People absorb b12 differently so while you may be doing well, another may not. It's good for people to be aware. As someone who experienced low b12, my doctor

People absorb b12 differently so while you may be doing well, another may not. It's good for people to be aware. As someone who experienced low b12, my doctor mentioned that some people develop symptoms and improve from treatment when their b12 levels are at lower bound compared to general population (but not below the lab specified threshold to be considered low).