--you can list all your lab results if you want (and you certainly wouldn't be the only one here who has).

B12 deficiency results in many problems--neurological, hematological, musculoskeletal . . .often, the symptoms are subtle and inspecific at first, but over time become more pronounced.

The good thing is that B12 deficiency can almost always be easily treated, and these days it can be treated through oral supplementation cheaply, without constant visits for B12 injections. But the recovery from B12 deficiency can be long and involve various relapses and remissions, peaks and valleys, as the body used it for rebuilding and then attempts to rebuild stores.