The effectiveness and safety of antacid medications may be altered by the use of some dietary supplements. If you are taking iron, be sure to take it 2 hours before or after the antacid. You’ll also want to avoid taking vitamin D supplements while taking antacids as they don’t mix well with antacids.
Certain herbal supplements may cause excessive drowsiness when taken with sedating antihistamines. The most common supplements this includes are kava and valerian.
Cold remedies containing ephedrine or pseudoephedrine should not be combined with the supplements ginseng (panax), hawthorn and St. John’s Wort.