The term "antacid" is used to describe certain compounds that directly neutralize stomach acid. Tums, Maalox Advanced Regular Strength, and Mylanta all fall into this category. The active ingredients in most antacids are various forms of calcium, magnesium, and aluminum. Antacids are useful mostly for symptomatic relief of uncomfortable "acid stomach" and also may be helpful for heartburn.

Many antacids are available today, including

  • Aluminum carbonate (Basaljel)
  • Aluminum hydroxide (ALternaGEL, Alu-Cap, Alu-Tab, Amphojel, Dialume, Nephrox)
  • Aluminum hydroxide/magnesium carbonate (Duracid)
  • Aluminum hydroxide/magnesium hydroxide (Alamag, Almacone, Aludrox, Gaviscon Liquid, Gelusil, Kudrox, Maalox Advanced Regular Strength, Magalox, Mintox, Mylanta, Rulox)
  • Aluminum hydroxide/magnesium hydroxide/calcium carbonate (Tempo)
  • Aluminum hydroxide/magnesium trisilicate (Alenic Alka, Gaviscon, Genaton, Foamicon)
  • Calcium carbonate (Alkets, Amitone, Chooz, Equilet, Gas-Ban, Mallamint, Mylanta Lozenges, Titralac, Tums)
  • Calcium carbonate/magnesium carbonate (Marblen, Mi-Acid Gelcaps, Mylanta Gelcaps, Mylagen Gelcaps)
  • Magnesium hydroxide (Milk of Magnesia, Phillips' Chewable)
  • Magaldrate or aluminum magnesium hydroxide sulfate (Iosopan, Riopan)
  • Magnesium oxide (Mag-Ox, Maox, Uro-Mag)
  • Sodium bicarbonate (Bell/ans, Bromo Seltzer)
  • Sodium citrate (Citra pH)

Other drugs work by reducing the stomach's production of acid. These are discussed separately in the articles on H2Blockers (eg, Zantac [ranitidine], Axid [nizatidine], Tagamet [cimetidine], Pepcid [famotidine]) and Proton Pump Inhibitors (Prilosec [omeprazole], Prevacid [lansoprazole]). These drugs produce a more powerful effect than antacids and are used for ulcers as well as for the treatment of esophageal reflux, commonly known as heartburn.

Supplementation Possibly Helpful

Research suggests that antacids physically bind to folate and reduce its absorption by the body.1 However, the decrease in folate absorption is relatively small, and this interaction may be clinically significant only in individuals who take antacids regularly and whose diets are low in folate content.

Supplementation Possibly Helpful, But Take at a Different Time of Day

Different types of antacids can interfere with the absorption of various minerals. Supplements containing the US Dietary Reference Intake (formerly known as the Recommended Dietary Allowance) of these minerals should be helpful, especially if you take them at a different time of day from when you take antacids, at least 2 hours before or after taking your antacid.

Any antacid can interfere with the absorption of iron, zinc, and possibly other minerals by neutralizing stomach acid.2

Aluminum-containing antacids can bind with phosphorus and interfere with its absorption, and this can further lead to calcium depletion.3,4

Antacids that contain calcium may also compete for absorption with iron.5-9 Although calcium antacids may alter the absorption of magnesium, the clinical importance of this effect appears to be minimal.10,11 Calcium-containing antacids, when taken with zinc supplements, might substantially decrease zinc absorption.12-16 However, the presence of a meal appears to mitigate this effect. Finally, calcium antacids might also impair the absorption of manganese and chromium.17,18,19

May Increase Aluminum Absorption

Concerns have been raised that the aluminum in some antacids may not be good for you.20 Since there is some evidence that calcium citrate supplements might increase the absorption of aluminum,21-25 it might not be a good idea to take calcium citrate at the same time of day as aluminum-containing antacids. Another option is to use other forms of calcium, or to avoid antacids containing aluminum.


1. Russell RM, Golner BB, Krasinski SD, et al. Effect of antacid and H 2 receptor antagonists on the intestinal absorption of folic acid. J Lab Clin Med. 1988;112:458-463.

2. Sturniolo GC, Montino MC, Rossetto L, et al. Inhibition of gastric acid secretion reduces zinc absorption in man. J Am Coll Nutr. 1991;10:372-375.

3. Spencer H and Kramer L. Antacid-induced calcium loss. Arch Intern Med 1983;143:657-658.

4. Lotz M, Zisman E, and Bartter FC. Evidence for a phosphorus-depletion syndrome in man. N Engl J Med. 1968;278:409-415.

5. Hallberg L, Brune M, Erlandsson M, et al. Calcium: effect of different amounts on nonheme- and heme-iron absorption in humans. Am J Clin Nutr. 1991;53:112-119.

6. Cook JD, Dassenko SA, and Whittaker P. Calcium supplementation: effect on iron absorption. Am J Clin Nutr. 1991;53:106-111.

7. Dawson-Hughes B, Seligson FH, and Hughes VA. Effects of calcium carbonate and hydroxyapatite on zinc and iron retention in postmenopausal women. Am J Clin Nutr. 1986;44:83-88.

8. Read MH, Medeiros D, Bendel R, et al. Mineral supplementation practices of adults in seven western states. Nutr Res. 1986;6:375-383.

9. Sokoll LJ and Dawson-Hughes B. Calcium supplementation and plasma ferritin concentrations in premenopausal women. Am J Clin Nutr. 1992;56:1045-1048.

10. Lewis NM, Marcus MS, Behling AR, et al. Calcium supplements and milk: effects on acid-base balance and on retention of calcium, magnesium, and phosphorus. Am J Clin Nutr. 1989;49:527-533.

11. Andon MB, Ilich JZ, Tzagournis MA, et al. Magnesium balance in adolescent females consuming a low- or high-calcium diet. Am J Clin Nutr. 1996;63:950-953.

12. Argiratos V and Samman S. The effect of calcium carbonate and calcium citrate on the absorption of zinc in healthy female subjects. Eur J Clin Nutr. 1994;48:198-204.

13. Dawson-Hughes B, Seligson FH, and Hughes VA. Effects of calcium carbonate and hydroxyapatite on zinc and iron retention in postmenopausal women. Am J Clin Nutr. 1986;44:83-88.

14. Hwang S-J, Lai YH, Chen HC, et al. Comparisons of the effects of calcium carbonate and calcium acetate on zinc tolerance test in hemodialysis patients. Am J Kid Dis. 1992;19:57-60.

15. Pecoud A, Donzel P, and Schelling JL. Effect of foodstuffs on the absorption of zinc sulfate. Clin Pharmacol Ther. 1975;17:469-474.

16. Crowther RS and Marriott C. Counter-ion binding to mucus glycoproteins. J Pharm Pharmacol. 1984;36:21-26.

17. Freeland-Graves JH and Lin PH. Plasma uptake of manganese as affected by oral loads of manganese, calcium, milk, phosphorus, copper, and zinc. J Am Coll Nutr. 1991;10:38-43.

18. Davidsson L, Cederblad , Lnnerdal B, et al. The effect of individual dietary components on manganese absorption in humans. Am J Clin Nutr. 1991;54:1065-1070.

19. Seaborn CD and Stoecker BJ. Effects of antacid or ascorbic acid on tissue accumulation and urinary excretion of chromium. Nutr Res. 1990;10:1401-1407.

20. Gaby AR. Aluminum: The ubiquitous poison. Nutr Healing. 1997;4:3,4,11.

21. Walker JA, Sherman RA, and Cody RP. The effect of oral bases on enteral aluminum absorption. Arch Intern Med. 1990;150:2037-2039.

22. Anonymous. Preliminary findings suggest calcium citrate supplements may raise aluminum levels in blood, urine. Family Practice News. 1992;22:74-75.

23. Weberg R and Berstad A. Gastrointestinal absorption of aluminum from single doses of aluminum containing antacids in man. Eur J Clin Invest. 1986;16:428-432.

24. Nolan CR, Califano JR, and Butzin CA. Influence of calcium acetate or calcium citrate on intestinal aluminum absorption. Kidney Int. 1990;38:937-941.

25. Slanina P, Frech W, Bernhardson A, et al. Influence of dietary factors on aluminium absorption and retention in the brain and bone of rats. Acta Pharmacol Toxicol (Copenh). 1985;56:331-336.

26. Maalox Total Relief and Maalox liquid products: medication use errors. US Food and Drug Administration website. Available at: Published February 17, 2010. Accessed March 2, 2010.

Last reviewed August 2013 by EBSCO CAM Review Board

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