Calcium supplements

Key points about calcium supplements

  • Calcium supplements are used to increase the amount of calcium in people taking other medicines for preventing or treating 'thinning' of the bones (osteoporosis).
  • Calcium supplements are also called Calci-Tab® or Arrow-Calcium®
  • Find out how to take it safely and possible side effects.
blue unaunahi tile generic
Print this page

Calcium supplements are used to increase the amount of calcium in your body. Having the right amount of calcium in your body is important for bone health and your heart, muscles and nerves also need calcium to function properly.

  • Calcium supplements most commonly come as tablets, dissolvable tablets or capsules, often in combination with vitamin D or magnesium, but they also come as powders and liquids.
  • They are available on prescription, or you can buy them without a prescription from pharmacies, health stores or on the internet.

Most people can get enough calcium by eating and drinking milk, cheese, yoghurt, bread, calcium-fortified soya milk, and some vegetables (spinach and watercress).

  • Getting calcium from your diet is the best way to ensure you get enough calcium. 
  • Dairy products are the richest source of calcium and two to three serves per day, e.g. a cup of milk, a pottle of yoghurt or two slices of cheese is recommended. Read more about calcium.

Although getting calcium from your diet is preferred, sometimes when there is not enough calcium in your diet for your body's needs then taking calcium supplements may be necessary.

Calcium supplements are also recommended for some people taking other medicines for preventing or treating 'thinning' of the bones (osteoporosis). 

Calcium tablets may also be used by people who have kidney problems. In some people with chronic kidney disease, the levels of phosphate in your body can be too high. In this case, calcium is used to bind to phosphate and this allows it to be removed, helping to keep the levels normal. Read more about calcium supplements for kidney disease.  

Studies suggest calcium from supplements may cause heart problems because it causes a spike in blood calcium levels, compared to the gradual rise that happens when you have calcium from food.

Taking too much calcium can cause kidney stones, constipation and other tummy problems. So before taking calcium supplements, talk to your doctor or pharmacist about whether you need it.  

Different products have different amounts of calcium. 

  • If you are prescribed calcium by your doctor, you will be told how many tablets to take each day and when to take them.
  • If you have bought calcium from a pharmacy, read the label on the bottle to find out how to take them. Don’t take more than the amount recommended on the bottle. Too much calcium may cause stomach upsets, such as bloating and constipation.

Calcium supplements can interfere with the way your body absorbs other medicines so you may need to take these at a different time to your calcium – ask your pharmacist for advice. 

Calcium supplements(external link) New Zealand Formulary Patient Information



Calcium – factsheet [PDF, 733 KB] Refugee Health Network and Auckland DHB, NZ, 2014 Amharic, [PDF, 269 KB] Arabic, [PDF, 415 KB] BurmeseDari [PDF, 374 KB]English, [PDF, 733 KB] Karen, [PDF, 949 KB] Persian-farsi, [PDF, 740 KB] Somali [PDF, 247 KB],Tamil [PDF, 1 MB]


Daily calcium calculator – ABC Australia(external link) Fracture risk assessment tool(external link)


  1. Bolland MJ, Avenell A, Baron JA, Grey A, MacLennan GS, Gamble GD, et al. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis(external link). BMJ 2010;341:c3691
  2. Reid, I. Bolland, MJ. Editorials: Controversies in Family Medicine – Does Widespread Calcium Supplementation Pose Cardiovascular Risk? Yes: The Potential Risk Is a Concern. Am Fam Physician. 2013 Feb 1;87(3):online. Full article(external link)
  3. Bhattacharya, RK. Editorials: Controversies in Family Medicine - Does Widespread Calcium Supplementation Pose Cardiovascular Risk? No: Concerns Are Unwarranted. Am Fam Physician. 2013 Feb 1;87(3):online. Full article(external link)


5 questions to ask about your medications

5 questions to ask about your medications

Health Quality and Safety Commission, NZ, 2019

Te reo Māori

Free helplines

Healthline logo

Text 1737 Helpline logo

Logo with link to Māori Pharmacists website

Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist, Auckland

Last reviewed:

Page last updated: