A recent study has revealed that nearly one in three adults in the U.S. might have an iron deficiency. Researchers at Boston’s Brigham and Women’s Hospital checked the iron levels of a nationally representative group of about 8,000 adults. These included individuals without typical conditions that trigger iron deficiency screenings, such as heart failure, chronic kidney disease, or anemia, where the body doesn’t have enough red blood cells to transport oxygen.
The findings showed that around 14% of the adults studied had absolute iron deficiency, meaning there wasn’t enough iron in their bodies. Symptoms of low iron include fatigue, shortness of breath, trouble focusing, and heart palpitations. Additionally, about 15% of participants had functional iron deficiency, where the iron is stored but not easily available for use by the body.
It’s important to distinguish between absolute and functional iron deficiency. Nearly half of the iron deficiency cases were functional, but the effects of untreated functional iron deficiency are still not well understood. The study suggests that more research is needed to determine who should be screened for iron deficiency.
Past research on iron deficiency in the U.S. typically focused on high-risk groups like infants, pregnant women, and those of childbearing age. However, European data indicated that 15% to 25% of blood donors, who aren’t usually at high risk, were actually iron deficient. This led researchers to examine data from over 8,000 Americans aged 18 and older between 2017 and 2020, finding similar results in the U.S.
Despite a significant portion of participants having some form of iron deficiency, only about 33% with absolute deficiency and 14% with functional deficiency had a potential medical reason for screening. This suggests that many wouldn’t typically be tested for iron deficiency. Furthermore, few of those with an iron deficiency were taking supplements, with 22% to 35% of women and 12% to 18% of men doing so.
Interpretation of these results is hindered by differences in how iron deficiency was previously measured, which means we can’t make direct comparisons with earlier studies. It seems, however, that absolute iron deficiency has become slightly more common. The research included a diverse American sample, making the findings broadly applicable across the U.S.
Certain factors increase the risk of iron deficiency: blood loss, increased iron needs, and reduced ability to absorb iron. Menstruating and pregnant women are at higher risk, with pregnant women needing more daily dietary iron than others. A 2022 study found that over 70% of iron deficiency cases might go undetected among pregnant women and young children.
Those who are breastfeeding should ensure they meet daily iron and nutrient needs through diet and supplements. Risk factors also include certain medications, gastrointestinal issues, prior surgeries, inflammatory conditions, and restrictive diets.
Typically, iron deficiency is only tested after low hemoglobin levels are discovered. If someone notices new fatigue or other related symptoms, they should ask their doctor to specifically test for iron deficiency. A transferrin saturation test may be recommended, as low levels of this main iron-binding protein might indicate a deficiency.
If found to be iron deficient, individuals should take iron supplements, with their doctor advising on the appropriate type and amount. Non-deficient individuals don’t need supplements but should ensure adequate dietary iron intake. Foods rich in iron include red meat, fish, legumes, soy, leafy greens, and nuts. While most can meet their iron needs through a balanced diet, the study suggests many cases may go undiagnosed.
Before making strong recommendations about routine screening, the broader effects must be understood. Those suspecting iron deficiency should discuss symptoms with their healthcare provider, as the signs can be vague and require thorough evaluation.
