Fe absorption may be decreased by concurrent administration w/ antacids, gastric acid suppressive medications, fluoroquinolone, bisphosphonates, levodopa, levothyroxine, penicillamine, tetracycline antibiotics or trientine. Products containing Ca, Mg, Fe, Cu or Zn may interact w/ orally administered antacids, antibiotics (tetracyclines, fluoroquinolones), levodopa, biphosphonates, penicillamine, thyroxine, trientine, digitalis, antiviral agents & thiazide diuretics. Oxalic acid (found in spinach & rhubarb) & phytic acid (found in whole cereals) may inhibit Ca absorption. Co-administration w/ other products should be separated by 2-3 hr interval.