Were you not aware that those same supplements (vitamin B12 i guess you referring to) are feed/ injected to livestock? And the “avoid death” is a bit overblowing B 12 is stored in the liver so it takes years to be depleted and same as animal products there are fortified foods which are more than enough to cover the 2.4mcg needed.

Granted, it will take you several years to die. If you're a woman you'll lose your menstrual cycle pretty quick, too.