Are We Missing Vitamin B12 Deficiency in the Primary Care Setting?

Rebecca Hilgen Bryan, MSN, APRN


Journal for Nurse Practitioners 

In This Article

Abstract and Introduction


Vitamin B12 deficiency is present in 5% to 20% of the elderly population and may begin in middle age, although there is a paucity of research to demonstrate this suspicion. One common cause, malabsorption, is affected by many factors often seen in the primary care setting, including prolonged use of proton pump inhibitors or metformin or as a result of gastric bypass surgery. The traditional sign of B12 deficiency, macrocytic anemia, can be masked by the folic acid supplementation in all enriched cereals/grains mandated by the US Food and Drug Administration since 1998. Vitamin B12 deficiency causes neurologic deficits that significantly impact quality of life and other conditions and is therefore worthy of recognition and treatment.


We were all educated to consider vitamin B12 deficiency as part of a differential when evaluating a patient for macrocytic anemia. Additionally, we have all had elderly patients in our offices requesting B12 injections during routine visits to "give them energy." B12 deficiency is well recognized in the geriatric population, with a prevalence of 5% to 20%.[1] Increasing age is independently associated with poor nutritional status, which may partly explain the poor clinical outcome in older patients.[2] However, have we stopped to consider that we might be missing B12 deficiency in our normocytic middle-aged and older patients? Routine screening practices rarely result in findings of macrocytic anemia in this age group, yet two recent cases have caused me to consider B12 deficiency as a differential, and research of the subject has confirmed that I have reason to be suspicious.