Many people who live with diabetes also struggle with a low number of red blood cells in the body (anemia.) 

But how are the two conditions related? 

Does one condition cause the other? 

And should you take iron supplements to help? 

This article will investigate the connection between diabetes and anemia. It will also cover what you should know about iron supplements if you struggle with this condition. 

Doctor holds a chalkboard sign that says "anemia"

What is anemia? 

According to the National Heart, Lung, and Blood Institute, anemia occurs when the body’s blood doesn’t have enough red blood cells to function properly. This leads to reduced oxygen flow to the organs. 

Sometimes this disease does not even have symptoms and often goes undiagnosed. 

It’s an extremely common condition. Over three million new cases are diagnosed annually in the United States.

Anemia can have many causes including:

  • Unintentional blood loss 
  • A lack of production of red blood cells 
  • High rates of red blood cell destruction 

Some associated conditions that may cause anemia include heavy periods, pregnancy, and in some cases, diabetes. 

What are the symptoms of anemia? 

The symptoms of anemia vary and may include: 

  • Pale skin
  • Rapid pulse/heart rate
  • Fatigue
  • Shortness of breath
  • Low body temperature
  • Dizziness
  • Lightheadedness 
  • Headache
  • Cold extremities (hands and feet)  

If you have diabetes and have any of these symptoms, you should check your blood sugar often. 

This is so you don’t mistake a low or high blood sugar level for anemia. 

Call your doctor to ask about being tested for anemia if you are suffering from these symptoms for several weeks with normal blood sugar levels and no ketones. 

Diabetes does not cause anemia, and anemia does not cause diabetes. 

However, the two conditions are related. But having one condition does not result in the development of the other.

Studies show that up to 1 in 4 adults who have diabetes also have anemia, and it often goes undiagnosed. 

Anemia is especially common in people with type 2 diabetes who suffer from diabetes complications such as renal dysfunction and chronic kidney disease (CKD.)

This is common because damaged or failing kidneys do not produce a hormone called erythropoietin (EPO).

EPO signals to the bone marrow that the body needs more red blood cells to function. And anemia is simply a low count of those healthy red blood cells. 

If you have diabetes, the early stages of kidney disease and dysfunction can oftentimes be asymptomatic. 

However, if you receive an anemia diagnosis and you live with diabetes, it’s best to have your kidney function checked, as many patients with diabetes and kidney issues develop anemia. 

Diabetes also causes inflammation of the blood vessels. This prevents the bone marrow from even receiving the hormone EPO signal to create more blood cells to start. Anemia is more likely to occur. 

On the other hand, if you have anemia and then are diagnosed with diabetes, it may contribute to the development of complications. 

These can include retinopathy as well as eye and nerve damage (neuropathy). 

If you’re anemic and lack healthy red blood cells, your artery, heart, and kidney health may worsen. These organs are already at risk when someone has diabetes. 

Is having diabetes and anemia dangerous? 

Having the two conditions just means that there is more to manage. However, anemia may affect blood sugar levels. 

A 2010 study found that anemia produced false high blood sugar levels on home glucometers. 

This led to dangerous hypoglycemic (low blood sugar) episodes in patients (due to overdosing on insulin for a false high blood sugar.)

This can be extremely dangerous for patients with diabetes. 

Alternatively, there is a direct link between anemia caused by iron deficiency and higher amounts of glucose in the blood. 

In 2017, several studies found that iron deficiency anemia was correlated with increased HbA1c levels in people both with and without diabetes. 

This happened naturally because more glucose molecules were sticking to fewer red blood cells. 

After iron-replacement therapy, HbA1c levels in the patients decreased and returned to normal. 

Can my diabetes medications be causing anemia? 

Insulin will not cause anemia. 

However, there are other diabetes medications that may contribute to the development of anemia. 

These include metformin, fibrates, thiazolidinediones, and ACE inhibitors, which can drop a person’s protein hemoglobin—which is crucial to carry oxygen throughout the bloodstream. 

If you take any of these medications, it can increase your risk of developing anemia. Contact your doctor if you’re concerned. 

Metformin can be particularly worrisome. This is because it can cause malabsorption of Vitamin B12. 

Long-term use of the drug can lead to a Vitamin B12 deficiency—observed in up to 30% of people who use it. This can cause anemia. 

Studies have drawn a strong correlation between metformin use and megaloblastic anemia

So, you should ask for a regularly-drawn blood panel (known as a CBC or a complete blood count) if you have diabetes and have taken metformin for a long time.

Since blood loss is also a major cause of anemia, if you have diabetes and are on kidney dialysis, talk with your doctor about the increased risk of anemia.

How is anemia treated? 

Depending on the underlying cause, treating anemia can be remarkably simple. 

Anemia caused by an iron deficiency can be remedied by taking an oral iron supplement. 

You may simply opt to eat more iron-rich foods such as:

  • Legumes 
  • Lentils
  • Beans 
  • Green leafy vegetables 
  • Tofu 
  • Red meat 
  • Fish 
  • Liver 
  • Oysters 
  • Prunes and raisins

If you take metformin and have anemia, you may want to talk with your doctor about changing your diabetes medication for an alternative or tapering your dose of metformin. 

If you receive kidney dialysis treatment, opt to have iron injected directly into your vein by your doctor. For many patients, this will raise their hemoglobin enough. 

However, it can also increase the risk of both heart attack and stroke. 

If your kidneys are damaged and they’re not producing enough of the hormone EPO, you may be prescribed a synthetic form of the hormone (rhEPO) to promote red blood cell production. 

However, between 5-10% of patients on rhEPO therapy develop resistance to this therapy. 

Your doctor should closely monitor you if you receive this treatment.  

Finally, in severe cases, you may need a blood transfusion. 


While diabetes doesn’t cause anemia and anemia doesn’t cause diabetes, the two conditions are closely linked. 

Diabetes complications, such as kidney disease and inflamed blood vessels, can contribute to the development of anemia. 

This is due to lower levels of the hormone erythropoietin (EPO) being produced in the body. 

This hormone typically signals to the bone marrow that the body needs more red blood cells produced. 

However, without EPO giving the signal, red blood cell levels fall. 

When blood vessels are inflamed, it prevents the bone marrow from receiving the EPO signal, making anemia more likely as well. 

Additionally, some medications, such as fibrates, ACE inhibitors, thiazolidinediones, and especially metformin, can contribute to the development of anemia. 

If you use metformin long-term, consider supplementing your diet with B12 or iron. 

If you have anemia, you may find your diabetes harder to manage. 

A lack of healthy red blood cells can exacerbate diabetes complications, including kidney, eye, nerve, artery, and heart health. 

You may also struggle with persistently higher blood sugar and HbA1c levels. 

However, anemia is treatable. 

You may opt for dietary or supplement changes or additions. 

You may also change your diabetes medications, or you may even require a blood transfusion. 

Talk with your doctor if you’re concerned about developing anemia or if you’ve been recently diagnosed with the condition.