@pfbacon, I take two 3000 mcg capsules of B12 in the morning and two in the evening as part of the supplements I take for my neuropathy. It's not a cure (there is no cure) but it seems to be helping me and it's not hurting anything. I have no medical background or training but from my research B12 has not been known to cause any harm. The National Institutes of Health has some good information on it.
https://ods.od.nih.gov/factsheets/VitaminB12-Consumer/