Glutathione Skin Whitening Injection Glutathione Benefits Fairness injection treatment B12 Injection CITIZEN MEDS Compounded Methylcobalamin (Vitamin B12) Injection, 5mg mL A little insight to the importance of the b12 injections. My client hadn't been feeling well & had some bloods done with her GP. The results identified a severe deficiency in b12. I receive monthly intramuscular vitamin B12 (cobalamin) injections, but my serum B12 level measured two weeks after the injection is only 268 pg mL; why is it low and how should the dosing