Is too much iron a health problem?

You may have heard about iron deficiency anemia, but did you know that too much iron is also a health risk?

Excess iron intake from dietary sources is very unlikely in adults with normal intestinal function, as usually only 8–10% of iron from the diet is absorbed. However, there are specific situations where iron overload can occur, including by intaking too much iron in supplements or medicines or in people affected by hemochromatosis.

What is hemochromatosis?
Hemochromatosis is an inherited disorder where the body absorbs three to four times more iron than normal (1). This excess iron cannot be naturally excreted from the body, so it accumulates in organs and tissues, eventually causing serious health complications. The symptoms of hemochromatosis include fatigue, joint pain, abdominal pain, memory problems, depression, decreased sex drive, shortness of breath, and heart flutters. Further serious complications can occur in untreated individuals, including heart failure, liver cirrhosis and disease, and endocrine problems (2).

How common is hemochromatosis?
About 1 in 10 whites carry the most common genetic mutation that causes hemochromatosis. However, two copies of the mutation are usually required for extra iron absorption to occur, and only about 4.4 whites per 1000 carry two copies and have hemochromatosis (3).

Is hemochromatosis treatable?
Thankfully hemochromatosis is easily treated by blood removal (phlebotomy), which also removes the excess iron. Hemochromatosis patients should also limit their dietary iron intake and avoid iron and vitamin C supplements, as vitamin C increases the absorbance of iron (3).

Unfortunately, many people with hemochromatosis are unaware of their diagnosis until symptoms occur, and by then the excess iron may have already caused tissue and organ damage that is not repaired by phlebotomy.

What are the symptoms associated with excess iron from supplements?
Gastrointestinal upsets are common from acute intakes of more than 20 mg/kg iron. Symptoms can include constipation, nausea, abdominal pain, and vomiting. If a very high dose is ingested, serious complications can occur, such as multisystem organ failure, coma, convulsions, or death (3).

How can I get my iron levels checked?
We offer several tests that can determine your iron status. All of these tests just require a simple finger prick blood sample for an accurate analysis.

  • The iron test measures the levels of iron circulating in the blood. Serum iron levels above 150 ug/dL occur in hemochromatosis patients.
  • Ferritin is a protein that helps store iron. The ferritin test measures how much of the iron stores have been used. Ferritin levels above 300 ng/mL in males or 200 mg/mL in females are indicative of hemochromatosis (4).
  • Transferrin is the main protein that binds and transports iron around the body. The transferrin test measures your levels of transferrin, while the transferrin saturation test calculates the percentage of transferrin that is bound to iron. Transferrin saturation levels above 45–50% indicate iron overload (4).

These tests are available as individual tests as well as a cost-saving combination test.

1. Witte DL, et al. (1996). Hereditary hemochromatosis. Clinica Chimica Acta. 245(2), 139-200.
2. Beutler E, Felitti V, Gelbart T, Ho N. (2001) Genetics of Iron Storage and Hemochromatosis. Drug Metab Dispos. 29(4):495-499.
3. Iron, Fact Sheet for Health Professionals. NIH. Updated March 2021.
4. Crownover BK, Covey CJ. (2013) Hereditary Hemochromatosis. Am Fam Physician. 87(3):183-190.