pernicious anemia is treated with injections of vitamin b12 because Symptoms and treatment for due to deficiency? – PlexusDx Overview of Pernicious Anemia (Vitamin

It may also cause allergic reactions in some individuals

(source) Heffernan MA, Thorburn AW, Fam B, Summers R, Conway-Campbell B, Waters MJ, Ng FM

Cyanocobalamin, which must be processed by the body into the active form, is the most common type used in supplements

This method may also be useful for children or individuals who have trouble swallowing pills

Anaphylactic shock and death have been reported with administration of parenteral Vitamin B 12 (see WARNINGS)

Essential Guideline #5: Intramuscular Administration Protocols For those with vitamin B12 deficiency, intramuscular injections are a direct and effective treatment