[The problem of vitamin B12 deficiency: relevance, diagnosis and targeted therapy (based on materials of an interdisciplinary expert council with international participation)].

Deficiency of vitamin B 1 2 occurs much more often than it is commonly believed and leads to a wide range of various disorders, the emergence of primarily neurological manifestations, while there is a lack of awareness among clinicians in the field of its causes, nonspecific manifestations, diagnostic methods and effective therapy. The conference «The problem of vitamin B 1 2 deficiency and the experience of use in Germany» was devoted to this urgent clinical problem, within the framework of which an interdisciplinary council of experts, at which the most pressing issues were considered, associated with B 1 2 deficiency.