Many Diabetics are B-12 deficient, but not all.

And if you actually need it to be supplemented you need it at clinically relevant levels (injection from Doctor or Pharmacist) "after" having your levels tested.

You can "overdose" on B Vitamins so you need to be careful and if you want to use B-12 as a (treatment) you can't get a strong enough dose in the over the counter varieties - so for that one you are best talking to your Doc and getting your level checked and then injection if needed.

The others you note along with Primrose Oil, Ginkgo, Ginseng, Magnesium (which is generally a good supplement for anything Diabetes) and a few others have also been traditionally used.

But it is still wise to get advice from (someone - Pharmacist or naturopath who is licensed etc) with regards to dosage and interactions etc. Most times you can not get a "therapeutic" dosage from the over the counter supplements which are dispensed at "very safe levels" on purpose because they are just that, intended as supplements and not treatments.

I do believe in supplements and take a few myself. But as "part" of my overall treatment rather than trying to rely on them as the sole treatment - make sure you temper your expectations.

Because with neuropathy it is very likely that a single 25mg dose of Pregabalin by prescription will provide far more relief than a basket load of supplements from the drug store shelf.

Not trying to discourage you, but that is why you would probably be well served by getting professional advice from someone has access to your entire medical history before trying a home remedy for a true complication.

I take 600 mgs of alpha lipoic acid each night. Borage oil 2000 mgs (for the GLA) each night, and benfotiamine 600 mgs am and 600 pm. If I keep my sugars under control, I no longer have an issue with burning and tingling.