I've been swallowing B12 tablets and they appear to work fine for me. I wouldn't call injections a waste of time or anything, though swallowing them might raise my levels well enough on its own.
Seeking input from others here. My vitamin B12 level returned as 259. Though it sits inside the usual limits the lab flagged it as potentially low for some people noting that five to ten percent of those with readings from 200 to 400 can run into nerve or blood issues tied to undetected shortages. This has me considering injections to raise it but my physician declined to write a prescription. I wonder where such shots might be available. A daily supplement blend has not produced any real change so far. My aim is lifting stamina since I fade hard by mid afternoon. Protein drinks likewise offer little relief. My iron storage marker came back slightly high leaving me unsure whether extra protein would even help. The doctor said the full set of tests looked normal yet looking at the numbers myself makes me question if the B12 and ferritin values play a role in that daily slump. At the moment I am using just one medication. Any ideas?