Calcium is a metal. It readily oxidizes in air. Because it makes up such a large part of the skeleton, about one-third of the mass of human body comes from calcium, after water has been removed.
Tomihahndorf, Creative Commons License
Calcium is one of the elements you need in order to live, so it's worth knowing a little bit about it. Here are some quick facts about the element calcium. You can find more calcium facts on the calcium facts
- Calcium isn't found free in nature, but it can be purified into a soft silvery-white alkaline earth metal.
- Calcium is the 5th most abundant element in the Earth's crust, present at a level of about 3% in the oceans and soil.
- The element is essential for animal and plant nutrition. Calcium participates in many biochemical reactions, including building skeletal systems and moderating muscle action.
- Vitamin D is essential for calcium absorption by the human body. Vitamin D is converted to a hormone which causes intestinal proteins responsible for calcium absorption to be produced.
- While calcium and its compounds are not considered to be toxic, ingesting too many calcium carbonate dietary supplements or antacids can cause milk-alkali syndrome, which is associated with hypercalcemia sometimes leading to fatal renal failure. Excessive consumption would be on the order of 10 g calcium carbonate/day, though symptoms have been reported upon ingesting as little as 2.5 g calcium carbonate daily.
- Calcium is used for making cement, making cheese, removing nonmetallic impurities from alloys, and as a reduction agent in the preparation of other metals.
- Pure calcium metal reacts vigorously and sometimes violently with water and acids.
- The element name "calcium" comes from the Latin word "calcis" meaning "lime".
- Calcium has been known since the 1st century, when the ancient Romans were known to make lime from calcium oxide.
- Though calcium has been known for thousands of years, it was not purifed as an element until 1808 by Sir Humphrey Davy (England).