Iron deficiency, one of the most widespread nutritional deficiencies worldwide, continues to pose a serious public health challenge. Affecting roughly one in three people, the condition can lead to severe developmental and cognitive issues, particularly in children, pregnant women, and individuals with certain medical conditions. Despite its prevalence, questions remain about when intervention is necessary and the best methods of treatment.
For Megan Ryan, a single mother from upstate New York, the signs of iron deficiency were easy to dismiss. She attributed her fatigue and breathlessness to the demands of raising a young child while working full-time. It wasn’t until a routine blood test in June 2023 that she was diagnosed with iron deficiency anemia. Looking back, there had been warning signs, including a craving for ice, a well-documented symptom of the condition.
A Widespread Yet Overlooked Condition
Iron deficiency is especially common among women of reproductive age, as menstruation, pregnancy, and childbirth deplete iron stores. Studies indicate that nearly 46% of UK women develop anemia during pregnancy, though not all cases are caused by iron deficiency.
Children are also highly vulnerable. Iron is essential for brain development, and deficiencies in early childhood have been linked to behavioral issues, impaired motor skills, and reduced cognitive abilities. Research suggests that infants with iron-deficiency anemia may experience long-term developmental setbacks, even after their iron levels are restored.
“It’s a major global problem,” says Michael Zimmermann, a professor of human nutrition at the University of Oxford. “It’s not going away very fast, and it is associated with a lot of disability.”
Who is Most at Risk?
In addition to women and children, iron deficiency is common among:
- Athletes (due to increased physical exertion)
- Vegetarians and vegans (who may struggle to get enough iron from plant-based foods)
- Frequent blood donors
- Individuals with medical conditions such as kidney disease or celiac disease, which affect iron absorption
The condition is particularly severe in low-income countries, where up to 70% of infants between six and twelve months old suffer from iron-deficiency anemia. Even in wealthier nations, iron deficiency remains a concern, with up to 15% of US toddlers affected.
Should Everyone Take Iron Supplements?
Despite the clear risks associated with iron deficiency, experts remain divided on when supplementation is necessary.
Some studies suggest that iron supplementation improves fatigue levels in deficient individuals. However, research led by Sant-Rayn Pasricha, a clinical hematologist from the Melbourne School of Population and Global Health, found that iron-deficient adults without symptoms saw no improvement in energy levels after taking supplements.
Similarly, a large-scale study in Bangladesh involving 3,300 infants found that while iron supplementation improved hemoglobin levels, it did not enhance overall child development. Other studies have linked excessive iron supplementation in young children to slower weight gain, altered gut microbiomes, and even poorer cognitive performance later in life.
“This complexity lies at the heart of all nutrition research,” Zimmermann explains. “Is it the absence of a nutrient that causes problems, or is deficiency just a sign of something else going on?”
Finding the Right Balance
While iron deficiency remains a significant global health issue, there is still no clear-cut approach to treatment. Experts stress the importance of targeted interventions, focusing on individuals who are truly at risk rather than promoting widespread supplementation.
For now, regular screening and a balanced diet remain the most effective strategies for preventing iron deficiency, particularly for high-risk groups. However, as research continues, the debate over how and when to supplement iron is far from over.
