An impaired awareness of hypoglycemia improved after vitamin B12 treatment in a type 1 diabetic patient

Abstract

An impaired awareness of hypoglycemia is a serious problem in diabetic patients, which can lead to life-threatening severe hypoglycemia. Recurrent hypoglycemia attenuates the function of the central, mainly hypo-thalamic, nervous system and it causes an impaired awareness of hypoglycemia. Vitamin B12 deficiency is also associated with the dysfunction of central nervous system. We report a 72-year-old type 1 diabetic patient with vitamin B12 deficiency whose impaired awareness of hypoglycemia improved after 4 weeks of vitamin B12 administration with an increased counter-hormone secretion in response to hypoglycemia. We should recognize vitamin B12 deficiency as one of the causes of an impaired awareness of hypoglycemia in diabetic patients.