A new study suggests that nearly one in three Americans may have an undiagnosed iron deficiency, which can lead to fatigue, confusion, and difficulty concentrating.
An analysis of data from more than 8,000 U.S. adults found that 14 percent had absolute iron deficiency, where the iron levels in the blood are low, and 15 percent had functional iron deficiency, where the iron levels are adequate but the body can’t properly use the essential mineral, the American Heart Association said. The report was published Tuesday in JAMA Network Open.
Doctors don’t typically test adults for iron deficiency, which is why the condition goes unnoticed in many people.
But the researchers weren’t surprised by the results, as other studies had provided clues. Research suggests iron deficiency It may be more widespread than doctors think.
“This is a common but underappreciated public health problem.” “What’s unique about our study is that it involved a general population that would not normally be tested or screened,” said study co-author Leo Buckley, a clinical pharmacology specialist at Brigham and Women’s Hospital in Boston.
Dr. Andrew Eisenberger, an associate professor of medicine and hematologist at Columbia University’s Vagelos School of Medicine, said iron deficiency “is rarely life-threatening, but it has a significant impact on quality of life.”
“Tens of millions of people in the United States are essentially out of gas because they don’t have enough fuel in their fuel tanks or the tanks are not connected properly to their engines,” said Eisenberger, who was not involved in the new study. “Our society is wired for us to perform at our best, and because iron deficiency is so prevalent, many people are unable to perform at their best.”
He hopes the study will raise awareness among doctors and patients of how common the problem is.
Doctors often test for anemia, a condition in which a person has too few red blood cells due to iron deficiency, during routine blood tests, but symptoms of iron deficiency can appear even when a person has enough red blood cells.
“This is an amazingly preventable disease,” Eisenberger said. “I have a lot of people who come to me with this problem for years, and doctors miss it, ignore it, or don’t know what to do about it. People suffer so much. This is one of the most satisfying things to treat, because it improves people’s quality of life so much.”
In the new study, researchers from Brigham and Women’s Hospital looked at health information collected from 8,021 adults from the National Health and Nutrition Examination Survey between 2017 and 2021. The average age of participants was 48 years old.
None of the participants had health conditions typically associated with iron deficiency, such as anemia, kidney disease, heart failure or pregnancy.
Although many people in the study were iron deficient, Buckley doesn’t think everyone should be tested. He suggests doctors focus on people who have symptoms of iron deficiency, such as fatigue or brain confusion, and those at high risk of iron deficiency, such as pregnant women.
Who is at risk for iron deficiency?
The biggest risk factor for iron deficiency is being female.
Pregnant women are especially at risk: “The average pregnant woman needs an extra 1,000 to 1,500 milligrams of iron,” Eisenberger said, adding that many women don’t get their iron levels tested until the third trimester. “At that point, there’s not enough time for it to improve before birth, and the baby will be iron-deficient throughout the entire pregnancy.”
Iron deficiency in pregnant women Eisenberger said these gene mutations are associated with long-term cognitive impairment in children, small size at birth and premature birth.
Postpartum women are also at risk for iron deficiency, said Dr. Joanna Contreras, a heart failure and transplant specialist at Mount Sinai Fuster Heart Hospital in New York City.
Additionally, menstrual bleeding can lead to iron deficiency, especially in women and girls with heavy periods, because large amounts of iron are shed with the lost blood.
Experts say rates of iron deficiency in men and women become more similar after menopause.
Both women and men can develop functional iron deficiency if they have an inflammatory disease such as rheumatoid arthritis, said Dr. Hossein Aldehali, director of the Cardiovascular and Kidney Institute at Northwestern University Feinberg Medicine’s Center for Molecular Cardiology.
Nutritional Iron Sources
Aldehhali, who was not involved in the new study, said certain diets, such as vegetarian or vegan, could also cause iron deficiency.
Aldehali added that the best food source of iron is red meat, which contains heme, and that it is difficult to get enough iron on a meat-free diet.
According to Aldehari, other food sources high in iron besides meat include:
seafood
Shellfish
beans
Dark green leafy vegetables such as spinach
Raisins
apricot
Iron-fortified foods, such as cereals
Research hasn’t yet proven whether iron deficiency leads to serious long-term health problems, but there are other possible risks.
“Severe anemia can cause people to faint, hit their head, or have a stroke or heart attack,” Eisenberger says, “but this is very rare. Usually people are so tired that they go to the emergency room or see a doctor before it gets to this point.”
While iron deficiency isn’t a cause, it can be a sign of serious health problems, including gastrointestinal bleeding and colon cancer, Ardehali said.
In general, “functional iron deficiency can be a sign of poor health conditions, such as heart failure,” he added.
