[Vitamin B12 deficiency in the context of obesity surgery].

Bariatric surgery is an efficient treatment option allowing long term weight loss as well as mortality risk reduction and cardiovascular comorbid conditions profile improvement. The number of procedure performed each year is on a constant rise worldwide. Obesity surgery techniques combining malabsorption with a restrictive procedure are associated with a greater excess weight reduction but will also carry more metabolic complications amongst which vitamin B12 deficiency is particularly frequent. The purpose of the present work is to review the hematologic and neurologic complica. tions associated with vitamin B12 deficiency in the specific context of bariatric surgery.