Calcium Carbonate side effects and drug information

Calcium is a vital mineral that helps strengthen bones. It is also needed by the body to help muscles and blood vessels expand or contract, secrete hormones or enzymes and send messages to the brain. It is one of the most abundant minerals in the human body, making up 1-2 per cent of the adult body weight. Most calcium in the body is stored in the teeth and bones, and one per cent is in the muscles, tissues and blood.

ChemSpider ID9708
Melting point825 °C
Density2.71 g/cm³
IUPAC IDCalcium carbonate
Molar mass100.0869 g/mol


The skeletal system is made up of living tissues that continuously breaks down and builds up. A person below the age of 30 years needs adequate amounts of calcium and regular physical exercise for the body to build up bone than break it down. Most of adult bone mass is reached by age 18 years in girls and 20 years in the body. After this stage, bone breakdown exceeds the volume of bone built.

This is the reason why maximizing calcium storage in bones is essential while it is still possible. By age 30, the bone loss will be impacted even more by physical activity level, ethnicity, genetics, diet, sex hormone levels and gender. Choosing a healthy diet and regular activity level will help replace what you lose, but it will no longer increase the amount of what you store.

Calcium carbonate is a dietary supplement that you can use when your calcium intake is inadequate. It can help replace calcium loss and maintain healthy muscles, nervous system, heart and bones. Likewise, calcium carbonate is also used to relieve acid indigestion, heartburn and upset stomach. You can get this drug from the pharmacy with or without prescription.

Uses of Calcium Carbonate

This medication is prescribed to treat or prevent low calcium levels in the blood. People who do not get adequate calcium from their diet should take this medication. Likewise, people with health conditions associated with low calcium levels like weak bones, bone loss, specific muscle disease and decreased parathyroid activity need calcium carbonate. Similarly, it is used by some patients to ensure that they get enough calcium for their condition like pregnant, postmenopausal and nursing women.

Apart from being a popular calcium supplement, this medication is also used to treat symptoms caused by excess stomach acid. It is used to relieve upset stomach, heartburn and indigestion. As an antacid, it works by lowering the amount of stomach acid.

Make sure to check the ingredients even if you have used this medication before. Keep in mind that products with similar names may have different components for different purpose or condition.

Side Effects

Taking calcium carbonate may cause side effects. If your doctor prescribes this, it means that you need this more than the risk of side effects. In most cases, people using this medication do not experience any severe side effects. Some common symptoms experienced include:

Gas, constipation and burping are common side effects. If these persist or worsen, inform your doctor immediately. You should also notify them right away of any unlikely but severe side effects such as nausea and vomiting, weight loss, headache, weakness, loss of appetite, bone or muscle pain and mood changes. Likewise, an increase or decrease in the amount of your urine while taking this medication can indicate signs of kidney issues.

Allergic Reactions

It is rare to experience severe allergic reactions to this medication, however, if you notice symptoms of an allergic reaction such as itching/swelling (especially of the face or throat), rash, trouble breathing and severe dizziness.

Indication and Dosage

The usual recommended dose of calcium carbonate for replacement is 1 to 1.2 g taken daily in 2 to 4 doses with meals. Likewise, for use as an antacid, 2 to 4 tablets per 24 hours not exceeding 7 g per day is recommended. 

This product is taken orally as directed. Calcium carbonate comes in tablet, capsule, chewable tablet, liquid, soft chew and gummies form. They are usually taken 1 to 4 times per day depending on the formulation.

  • Chewable Tablets – taken with a meal. Should be chewed thoroughly before swallowing.
  • Soft Chews and gummies – can be taken with or without food.
  • Powdered Form – should be thoroughly mixed with water before drinking.

Be sure to drink a glass of water after taking regular calcium carbonate capsules or chewable.

If you miss a dose from your regular schedule, take it as soon as you remember. If it is almost time for the next dose, skip the missed one and take the following dose at the right schedule. Don’t take two doses of this medication at a time.

Drug Interaction

If you are taking other medications, whether prescription, non-prescription, vitamins and supplements, inform your doctor during your visit. You must inform your doctor if you are receiving any of the following medications which have potential interaction with calcium carbonate:

  • Bisacodyl (Dulcolax)
  • Sodium Bicarbonate
  • Calcitonin (Fortical)
  • Iron Supplements like ferrous gluconate, ferrous sulfate and ferrous fumarate
  • Antifungal medicines such as itraconazole and ketoconazole
  • Tetracycline antibiotics like doxycycline and minocycline
  • Fluoroquinolone antibiotics such as gemifloxacin, ciprofloxacin, norfloxacin and ofloxacin
  • Bisphosphonates such as ibandronate and alendronate

There are other calcium carbonate drug interactions, discuss with your doctor or pharmacist potential interactions with other medications that you are taking.

Food Interactions

Certain foods may also have harmful interactions with your natural remedies medications. With calcium carbonate, there are no specific foods that you should avoid if you are taking this medication.

Warnings and Precautions

Before taking calcium carbonate, you have to inform your doctor or pharmacist if you are allergic to it or if you have any other drug allergies. This medication may contain ingredients which may cause allergic reactions and other problems.

Likewise, consult your pharmacist or doctor if you have the following health problems before taking this medication:

  • Stomach or intestinal blockage
  • High calcium levels (hypercalcemia)
  • Kidney problems (kidney stones)

Some products may also contain aspartame. If you have conditions that restrict your intake of aspartame, inform your doctor so that they can give you the right prescription.

If pregnant, use calcium carbonate with caution and only if the benefits outweigh the risks. More so, calcium carbonate is passed on to breastmilk. It is deemed safe to use when breastfeeding. However, it is still best to consult your doctor for any queries.

Overdose and Contraindication

Calcium can make it harder for the body to absorb some medications. It binds quinolone and tetracycline antibiotics in the digestive tract and prevents its absorption into the body. To avoid this, antibiotic doses should be separated into three or four hours from your calcium doses.

Products containing calcium carbonate also restricts the acidity in the stomach. It results in a decrease in iron absorption in the intestine. Thus, your intake of calcium and iron products should be several hours apart.

Similarly, calcium carbonate products bind sodium polystyrene sulfonate, a medication for treating high potassium levels, in the intestine. Therefore, the doses of these drugs should be separated by several hours to avoid contraindication.

When drug interaction happens, you may experience these symptoms and conditions:

  • Low phosphate levels
  • Hypersensitivity
  • Kidney stones
  • High calcium levels in the urine
  • Suspected digoxin toxicity

Abuse and Overdose

In case you took too much calcium carbonate, seek immediate medical attention or contact the local poison control center. If it is administered in a medical setting, an overdose of the medication is unlikely to happen. Still, if you suspect overdosing, seek immediate medical attention.

Long Term Effects

Long term use of the medication may result in high calcium levels as well as high calcium present in urine.

Clinical Pharmacology

Calcium carbonate becomes calcium chloride as gastric acids convert it. It is not fully absorbed into the body through the intestines, and the unabsorbed portion will is excreted through feces and urination.

Medication Guide

This medication should be kept in its original container, tightly closed and out of children’ reach. It should be stored at room temperature and away from excess moisture and heat.

Medications that are not used should be disposed of in proper ways to ensure that other people, pets and children will not accidentally consume them. But you should not flush this down the drain. You may consult with your pharmacists if they have a take-back program to dispose of your unneeded medications.

Like other medication, keep out of sight and reach of children, especially if the container is not child-resistant. Protect children from poisoning by ensuring safety cap locks and by keeping them in a safe location.

Take note of all your appointments with your doctor to monitor your response to your medication. Do not let other people take your medicine. Ideally, you should also keep a list of all your prescription and non-prescription medications, including other minerals, vitamins and supplements. Bring this with you whenever you visit your doctor or if you need to go to the hospital. It is also important to have this list with you during emergencies.