intramuscular administration Subcutaneous (into fatty tissue of abdomen, typically 1-2 inches lateral to navel, using a 25-27 gauge, 5/8-inch needle): 28% report injection-site soreness Easier for self-administration Slower absorption (peak serum B12 at 12-18 hours vs
Arteriosclerosis, Thrombosis, and Vascular Biology, 25 (4), 809814
Mylchreest, E., Sar, M., Cattley, R
When a supplement might make sense A supplement conversation can be reasonable if someone has factors like: Very low protein intake or restrictive dieting Significant gut issues affecting digestion and absorption Higher oxidative stress burden, higher toxicant exposure, or intense lifestyle strain A medical context where a clinician is monitoring symptoms and labs If none of that applies, the best first step is almost always food and fundamentals