Losing that much weight is seriously impressive, not to mention your A1C level.

I supplement with B-12 (and a huge number of other things) but I'm glad you brought it up; I know others on metformin and I'll pass your info along to them. Most people are borderline-deficient in B-12 as it is, metformin or no. Benfotiamine showed a dramatic positive effect at 1050mg/day in one study and I've been taking that much ever since; didn't know it was a precursor to other B vitamins though. Carnosine is another strong inhibitor of glycation that works best at higher doses; I take about 2,000mg.

Keep on staying healthy; you're a great resource here.