diabetes supplement
Diabetes Medication

Most People with Diabetes Should Stop Iron Supplements

When you have too much iron in your blood or stored elsewhere in your body might be why your blood glucose level is above normal. In fact, too much iron can even be why you got diabetes. Yet about one out of every five Americans regularly takes an iron supplement.

For years researchers have suspected that when your body accumulates too much iron you are at risk of a host of diseases, according to Berkeley Wellness. In addition to diabetes, iron overload is linked to colorectal cancer, high blood pressure, and hardening of the arteries, as well as to strokes, Alzheimer’s Disease, and Parkinson’s disease.

But only now do we have studies demonstrating the connection between excess iron and diabetes.

“Even mildly elevated body iron contributes to the prevalence and incidence of type 2 diabetes,” states the news release from the University of Eastern Finland announcing the publication of these studies.

One of these recent studies looked at why men are more likely to have diabetes than women. The International Diabetes Federation estimated that 215.2 million men and 199.5 million women — a difference of more than 15 million people — had diabetes worldwide in 2015.

A gender difference

Only the abstract of this study, “Gender difference in type 2 diabetes and the role of body iron stores,” is free online. But the lead author, Alex Aregbesola, M.D., Ph.D., emailed me the full text upon my request. Dr. Aregbesola is a researcher at the Institute of Public Health and Clinical Nutrition, University of Eastern Finland. This study, which includes a prospective analysis of 1,506 men and women, “showed for the first time that body iron… explains about two-fifths and one-fifth of the gender difference observed in the prevalence and incidence of type 2 diabetes, respectively.”

While this study doesn’t explain the cause of this gender difference, Dr. Aregbesola’s Ph.D. dissertation, which is based on this study and on two earlier ones, does. In November 2016, The University of Eastern Finland published the dissertation in English as “Role of body iron stores in glucose homeostasis and type 2 diabetes.” The gender difference is mostly, if not entirely, the loss of blood during menstruation, it concluded.

Iron supplements

This is likely the reason why more females — 21 percent — than males — 15 percent — take an iron supplement. But a higher proportion of even postmenopausal women than men take an iron supplement. And this may not be a wise choice.

In fact, “no one should be taking iron supplements without a doctor’s recommendation to do so,” according to Andrew Weil, M.D., in an article on his website.

“Iron deficiency is rare in men and postmenopausal women, and most should avoid supplements containing iron to reduce the risk of organ damage from too much iron,” according to Jane E. Brody in The New York Times. Her article cites a Framingham Heart Study where researchers found that only about three percent of elderly subjects studied had too little iron in their blood or stored in their bodies, while 13 percent had levels that were too high.

Too much iron

Iron used to be the most common nutritional deficiency in the U.S. It still is in much of the world, so the recommendations to avoid iron supplements don’t necessarily apply there. But here most Americans get too much iron.

Several years ago, I decided to not eat meat for spiritual and environmental reasons, little realizing that this may also help prevent my iron stores from going too high. Dr. Aregbesola suggests in his Ph.D. dissertation that my decision also made sense from a health standpoint.


He wrote that avoiding “excessive intakes of both dietary iron, especially heme iron-containing food products such as red meat and poultry… could prove useful in preventing iron-induced type 2 diabetes incidence and prevalence.”

Another way to reduce excess iron stores is moderate exercise. Also, if a lab test shows that you have too much iron in your body, he writes that you might consider a “regular blood donation of at least two times a year.”

The easiest strategy

But I think that his most important message is to avoid supplemental iron. It’s the easiest strategy for most of us.

Maybe you think that you aren’t taking an iron supplement. But six of the 10 best-selling multivitamin/multimineral products, which the major online retailer iHerb sells, include iron.

A good idea

I took one of these best-selling multivitamin/multimineral products every day until a few years ago when I read Dr. Weil’s warning. When I read what he wrote, I assumed that avoiding iron in my multivitamin/multimineral supplement was a good idea.

Now I know that it was. Have you stopped taking supplemental iron yet?

This article is based on an earlier version of my article published by HealthCentral.

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  • Rebecca at

    Thank you for this article on iron supplements. I have heredity hemochromatosis and found out the hard way about iron and diabetes. My iron overload is under control now, but I still have the diabetes and other organ damage. With the supplementation in foods today, it would be the rare person needing extra iron.

  • Wendy Wright at

    I would like to add that vegetarian children and women who are pregnant or menstruating and a special vegetarian women do need iron supplementation. I give my three children iron several days a week (15 mg) and get their iron stores checked annually and they tend to run a little low.
    I try to eat low-carb for my blood sugar and I am vegetarian. I find it really challenging. Do you have any suggestions? Is there a section on your website that reveals how to be a low-carb veggie? I mostly eat nuts and vegetables.

    • David Mendosa at

      You are right about those exceptions, Wendy. That’s why I wrote that most people should not take an iron supplement, but I well could have mentioned those exceptions.

      It is challenging to be both a vegetarian and follow a low-carb diet at the same time. I know, because that’s exactly what I do myself. As a vegetarian, you have to make sure that you get enough protein, and that is the reason why I start every day with a plant-based protein drink that I make with almond milk. You do need to make sure that you get enough fat for energy to replace the carbs that you were consuming for energy. The high-carb foods that you most need to avoid are the grains and potatoes. And limit the lentils. I don’t have a section on my website about these issues but I have written many articles about them. See, in particular:

      Vegetarian and Low-Carb Diets for Diabetes – Diabetes Developments
      Jan 31, 2015 – Vegetarian and Low-Carb Diets for Diabetes. About a month ago I became a vegetarian. … Different people become vegetarians for various reasons. Some people choose to avoid meat, poultry, fish, and seafood for their own health and others for religious, ethical, and environmental concerns.

      The New Breakfast for People with Diabetes – Diabetes Developments
      Mar 26, 2015 – But even I believed it would be difficult to combine my very low-carb diet with one that is also vegetarian — for ethical reasons I began to do …

      The Low-Carb Vegetarian
      Feb 24, 2008 – Being a vegetarian limits what Barry can eat. Some of the low-carb mainstays — meat, poultry, and fish — are off the table. If he were a vegan — a vegetarian who won’t eat any animal products like eggs or dairy — the restrictions would be even greater.

      Manage Your Diabetes With A Low-Carb Vegetarian Diet
      Nov 15, 2016 – Nor do most people follow a vegetarian diet. But some people with diabetes, including the more than 3,700 members of The Vegetarian Low …

      Four Ways to Make Vegetarian Sandwiches Without Bread
      Apr 12, 2016 – If you follow a very low-carb diet, you may have assumed that sandwiches were off limits for you. And if you are also a vegetarian, you were …

      Omega-3 for Vegetarians with Diabetes
      Apr 22, 2013 – Many of us want to manage our diabetes by following a vegetarian diet. Most vegetarians object to eating meat because of ethical motivations …