An alarming or concerning B12 level is below 200 picograms per milliliter (pg/mL)
Its do maddening isnt it In all fairness to the nurse, I dont think the current teaching does cover the ins and outs of B12 and The various causes of deficiency
(ref) Seiwerth S, Sikiric P, Grabarevic Z, Zoricic I, Hanzevacki M, Ljubanovic D, Coric V, Konjevoda P, Petek M, Rucman R, Turkovic B, Perovic D, Mikus D, Jandrijevic S, Medvidovic M, Tadic T, Romac B, Kos J, Peric J, Kolega Z
For example, additives such as carboxymethyl cellulose and mannitol can cause acute reactions
Most common is the use of 2-deoxy-2-(18F) fluoro-D-glucose positron emission tomography (PET), which measures energy demand by trapping a non-metabolizable glucose analog that carries a PET label