Vitamin B12 and Mortality in the Critically Ill

Abstract

Vitamin B12 is an essential micronutrient, with significant intracellular functions. Vitamin B12 deficiency is common in the critically ill population and is associated with significant deficiency syndromes. Increased vitamin B12 levels are associated with worse outcomes in critically ill patients and warrant systemic workup for malignancies and chronic diseases, particularly of the hepatic and hematological systems. Normal serum levels of vitamin B12 should be aimed for in the critically ill; however, there seems to be a minimal role for therapeutic use of vitamin B12 in the absence of deficiency.