> will I deprive myself of B12?

90% of all B12 supplementation occurs in livestock, join the party!

B12 is a product of bacteria living on the surface of roots in soil. Once you add herbicides, pesticides and general monoculture practices (barren soil baking in the sun, heavy tilling, artificial fertilizers), the conditions for producing B12 fall off a cliff.

The vast majority of our B12 is added via fortification. Heck, a can of Red Bull is >200% of your daily requirement, but unlike the dairy industry they aren't trying to make it sound as if they're the only source of B12 in the world.