Where Is Calcium Found?
Calcium is one of the most important elements in the human body, but it is also found in many more places around the world in different forms. Calcium is found on Earth in the form of a compound or a salt. A salt is a compound that is held together by electrostatic forces generated by charged ions. The term “salt” is a molecule of two or more oppositely charged ions. Some calcium salts are very soft or dissolve in water and others are very hard and inert like granite.
Calcium can be found in your diet, in every day items, and in numerous other places. Looking at a few different examples is a great way to understand where calcium can be found.
In Everyday Items
Many common every day items are made of various calcium compounds. For example, when you were in school your teacher probably wrote on a blackboard with a piece of chalk. Chalk is made of calcium carbonate.
Other forms of calcium carbonate are limestone and granite. The only difference between these is how the calcium carbonate molecules are attached to each other.
In the Body
Within your very own body, calcium is the fifth most abundant element. Calcium serves many functions in the body including bones and teeth. Your bones and teeth contain hydroxylapatite, a salt of calcium and phosphate.
Virtually every animal on Earth, including humans, have bones and teeth made up of this form of calcium. Even shelled mollusks like clams and oysters are made of a calcium salt.
Your whole body, in fact, is made up of calcium. Calcium ions within your body even control many of the other cellular processes within the body.
Sources of Calcium
Various calcium salts and derivatives are also used as calcium supplements for nutrition. Some of the more common forms in supplements include calcium carbonate, calcium citrate and calcium gluconate.
Other nutritional sources of calcium include:
- Cow’s milk
- Cheese
- Kelp
- Beans
- Oranges
- Broccoli
Getting enough calcium in your diet or through supplementation is very important in fighting several health issues:
- Osteoporosis
- Proper functioning of your heart
- Alleviating stomach gas and indigestion. Calcium carbonate is a major ingredient in antacid tablets.
- Inhibiting the occurrence of colon polyps that can lead to cancer
Calcium Found in Nature
Calcium is the fifth most abundant metal in the Earth’s crust. It is contained in all types of rocks. In sedimentary rocks, calcium appears as minerals such as dolomite, calcite and gypsum. In igneous and metamorphic rocks, calcium appears as silicate minerals. For example, garnets and pyroxenes are both examples of silicate minerals.
Calcium carbonate is also the salt that makes hard water. Hard water is a severe problem in many parts of the world.
Rock Formations from Calcium
Some rocks and rock formations found in nature are forms of calcium carbonate.
Limestone
Limestone is a slightly soft stone found in the earth. Limestone, because it is made of calcium carbonate, can dissolve when exposed to acidic water.
When rain water passes through polluted air, it becomes acidified. This water then seeps into the ground and may pass across limestone.
Subterranean Caves
When acidified rain dissolves limestone, a space is left in the place where the limestone was. Over time, the space will enlarge and can form a subterranean cave.
Within the cave, the water that drips from the ceiling and walls will begin to form stalactites and stalagmites on the floor and from the ceiling of the cave. These are formed from calcium carbonate that drops out of the water solution.
Calcium in Industry
When calcium carbonate is heated to a high temperature and then water is added at a slow and controlled rate, a new salt is produced. Calcium hydroxide is the product of the process. Lime is a more common name for this calcium hydroxide compound.
Lime is corrosive and has many uses in industrial applications. It is one of the major components of mortar and cement, for example. When lime is exposed to carbon dioxide, the product of the reaction is plaster.