Researchers publishing in the May 20, 2010 "British Medical Journal" said that metformin, a drug used by type 2 diabetics, put users at risk for vitamin B-12 deficiency. They revealed that the deficiency is quite pervasive and gets worse over time. Metformin helps diabetics control their blood sugar and improve their body's response to insulin. Participants who took the drug over the study's four-year period had a 19 percent drop in B-12 levels. The authors recommended that diabetics taking this medication be routinely assessed for their B-12 levels. They said for some of the participants, B-12 levels dropped so low that treatment with supplements may be the only way to correct the problem. A March 2010 study in the "Southern Medical Journal" reported similar consequences of chronic metformin use; 30 percent of participants experienced a serious deficiency. Their risk for anemia and nerve damage increased, and the author suggested annual assessment or a B-12 injection to stop the progression of B-12 deficiency in the diabetic patients.
Vitamin B-12
Vitamin B-12 is one of the eight components of the vitamin B complex. It plays a number of important roles in your body, including developing DNA and red blood cells. It assists in metabolic and nervous system processes as well. Vitamin B-12 is perhaps most noted for its ability to help you maintain your energy level, produce sound sleep, boost your immune system and improve your mood. With adequate amounts of vitamin B-12, you should experience normal cell growth and repair, normal heart function and properly process nutrients you eat.
Diabetes Drug May Cause Vitamin B-12 Deficiency
Researchers publishing in the May 20, 2010 "British Medical Journal" said that metformin, a drug used by type 2 diabetics, put users at risk for vitamin B-12 deficiency. They revealed that the deficiency is quite pervasive and gets worse over time. Metformin helps diabetics control their blood sugar and improve their body's response to insulin. Participants who took the drug over the study's four-year period had a 19 percent drop in B-12 levels. The authors recommended that diabetics taking this medication be routinely assessed for their B-12 levels. They said for some of the participants, B-12 levels dropped so low that treatment with supplements may be the only way to correct the problem. A March 2010 study in the "Southern Medical Journal" reported similar consequences of chronic metformin use; 30 percent of participants experienced a serious deficiency. Their risk for anemia and nerve damage increased, and the author suggested annual assessment or a B-12 injection to stop the progression of B-12 deficiency in the diabetic patients.
Consequences of B-12 Deficiency
In addition to anemia and nerve damage, diabetics in the "British Medical Journal" study experienced a surge in homocysteine levels as their B-12 levels dropped to deficiency level. Homocysteine is an amino acid found in your bloodstream. Having too much of it increases your risk of coronary heart disease, stroke and fatty deposits in your blood vessels. The B complex vitamins break down homocysteine, but B-12 is among the ones with the greatest effect, according to the American Heart Association. The association says most people should strive to get their B-12 through diet, but recognizes that with serious deficiency, supplements may be necessary.
Recommended Intakes
The Institute of Medicine says most adults need 2.4 mcg of B-12 daily, and Harvard's Joslin Diabetes Center recommends B-12 supplementation for certain populations, such as women and seniors. Those with a B-12 deficiency should consult their health care providers for their specific needs. The author of the "Southern Medical Journal" report recommended that diabetics with a Metformin-induced B-12 deficiency receive annual injection containing 1,000 mcg, which was said to be "sufficient to cover vitamin B12 needs for at least a year." Injections are available by prescription only.
References
- "British Journal of Nutrition"; Long Term Treatment with Metformin in Patients with Type 2 Diabetes and Risk of Vitamin B-12 Deficiency: Randomised Placebo Controlled Trial; Jolien de Jager et al.; May 20, 2010
- "Southern Medical Journal"; Metformin-Induced Vitamin B12 Deficiency Presenting as a Peripheral Neuropathy; David Bell; March 2010
- "Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline"; Institute of Medicine; 1998
- Institute of Medicine: Dietary Reference Intakes
- Joslin Diabetes Center: What are the Best Vitamins and Supplements to Take?
- "Diabetes Forecast"; Metformin: A New Shine on an Old Medication; Erika Gebel; December 2010
