Calcium carbonate: Uses, How It Works, Medicines
Calcium carbonate is a calcium supplement used to top up calcium when food does not give enough. Calcium helps build and maintain bones and teeth. Supplements are used only when needed, because too much can cause stomach pain, diarrhoea and, over time, kidney problems. It is often sold together with vitamin D.
Also known as: Calcium carbonate tablet, Calcium carbonate 1250 mg, Calcium supplement, Elemental calcium 500 mg, Calcium, Cipcal
Pharmacist review in progress. This page is based on the sources listed below and is being checked by our registered pharmacist.
How does Calcium carbonate work?
The stomach acid turns calcium carbonate into calcium that is absorbed in the gut and used to build and maintain bones and teeth and to support muscles and nerves. Taking it with food helps the body absorb it.
How to take Calcium carbonate
Follow the label or your doctor's advice. Most adults need about 700 mg of calcium a day from all sources, mostly from food, so supplements are only a top-up.
Side effects of Calcium carbonate
Calcium supplements are well tolerated by most people at the label dose. Some side effects are mild, but a few need medical help.
Uncommon or mild
- Constipation
- Wind, bloating or an upset stomach
- Nausea
Rare but serious: get medical help
- Severe stomach pain, ongoing vomiting or severe constipation
- Excess thirst, passing a lot of urine, confusion, muscle weakness or an irregular heartbeat (possible high blood calcium)
- Pain in the side or back with blood in the urine (possible kidney stone)
- Swelling of the face, lips or throat, or difficulty breathing (severe allergic reaction). Call 112
Who should be careful
Some people need to check with a doctor before taking calcium supplements.
When the label says not to use it
- High levels of calcium in the blood or urine
- Kidney stones caused by calcium, unless a doctor advises
- Allergy to any ingredient of the tablet
- Kidney disease or a past kidney stone
- High calcium in the blood or in the urine
- Taking more than the label says, or taking several supplements that each contain calcium or vitamin D
- Heart rhythm problems, or taking digoxin
- Sarcoidosis or some other conditions that raise blood calcium
- Pregnancy and breastfeeding: ask your doctor before using supplements
Medicines and things that interact with Calcium carbonate
Calcium can reduce how well some medicines are absorbed, and some medicines change how the body handles calcium. Tell your doctor or pharmacist about everything you take.
- Thyroid hormone tablets such as levothyroxine: keep a gap between doses
- Some antibiotics, including tetracyclines and fluoroquinolones: keep a gap between doses
- Iron tablets: calcium can reduce how much iron is absorbed
- Bone-strengthening tablets (bisphosphonates): keep a gap between doses
- Water tablets of the thiazide type: together with calcium they can raise blood calcium
- Digoxin: high calcium can affect the heart rhythm
If someone takes too much
Taking too much calcium over time can cause stomach pain, constipation, thirst, confusion and kidney problems. If someone has taken much more than the label says, call 112 or go to the nearest hospital and take the medicine pack with you.
Regulatory status in India
Sold in India as a calcium supplement. Calcium carbonate is not on the CDSCO list of medicines banned under section 26A of the Drugs and Cosmetics Act as a single ingredient, and was not found in Schedule H of the Drugs Rules 1945. Whether a particular product is licensed as a medicine or a food supplement, and any prescription status, must be read from the pack.
Type of medicine
Calcium carbonate belongs to this type of medicine.
Medicines that contain Calcium carbonate
These medicines sold in India contain Calcium carbonate. They are listed A to Z, not ranked.
- Cipcal 500 · 500 mg elemental calcium tablet
- Shelcal 500 · 500 mg elemental calcium tablet
What is Calcium carbonate used for?
Combination medicines that contain Calcium carbonate are used for these conditions.
Common questions
What is calcium carbonate used for?
Calcium carbonate is used to supply calcium when diet does not give enough. Calcium helps maintain bones and teeth. Most adults need about 700 mg of calcium a day, mostly from food, so supplements are only a top-up when a doctor or pharmacist advises one.
Should calcium carbonate be taken with food?
Calcium carbonate needs stomach acid to be absorbed, so it is usually taken with a meal. Follow the label or your doctor's advice about timing, and keep a gap from medicines that it can interfere with.
Can I take too much calcium?
Yes. The NHS says 1,500 mg a day or less is unlikely to cause harm, but more can cause stomach pain and diarrhoea, and long-term excess can harm the kidneys. Count calcium from food, antacids and other supplements, and follow the label.
Does calcium cause constipation?
It can, as can gas and bloating. Drinking enough fluid and eating fibre may help. If constipation is troublesome, tell your doctor or pharmacist rather than stopping or changing the supplement on your own.
Sources
- Calcium. NHS (UK)
- Osteoporosis. NHS (UK)
- ATC/DDD Index: A12AA04 Calcium carbonate. WHO Collaborating Centre for Drug Statistics Methodology
- List of drugs prohibited for manufacture and sale through gazette notifications under section 26A of the Drugs & Cosmetics Act 1940. Central Drugs Standard Control Organisation (CDSCO)
- The Drugs Rules, 1945 (consolidated, September 2024 edition), Schedule H: prescription drugs. Central Drugs Standard Control Organisation (CDSCO)