Anemia & Diabetes: Cause or Effect?

08/09/2022 | 5 min. read

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If you’re feeling tired and easily fatigued for no good reason, ask your doctor about testing for anemia. Fatigue may have many causes, but anemia is a fairly common one. 

This is especially true for women who are pregnant or of childbearing age, vegetarians, Blacks, Hispanics, and people over age 65. All these groups have an increased risk of developing anemia.

Yet, there’s another risk factor that’s often overlooked, even though it affects 1 in 10 Americans. Diabetes doubles, and can even triple, your likelihood of developing anemia. Plus, having both diabetes and anemia raises your risk of diabetic complications. 

What Is Anemia?

Anemia affects the red blood cells. Produced in the bone marrow, red blood cells contain a protein called hemoglobin that transports oxygen from the lungs to cells throughout the body. When you don’t have enough healthy red blood cells to deliver sufficient oxygen to your tissues, you feel tired and perhaps dizzy, weak, and short of breath.

There are three main causes of anemia:

  1. Blood loss due to trauma surgery, heavy menstrual periods, gastrointestinal bleeding, etc.
  2. Destruction of red blood cells, a rarer form of anemia that may be inherited or result from an infection, autoimmune disease, blood cancer, or other diseases. 
  3. Decreased production of healthy red blood cells, which is often caused by deficiencies in essential nutrients such as iron, vitamin B12, and folate. Damage to the kidneys and other systems that play a role in the creation of red blood cells can also curb their production. The anemia-diabetes link falls into this category. 

How Does Diabetes Cause Anemia?

The following complications of diabetes increase the risk of developing anemia: 

Diabetic Kidney Disease 

Erythropoietin (EPO) is a hormone made in the kidneys that signals the bone marrow to make more red blood cells. If the kidneys fail to produce enough EPO, red blood cell production declines.

For people with healthy kidneys, this isn’t a problem. When blood oxygen levels are low, their kidneys make more EPO, and red blood cell production increases. Damaged kidneys, however, secrete less EPO—and as kidney disease progresses, EPO output becomes less and less efficient.

Given that up to 40% of people with diabetes have some degree of kidney disease (diabetic nephropathy), it’s little wonder that anemia is so common in people with diabetes.

Iron, Vitamin B12, or Folate Deficiencies 

Diabetic neuropathy, or nerve damage, is another common complication. It affects nerves and impairs function in organs throughout the body, including the gastrointestinal tract. This interferes with the absorption of iron, which is a major component of hemoglobin, as well as vitamin B12 and folate, which are required for red blood cell production. 

Diabetes Drugs 

Metformin, a popular treatment for type 2 diabetes, can cause vitamin B12 deficiencies and has been linked with an increased risk of anemia.

Can Anemia Cause Diabetes or Make It Worse? 

Now, let’s look at how anemia affects diabetes. To be clear, anemia does not cause diabetes. However, anemia can have serious consequences for people who already have diabetes:

  • Anemia increases the risk and severity of diabetic ulcers, eye problems, kidney disease, neuropathy, heart disease, and other diabetic complications.
  • It compounds diabetes’ adverse effects on other organs and systems. For example, untreated anemia is an independent risk factor for cardiovascular disease.
  • Anemia further elevates markers of chronic inflammation, which contributes to a host of health problems.

As you can see, it’s a vicious circle, underscoring the importance of testing, monitoring, and treating both conditions.

Testing & Treatment of Anemia

Despite these strong links, anemia goes undiagnosed and untreated in a significant percentage of patients with diabetes. 

Most doctors test hemoglobin and hematocrit (the percentage of red blood cells by volume of blood) to diagnose anemia. It’s also a good idea to measure ferritin, a protein that stores iron in the body, as it gives a better picture of iron status—including moderately high levels and iron overload (hemochromatosis), a relatively rare but serious inherited condition.

Work with your doctor to determine the underlying cause of anemia. Once you do, treat it accordingly. Iron, B12, and folate deficiencies can usually be corrected with diet changes and vitamin and mineral supplements. 

Never take iron supplements unless directed by a physician. Excess iron in the body alters the gut microbiota, raises the risk of infection, unleashes free radical activity, and increases the risk of diabetes and other serious health challenges.

Important Notice on A1C Testing & Anemia 

Routine testing for individuals with diabetes includes hemoglobin A1C. This blood test, which estimates the average blood sugar level over the previous three months, is used by physicians to diagnose and monitor diabetes. 

It’s a great test, but there’s one important thing you need to know about the A1C test as it relates to anemia. 

Untreated anemia caused by iron, vitamin B12, or folate deficiency can elevate A1C results, even when blood sugars are normal. Conversely, taking iron or B12 supplements to treat anemia can cause the A1C level to be erroneously low.

In other words, if you have anemia, treated or untreated, it’s possible to be falsely diagnosed with diabetes based on a skewed A1C test—or to have worse blood sugar control than indicated on A1C testing. 

Anemia & Diabetes Recap

Up to a quarter of patients with diabetes have anemia, and many have not been diagnosed. Talk to your doctor about testing for anemia and work together to treat the underlying cause.   

Deficiencies in vitamin B12, folate, and other nutrients are common in individuals with diabetes, so I recommend a good daily multivitamin and mineral supplement. Unless you have a proven iron deficiency, do not take supplemental iron, and avoid multivitamins with iron. (Read labels carefully. Many multis contain iron.) 

Above all, do everything you can do to control your diabetes with serious attention to weight loss, diet changes, exercise, berberine, and other supportive supplements. 

These and other natural therapies have the potential of not only lowering your blood sugar and protecting against anemia and other complications of diabetes but also improving all aspects of your health and well-being. 

Dr. Julian Whitaker

Meet Dr. Julian Whitaker

For more than 30 years, Dr. Julian Whitaker has helped people regain their health with a combination of therapeutic lifestyle changes, targeted nutritional support, and other cutting-edge natural therapies. He is widely known for treating diabetes, but also routinely treats heart disease and other degenerative diseases.

More About Dr. Julian Whitaker