Patients may experience aseptic meningitis syndrome, which is a non-infectious inflammation of the meninges (membranes that line the brain and spinal cord) that causes headaches and a stiff neck, but this will go away with increasing fluid intake, rest and Tylenol
Tailoring Formulations for Intranasal Nose-to-Brain Delivery: A Review on Architecture, Physico-Chemical Characteristics and Mucociliary Clearance of the Nasal Olfactory Mucosa
However, injections bypass the digestive system and go straight to your bloodstream
Humans and other eukaryotic organisms lack the enzymatic machinery necessary for de novo Cbl synthesis and rely on external sources, such as diet or symbiotic bacteria, to obtain Cbl [85, 86]
2013 Jul;169 Suppl 2(0 2):1-8
However, some studies suggest that people with kidney function loss may experience quicker kidney deterioration with very high doses of vitamin B12