Lactoferrin's N-terminal and C-terminal lobes each bind one Fe³⁺ ion with a dissociation constant of ~10⁻²⁰ M at neutral pH — dramatically exceeding transferrin's binding affinity (~10⁻¹⁵ M). This extraordinary iron-binding capacity creates an iron-depleted microenvironment at infection sites and mucosal surfaces that most bacteria cannot survive.

Can lactoferrin cause iron deficiency?

At standard supplement doses (200–300 mg/day), lactoferrin's iron chelation is not sufficient to cause iron deficiency in healthy individuals. In iron-supplementation contexts, lactoferrin actually improves iron bioavailability by safely chelating iron for better absorption.

Does lactoferrin affect ferritin levels?

In iron-overloaded individuals, lactoferrin may reduce serum ferritin over weeks to months of supplementation. In iron-replete individuals, ferritin effects are minimal. In iron-deficient individuals, iron-bound lactoferrin (holactoferrin) may improve iron delivery to cells.