Approximately one-third of American adults potentially suffer from iron deficiency, according to research findings.
A significant chunk of adults in the United States, approximately one-third, might be suffering from one of two types of iron deficiency, even if they don't have any medical conditions that would typically lead to its detection, such as anemia, heart failure, or chronic kidney disease, according to a new study.
This study, published on Tuesday in the medical journal JAMA Network Open, warns that iron deficiency could be a pervasive and overlooked public health issue in the United States.
Approximately 14% of the adults in the study met the criteria for absolute iron deficiency, which occurs due to a severe reduction or absence of iron stored in the body. Similarly, about 15% of the adults met the criteria for functional iron deficiency, where there are sufficient iron reserves, but they are not adequately mobilized to support the body's needs.
Dr. Leo Buckley, the lead author of the study and a clinical pharmacy specialist at Brigham and Women's Hospital, stated that it's crucial to differentiate between absolute and functional iron deficiency. Functional iron deficiency is common across all age groups and sexes. Conditions like obesity, diabetes, and kidney disease, which are prevalent in the US, can lead to functional iron deficiency.
Absolute iron deficiency can be treated with iron supplements, and functional iron deficiency is managed by addressing the underlying conditions, Buckley mentioned, adding that the long-term effects of functional iron deficiency are under investigation.
The study found that absolute iron deficiency was most common in pre-menopausal women, according to Buckley, who also noted that it was common among older women and men, a population that may be more susceptible to the effects of iron deficiency. In older adults, blood loss through the gastrointestinal tract and inadequate intake might be the causes. They also have several chronic conditions that can hinder iron absorption.
Iron is a vital mineral essential for maintaining various body functions and development. The body uses iron to produce a protein in red blood cells called hemoglobin. Iron deficiency has been linked to restless leg syndrome, fatigue, hair loss, heart failure, anemia, and other negative outcomes.
Certain groups of people are more prone to iron deficiency, such as women who menstruate, pregnant individuals, children, vegetarians, and frequent blood donors. A 2022 study estimated that more than 70% of iron deficiency may go undiagnosed among children and pregnant women.
Iron deficiency can be prevented or treated using iron pills, intravenous iron infusions, non-prescription iron supplements, or by consuming iron-rich foods like lean meats, seafood, nuts, beans, lentils, and spinach. However, the new study suggests that many people may not be aware that they are iron deficient.
The researchers analyzed data on a nationally representative sample of 8,021 adults in the United States. The data came from the National Health and Nutritional Examination Survey, including blood test assessments on each person's iron levels from 2017 to 2020.
Even among adults without medical conditions associated with iron deficiency, such as anemia, heart failure, chronic kidney disease, or pregnancy, the estimated prevalence of absolute iron deficiency was 11%, and functionality iron deficiency was 15%.
Only about 33% of adults with absolute iron deficiency and 14% of adults with functional iron deficiency had a potential medical reason to screen for iron deficiency, such as anemia, heart failure, chronic kidney disease, or pregnancy. This suggests that most adults with either type of condition might not be screened for it unless they specifically ask their doctor.
The researchers also found that the use of iron supplements was infrequent among adults with iron deficiency. Only up to 35% of women and up to 18% of men with the condition reported taking them.
Dr. Jacob Cogan, an assistant professor of medicine at the University of Minnesota, stated that many health professionals suspect that iron deficiency is more common than generally believed, and this study might provide more evidence for this theory.
However, Cogan expressed doubts about the study's potential selection bias, as only patients with concerns for iron deficiency might have been tested. As a result, these estimates might only reflect the population with initial concerns instead of the general population.
Cogan's own research, published last month, found that 58% of adults diagnosed with iron deficiency still had not resolved their condition three years later, indicating they still had not achieved normal iron levels.
It's difficult to determine the exact prevalence of iron deficiency, according to Cogan, but he believes it is more common than people realize.
“People who menstruate lose iron to some extent with each menstrual cycle, and we do not absorb iron very well in our diet, so it’s relatively easy to become iron deficient. Since we do not currently screen for iron deficiency – and I am not necessarily saying that we should, as we do not have enough data yet to support anything like that – many people are likely walking around deficient without realizing it,” Cogan said.
“Iron deficiency is typically associated only with anemia. However, we know that iron deficiency can cause symptoms before a patient becomes anemic, as anemia is a late-stage manifestation of iron deficiency. But if a patient gets basic blood testing and is found not to be anemic, providers may not look further than that,” such as by ordering iron tests.
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The latest discoveries mirror the realities observed within the medical field: Iron deficiency might be a hidden issue often overlooked, noted Dr. Theodore Strange, the head of medicine at Northwell's Staten Island University Hospital, who wasn't involved in the new research.
However, for most individuals, regular medical check-ups or doctor appointments usually involve a complete blood count test, which can point towards potential iron deficiency and the need for furtheriron level assessments, according to him.
Additionally, people can always approach their doctors to get their iron levels checked if they have any apprehensions, and it's crucial to maintain a balanced diet, including an adequate intake of fruits and vegetables. Vegetables, in particular, are rich in iron reserves, as is red meat. Moreover, if there's any suspicion of excessive bleeding, we should investigate potential sources of bleeding to determine if there's a potential risk of iron deficiency, said Strange.
This new study highlights that iron deficiency could be a widespread issue, as approximately 11% of adults without medical conditions associated with iron deficiency were found to have absolute iron deficiency, and 15% had functional iron deficiency. Regular medical check-ups or doctor appointments often include a complete blood count test, which can indicate potential iron deficiency.
