Why Do I Feel Worse After My B12 Injection? Causes & Management Bolt Pharmacy How Long Does It Take to Recover from Vitamin B12 Deficiency? Urine Color After Vitamin B12 Injection A physician orders Schilling Test to be performed for a client suspected of having pernicious anemia. Order the steps below in completing this procedure. 1. Give oral radioactive vitamin B12 supplement before When the marrow wakes up potassium disappears B12 replacement triggers a metabolic surge Cells pull potassium inside serum levels crash The recovery phase is actually the danger