Iron Deficiency and Excess: Recognize the Symptoms and Causes

Why Fortified Grains and Gummy Vitamins should be consumed in moderation

By Roberta H. Anding, MS, Baylor College of Medicine and Texas Children’s Hospital
Edited by Kate Findley and proofread by Angela Shoemaker, Wondrium Daily

How do you know if you’re anemic? Sometimes the signs are obvious, but other times they can sneak up on you. Professor Anding explains what to look for and what happens when you consume too much iron.

Close up of iron tablets
Excess iron intake causes detrimental health conditions for people of all ages. Photo By MIA Studio / Shutterstock

Symptoms of Iron Deficiency

Surprisingly, the major causes of anemia, or iron deficiency, are non-dietary in nature, including pain medications, which impact iron bioavailability. Symptoms of iron deficiency include short attention span, but that’s mostly in children. In adults, it can result in extreme fatigue or poor immune system functioning. 

Other biological markers that you might actually be able to see are pale inner eyelids, mucosal tissue, behavioral changes, and concave and pale nail beds. Iron deficiency occurs in stages. 

“I want you to think about your bank account … the amount of money that you have in your bank,” Professor Anding said. “Ferritin is actually an iron-containing protein in your cells and it’s a measure of your stored iron. … So it’s kind of like the amount of money that you have deposited in your bank account.”

When you’re removing money from your bank account, it doesn’t seem like much until you’ve spent everything and you’re down to zero. In the same way, as ferritin becomes depleted, you’ll eventually have decreased hemoglobin.

Thus, if you want to see if you’re on the verge of iron depletion, have your physician check your ferritin levels. As bone marrow iron stores become more and more depleted, the amount of iron that you absorb increases to compensate. 

Your body tries to rally, but it may not be able to rally in a fast enough fashion. Eventually, deficiency will impair red blood cell synthesis, and the results are an iron deficiency anemia. This anemia is microcytic, or small cell, and hypochromic, or pale color.

Iron Toxicity

Just as it is possible to have iron deficiency, it is also possible to have an excess of iron. Iron toxicity can occur due to the overconsumption of dietary iron.

The excessive amount of iron acts as an oxidant. Iron overload can have negative health implications, including a worsening of insulin resistance that can make nonalcoholic steatohepatitis worse. 

“Now, iron poisoning is common when children eat vitamins like candy; so, I want you to think about the vitamins that you have in your home, whether for your children or your grandchildren,” Professor Anding said. “Treat them like drugs. Iron overdose from vitamins is one of the leading causes of poisoning in children under the age of six years old.”

Iron supplementation in those with normal iron stores can actually increase the level of oxidative DNA damage and the likelihood of cancer risk. You’ve likely heard about the importance of antioxidants, which are substances that prevent damage to cells caused by oxidants, which  introduce free radicals. 

With excess iron, we’ve introduced an oxidant. Too much iron actually increases the risk of cancer. 

Concerns for Athletes

“Individuals who consume large amounts of calories are also at risk of iron overload, and in my athletic population, this is a real concern,” Professor Anding said.

Most processed grain products are fortified with iron, including breakfast cereals and energy bars. Thus, athletes who consume large amounts of highly fortified food should read labels, but they’re going to struggle to find foods that are not fortified with iron. For the athletes that Professor Anding works with, she has often advised them to donate blood. 

“You eat a large amount of calories, you’re eating a large amount of fortified foods, and certainly, we now test particularly male athletes for iron overload,” Professor Anding said. “People who receive repeated blood transfusions are at high risk for iron poisoning, as are people who consume large amounts of alcohol … large amounts of alcohol can actually increase the uptake of iron in mucosal cells.”

The upper limit of safety for iron is 45 milligrams per day for adults, and approximately 40 milligrams per day for teens and children. If you have an overt deficiency, your physician may prescribe higher doses than that—these limits are for individuals who have adequate amounts of iron. 

Additionally, iron can reduce the effectiveness of antibiotics and bisphosphonates, which are used for the prevention of osteoporosis. Overall, then, as with most things, when you take too much iron, the harm outweighs the benefits of the mineral.

This article was edited by Kate Findley, Writer for Wondrium Daily, and proofread by Angela Shoemaker, Proofreader and Copy Editor for Wondrium Daily.

Professor Roberta H. Anding is a registered dietitian and Director of Sports Nutrition and a clinical dietitian at Baylor College of Medicine and Texas Children’s Hospital. She also teaches and lectures in the Baylor College of Medicine’s Department of Pediatrics, Section of Adolescent Medicine and Sports Medicine, and in the Department of Kinesiology at Rice University.