--B12's effecton flagging energy levels has been known about for over a century. In fact, the first line of defense for sagging "pep", as they used to say in the 50's, was a B12 shot, and many mid-20th century doctors gave them for just that reason. (I also suspect that they gave them quite often to women they suspected of being "vaguely depressed". Of course, if you lived like most women in this country did in the 50's--even in higher socioeconomic strata--you'd be depressed, too.)

I think my taking of methylcobalamin (though I never took quite as much as that--my max was 2500mcg/day) has helped me to combat the sluggishness that gabapentin (Neurontin) tends to foster (though it hasn't stopped the carb-craving weight gain gabapentin also can cause--in fact, it may have eaxcerbated it, as most of the b-vitamins are good appetite stimulants!).

Hey, if it's giving you more energy to that extent, you may well have not had optimal levels, even if you would have had no symptoms from it. That serum B12 reference range of 200-1100 is just flat outdated--even the Japanese/European reference range of 500-1300 may be too low. I think an optimum "cell-bathing" range would be at least 4 digits.

My last B12 level was 1864. I had taken my supplement a few hours before, so I may have had an exaggerated reading. My neuro, though, knows all about what I do, so he just smiled.