A G.I. Doctor Breaks Down How Your Beloved Antacid Tablets Affect Your Gut

When acid indigestion strikes, many people weigh one of two options: Suffer through the stomach pain and discomfort or pop an antacid tablet in hopes of getting some relief. Those little tablets are handy to keep around for “just-in-case” scenarios, and they’re easy to get at your local drugstore. Besides taking antacid tablets for digestive issues, some people take them daily to try to up their calcium levels whether they have indigestion or not. But is this a good idea? Below, doctors break it all down.

What’s in antacid tablets, again

Most antacid tablets, including Tums and Rolaids, are made of calcium carbonate, according to the U.S. National Library of Medicine. This can relieve heartburn, acid indigestion, and upset stomach, but it can also be used as a dietary supplement when you don’t have enough calcium in your diet. (Calcium, in case you’re rusty on it, is an essential mineral that your body needs to build and maintain strong bones and to carry out plenty of other important functions, according to the National Institutes of Health.)

Everyone’s calcium needs are slightly different, but it’s generally recommended that healthy adults get between 1,000 and 1,200 milligrams of calcium a day. Tums, for example, contains 200 milligrams of calcium per tablet.

While calcium carbonate is a popular form of antacids, some tablets use a combination of aluminum hydroxide and magnesium hydroxide to relieve heartburn, acid indigestion, and upset stomach, the U.S. National Library of Medicine says. (Maalox is a popular brand.)

What typically causes indigestion

Indigestion is a general term used to describe a group of gastrointestinal symptoms that happen together, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Those symptoms can include pain, burning, discomfort in your upper abdomen, feeling full too soon when you eat, and feeling uncomfortably full afterward.

Indigestion is common: It impacts about one in four people in the U.S. each year, the NIDDK says. Certain habits can raise your risk of having indigestion, including drinking too much alcohol, having too much coffee or other caffeinated drinks, eating too fast, indulging in too many spicy, fatty, or greasy foods, having foods with a lot of acid, like tomatoes and citrus fruits, stress, and smoking.

How do antacid tablets work in the gut

Antacid tablets are alkaline, meaning they’re not acidic. “They’re anti-acid and help neutralize the acid in your stomach,” says Ashkan Farhadi, MD, a gastroenterologist at MemorialCare Orange Coast Medical Center in Fountain Valley, California. “They are like putting out the fire, and they neutralize the acid right away.” Both calcium carbonate and aluminum hydroxide, and magnesium hydroxide tablets work this way.

If you have heartburn or acid reflux, antacid tablets are very effective,” Dr. Farhadi says. The effect is “immediate,” he says, but relief doesn’t last long.

Is it OK to take antacid tablets daily

While plenty of people use calcium carbonate antacid tablets as a source of calcium, this can be tricky to navigate. “Be careful,” says Jamie K. Alan, PhD, an associate professor of pharmacology and toxicology at Michigan State University. “If you take too many at a time, your stomach starts pumping out acid, and you get a ‘rebound effect’ where you produce a large amount of acid.” This, she says, “can be quite uncomfortable.”

Dr. Farhadi agrees. “You have a thermostat in your body,” he says. “When you neutralize acid right away, the body is going to make acid, and it will come back with revenge.” If you rely solely on calcium carbonate antacid tablets for your calcium source, you could be popping up to five a day—and that can raise your risk of rebound indigestion, Dr. Farhadi says.

The U.S. National Library of Medicine also points out that calcium carbonate tablets can cause a slew of potential side effects, including:

• upset stomach
• vomiting
• stomach pain
• belching
• constipation
• dry mouth
• increased urination
• loss of appetite
• metallic taste

Aluminum hydroxide and magnesium hydroxide tablets aren’t perfect either. The U.S. National Library of Medicine lists the following as potential side effects:

• diarrhea
• constipation
• loss of appetite
• unusual tiredness
• muscle weakness

Dr. Farhadi says there are some concerns about aluminum toxicity if you take them regularly. While some observational studies have also found a link between aluminum and dementia, a large meta-analysis of nine observational studies of more than 6,000 people did not find a link between regular antacid use and Alzheimer’s disease. That also held true when the analysis only looked at people who used antacids regularly for more than six months. Still, Dr. Farhadi says, “I would not take them for maintenance—just for acute problems and issues.”

If you’re already dealing with the occasional heartburn or acid indigestion, experts say it’s best to get your calcium supplementation elsewhere. The taste of antacid tablets can also be a little much to take. “I prefer the calcium tablets that you swallow,” Dr. Alan says.

What should you do if you’re struggling with constant acid indigestion

Having a little heartburn and acid indigestion here is pretty common, Farhadi says. But, if you notice that it’s a regular thing for you and you’re taking antacid tablets often (read: several times a week) as a result, he recommends talking to your doctor to see if you might have an underlying health condition.

That’s especially true if you’ve been relying on antacid tablets for your calcium intake. There’s a chance this habit could actually be giving you acid indigestion without you even realizing it.

Either way, talking to your doctor about what’s going on in your body, along with any supplements you’re taking (Tums and Maalox included), is crucial to help you get relief, Dr. Farhadi says.

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