With regard to curative treatment by orally administered cobalamin (1% of free vitamin B12 is absorbed passively, independently of the IF and of its receptor [cubilin]), a therapeutic scheme has yet to be definitely validated, given the present state of knowledge.In PA, the doses conventionally administered should in all cases greatly exceed those required physiologically, ranging from 1000–2000 μg/day of cyanocobalamin.In the authors’ experience of oral administration, this therapeutic mode should be reserved for primarily hematological consequences of vitamin B12 deficiency. Currently, it is always recommended to use the parenteral route in severe neurological forms. Alternatively, the oral route could curtail or avoid the inconvenience related to discomfort of injections and of likely higher costs (nursing care). It can also be particularly useful in patients under anticoagulant or antiplatelet agent therapy in whom intramuscular injections are contraindicated.