Start guide
B12 basics
The one nutrient a plant-based diet cannot supply on its own, and the simple way to cover it.
Why it matters
Vitamin B12 is needed for nerves and blood cells. It is made by microbes and reaches people mainly through animal foods. Plant foods are not a reliable source, and deficiency develops slowly, sometimes over years, before symptoms appear.
What to do
Anyone eating little or no animal food should take a B12 supplement or eat fortified foods every day. Supplements are inexpensive and effective.
- The Vegan Society advises at least 10 micrograms of B12 in a daily supplement, or at least 2000 micrograms in a weekly supplement. These are maintenance schedules, not treatment for diagnosed deficiency.
- Alternatively, the Vegan Society advises fortified foods two or three times a day supplying at least 3 micrograms of B12 in total; check labels.
- Ask for a blood test if you have been vegan for a while without supplementing.
A note on health information. This page summarises published evidence for a general audience. It is not medical advice and cannot account for your circumstances. If you are changing your diet with a health condition, during pregnancy, or for a child, talk to a doctor or registered dietitian.