B12 and possibly lower vitamin B12 in serum and body stores, frank megaloblastic anemia would require megadoses of ascorbic acid ingested over several years.

Severity

Minor

Onset

Delayed

Evidence

Probable

How To Manage Interaction

Ascorbic acid should be administered two or more hours after a meal or vitamin B12 supplements.

Mechanism Of Interaction

Unknown

Cyanocobalamin Overview

• Cyanocobalamin injection is used to treat and prevent a lack of vitamin B₁₂ that may be caused by any of the following: pernicious anemia (lack of a natural substance needed to absorb vitamin B₁₂ from the intestine); certain diseases, infections, or medications that decrease the amount of vitamin B₁₂ absorbed from food; or a vegan diet (strict vegetarian diet that does not allow any animal products, including dairy products and eggs). Lack of vitamin B₁₂ may cause anemia (condition in which the red blood cells do not bring enough oxygen to the organs) and permanent damage to the nerves. Cyanocobalamin injection also may be given as a test to see how well the body can absorb vitamin B₁₂. Cyanocobalamin injection is in a class of medications called vitamins. Because it is injected straight into the bloodstream, it can be used to supply vitamin B₁₂ to people who cannot absorb this vitamin through the intestine.

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Definitions

Severity Categories

Contraindicated

These drugs, generally, should not be used together simultaneously due to the high risk of severe adverse effects. Combining these medications can lead to dangerous health outcomes and should be strictly avoided unless otherwise instructed by your provider.

Major

This interaction could result in very serious and potentially life-threatening consequences. If you are taking this drug combination, it is very important to be under close medical supervision to minimize severe side effects and ensure your safety. It may be necessary to change a medication or dosage to prevent harm.

Moderate

This interaction has the potential to worsen your medical condition or alter the effectiveness of your treatment. It's important that you are monitored closely and you potentially may need to make adjustments in your treatment plan or drug dosage to maintain optimal health.

Minor

While this interaction is unlikely to cause significant problems, it could intensify side effects or reduce the effectiveness of one or both medications. Monitoring for changes in symptoms and your condition is recommended, and adjustments may be made if needed to manage any increased or more pronounced side effects.

Onset

Rapid: Onset of drug interaction typically occurs within 24 hours of co-administration.

Delayed: Onset of drug interaction typically occurs more than 24 hours after co-administration.

Evidence

Level of documentation of the interaction.

Established: The interaction is documented and substantiated in peer-reviewed medical literature.

Theoretical: This interaction is not fully supported by current medical evidence or well-documented sources, but it is based on known drug mechanisms, drug effects, and other relevant information.

How To Manage The Interaction

Provides a detailed discussion on how patients and clinicians can approach the identified drug interaction as well as offers guidance on what to expect and strategies to potentially mitigate the effects of the interaction. This may include recommendations on adjusting medication dosages, altering the timing of drug administration, or closely monitoring for specific symptoms.

It's important to note that all medical situations are unique, and management approaches should be tailored to individual circumstances. Patients should always consult their healthcare provider for personalized advice and guidance on managing drug interactions effectively.

Mechanism Of Interaction

The theorized or clinically determined reason (i.e., mechanism) why the drug-drug interaction occurs.

Disclaimer: The information provided on this page is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional regarding your specific circumstances and medical conditions.

Where Does Our Information Come From?

Information for our drug interactions is compiled from several drug compendia, including:

• Gold Standard Drug Database
• Micromedex
• Lexicomp
• DrugBank

The prescribing information for each drug, as published on DailyMED, is also used. 

Individual drug-drug interaction detail pages contain references specific to that interaction. You can click on the reference number within brackets '[]' to see what reference was utilized.

The information posted is fact-checked by HelloPharmacist clinicians and reviewed quarterly.