B-12 deficiency can mimic Neuropathy in many ways, your wife's number needs to be above 400. Also if there is any doubt about whether she is a diabetic, the A1c will give an average of blood glucose over the last two weeks. I was diabetic for a couple of years at age 45 before diagnosed. Diabetic Neuropathy is one of the many types of Neuropathy. Good Luck, Ken in Texas.