Can I take Omeprazole and Vitamin B12 together?
Drug interaction guide
Originally published 25 Jan 2026
Meets Patient’s editorial guidelines
- DownloadDownload
- Share
- Language
- Discussion
- Audio Version
Taking omeprazole for a long time can make it harder for your body to absorb vitamin B12 from the food you eat. Over several years, this could lead to a vitamin B12 deficiency.
In this article:
Video picks for Drug interactions
Continue reading below
Why this happens
Vitamin B12 is naturally bound to proteins in food. To release the vitamin so your body can use it, you need stomach acid. Omeprazole works by reducing the amount of acid your stomach produces. With less acid available, the B12 stays 'locked' in the food and passes through your system without being fully absorbed.
What you should do
Back to contentsIf you take omeprazole for more than 2 to 3 years, ask your doctor to check your vitamin B12 levels with a blood test. You should also watch for signs of low B12, such as feeling very tired, having a sore tongue, or feeling 'pins and needles'. If you need a supplement, high-dose oral tablets or B12 injections usually work well because they don't rely as much on stomach acid for absorption.
Continue reading below
Important precautions
Back to contentsVitamin B12 deficiency
Long-term use of omeprazole can prevent your body from absorbing Vitamin B12 properly, which may lead to nerve damage or anaemia.
Severe diarrhoea
Contact your doctor immediately if you develop severe or persistent watery diarrhoea, as omeprazole can increase the risk of a serious bowel infection called Clostridium difficile.
Lupus (SLE)
Seek medical advice if you develop a skin rash, especially in areas exposed to the sun, as omeprazole can trigger or worsen a rare autoimmune condition called Subacute Cutaneous Lupus Erythematosus.
Food and drink warnings
Back to contentsAlcohol
It is best to avoid or strictly limit alcohol while taking omeprazole. Alcohol can increase the amount of acid your stomach produces, which may worsen your symptoms or make the medicine less effective. Additionally, both alcohol and omeprazole can irritate the stomach lining.
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.
General Food Timing
Omeprazole works best if you take it 30 to 60 minutes before a meal, preferably breakfast. Taking it with food can slow down how quickly the medicine starts to work.
Continue reading below
Using other medicines
Back to contentsTaking 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.
Patient picks for Drug interactions

Treatment and medication
Can I take Atorvastatin and Rivaroxaban together?
Taking atorvastatin and rivaroxaban together may slightly increase the levels of rivaroxaban in your blood. This could potentially increase the risk of bleeding, such as bruising more easily, nosebleeds, or bleeding from the gums.

Treatment and medication
Can I take Atorvastatin and Royal sun together?
Taking Royal Sun (Agaricus blazei) alongside atorvastatin may increase the risk of liver irritation or damage. Both substances are processed by the liver, and there have been rare reports of this mushroom causing liver inflammation (hepatitis). Combining them could potentially put extra strain on your liver.
Continue reading below
Article history
The information on this page is written and peer reviewed by qualified clinicians.
25 Jan 2026 | Originally published

Ask, share, connect.
Browse discussions, ask questions, and share experiences across hundreds of health topics.

Feeling unwell?
Assess your symptoms online for free
Sign up to the Patient newsletter
Your weekly dose of clear, trustworthy health advice - written to help you feel informed, confident and in control.
By subscribing you accept our Privacy Policy. You can unsubscribe at any time. We never sell your data.