Can I take Folic acid and Vitamin B12 together?
Drug interaction guide
Originally published 25 Jan 2026
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Taking folic acid on its own can hide (mask) a vitamin B12 deficiency. If you have low B12 levels and take high doses of folic acid, it can fix the blood problems (like anaemia) but allow serious nerve damage to continue and get worse without being noticed.
Why this happens
Both folic acid and vitamin B12 are needed to make red blood cells. If you are low in B12, folic acid can 'bypass' the blockage in blood cell production, making your blood tests look normal. However, folic acid cannot fix the damage to the nervous system caused by low B12, which can lead to permanent nerve damage if the B12 deficiency isn't found and treated.
What you should do
Before starting a folic acid supplement, it is important to ensure your vitamin B12 levels are normal. If you are taking folic acid, your doctor should monitor your B12 levels regularly. If you experience numbness, tingling, or weakness in your hands or feet, speak to your doctor immediately.
Important precautions
Vitamin B12 deficiency (Pernicious Anaemia)
Folic acid can mask the symptoms of vitamin B12 deficiency. If you have B12 deficiency, taking folic acid alone can allow serious nerve damage to progress even though your blood count appears normal. Your doctor must ensure your B12 levels are checked before or during treatment.
Food and drink warnings
Alcohol
It is best to avoid or strictly limit alcohol when taking these vitamins. Alcohol interferes with the body's ability to absorb and store both folic acid and vitamin B12, which can make your treatment less effective. Chronic alcohol use is a common cause of these vitamin deficiencies.
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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