Benfotiamine would be a place to start, if you drink alcohol, or eat alot of sugar and carbs. People with insulin resistance or beginning impaired glucose tolerances, find it very helpful.
300mg a day for about 2 months.

Make sure you are using a good magnesium product, at 200mg a day elemental (which is 1/2 the RDA)
And you can try the fish oil/ krill oil, for anti-inflammatory effects.
3 fish oil or 2 Krill oil daily.

The acetyl carnitine would be for those who have toxin induced symptoms either from drugs or chemicals. But if you want to try it, start at 500mg a day in two divided doses of 250mg each.

See what happens in 2-3 months on this, including your B12.