I'm new to issues related to PN but was on two medications that we think led to b12 deficiency (daily dose of protonix for acid reflux for over 10 years and recently, was on daily dose at a level of 2000MG of Metformin for 18 months).

My b12 serum was over 800 but I had (and still have) significant neurological issues (PN in feet, ankles, lower legs and trembling, muscle twitches throughout body). Mine presents more like a polyneuropathy which also is indicative of b12 deficiency.

I recently read that low serum b12 is a lagging indicator of a deficiency and that being symptomatic of neuro damage is enough to warrant aggressive b12 therapy (1000 mg daily injections of methylcolobalamin for 2 to 3 weeks; then weekly injections).

First and foremost it's important to stop the progression of the damage, so we started the b12 therapy without doing any other testing. It could take a month to schedule and get further testing; if it's b12, we'll know in a couple of months. So far my symptoms have not worsened, but they also have not improved other than it seems I am walking better ... feeling a bit more sure-footed.

Once again - I am new to all of this so others who are better informed should feel free to correct or add to this information.