English Reference

Word

calcium

Phoneticscal·ci·um

US/ˈkæɫsiəm/

UK/kˈælsiəm/

Definitions

01the mineral for health

B2 · Medicine

n. a substance found in foods like milk and cheese that helps you grow strong bones and teeth.

n. the chemical element considered as a dietary mineral essential for the maintenance of skeletal structure and various physiological functions.

“Drinking milk is a good way to get enough calcium for your bones.”

“A diet deficient in calcium during adolescence can lead to decreased bone density and a higher risk of fractures in later life.”

Usage

Usually uncountable when referring to the nutrient in food or the body.

02the chemical element

C1 · Science

n. a soft, silver-white metal that is found in rocks like limestone.

n. the alkaline earth metal with atomic number 20, occurring naturally in compounds such as limestone, gypsum, and fluorite.

“The scientist explained that calcium is a very reactive metal in its pure form.”

“In its elemental state, calcium is a silvery-white metal that reacts steadily with water to form calcium hydroxide and hydrogen gas.”

Technical

Real-World Examples

“He found that some people on these drugs may not get enough vitamin D, vitamin B12, iron, calcium and protein.”
The Guardian · 11 Sept 2026
“An empty snail shell provides calcium for deer in winter or becomes a home for native bees in spring.”
Phys.org · 21 Aug 2026

Etymology

Coined by British chemist Humphry Davy in 1808, from Latin calx (“lime, limestone”) because it occurs in limestone. By surface analysis, calc- + -ium.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Collocations

calcium carbonate

Related words

This entry

Level
B2 · Upper Intermediate
Frequency
Frequent
Updated

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