Can I take Anastrozole and Vitamin B12 together?
Drug interaction guide
Originally published 25 Jan 2026
Meets Patient’s editorial guidelines
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There is no known interaction between anastrozole and vitamin B12. It is generally considered safe to take these two together.
Why this happens
Anastrozole and vitamin B12 are processed by the body through different pathways. Anastrozole is primarily broken down by the liver, while vitamin B12 is absorbed in the gut and used for nerve health and blood cell production. They do not interfere with each other's absorption, metabolism, or effectiveness.
What you should do
You can continue taking both as prescribed. However, it is always a good idea to inform your doctor or pharmacist about all supplements you are taking, especially during cancer treatment.
Important precautions
Pregnancy and breastfeeding
You must not take anastrozole if you are pregnant or breastfeeding, as it can harm the developing baby. It is only for use in women who have gone through the menopause.
Osteoporosis (bone thinning)
Anastrozole lowers oestrogen levels, which can significantly weaken your bones and increase the risk of fractures. Your doctor should monitor your bone density before and during treatment.
Food and drink warnings
Alcohol
Excessive alcohol consumption can interfere with the absorption of Vitamin B12 in the digestive tract. If you are taking B12 to treat a deficiency, heavy drinking may make the treatment less effective.
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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