Dairy Interactions

Calcium in dairy products significantly reduces iron absorption by up to 50%.

Calcium in dairy binds to thyroid medication, reducing absorption by up to 40%.

Calcium in dairy products binds to tetracycline and fluoroquinolone antibiotics, reducing their effectiveness.

Calcium and magnesium in dairy products chelate with fluoroquinolone antibiotics (ciprofloxacin, levofloxacin, moxifloxacin) in the gut, forming insoluble complexes that the body cannot absorb. Co-ingestion can reduce fluoroquinolone bioavailability by 30-50%, potentially causing treatment failure.

Calcium competes with zinc for absorption, potentially reducing zinc uptake.

Dairy products contribute calcium that, when combined with intravenous calcium or high oral loads, can potentiate digoxin's effects on the heart and increase the risk of arrhythmias. Dietary fiber and milk proteins may also modestly reduce digoxin absorption from oral capsules and tablets.