Quick Summary
-
Health benefits of calcium:
It is important that you get an adequate amount of calcium, as it is essential to maintaining your bones and plays critical roles in nerve transmission, muscle contraction, and your cardiovascular system. In fact, getting sufficient calcium each day (1,000 to 1,200 mg for adults) from your diet (i.e., not all from supplements) may decrease your risk of dying from cardiovascular disease. For details, see What It Does.
-
Good sources of calcium:
You may already get enough calcium in your diet from dairy, beans, green-leafy vegetables, and other foods. With the exception of girls ages 9 to 18, most individuals take in enough calcium from what they eat. For the recommended intakes of calcium and to learn how much you may already get from food, see What to Consider When Using.
-
Safety and side effects of calcium supplements:
If you're not getting enough calcium from your diet, supplements can help. Calcium supplements have shown some modest benefits for postmenopausal women, particularly those on hormonal therapy after hysterectomy (see What It Does). But be careful! Getting too much calcium from supplements (generally over 1,000 mg per day-or if taken when you already get at least 805 mg of calcium from your diet) may increase the risk of heart attack and stroke. There is mixed evidence as to whether calcium intake affects prostate cancer risk. Calcium supplements also increase the risk of kidney stones in postmenopausal women. See Concerns and Cautions for more information.
-
What's the best form of calcium?
Calcium carbonate is the most common form of calcium in supplements, but other forms, such as calcium citrate, may be better absorbed if you have low levels of acid in your stomach. A slight downside to these other forms is that they require larger pills (or more pills) to get the same amount of calcium compared to calcium carbonate. Other forms include calcium malate, triphosphate, and hydroxyapatite (derived from cow bone), as well as "plant-based" calcium such as Aquamin and AlgaeCal (derived from algae). For more about the pros and cons of each form, see What to Consider When Using.
-
How much calcium to take?
Since you can't absorb more than about 500 mg of calcium at a time, consider limiting intake from supplements to 500 mg or less at a time and, certainly, no more than 1,000 mg total per day. Also, be sure you are getting enough vitamin D, as it is necessary for your body to absorb and utilize calcium from both foods and supplements and may reduce some of the risks associated with calcium supplements. Vitamin D is in many of the supplements tested in this Review. For extensive information about vitamin D, see the Vitamin D Supplements Review.
Which calcium supplement is best?
Not all supplements are properly made and live up to their ingredient claims. In fact, one combination product failed our tests because it provided only 81% of a promised key ingredient (see What CL Found and How Products Were Evaluated). ConsumerLab selected several Top Picks among calcium-containing supplements that were Approved in testing— some of which provide a good dose of calcium for just pennies a day. Use our Results table to narrow in on an Approved product that provides the right amount of calcium and other ingredients (e.g., magnesium, vitamin D, vitamin K, and/or boron) to meet your needs.
Brands tested in this Review are AlgaeCal, Bayer Citracal, Caltrate, GNC, Kirkland, Life Extension, Metagenics, New Chapter, NuBest, Solaray, Sundown, and USANA. Other products discussed include Jarrow BoneUp, Swanson Calcium Aspartate, EZorb Calcium, Webber Naturals Calcium Citrate Vitamin D3, and Country Life Magnesium Complex.)
-
When and how to take calcium?
If your calcium supplement includes vitamin D and/or vitamin K, take it with the meal that contains the most fats and oils, as this may increase absorption of those vitamins. Otherwise, you can take calcium with any meal, but it may be best not to take it at the same time as other mineral supplements, as they may compete for absorption. If you are taking calcium citrate, you may be able to take it with or without food. Follow the directions on the supplement label (see How to Take).
Products tested in 2024 and 2025
+— 109 sources
In addition the results of its expert testing, ConsumerLab uses only high-quality, evidence based, information sources. These sources include peer-reviewed studies and information from agencies such as the FDA and USDA, and the National Academy of Medicine. On evolving topics, studies from pre-print journals may be sourced. All of our content is reviewed by medical doctors and doctoral-level experts in pharmacology, toxicology, and chemistry. We continually update and medically review our information to keep our content trustworthy, accurate, and reliable. The following sources are referenced in this article:
- Akhtar, Cureus 2024
- Bailey, JBMRPLUS 2019
- Baron, NEJM 2015
- Coombs, J Bone Miner Res 2025
- Crockett, Gut 2018
- Datta, Crit Rev Onc Heme 2013
- Gopinath Br J Nutr 2014
- Greene, Osteoporosis Int 2011
- Juliano, BMJ 2021
- Kakigi, JAMA Ophthalmol 2015
- Kassis, Heart 2022
- Langsetmo, J Clin Endocrinol Metab 2013
- Lappe, JAMA 2017
- Manson, JAMA 2024
- Mursu, Arch Int Med 2011
- Papageorgiou, Osteoporos Int 2026
- Robbins, Menopause 2013
- Schwartz, Canc Epidemiol Biomarkers 2012
- Sun, Research Square 2020 — preprint, not peer-reviewed
- Thorpe, Am J Clin Nutr 2021
- Tisdale, JAMA Opthal 2019
- Xiao, JAMA Intern Med 2013
- Orlando, Molecules 2019
- Szterk, Food Chem 2018
- Adluri, Mol Cell Biochem 2010
- Biquet, Osteoporos Int 1996
- Brennan, Calcif Tissue Int 2017
- Bristow, Br J Nutr 2014
- Brogren, Asia Pac J Clin Nutr 2003
- Frestedt, Nutr J 2008
- Hansen, J Bone Miner Res 2010
- Hany, SOARD 2024
- Heaney, Am J Clin Nutr 1988
- Heaney, Am J Clin Nutr 1999
- Heaney, J Am Col Nutr 2001
- Heaney, Osteoporos Int 1999
- Institute of Medicine Dietary Reference Intakes 1997
- Kaats, Int J Med Sci 2011
- Kamalapriya, Cureus 2023
- Michalek, Nutr J 2011
- Moor, HSS J 2006
- Nafea, Cureus 2026
- Naghii, Biol Trace Elem Res 1997
- Neilson, FASEB J 1987
- O'Connell, Am J Med 2005
- Rainey, J Am Diet Assoc 1999
- Reginster, Osteopor Int 1993
- Sheikh, N Engl J Med 1987
- Shkembi, Nutrients 2022
- Spencer, J Am Coll Nutr 1994
- USDA National Nutrient Database
- Yang, Curr Gastro Rep 2012
- Zenk, J Med Food 2018
- von Unruh, JASN 2004
- Alenezi, J Clin Med 2024
- American Bone Health 2022
- Anderson, J Am Heart Assoc 2016
- Ann Dermatol Venereol 2011
- Bailey, J Nutr 2010
- Baron, Cancer Epidemiol Biomarkers Prev 2005
- Bazarbashi, JACC Cardiovasc Imaging 2020
- Biehler, J Nutr 2011
- Bolland, British Medical Journal 2010
- Bolland, British Medical Journal 2011
- Borel, Br J Nutr 2017
- Borghi, N Engl J Med 2002
- Cimpeanu, SAGE Open Med Case Rep 2020
- Coburn, Am J Kidney Dis 1991
- Corte-Real, Food Chem 2016
- European Medicines Agency 2020
- Fosamax Prescribing Information 2012
- Gallagher Menopause 2014
- Gatta, Front Endocrinol (Lausanne
- Ghasemifard, Lancet Reg Health West Pac 2025
- Hakim, Can Med Assoc J 1979
- IOM, 2011
- Institute of Medicine, Dietary Reference Intakes for Calcium and Vitamin D 2010
- Kendler, J Clin Densitom 2006
- Kern, Neurology 2016
- Kim, Eur Heart J Cardiovasc Pharmacother 2021
- Kolitz, JAAD Case Rep 2021
- Krueger, J Clin Densitom 2006
- Li, Am J Clin Nutr 2013
- Li, Heart 2012
- Liu, Ther Clin Risk Manag 2023
- Loftus, J Am Soc Nephrol Abstract Supplement p. 584A 2015
- Mehta, Cleve Clin J Med 2025
- Michaelsson, BMJ 2013
- Michos, JAAC Cardiovasc Imaging 2021
- Mirza, J Nutr Health Food Sci 2016
- Morini, Endocrine 2018
- NIH ODS 2013
- Neuvonen, Drugs 1976
- Nguyen, Cureus 2026
- Opuku, Cureus 2023
- Patel, J Am Soc Nephrol 2021
- Pletz, Antimicrob Agents Chemother 2003
- Purdue-Smith, Am J Clin Nutr 2017
- Rabec, Australas J Ageing 2026
- Reid, Heart 2012
- Rossom, J Am Geriatr Soc 2012
- Sakhaee, Bone Miner 1993
- Wallace, Am J Clin Nutr 2011
- Warensjo, BMJ 2011
- Williams, J Appl Lab Med 2023
- Williams, Prev Chronic Dis 2012
- Zamfirescu, Thyroid 2011
- de Abajo, J Am Heart Ass 2017
- de Leon, J Nutr Gerontol Geriatr 2018
As a ConsumerLab.com member, you may print a copy of this report for your personal use.
You can access a special print version by clicking the "Print" icon in the upper right corner of this report.
You can then use your web browser's print functions to print the whole report or just selected pages.
You may also email or post a link to this report using the web address above.
Non-members using the link will see a free summary and can join to view the full report.
Other means of copying or distributing this report, in part or full, are not permitted.
If you are sight-impaired and your computer is having trouble converting the text in this report to speech,
contact us for assistance at [email protected] or by
phone at 914-722-9149.
The "Latest Update" date indicates when new clinical or product information was most recently added. In the full review (available to CL members), the newest information is highlighted in yellow and, if a new product is added, it is footnoted in the results table, showing the date added to the review. The year(s) when testing was completed for the products in the review appears at the end of the Summary section.
|