Vitamin B12 deficiency is a significant concern among patients with end-stage renal disease undergoing dialysis. However, there hasn't been extensive research conducted on this particular patient group. The reported incidence rates vary widely, ranging from 20% to 90%, reflecting the complexity of its diagnosis. Dialysis patients often face multiple nutritional deficiencies, including a lack of essential vitamins, due to factors such as dietary restrictions, impaired absorption, and nutrient loss during dialysis. Diagnosing vitamin B12 deficiency in these patients is challenging, and addressing it is crucial to prevent complications and improve their overall quality of life. This review paper delves into the available body of evidence on vitamin B12 deficiency in dialysis patients, examining the contributing risk factors, diagnostic challenges, potential complications, and available treatment options. It provides a well-rounded perspective on the topic, making it a valuable resource for researchers, healthcare practitioners, and policymakers interested in addressing the nutritional needs of dialysis patients.

An 80 year old female with a past medical history of hypertension, hyperlipidemia, hypothyroidism, and chronic back pain presented to the hospital with fatigue and was found to have a severe macrocytic anemia. Blood work showed pancytopenia and positive markers of hemolysis. Additional work up was consistent with severe vitamin B12 deficiency and pernicious anemia. Her blood counts improved with blood transfusions and vitamin B12 repletion. We discuss the proposed pathophysiology of this rare case of pernicious anemia presenting with hemolysis.