Iron Deficiency
Jen Hand
Approximately 14% of adults in the United States are affected by absolute iron deficiency, while 10 million more have iron-deficiency anemia, according to a review article published March 30, 2025, in JAMA.
Researchers focused on the screening, diagnosis, and treatment of absolute iron deficiency with or without anemia in the narrative review, citing 86 articles chosen from 350 published research papers over a nearly 11-year period ending in November 2024. They found that once a deficiency is verified, its cause should be determined in patients to prevent recurrence, guide the route of iron repletion, and identify conditions that may require separate treatments.
Testing and treatment
The JAMA review authors said that testing for iron deficiency with a serum ferritin and/or transferrin saturation is appropriate for anyone with symptoms or risk factors of iron deficiency. They maintained that adequate dietary iron is important for preventing iron deficiency, but once it develops, the typical iron deficit of 1,000 mg plus daily needs of 1 to 5 mg cannot be provided by diet alone. Recommendations for routine screening of asymptomatic, at-risk people for iron deficiency vary by professional organization, and the American Society of Hematology is currently developing guidelines, researchers noted.
Oral iron is usually the first line of treatment for most patients. A typical dose (ferrous sulfate, 325 mg) contains 60 mg of elemental iron taken once daily. However, the review’s authors emphasized that iron ingestion every other day has a similar efficacy and fewer adverse effects. Prior research has shown that use of enteric-coated and timed-release oral iron preparations reduces iron absorption, as does consuming calcium, fiber, tea, and coffee within 1 hour before and after taking oral iron. Vitamin C may increase absorption, however.
I.V. iron is appropriate for people who do not tolerate or have impaired absorption of oral iron, those with ongoing blood loss, certain chronic inflammatory conditions, and during the second and third trimesters of pregnancy.
Women and iron deficiency
“Iron deficiency, with or without anemia, is nearly ubiquitous in women of reproductive age,” said Michael Auerbach, MD, lead author of the article and owner of Auerbach Hematology and Oncology in Baltimore. “It causes significant symptoms and morbidity.”
In high-income countries, around 38% of nonpregnant, reproductive age women have iron deficiency without anemia, 13% have iron-deficiency anemia, and during the third trimester of pregnancy, it affects up to 84% of women, found the review team. They also said that iron deficiency may be associated with adverse fetal, neonatal, and maternal outcomes.
Growing awareness
“If pharmacists in the community setting have patients who are purchasing over-the-counter supplements that are advertised as improving fatigue, it might be a useful time to share more information about this condition and recommend, if appropriate, that they see a health care provider,” said Lisa Holle, PharmD.
Potential symptoms of iron deficiency include depression, fatigue, brain fog, exercise intolerance, restless legs syndrome, pica, mood changes, and worsening heart failure. If the cause of iron deficiency is not diagnosed and treated, iron-deficiency anemia may develop, said the authors of the JAMA article.
Iron plays an important role in several biological functions including the production of hemoglobin and myoglobin. It is found in many foods, added to fortified food products, and available in multivitamin/mineral supplements or on its own in different forms.
Holle, a clinical professor of pharmacy practice at the University of Connecticut School of Pharmacy, acknowledged that pharmacists are positioned to help the health care team consider factors for patients that may affect ideal outcomes, such as including ways to optimize absorption of oral iron and ensuring parenteral iron therapy is fitting and administered properly so adverse drug reactions—and costs—are minimized.
“Pharmacists can play a pivotal role in providing patients with information they need to manage iron-deficiency treatment,” she said. ■