Taking Metformin to Manage Your Diabetes? Make Sure Your Doctor Checks Your Vitamin B12 Levels!

Prescription Drugs

By Joy Stephenson-Laws, JD, Founder


If you have type 2 diabetes, the odds are you are taking the prescription medicine metformin to help manage it. Also known by the brand names Glucophage, Carbophage, Riomet, Fortamet, Gluformin and Diaformin, among others, metformin is believed to be the world’s most prescribed antidiabetic medication since it first appeared in scientific literature almost 100 years ago. Metformin became commercially available in the United Kingdom in the late 1950s, in Canada in the early 1970s and in the United States in 1995.  

Metformin helps your body better respond to the insulin it produces while also decreasing the amount of sugar that your liver makes and your body absorbs.  

This action, combined with diet and exercise, has helped countless type 2 diabetics better control their blood sugar levels. Metformin may also play a role in helping delay the progression of prediabetes to diabetes and is used in the treatment of polycystic ovary syndrome (PCOS). Some studies suggest it may even reduce the amount of insulin someone with type 1 diabetes may need.  

And while the physical side effects of metformin, such as nausea or gas, are usually not serious and go away on their own, there is one side effect that you should talk with your doctor about since it can impact your overall health. Metformin, as other prescription medications, may impact how your body absorbs and metabolizes the vitamins, minerals and other nutrients you need to be your healthiest and feel your best physically and mentally.  

In the case of metformin, recent research has shown a link between its use and vitamin B12 deficiency. B12 deficiency can increase the risk of developing peripheral nerve damage.  Peripheral nerve damage, especially in the legs and feet, is one of the most common complications of diabetes.

In this particular study, almost 10 percent of diabetes patients taking metformin had a vitamin B12 deficiency and only six percent of those were being treated for this nutrient deficiency.  Exacerbating the problem was that some 64 percent of study participants had not been tested for vitamin B12 deficiency, and if they were to develop nerve damage it would likely be blamed on having diabetes rather than other causes.

Metformin Also Impacts Vitamin B9 and CoQ10

In addition to vitamin B12, metformin has been shown to decrease your levels of vitamin B9 (also known as folic acid) and CoQ10. Vitamin B9, as do vitamin B12 and other B vitamins, help your body convert food into fuel as well as help it use fats and protein. It also plays a role in helping your liver, skin, hair and eyes stay healthy. Especially important for diabetics, B9 helps the nervous system function properly. It also works with B12 and B6 to better control blood levels of homocysteine (an amino acid in the blood), which has been linked to heart disease.

CoQ10, which has gained a certain level of popularity and visibility in recent years, is a naturally-occurring antioxidant that is important for cell growth and maintenance. A CoQ10 deficiency, as can be caused by metformin and other medications, has been linked to muscle pain, cramping and cardiovascular problems.  

How to be Proactive

The most important thing you can do if you’re taking metformin is to ask your doctor to test your levels of vitamin B12 as well as other nutrients such as vitamin B9 and CoQ10. For vitamin B12, researchers are recommending that anyone taking metformin have their levels tested at least once a year as part of an annual physical. And if your doctor is recommending that you start taking metformin, you should get a baseline level test before you start taking the medication. This will allow you and your healthcare provider to better track the impact metformin may have on any of your nutrient levels.

There also is a lot you can be doing to make sure your diet includes plenty of the foods that will give your body the vitamins and minerals it needs.  Fresh foods, lots of fruits and vegetables, prepared at home are the way to go since they provide nutrients in the best form for your body to absorb and use. Plus, you also know exactly what you are eating when you cook the meals yourself. Processed foods have a lot of additives and are usually void of nutrients. Vitamin B12 is plentiful in eggs, fish, beef, clams, salmon and chicken.

For getting your vitamin B9, make sure your diet includes citrus fruits, green leafy vegetables, beets, turnips, soybeans, kidney beans, avocados, orange juice, brewer’s yeast and cereals.  It’s also worth keeping in mind that many breakfast cereals are fortified with vitamin B9.   

It’s also easy to get CoQ10 by eating organ meats, such as liver, as well as whole grains and vegetables such as cauliflower and spinach.  

If you are concerned about the side effects of metformin or other prescription medicines and how they may impact your nutrient levels, be sure to talk with a competent healthcare provider about them. Always remember that your physician has prescribed the medications you are taking because she/he is confident that the benefits outweigh any possible side effects, including a possible nutrient deficiency. You should not decide on your own to stop taking or change the dose of metformin or any other medicine. You should, however, be aware how these medicines can affect your body and how to be proactive about replenishing the nutrients your body needs.  

Enjoy your healthy life!


The pH professional health care team includes recognized experts from a variety of health care and related disciplines, including physicians, attorneys, nutritionists, nurses and certified fitness instructors. This team also includes the members of the pH Medical Advisory Board, which constantly monitors all pH programs, products and services. To learn more about the pH Medical Advisory Board, click here.


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