The biggie (and probably the most controversial). It need not be. Ensure that you get a reliable source of vitamin B12 through fortified foods (eat at least two a day at different meals) or cyanocobalamin supplements (25-100mcg a day is ideal or 2,500 mcg taken just once a week).
In the US it is recommended that everyone over the age of 50, regardless of diet, take a daily B12 supplement. So if you’re over 50 then that’s exactly what you should do. You’ll find a range of great, vegan-friendly B12 options online and in shops.
Fortified foods. You’ll hear that a lot. But what does it actually mean? Well in this case, it means that it has B12 added and if you eat these foods regularly, i.e. several times a day, then you may be getting enough B12 to hit your RDA (at least three micrograms per day). If this seems like it might be difficult then take a daily B12 supplement and worry no more. Examples of some fortified foods are, fortified non-dairy milks and yoghurts, fortified nutritional yeast (known as ‘nooch’ within the vegan community!) and marmite.
As B12 is non-toxic there is no harm in taking higher levels if you choose to.
It is important to note that if you are concerned about your B12 levels, you should get them checked by a medical professional. If you are low in B12, you may have an issue with absorbing it and regardless of how much you have in your diet, medical intervention may be required. This is relevant to everyone, regardless of their current diet.