Antidiabetic medications - biguanides


Biguanides antidiabetics include:

Metformin (Glucophage and Glucophage XR)


Vitamin B9 (Folic Acid)

Low levels of folic acid have been linked to:

  • Anemia
  • Heart disease
  • Birth defects
  • Colon cancer

Symptoms may include fatigue, mouth sores, swollen tongue, depression, and poor growth.

Vitamin B12 (Cobalamin)

Noticeable symptoms of a vitamin B12 deficiency can take years to develop. Irritability, weakness, numbness, anemia, loss of appetite, headache, personality changes, and confusion are some of the signs and symptoms associated with very low levels of vitamin B12. Low levels of this vitamin may also be associated with an increased risk of:

  • Colon cancer
  • Heart disease
  • Brain problems
  • Birth defects

Editorial Note

The information presented here covers some of the nutrients that may be afftected when you take certain medications. If you have the signs and symptoms listed, it does not always mean you have low levels of these nutrients. Many things affect the level of nutrients, including your:

  • Medical history
  • Diet
  • Lifestyle

As well as how long you have been taking the medication. Please talk with your health care provider. They can best address your health care needs and determine whether you are at risk for low levels of any nutrients.

Supporting Research

Andrès E, Federici L. Vitamin B12 deficiency in patients receiving metformin: clinical data. Arch Intern Med. 2007;167(7):729; author reply 730-1.

Buvat DR. Use of metformin is a cause of vitamin B12 deficiency. Am Fam Physician. 2004;69(2):264; author reply 264, 266.

Dali-Yousef N, Andres E. An update on cobalamin deficiency in adults. QJM. 2009;102(1):17-28.

Fisman Ez, Motro M, Tenenbaum A. Non-insulin antidiabetic therapy in cardiac patients: current problems and future prospects. Adv. Cardiol. 2008;45:154-70.

Fitzgerald MA. Drug-induced vitamin B12 deficiency. Nurse Pract. 2007;32(9):6-7.

Hvas AM, Nexo E. Diagnosis and treatment of vitamin B12 deficiency -- an update. Haematologica. 2006;91(11):1506-12.

Liu KW, Dai LK, Jean W. Metformin-related vitamin B12 deficiency. Age Ageing. 2006;35(2):200-1.

Moretti R, Torre P, Antonello RM, Cazzato G, Cattaruzza T, Scapicchio PL. Vitamin B12 and folate depletion: clinical evidence in a neurological population. Neurologist. 2004;10(6):338-43.

Pelton R, LaValle J, Hawkins EB, et al. Drug Induced Nutrient Depletion Handbook. Hudson, OH: LexiComp, Inc.;2001:409-410.

Reynolds E. Vitamin B12, folic acid, and the nervous system. Lancet Neurol. 2006;5(11):949-60.

Svenson J. Neurologic disease and vitamin B12 deficiency. Am J Emerg Med. 2007;25(8):987.e3-4.

Version Info

  • Last reviewed on 8/27/2014
  • Steven D. Ehrlich, NMD, Solutions Acupuncture, a private practice specializing in complementary and alternative medicine, Phoenix, AZ. Review provided by VeriMed HealthCare Network. Also reviewed by the A.D.A.M. Editorial team.

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