Overgrowth of bacteria: Some people develop vitamin B 12 deficiency as a result of conditions that slow the movement of food through the intestines (diabetes, scleroderma, strictures, diverticula), allowing intestinal bacteria to multiply and overgrow in the upper part of the small intestine
A B12 shot is a quick intramuscular injection of vitamin B12 (cobalamin) that bypasses the stomach acid, liver metabolism, and intestinal absorption issues that limit oral B12 to roughly 1% bioavailability in most adults
AICAR is itself a potent AMPK activator, the same intermediate compound that the pharmaceutical agent AICAR infusion uses to mimic exercise in rodent studies
10.1038/s41598-017-16130-w 46 CherniackE
The diagnosis of vitamin B12 deficiency typically relies on low total B12 levels and elevated concentrations of homocysteine (Hcy), as well as levels of transcobalamin-bound B12 (holoTC) and methylmalonic acid (MMA), which serve as functional indicators of cobalamin insufficiency (Carmel and Sarrai, 2006)