how long b12 injection last Does a Shot In Your Body? How Long Does a B12

Clin Neuropharmacol 35 , 205207 (2012)

Nutrient support: This helps address potential nutritional deficiencies, particularly if you are consuming fewer calories or eating less overall, ensuring your body still receives the essential nutrients it needs

[15] In practice, hydroxocobalamin injections achieve higher and more sustained vitamin B concentrations compared to cyanocobalamin

I read further information on the studies you listed on kidney storage as this seems to be where b12 is mostly found other than the liver

Anaphylactic shock and death have been reported after parenteral vitamin B 12administration

Adjustments are often made based on both lab results and your symptoms