Certain types of diabetes medications may result in some people developing a vitamin B12 deficiency. As such, they may benefit from taking vitamin B12 supplements.

Vitamin B12 is an important vitamin for blood cells and the nervous system. A person can become deficient in B12 when they do not get enough through their diet.

Diabetes is a chronic metabolic disorder that disrupts the body’s ability to regulate blood sugar levels. Type 1 diabetes is an autoimmune disease that causes the body to attack the cells that produce insulin, a hormone that manages blood sugar levels. Type 2 diabetes occurs when the body can no longer effectively use insulin.

B12 deficiency has a multifaceted relationship with diabetes. Medical research is giving increasing attention to help determine the relationship between diabetes and B12.

This article explores B12 in more detail and the research surrounding its connection with diabetes.

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Research is ongoing to understand the exact relationship between diabetes and vitamin B12.

Evidence notes that vitamin B12 deficiency can occur in individuals with type 2 diabetes who take metformin. The risk of low vitamin B12 levels also increases with higher metformin doses and longer treatment duration.

While the exact mechanisms remain unclear, it is likely that metformin impedes the absorption of vitamin B12, which can lead to a deficiency. Therfore, the American Diabetes Association (ADA) notes it may be beneficial for an individual taking metformin to supplement with B12. However, they should first discuss this with a healthcare professional.

Learn more about whether certain vitamins can help with diabetes.

Additionally, growing evidence suggests a potential association between low levels of B12 and a higher risk of developing diabetes. However, a 2020 report highlights that further research is necessary to understand the potential role of vitamin B12 in the development of diabetes.

In addition to metformin interfering with B12 absorption, other factors can lead to a deficiency.

Vitamin B12, or cobalamin, is important for various bodily processes. Vitamin B12 naturally occurs in animal products such as fish, meat, and poultry. As such, there is a higher rate of vitamin B12 deficiency in people who follow a vegan or vegetarian diet.

Gastrointestinal conditions, such as Crohn’s disease, can also lead to vitamin B12 deficiencies due to their effect on nutrient absorption. Crohn’s disease belongs to a group of conditions known as inflammatory bowel disease (IBD). Evidence notes that IBD is more common in people with type 1 diabetes than the general population.

Vitamin B12 deficiency can cause anemia. This is because B12 is essential for the production of red blood cells (RBCs). If someone does not consume or absorb enough B12, their RBC count may be low. Additionally, as B12 is also necessary for brain and nerve function, a person may begin to notice brain and nervous system symptoms.

Symptoms of vitamin B12 deficiency may include:

Untreated vitamin B12 deficiency can lead to severe complications. This can include:

Neuropathy is an umbrella term encompassing a range of conditions that involve damage to the nervous system. While the symptoms of neuropathy vary depending on the type of nerves affected, a person may experience cramps and tingling sensations.

Both diabetes and vitamin B12 deficiency can independently lead to neuropathy. In diabetes, extended periods of high blood sugar levels can cause nerve damage. Vitamin B12 is necessary for healthy nerve function, and deficiency of the vitamin can lead to neuropathy.

Older 2014 research suggests that when both type 2 diabetes and vitamin B12 deficiency coexist, it can increase the severity of peripheral neuropathy.

Diagnosis of B12 deficiency will start with an initial evaluation with a doctor. They may suggest a combination of laboratory tests. Primarily, a person will undergo blood tests to assess their B12 levels.

A medical professional may also use tests that examine other markers. For example, they may check for levels of homocysteine and methylmalonic acid. As B12 deficiency results in the accumulation of these compounds, levels will appear elevated.

People living with diabetes should note any new or worsening symptoms they experience. If issues such as unexplained fatigue, tingling or pain, and memory issues develop, it is important to consult a healthcare professional.

It is also advisable for a person without diabetes to contact a doctor if they notice an increase in thirst, urination, and appetite.

Early intervention can help prevent the progress of both diabetes- and B12-deficiency-related complications.

The link between diabetes and vitamin B12 is multifaceted and requires more research. Evidence notes that metformin, a common type 2 diabetes medication, can cause a vitamin B12 deficiency. Additionally, some evidence suggests that B12 deficiency can increase the risk of developing diabetes.

Therefore, it may be advisable for a person with diabetes to take vitamin B12 supplements. However, they should first discuss this with a healthcare professional.