I was a bit startled to read that vegans can end up deficient in vitamin B12. There’s little or no B12 in a plant-based diet, so vegans have to get it some other way. Some breakfast cereals have it added in small quantities, but the only serious option is to take a supplement.
Medical advice is that an average person needs to absorb 2.4 micrograms each day (that’s millionths of a gram, or on labels µg).
However, what you take into your mouth doesn’t all get absorbed, especially as you get older, so the recommendation is at least 10 micrograms each day.
What do I do?
I checked, and my own multivitamin contains 25 micrograms, so I’m reassured.
By the way, you can’t have too much B12, as the body just gets rid of what it doesn’t need.