Can I take Vitamin B12 and Vitamin C together?
Drug interaction guide
Originally published 25 Jan 2026
Meets Patient’s editorial guidelines
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Taking high doses of Vitamin C at the same time as Vitamin B12 can reduce the amount of Vitamin B12 your body absorbs and uses. This could potentially lead to a Vitamin B12 deficiency over time if you take them together regularly.
Why this happens
Vitamin C is an antioxidant that can chemically break down Vitamin B12 in the digestive tract, making the B12 inactive and harder for the body to absorb.
What you should do
To avoid this interaction, take Vitamin C at least 2 hours after taking your Vitamin B12 supplement. This allows enough time for the Vitamin B12 to be absorbed properly.
Important precautions
Kidney stones
High doses of vitamin C can increase the amount of oxalate in your urine, which significantly raises the risk of developing kidney stones, especially if you have had them before.
G6PD deficiency
Very high doses of vitamin C can cause oxidative stress and lead to the breakdown of red blood cells (haemolysis) in individuals with G6PD deficiency.
Food and drink warnings
Alcohol
It is best to avoid or strictly limit alcohol while taking Vitamin B12. Heavy alcohol consumption can interfere with the body's ability to absorb Vitamin B12 from the gut and can reduce the amount of the vitamin stored in the liver.
Using other medicines
Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.
Disclaimer
This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.
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Article history
The information on this page is written and peer reviewed by qualified clinicians.
Article also available in English, German, Spanish, French, Italian, Portuguese, Hindi, Hebrew, Arabic, and Swedish.
25 Jan 2026 | Originally published

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