Type 2 diabetes is a disease characterized by higher than normal levels of sugar in your blood. Metformin is a medicine used alone or in combination to treat Type 2 diabetes. Metformin helps control your blood sugar levels. It decreases the amount your body absorbs from food, and it increases your body's sensitivity to insulin, a hormone that helps regulate blood sugar. Metformin can lower your vitamin B-12 levels.
B-12 Significance
Vitamin B-12 is one of eight vitamins that make up what is known as B complex. B-12 plays an important role in red blood cell formation, neurological function, tissue repair, energy production, and DNA and RNA formation, which is your body's genetic material. The recommended B-12 intake is 2.4 mcg for adults and teens 14 or older. Vitamin B-12 is naturally found in animal products, such as milk, poultry, eggs, fish and meats.
Long-Term Metformin Effects on B-12
The association between metformin and B-12 deficiency has been evaluated since the early 1970s. A study published in the June 1971 issue of "British Medical Journal" reported this problem. According to the study, conducted by the Sir George E. Clark Metabolic Unit, Royal Victoria Hospital in the U.K., B-12 malabsorption has been found in diabetic patients taking long-term metformin therapy. The study found that stopping metformin therapy reversed malabsorption and returned the patients' B-12 levels to normal.
Short-Term Metformin Effects on B-12
A study published in the November 2003 issue of "Journal of Internal Medicine" examined short-term effects of metformin therapy. The study, conducted for 16 weeks, found that metformin decreased vitamin B-12. In addition, metformin decreased folate, another B vitamin, and increased homocysteine, an amino acid associated with cardiovascular disease when elevated.
Effects
Low B-12 can cause low red blood cells, which is called anemia. Red blood transports oxygen from your lungs to your organs and tissues, and carbon dioxide to your lungs for exhalation. When your red blood cells are low, your body is deprived of the oxygen and nutrients it needs to function optimally.
Treatment
Low B-12 caused by malabsorption is generally treated with monthly B-12 injections. If you are taking metformin and your B-12 levels are low, discuss your options with your doctor.
References
- Medlineplus: Metformin; April 2011
- Office of Dietary Supplements; Dietary Supplement Fact Sheet: Vitamin B12
- "British Medical Journal"; Vitamin B12 Status of Patients on Long-term Metformin Therapy; G. H. Tomkin, et al.; June 1971
- "Journal of Internal Medicine"; Effects of Short-term Treatment with Metformin on Serum Concentrations of Homocysteine, Folate and Vitamin B12 in Type 2 Diabetes Mellitus: a Randomized, Placebo-controlled Trial; M.G Wulffelé, et al.; November 2003
