Metformin and Potential Vitamin Deficiency


METFORMIN (Brand names: Glucophage, Glumetza, Fortamet, Riomet) is an oral medication commonly used to treat type 2 diabetes. It is also commonly being used in patients with irregular periods and/or Polycystic Ovary Syndrome (PCOS) to aid with menstrual regulation and ovulation. In patients with metabolic syndrome, Metformin can prevent the progression to type 2 diabetes. At this time, Metformin is only FDA-approved for the treatment of diabetes.

Metformin reduces the amount of glucose released by the liver and increases glucose uptake in muscle. The net effect is Metformin that enhances insulin sensitivity and lowers fasting blood glucose and insulin in patients with type 2 diabetes. In patients with PCOS, Metformin can lower insulin and androgen (male hormones) leading to increased frequency of ovulation and possibly a reduced risk of miscarriage.

Metformin is often associated with GI side effects including nausea, bloating, abdominal distension and diarrhea.

Metformin is thought to induce malabsorption of vitamin B-12 in the small intestine. Studies have shown that Metformin is associated with Vitamin B12 deficiency in up to 30% of patient taking it on a long-term basis. . Vitamin B12 is required for proper red blood cell formation, synthesis of DNA and nervous system function. Symptoms of Vitamin B12 deficiency may include macrocytic anemia (low red blood cell count), mental symptoms including fatigue, depression and nerve damage (peripheral neuropathy).

Natural food sources of B12 are meat, poultry, eggs, fish milk, and dairy products. For vegetarians or vegans, non-animal sources include fortified breakfast cereals and yeast extracts or spreads. The Recommended Dietary Allowance or RDA for Vitamin B12 is 2.4 mcg per day for adults.

Metformin has also been associated with depletion of folic acid and CoQ10.

At this time, it appears that patients using Metformin should be on a daily multivitamin containing the RDA for Vitamin B12 and Folic acid. Supplementation with CoQ10 may be a good idea, especially in patients with diabetes or taking Statin drugs. Typical doses are 50 to 200 mg daily taken. Patients should take CoQ10 with a meal with some fat for best absorption. The softgel or chewable forms are advised.