Should You Stop Taking an Iron Supplement?

by David Mendosa Patient Advocate

Having too much iron in your blood or stored elsewhere in your body might be a reason why your blood glucose level is above normal. 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.

Excess iron and diabetes

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?

David Mendosa
Meet Our Writer
David Mendosa

David Mendosa was a journalist who learned in 1994 that he had type 2 diabetes, which he wrote about exclusively. He died in May 2017 after a short illness unrelated to diabetes. He wrote thousands of diabetes articles, two books about it, created one of the first diabetes websites, and published a monthly newsletter, “Diabetes Update.” His very low-carbohydrate diet, A1C level of 5.3, and BMI of 19.8 kept his diabetes in remission without any drugs until his death.