Growing evidence suggests we need to rethink iron deficiency treatment
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Industry Buzz
"Depending on the patient’s comorbidities and indication for supplementation, dosing or delivery route— oral or intravenous—may need to be adjusted." - Adam L. Booth, MD, FCAP, Assistant Professor of Pathology and Immunology at Washington University School of Medicine
Find more of your peers' perspectives and insights below.
Growing evidence suggests that iron supplementation, which is commonly used to treat iron-deficiency anemia and bleeding issues, may negatively affect the gut, especially when taken incorrectly.
A report published in 2022, for example, reviewed 141 articles and highlighted how iron supplementation may worsen inflammation, alter the gut microbiome, and cause gastrointestinal (GI) side effects like nausea, diarrhea, and constipation.[] “Unfortunately, iron pills do tend to hurt the stomach,” says Daniel Landau, MD, an oncologist, hematologist, and contributor to The Mesothelioma Center at Asbestos.com.
Trista Best, MPH, RD, LD, a registered dietitian with Balance One Supplements, says that these effects may occur when excess iron builds up in the gut, leading to inflammation and irritation. “This is especially true when taking ferrous sulfate—a poorly absorbed form of iron—which interacts poorly with gut bacteria,” Best says.
Possible cancer risk
Some studies also suggest that iron supplementation may, over time, increase the risk of cancer.[][] “Excess iron can generate reactive oxygen free radicals, increased inflammation, altered cytokine activity, and gut microbiome dysbiosis which may lead to DNA damage, promoting carcinogenesis,” says Adam L. Booth, MD, FCAP, Assistant Professor of Pathology and Immunology at Washington University School of Medicine.
What does this mean for patients who need to take iron? Doctors should closely follow iron supplementation guidelines to prevent patients from ingesting too much of the nutrient. This is particularly important for at-risk patients, such as older adults and individuals with preexisting gut health issues.
Best says there are two solutions to consider for at-risk patients. The first is to prescribe a lower dose of iron throughout the day rather than a high, once-per-day dose. Another option is to utilize intravenous iron to alleviate the side effects of absorption among people with digestive disorders.
“When we give iron in the vein instead of the mouth, we absorb much more of the iron and don't have issues with constipation,” says Dr. Landau.
Mitigating GI symptoms
Finally, doctors can guide patients to be intentional about when they take their iron supplements. To mitigate GI symptoms, Dr. Landau suggests, patients should take the pills with a very light meal and something acidic, such as orange juice. “This can help with absorption and protect the belly from some of the side effects,” he says.
Iron therapy isn’t a one-size-fits-all solution, Dr. Booth says. “Depending on the patient’s comorbidities and indication for supplementation, dosing or delivery route— oral or intravenous—may need to be adjusted,” he says.