giving b12 injections to cats Shot for Ferguson the Kitten Vitamin B12 for Cats: Overview,

Large doses of folic acid given to an individual with an undiagnosed vitamin B 12 deficiency can correct megaloblastic anemia without correcting the underlying vitamin B 12 deficiency, leaving the individual at risk of developing irreversible neurologic damage (21)

It's important to note that these side effects are uncommon, and most people tolerate B12 Methylcobalamin Injections well

Similarly, long-term travelers or individuals with underlying health conditions may require extra precautions

Similarly, compared with type 1 diabetic patients following peripheral neuropathy, those patients with low cardiac vagal tone had more serious impairing of gastric motility and colonic transit [23]