Vitamin B12 Deficiency

Justin D. Chaltry, DO and Katie L. Westerfield, DO Reviewed 06/2018
 


BASICS

  • Vitamin deficiency related to inadequate intake or absorption of cobalamin (vitamin B12)

  • Cobalamin is critical for CNS myelination and normal functioning.

  • Deficiency can cause a multitude of symp...

DIAGNOSIS

Symptoms and physical exam findings: 
  • Asymptomatic patients may be diagnosed by the incidental finding of anemia or an elevated mean corpuscular volume (MCV) during routine testing or evaluat...

TREATMENT

MEDICATION

  • Parenteral cyanocobalamin replacement recommended in patients with severe neurologic symptoms: IM cyanocobalamin (2)[C]

    • 1,000 μg/day for 7 days, then

    • 1,000 μg weekly for 4 weeks, t...

ONGOING CARE

FOLLOW UP RECOMMENDATIONS

Patient Monitoring

  • Hematologic

    • Reticulocytosis in 1 week

    • Rise in hemoglobin beginning at 10 days; usually will return to normal in 6 to 8 weeks

    • Monitor potassium in...

REFERENCES

1 Lachner C, Steinle NI, Regenold WT. The neuropsychiatry of vitamin B12 deficiency in elderly patients. J Neuropsychiatry Clin Neurosci.  2012;24(1):5–15.  [View Abstract]
2 Stabler...

ADDITIONAL READING

  • Allen LH. How common is vitamin B-12 deficiency? Am J Clin Nutr.  2009;89(2):693S–696S.  [View Abstract]

  • Aroda VR, Edelstein SL, Goldberg RB, et al; Diabetes Prevention Program...

CODES

ICD10

  • E53.8 Deficiency of other specified B group vitamins

  • D51.0 Vitamin B12 defic anemia due to intrinsic factor deficiency

  • D51.3 Other dietary vitamin B12 deficiency anemia

  • D51.1 Vitamin B12 defic...

CLINICAL PEARLS

  • Consider screening for B12 deficiency in high-risk patients including the elderly and monitoring B12 levels annually if on metformin or on chronic PPIs.

  • Correcting folate deficiency wit...

Subscribe to Access Full Content

Sign Up for a 10-Day Free Trial

Sign up for a 10-day FREE Trial now and receive full access to all content.

×