I have been on this forum for a month now and have been supplementing b12 for the same amount of time. I tested very low for b12 (159) as I have been vegan for 7 years. My symptoms were poor digestion, lost weight, low libido, anemia, and leg weakness.
I started a regimine of bi daily b12 shots as well as oral supplementation with sublingual and tablets. The initial response was a set of very strong neurological symptoms like twitching, dehydration, and anxiety for a week or so. Following that, I had great results with my symptoms. I had a stronger libido, better digestion, I gained some weight and felt strength in my legs for the first time in many years.
Now I'm at the month mark and my symptoms are returning with a vengeance even with 2-3 b12 injections per week and daily supplements. Bad weakness in the legs, foggy head, lethargy, very low libido. So I started off low, went up very high after starting supplementing, and now I'm lower than ever even without changing supplementation. I had my blood tested and my serum b12 is over 2000. There is plenty in my blood but I'm still failing here. It's like I've become resistance to the b12 now. Anybody have a similar experience?