Many many comments here overlook that there are very good natural and vegan sources of B12: Shiitake mushrooms are an excellent source of B12 (and it's in the

Many many comments here overlook that there are very good natural and vegan sources of B12: Shiitake mushrooms are an excellent source of B12 (and it's in the same form as the B12 from beef, liver, or fish, so it has a very good bioavailability). It's not widely known even by vegans. For both vegans and omnivores, the easiest way to keep an adequate level of B12 is with supplements. Omnivores have them fed to their steaks/cheese/milk during intensive farming. The best of best B12 supplement is hydroxycobalamin, if you can find it in sublingual tablets (it's not readily available in every countries, but you can import it).