Calcium is a soft, silver-white, metallic chemical element, one of the alkaline-earth metals, found in limestone, marble, chalk, etc., always in combination: it is used as a reducing agent and in fertilizer, and is the essential part of bones, shells, and teeth: symbol, Ca; at. no. 20
It occurs naturally in limestone, gypsum, and fluorite, and its compounds are used to make plaster, quicklime, Portland cement, and metallurgic and electronic materials. Atomic number 20; atomic weight 40.08; melting point 842°C; boiling point 1,484°C; specific gravity 1.54; valence 2.
Calcium is essential for healthy bones and is also important for muscle contraction, heart action, and normal blood clotting. Food sources of calcium include dairy foods; some leafy green vegetables, such as broccoli and collards; canned salmon; clams; oysters; calcium-fortified foods; and soy foods, such as tofu.
Up until the age of 20-25, calcium even builds upon the strength of the bones within the human body. Upwards of 99 percent of the calcium within our bodies is stored within the bones and teeth; however other areas that utilize calcium also store at least small portions of the element. This includes the muscles and the blood in order to regulate muscle contraction, normal heartbeat, and proper blood coagulation.
Sources of Calcium
Calcium is found in a variety of foods, but the amount that your body absorbs varies. Oxalic acid and phytic acid both interfere with the absorption of calcium. Foods rich in oxalic acid are spinach, rhubarb, sweet potatoes, and beans.
Foods rich in phytic acid are unleavened bread, nuts, seeds, and raw beans. People will absorb some of the calcium in these foods, but not as much as they would from foods that do not contain oxalic acid or phytic acid. For example, calcium absorption from dried beans is about half of what we absorb from milk, and calcium absorption from spinach is about one-tenth of that absorbed from milk.
A calcium deficiency can trigger life-threatening diseases over time, or generate symptoms such as as seizures and neck pain. Most popularly, osteoporosis has been linked time and time again to an inadequate calcium supply within the body. In the event of a serious shortage, the body will even begin to leech calcium from the bones in order to supply the much-needed calcium into other areas of the body, Souch as:
- Hypertension – also known as high blood pressure of arterial hypertension
- Abnormal heartbeat
- Chest pain
- Difficulty breathing
- Unusual changes in alertness of consciousness
Functions of Calcium
Calcium is tightly linked to many of the roles that vitamin D plays in the body. In bone health and other physiologic systems, calcium is a key player. Calcium is a mineral that must be constantly eaten to build bone and maintain the blood level of calcium.
Even though only 1 percent of the calcium in the body is found outside of bone, this form of calcium is critical for many functions in the body. Therefore, its level is maintained in a narrow range in the blood and tissues. Consider some of the key non-bone functions of calcium:
- It’s essential for blood clotting.
- It stabilizes blood pressure.
- It contributes to normal brain function.
- It’s critical for communicating essential information among cells.
Calcium Uses in General
The main role of calcium in the body is to provide structure and strength to the skeleton. In the earliest forms of exoskeleton and in shells, the structural rigidity is generally provided by calcium carbonate. Calcium has a wide variety of applications, almost all of which are associated with calcium compounds and salts.
- Calcium may be used as a reducing agent in the process of metal extraction
- Calcium is also used in the production of some metals, as an allying agent.
- Calcium carbonate is used to make cement and mortar and also in the glass industry.
- Calcium carbonate is also added to toothpaste and mineral supplements.
- Calcium carbide is used to make plastics and to make acetylene gas.
- Calcium arsenate acts as an insecticide and calcium phosphide can be used as a rodenticide, as well as in fireworks and flares.
- Calcium phosphate is used in animal feed and fertilizers.
- Calcium hydroxide solution is used as blackboard chalk and as Plaster of Paris in its hemihydrate form.
- Calcium gluconate is used as a food additive.
- Calcium stearate is used to make wax crayons, cosmetics, plastics and paints.