Iron is an essential mineral present in many foods. It participates in many physiological functions and is a critical component of hemoglobin. Low iron levels can cause anemia, fatigue, shortness of breath, and heart arrhythmias. Findings from a new study indicate that low iron levels reduce the body’s immune response to vaccination.

Vaccinations are the foundation of public health programs. Evidence indicates that for a single birth cohort, vaccines prevent more than 20,000 diseases and save more than 40,000 lives.

The authors of the study conducted a two-part investigation among children living in Kenya. In the first part of the study, they investigated whether iron status at the time of vaccination predicted the immune response to vaccines against several diseases: polio, diphtheria, tetanus, pertussis, influenza, pneumonia, and measles. In the second part of the study, children received a micronutrient powder containing 5 milligrams of iron daily or a micronutrient powder without iron for four months starting when they were about seven months old. They received their measles vaccines when they were nine and 18 months old, in compliance with the prescribed vaccine schedule in Kenya.

The authors found that children in the first part of the study who had low iron status at the time of their vaccinations were twice as likely to have a failed or impaired immune response to the vaccines. The children in the second part of the study who received the iron-rich micronutrient powder had a much more robust immune response to the measles vaccine, as evidenced by higher levels of antibodies and better pathogen recognition.

These findings suggest that addressing iron status in children improves immune response to vaccines and underscores the importance of early childhood nutrition. Learn more about other aspects of early childhood nutrition and immunity in our overview article about breast milk and breastfeeding.

• Link to full study.