noun, often attributive
cal·​ci·​um | \ ˈkal-sē-əm How to pronounce calcium (audio) \

Definition of calcium

: a metallic chemical element of the alkaline-earth group that occurs naturally only in combination and is essential to cellular functions in all known organisms — see Chemical Elements Table

Examples of calcium in a Sentence

Her doctor said she should eat more foods that are high in calcium, such as milk and cheese.
Recent Examples on the Web Purchase dairy products that are fortified with calcium. Jill Joyce, The Conversation, "Anti-nutrients – they’re part of a normal diet and not as scary as they sound," 12 Jan. 2021 Your bones begin to leak calcium, your muscles begin to shrivel, the immune system weakens, and arthritis can set in. Shi En Kim, Science, "To study aging, scientists are looking to outer space," 2 Dec. 2020 One of the distinctive characteristics of scale is that the insects exist under a protective calcium coating. Calvin Finch,, "Calvin Finch: How to kill the pests eating your winter garden in San Antonio," 26 Dec. 2020 Perovskite is calcium titanate, with the bewitching chemical symbol CaTiO3. Caroline Delbert, Popular Mechanics, "This Solar Cell Just Set an Astounding Efficiency Record," 21 Dec. 2020 In this disorder, a calcium compound created in the body is deposited in joints, causing pain and swelling. New York Times, "Her Wrist Was Swollen and Excruciatingly Painful. Steroids Didn’t Help Much.," 16 Dec. 2020 The National Osteoporosis Foundation recommends a total daily intake of 1,200 milligrams calcium and between 800 to 1,000 international units (IUs) of vitamin D for good bone health. Lindsay Warner, Outside Online, "The Athlete's Guide to Menopause," 8 Dec. 2020 Refinery 29, dietician and food blogger Libby Mills pointed out that almond milk is low in calories and often fortified with calcium. Tyler Jett, USA TODAY, "Fact check: No evidence that almond milk can give women larger breasts," 3 Dec. 2020 Its ability to assist in calcium absorption for good bone health is only one of its many critical biological benefits. Marcia Desanctis, Vogue, "Why Vitamin D May Be the Secret to Staying Healthy This Winter," 23 Nov. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'calcium.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of calcium

1808, in the meaning defined above

History and Etymology for calcium

New Latin, from Latin calc-, calx lime

Keep scrolling for more

Learn More about calcium

Time Traveler for calcium

Time Traveler

The first known use of calcium was in 1808

See more words from the same year

Statistics for calcium

Last Updated

19 Jan 2021

Cite this Entry

“Calcium.” Dictionary, Merriam-Webster, Accessed 22 Jan. 2021.

Keep scrolling for more

More Definitions for calcium


How to pronounce calcium (audio)

English Language Learners Definition of calcium

: a substance that is found in most plants and animals and that is especially important in people for strong healthy bones


cal·​ci·​um | \ ˈkal-sē-əm How to pronounce calcium (audio) \

Kids Definition of calcium

: a silvery soft metallic chemical element that is essential for strong healthy bones


noun, often attributive
cal·​ci·​um | \ ˈkal-sē-əm How to pronounce calcium (audio) \

Medical Definition of calcium

: a silver-white bivalent metallic element that is an alkaline earth metal, occurs only in combination, and is an essential constituent of most plants and animals symbol Ca — see Chemical Elements Table

Keep scrolling for more

More from Merriam-Webster on calcium

Nglish: Translation of calcium for Spanish Speakers

Britannica English: Translation of calcium for Arabic Speakers Encyclopedia article about calcium

Comments on calcium

What made you want to look up calcium? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Slippery Words Quiz—Changing with the Times

  • ducreux self portrait yawning
  • What is an earlier meaning of nice?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!