Stillhoping: if there is celiac in your family, and you have low B12 and a positive anti-gliadin IgG antibody--though that antibody result is the least specific, it is the most sensitive, often showing up first--it might well be worth the endoscopic biopsy.

Low B12 can absolutely be caused by celiac/gluten sensitivity. The most famous celiac poster in the on-line world, Cara, AKA jccglutenfree, found out about celiac in her family through low B12 levels. There may be deficiencies in other vitamins/minerals as well as absorprtion of these is compromised.

And, RunWriteMomHeal: that A1c level does correspond to a daily 100 or so average reading, but not a FASTING reading; that is the average of all your blood sugars over three months, including after eating meals. I'll bet your 12-hour fasting blood sugar levels are in two digits.

Pre-diabetic A1c levels are considered to start at 5.7 (used to be 6), frank diabetes at 6.5. I think you're relatively ok there.

Your 6.45 lower extremity intraepidermal nerve fiber reading is at the lower end of normal low, but not that low (about 20th percentile). The question is, what would it have been pre-symptoms . . .?