b12 injection iv or im Injections: Ultimate & Wellness in Bradenton B12 Shots vs. IV Therapy:

It may also be prescribed for certain cobalt deficiencies, certain pancreatic diseases, or intestinal malabsorption conditions

Moderate deficiency : Injections every 2-3 months are often recommended

Let me explain: How to Diagnose and Check for Vitamin B12 Deficiency The problem comes down to diagnosis

The compound's selectivity extends to its membrane permeability characteristics, which allow efficient cellular uptake without affecting membrane integrity or cellular viability up to 100 M concentrations

When you say it doesn't prove you cant utilise b12 from.stores in the liver what does it prove if symptoms return then relieved by a b12 injection then