Iron for Immune Function

Research suggests that iron plays a foundational role in immune function, with multiple reviews indicating that adequate iron levels are necessary for the growth and activity of key immune cells — including macrophages, T cells, and B cells — and that iron deficiency is associated with increased susceptibility to infection across all life stages. Studies indicate that iron serves as a critical cofactor in immune signaling, energy production, and gene regulation, and that deficiencies, which are widespread globally and disproportionately affect pregnant women and young children, can meaningfully impair immune competence. The available evidence comes primarily from narrative and clinical reviews rather than randomized controlled trials, and findings are notably nuanced: while correcting iron deficiency appears beneficial for immunity, the relationship between iron and immune function is bidirectional and complex, with iron metabolism also influencing inflammation, pathogen competition for iron during infection, and even forms of iron-dependent cell death called ferroptosis. Some studies caution that supplementation in individuals without identified deficiency is generally not recommended and may interfere with the body's natural processes, underscoring that the research supports targeted repletion of iron in deficient populations rather than broad supplementation as an immune-enhancement strategy.