20 potassium ← calcium → scandium Mg ↑ Ca ↓ Sr Periodic table - Extended periodic table
General
Name, symbol, number	calcium, Ca, 20
Chemical series	alkaline earth metals
Group, period, block	2, 4, s
Appearance	silvery white
Standard atomic weight	40.078(4) g·mol−1
Electron configuration	[Ar] 4s2
Electrons per shell	2, 8, 8, 2
Physical properties
Phase	solid
Density (near r.t.)	1. Potassium (pəˈtæsiəm is a Chemical element. It has the symbol K (kalium from qalīy Atomic number 19 and Atomic mass 39 Scandium (ˈskændiəm is a Chemical element that has the symbol Sc and Atomic number 21 Magnesium (mægˈniːziəm is a Chemical element with the symbol Mg, Atomic number 12 Atomic weight 24 Strontium (ˈstrɒntiəm /ˈstrɒnʃiəm/) is a Chemical element with the symbol Sr and the Atomic number 38 This is a typical display of the periodic table of the elements and contains the symbol and Atomic number of each element Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of Chemical elements, sorted by name Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of chemical elements by symbol, including the A table of Chemical elements ordered by Atomic number and color coded according to type of element In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in Biological occurrences Beryllium's low aqueous solubility means it is rarely available to biological systems it has no known role in living organisms and when encountered In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in In the Periodic table of the elements, a period is a horizontal row of the table A block of the Periodic table of elements is a set of adjacent groups The respective highest-energy electrons in each element in a block belong to the same Atomic Biological occurrences Beryllium's low aqueous solubility means it is rarely available to biological systems it has no known role in living organisms and when encountered A period 4 element is one of the Chemical elements in the fourth row (or period) of the periodic table of the elements. See also Electron configuration The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass To help compare different orders of magnitude, the following list describes various Mass levels between 10&minus36&thinsp kg and 1053&thinspkg Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) In Atomic physics and Quantum chemistry, electron configuration is the arrangement of Electrons in an Atom, Molecule, or other This article pertains to the chemical element For other uses see Argon (disambiguation. The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J An electron shell may be crudely thought of as an Orbit followed by Electrons around an Atom nucleus. In the Physical sciences a phase is a Set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties A solid' object is in the States of matter characterized by resistance to Deformation and changes of Volume. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different Room temperature (also referred to as ambient temperature) is a common term to denote a certain Temperature within enclosed space at which humans are accustomed 55 g·cm−3
Liquid density at m.p.	1. Kilogram per cubic metre is the SI measure of Density and is represented as kg/m³ where kg stands for Kilogram and m³ stands for Cubic metre The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different The melting point of a solid is the temperature range at which it changes state from solid to Liquid. 378 g·cm−3
Melting point	1115 K (842 °C, 1548 °F)
Boiling point	1757 K (1484 °C, 2703 °F)
Heat of fusion	8. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 The standard Enthalpy of fusion (symbol \Delta{}H_{fus} also known as the heat of fusion or specific melting heat, is the amount of 54 kJ·mol−1
Heat of vaporization	154. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material The enthalpy of vaporization, (symbol \Delta{}_{v}H also known as the heat of vaporization or heat of evaporation, is the Energy required 7 kJ·mol−1
Specific heat capacity	(25 °C) 25. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material Specific heat capacity, also known simply as specific heat, is the measure of the heat energy required to increase the Temperature of a unit quantity 929 J·mol−1·K−1
Vapor pressure P/Pa 1 10 100 1 k 10 k 100 k at T/K 864 956 1071 1227 1443 1755
Atomic properties
Crystal structure	face centered cubic
Oxidation states	2 (strongly basic oxide)
Electronegativity	1. Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. The oxidation number of a central atom in a coordination compound is the charge that it would have if all the Ligands were removed along with the Electron pairs In Chemistry, a base is most commonly thought of as an aqueous substance that can accept Protons This refers to the Brønsted-Lowry theory of acids and " Electronegativity " is the opposite of " Electropositivity," which describes an element's ability to donate electrons 00 (Pauling scale)
Ionization energies (more)	1st: 589. The ionization potential, ionization energy or EI of an Atom or Molecule is the Energy required to remove an Electron These tables list the Ionization energy in kJ/mol necessary to remove one mole of Electrons from one mole of neutral gaseous Atoms (first energy respectively 8 kJ·mol−1
	2nd: 1145. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material 4 kJ·mol−1
	3rd: 4912. 4 kJ·mol−1
Atomic radius	180 pm
Atomic radius (calc. Atomic radius, and more generally the size of an atom, is not a precisely defined Physical quantity, nor is it constant in all circumstances A picometre ( American spelling: picometer, symbol pm) is a unit of Length in the Metric system, equal to one trillionth )	194 pm
Covalent radius	174 pm
Miscellaneous
Magnetic ordering	paramagnetic
Electrical resistivity	(20 °C) 33. The covalent radius, r cov is a measure of the size of Atom which forms part of a Covalent bond. In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials. Paramagnetism is a form of magnetism which occurs only in the presence of an externally applied magnetic field Electrical resistivity (also known as specific electrical resistance) is a measure of how strongly a material opposes the flow of Electric current. 6 nΩ·m
Thermal conductivity	(300 K) 201 W·m−1·K−1
Thermal expansion	(25 °C) 22. In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. When the Temperature of a substance changes the energy that is stored in the Intermolecular bonds between atoms changes 3 µm·m−1·K−1
Speed of sound (thin rod)	(20 °C) 3810 m/s
Young's modulus	20 GPa
Shear modulus	7. Sound is a vibration that travels through an elastic medium as a Wave. In Solid mechanics, Young's modulus (E is a measure of the Stiffness of an isotropic elastic material In Materials science, shear modulus or modulus of rigidity, denoted by G, or sometimes S or μ, is defined as the ratio of Shear 4 GPa
Bulk modulus	17 GPa
Poisson ratio	0. Poisson's ratio ( ν) named after Simeon Poisson, is the ratio of the relative contraction strain, or transverse strain (normal to 31
Mohs hardness	1. The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material 75
Brinell hardness	167 MPa
CAS registry number	7440-70-2
Selected isotopes
Main article: Isotopes of calcium iso NA half-life DM DE (MeV) DP 40Ca 96. The Brinell scale characterizes the indentation Hardness of materials through the scale of penetration of an indenter loaded on a material test-piece CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to Calcium ( Ca) has four stable Isotopes (40Ca and 42Ca through 44Ca plus two more isotopes (46Ca and 48Ca Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides In Chemistry, natural abundance (NA refers to the abundance Isotopes of a Chemical element as naturally found on a planet Half-Life (computer-game page here It's already listed in the disambiguation page Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. The decay energy is the Energy released by a Nuclear decay. The energy difference of the Reactants is often written as Q: where Q In Nuclear physics, a decay product, also known as a daughter product, daughter isotope or daughter nuclide, is a Nuclide 941% 40Ca is stable with 20 neutrons 41Ca syn 1.03×105 y ε - 41K 42Ca 0. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in To help compare Orders of magnitude of different times this page lists times between 32 000 Years and 320 000 years (1012 Seconds mdasha terasecond Electron capture (sometimes called inverse beta decay) is a Decay mode for Isotopes that will occur when there are too many Protons in the Potassium (pəˈtæsiəm is a Chemical element. It has the symbol K (kalium from qalīy Atomic number 19 and Atomic mass 39 647% 42Ca is stable with 22 neutrons 43Ca 0. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. 135% 43Ca is stable with 23 neutrons 44Ca 2. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. 086% 44Ca is stable with 24 neutrons 45Ca syn 162.7 d β- 0. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in To help compare Orders of magnitude of different times this page lists times between 116 Days and 1157 days or 3 In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted 258 45Sc 46Ca 0. Scandium (ˈskændiəm is a Chemical element that has the symbol Sc and Atomic number 21 004% >2.8×1015 y β-β-  ? 46Ti 47Ca syn 4.536 d β- 0. To help compare Orders of magnitude of different times this page lists times longer than 1019 Seconds (317 billion years In the process of Beta decay, unstable nuclei decay by converting a Neutron in the nucleus to a Proton and emitting an Electron and an electron Titanium (taɪˈteɪniəm is a Chemical element with the symbol Ti and Atomic number 22 A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in To help compare Orders of magnitude of different Times this page lists times between 105 seconds and 106 seconds (approximately 27 In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted 694, 1. 99 47Sc γ 1. Scandium (ˈskændiəm is a Chemical element that has the symbol Sc and Atomic number 21 Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions 297 - 48Ca 0. 187% >4×1019 y β-β-  ? 48Ti
References
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Calcium (pronounced /ˈkælsiəm/) is the chemical element with the symbol Ca and atomic number 20. To help compare Orders of magnitude of different times this page lists times longer than 1019 Seconds (317 billion years In the process of Beta decay, unstable nuclei decay by converting a Neutron in the nucleus to a Proton and emitting an Electron and an electron Titanium (taɪˈteɪniəm is a Chemical element with the symbol Ti and Atomic number 22 Recommended values for many properties of the elements together with various references are collected on these data pages A chemical element is a type of Atom that is distinguished by its Atomic number; that is by the number of Protons in its nucleus. See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton It has an atomic mass of 40. 078. Calcium is a soft grey alkaline earth metal, and is the fifth most abundant element by mass in the Earth's crust. Biological occurrences Beryllium's low aqueous solubility means it is rarely available to biological systems it has no known role in living organisms and when encountered EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 In Geology, a crust is the outermost solid shell of a planet or moon Calcium is also the fifth most abundant dissolved ion in seawater by both molarity and mass, after sodium, chloride, magnesium, and sulfate. Seawater is Water from a Sea or Ocean. On average seawater in the world's oceans has a Salinity of about 3 Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22 The chloride Ion is formed when the element Chlorine picks up one Electron to form an Anion (negatively-charged ion Cl&minus Magnesium (mægˈniːziəm is a Chemical element with the symbol Mg, Atomic number 12 Atomic weight 24 ^[1]

Calcium is essential for living organisms, particularly in cell physiology, where movement of the calcium ion Ca²⁺ into and out of the cytoplasm functions as a signal for many cellular processes. The cell is the structural and functional unit of all known living Organisms It is the smallest unit of an organism that is classified as living and is often called Physiology (from Greek grc φύσις physis, "nature origin" and grc -λογία -logia) is the study of the mechanical physical The cytoplasm is the contents of a cell that is enclosed within the Plasma membrane. As a major material used in mineralization of bones and shells, calcium is the most abundant metal by mass in many animals. The M acro E xpansion T emplate A ttribute L anguage complements TAL, providing macros which allow the reuse of code across

Notable characteristics

Chemically calcium is reactive and soft for a metal (though harder than lead, it can be cut with a knife with difficulty). It is a silvery metallic element that must be extracted by electrolysis from a fused salt like calcium chloride. In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current Calcium chloride (CaCl2 is an ionic compound of Calcium and Chlorine. ^[2] Once produced, it rapidly forms a grey-white oxide and nitride coating when exposed to air. An oxide is a Chemical compound containing at least one Oxygen atom as well as at least one other element In chemistry a nitride is a compound of Nitrogen with a less Electronegative element where nitrogen has an Oxidation state of -3 It is somewhat difficult to ignite, unlike magnesium, but when lit, the metal burns in air with a brilliant high-intensity red light. Calcium metal reacts with water, evolving hydrogen gas at a rate rapid enough to be noticeable, but not fast enough at room temperature to generate much heat. Water is a common Chemical substance that is essential for the survival of all known forms of Life. In powdered form, however, the reaction with water is extremely rapid, as the increased surface area of the powder accelerates the reaction with the water. Part of the slowness of the calcium-water reaction results from the metal being partly protected by insoluble white calcium hydroxide. Calcium hydroxide, traditionally called slaked lime, hydrated lime, or pickling lime, is a Chemical compound with the chemical formula In water solutions of acids where the salt is water soluble, calcium reacts vigorously.

Calcium salts are colorless from any contribution of the calcium, and ionic solutions of calcium (Ca²⁺) are colorless as well. Many calcium salts are not soluble in water. When in solution, the calcium ion to the human taste varies remarkably, being reported as mildly salty, sour, "mineral like" or even "soothing. " It is apparent that many animals can taste, or develop a taste, for calcium, and use this sense to detect the mineral in salt licks or other sources. A salt lick is a Salt deposit that animals regularly lick In an ecosystem salt/mineral licks sometimes occur naturally providing the Sodium, Calcium ^[3] In human nutrition, soluble calcium salts may be added to tart juices without much effect to the average palate.

Calcium is the fifth most abundant element by mass in the human body, where it is a common cellular ionic messenger with many functions, and serves also as a structural element in bone. It is the relatively high atomic-numbered calcium in the skeleton which causes bone to be radio-opaque. Of the human body's solid components after drying (as for example, after cremation), about a third of the total mass is the approximately one kilogram of calcium which composes the average skeleton (the remainder being mostly phosphorus and oxygen). Cremation is the act of reducing a Corpse by burning, generally in a crematorium furnace or crematory fire

Occurrence

Calcium is not naturally found in its elemental state. Calcium occurs most commonly in sedimentary rocks in the minerals calcite, dolomite and gypsum. Sedimentary rock is one of the three main rock types (the others being igneous and Metamorphic rock) Calcite is a carbonate mineral and the most stable polymorph of Calcium carbonate ( Ca[[carbon C]] O 3 Dolomite (ˈdɒləmaɪt is the name of a Sedimentary Carbonate rock and a Mineral, both composed Gypsum is a very soft Mineral composed of Calcium sulfate dihydrate with the Chemical formula Ca[[sulfur S]] O 4·2 It also occurs in igneous and metamorphic rocks chiefly in the silicate minerals: plagioclase, amphiboles, pyroxenes and garnets. Igneous rocks (etymology from Latin ignis, fire are rocks formed by solidification of cooled Magma (molten rock Metamorphic rock is the result of the transformation of an existing rock type the protolith, in a process called Metamorphism, which means "change The silicate minerals make up the largest and most important class of rock-forming Minerals They are classified based on the structure of their silicate Ion group Plagioclase is a very important series of tectosilicate Minerals within the Feldspar family Amphibole (pronounced amfi-bowl defines an important group of generally dark-colored rock-forming inosilicate Minerals composed of double chain SiO4 The pyroxenes are a group of important rock-forming Silicate minerals found in many Igneous and metamorphic rocks. The garnet group includes a group of minerals that have been used since the Bronze Age as gemstones and abrasives

See also Calcium minerals.

Applications

Some uses are:

• as a reducing agent in the extraction of other metals, such as uranium, zirconium, and thorium. A reducing agent (also called a reductant or reducer) is the element or a compound in a Redox (reduction-oxidation reaction (see Electrochemistry Uranium (jʊˈreɪniəm is a silvery-gray Metallic Chemical element in the Zirconium (zɚˈkoʊniəm /ˌzɝˈkoʊniəm/ is a Chemical element with the symbol Zr and Atomic number 40 Thorium (ˈθɔːriəm is a Chemical element with the symbol Th and Atomic number 90
• as a deoxidizer, desulfurizer, or decarbonizer for various ferrous and nonferrous alloys. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 An alloy is a Solid solution or Homogeneous mixture of two or more elements, at least one of which is a Metal, which itself has
• as an alloying agent used in the production of aluminium, beryllium, copper, lead, and magnesium alloys. WikipediaNaming Beryllium (bəˈrɪliəm is a Chemical element with the symbol Be and Atomic number 4 Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 Characteristics Lead has a dull luster and is a dense, Ductile, very soft highly Magnesium (mægˈniːziəm is a Chemical element with the symbol Mg, Atomic number 12 Atomic weight 24
• in the making of cements and mortars to be used in construction. In the most general sense of the word a cement is a binder a substance which sets and hardens independently and can bind other materials together Mortar is a workable paste formed by mixture of Cement, Water and fine aggregate Masonry to bind construction blocks together and fill the gaps between In the fields of Architecture and Civil engineering, construction is a process that consists of the Building or assembling of Infrastructure
• in the making of cheese, where calcium ions influence the activity of rennin in bringing about the coagulation of milk. Cheese is a Food made from Milk, usually the milk of cows, Buffalo, Goats or sheep, by coagulation. An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Chymosin (or rennin) is an aspartic acid protease Enzyme found in Rennet. Coagulation is a complex process by which Blood forms Clots It is an important part of Hemostasis (the cessation of blood loss from a damaged vessel whereby

Calcium compounds

• Calcium carbonate (CaCO₃) used in manufacturing cement and mortar, lime, limestone (usually used in the steel industry); aids in production in the glass industry, also has chemical and optical uses as mineral specimens in toothpastes for example. Calcium carbonate is a Chemical compound with the Chemical formula Ca[[Carbon C]] O 3 In the most general sense of the word a cement is a binder a substance which sets and hardens independently and can bind other materials together Agricultural lime, also called garden lime, is a Soil additive made from pulverized Limestone or Chalk. Limestone is a Sedimentary rock composed largely of the Mineral Calcite ( Calcium carbonate: CaCO3 Toothpaste is a Paste or Gel Dentifrice used to clean and maintain the aesthetics and health of Teeth.
• Calcium hydroxide solution (Ca(OH)₂) (also known as limewater) is used to detect the presence of carbon dioxide by being bubbled through a solution. Calcium hydroxide, traditionally called slaked lime, hydrated lime, or pickling lime, is a Chemical compound with the chemical formula Lime water is the common name for saturated Calcium hydroxide Solution. It turns cloudy where CO₂ is present.
• Calcium arsenate (Ca₃(AsO₄)₂) is used in insecticides. Calcium arsenate ( Ca3 ( As[[Oxygen O4]]2 is an extremely poisonous Chemical compound. An insecticide is a Pesticide used against Insects in all developmental forms
• Calcium carbide (CaC₂) is used: to make acetylene gas (for use in acetylene torches for welding) and in the manufacturing of plastics. Calcium carbide is a Chemical compound with the Chemical formula of Ca[[Carbide C2]] Acetylene ( IUPAC name ethyne), C2H2 is a Hydrocarbon belonging to the group of Alkynes It is the simplest of all alkynes Originally a torch was a portable source of Fire used as a source of light usually a rod-shaped piece of wood with a rag soaked in pitch and/or some other Welding is a fabrication process that joins materials usually Metals or Thermoplastics by causing coalescence. Plastic is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products
• Calcium chloride (CaCl₂) is used: in ice removal and dust control on dirt roads, in conditioner for concrete, as an additive in canned tomatoes, and to provide body for automobile tires. Calcium chloride (CaCl2 is an ionic compound of Calcium and Chlorine. Ice is a Solid phase, usually crystalline, of a Non-metalic substance that is liquid or gas at Room temperature, such as Ammonia Dust is a general name for minute Solid particles with Diameters less than 500 micrometers. Concrete is a construction material composed of Cement (commonly Portland cement) as well as other cementitious materials such as Fly ash and Slag The tomato ( Solanum lycopersicum, syn Lycopersicon lycopersicum) is a herbaceous usually sprawling plant in the Solanaceae or nightshade family This article is about tires used on road Vehicles including pneumatic tires and solid tires.
• Calcium cyclamate (Ca(C₆H₁₁NHSO₃)₂) was used as a sweetening agent but is no longer permitted for use because of suspected cancer-causing properties. Cyclamate is an Artificial sweetener that was discovered in 1937 at the University of Illinois by graduate student Michael Sveda
• Calcium gluconate (Ca(C₆H₁₁O₇)₂) is used as a food additive and in vitamin pills. Food additives are substances added to food to preserve flavour or improve its taste and appearance A vitamin is an Organic compound required as a Nutrient in tiny amounts by an Organism.
• Calcium hypochlorite (Ca(OCl)₂) is used: as a swimming pool disinfectant, as a bleaching agent, as an ingredient in deodorant, and in algaecide and fungicide. Calcium hypochlorite is a Chemical compound with formula (2 It is widely used for Water treatment and as a Bleaching agent (bleaching A swimming pool, swimming bath, wading pool, or simply a pool, is an artificially enclosed Body of water intended for Swimming or Disinfectants are Antimicrobial agents that are applied to non-living objects to destroy Microorganisms, the process of which is known as disinfection. A bleach is a Chemical that removes color or whitens often via Oxidation. Deodorants are substances applied to the body particularly the Armpits mainly to reduce Body odor caused by the bacterial breakdown of Perspiration. An algaecide or algicide is a substance used for killing and preventing the growth of Algae. Fungicides are Chemical compounds or biological organisms used to kill or inhibit fungi or fungal spores
• Calcium permanganate (Ca(MnO₄)₂) is used in liquid rocket propellant, textile production, as a water sterilizing agent and in dental procedures. A textile is a flexible material comprised of a network of natural or artificial Fibres often referred to as thread or Yarn.
• Calcium phosphate (Ca₃(PO₄)₂) is used as a supplement for animal feed, fertilizer, in commercial production for dough and yeast products, in the manufacture of glass, and in dental products. Calcium phosphate is the name given to a family of Minerals containing Calcium Ions (Ca2+ together with orthophosphates (PO43- Fertilizers ( also spelt fertiliser are chemical compounds given to Plants to promote growth they are usually applied either through the soil for uptake by plant Dough is a paste made out of any Cereals (grains or leguminous crops by mixing the Flour with a small amount of Water. Yeasts are a growth form of eukaryotic Microorganisms classified in the kingdom Fungi, with about 1500 Species currently described Glass in the common sense refers to a Hard, Brittle, transparent Solid, such as that used for Windows many
• Calcium phosphide (Ca₃P₂) is used in fireworks, rodenticide, torpedoes and flares. Calcium phosphide ( CP, Ca3P2 is a chemical that has uses in Incendiary bombs It has the appearance of red-brown crystalline powder or grey lumps A firework is classified as a low explosive pyrotechnic device used primarily for aesthetic and entertainment purposes Rodenticides are a category of Pest control Chemicals intended to kill Rodents Single feed baits are chemicals sufficiently The modern torpedo (historically called an automotive automobile locomotive or fish torpedo is a self-propelled explosive Projectile weapon launched above or below A flare, also sometimes called a fusee, is a type of Pyrotechnic that produces a brilliant light or intense heat without an Explosion.
• Calcium stearate (Ca(C₁₈H₃₅O₂)₂ is used in the manufacture of wax crayons, cements, certain kinds of plastics and cosmetics, as a food additive, in the production of water resistant materials and in the production of paints. Calcium stearate is a non-toxic stabilizer and Lubricant. It is an Insoluble calcium salt of Stearic acid. Wax has traditionally referred to a substance that is secreted by Bees ( Beeswax) and used by them in constructing their A crayon is a stick of colored Wax, Charcoal, Chalk, or other materials used for writing and Drawing. In the most general sense of the word a cement is a binder a substance which sets and hardens independently and can bind other materials together Plastic is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products Food additives are substances added to food to preserve flavour or improve its taste and appearance Paint is any Liquid, liquifiable or mastic composition which after application to a substrate in a thin layer is converted to an opaque Solid
• Calcium sulfate (CaSO₄·2H₂O) is used as common blackboard chalk, as well as, in its hemihydrate form being more well known as Plaster of Paris. Calcium sulfate is a common laboratory and industrial chemical
• Calcium tungstate (CaWO₄) is used in luminous paints, fluorescent lights and in X-ray studies. Scheelite is a Calcium Tungstate Mineral with the Chemical formula Ca[[tungsten W]] O 4 Paint is any Liquid, liquifiable or mastic composition which after application to a substrate in a thin layer is converted to an opaque Solid A fluorescent lamp or fluorescent tube is a Gas-discharge lamp that uses Electricity to excite mercury Vapor. X-radiation (composed of X-rays) is a form of Electromagnetic radiation.

H and K lines

In the visible portion of the spectrum of many stars, including the Sun, show strong absorption lines of singly-ionized Calcium. The Sun (Sol is the Star at the center of the Solar System. A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range compared Prominent among these are the H-line at 3968. 5 Å and the K line at 3933. An ångström or angstrom (symbol Å) (ˈɔːŋstrəm Swedish: ˈɔ̀ŋstrœm is an internationally recognized non- SI unit of length equal 7 Å of singly-ionized Calcium, or Ca II. For the Sun and stars with low temperatures, the prominence of the H and K lines can be an indication of strong magnetic activity in the chromosphere. The chromosphere (literally "colour sphere" is a thin layer of the Sun 's atmosphere just above the Photosphere, roughly 10000 kilometres deep Measurement of periodic variations of these active regions can also be used to deduce the rotation periods of these stars. ^[4]

History

Calcium (Latin calx, meaning "limestone") was known as early as the first century when the Ancient Romans prepared lime as calcium oxide. Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. Ancient Rome was a Civilization that grew out of a small agricultural community founded on the Italian Peninsula as early as the 10th century BC Calcium oxide ( CaO) commonly known as burnt lime, lime or quicklime, is a widely used Chemical compound. It was not isolated until 1808 in England when Sir Humphry Davy electrolyzed a mixture of lime and mercuric oxide. England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland Sir Humphry Davy 1st Baronet FRS MRIA (17 December 1778 &ndash 29 May 1829 was a British Chemist and inventor In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current Davy was trying to isolate calcium; when he heard that Swedish chemist Jöns Jakob Berzelius and Pontin prepared calcium amalgam by electrolyzing lime in mercury, he tried it himself. Friherre Jöns Jacob Berzelius (20 August 1779 &ndash 7 August 1848 was a Swedish chemist He worked with electrolysis throughout his life and also discovered/isolated sodium, potassium, magnesium, boron and barium. Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22 Potassium (pəˈtæsiəm is a Chemical element. It has the symbol K (kalium from qalīy Atomic number 19 and Atomic mass 39 Magnesium (mægˈniːziəm is a Chemical element with the symbol Mg, Atomic number 12 Atomic weight 24 Boron (ˈbɔərɒn is a Chemical element with Atomic number 5 and the chemical symbol B. Barium (ˈbɛəriəm is a Chemical element. It has the symbol Ba, and Atomic number 56

Compounds

Calcium, combined with phosphate to form hydroxylapatite, is the mineral portion of human and animal bones and teeth. A phosphate, an Inorganic chemical, is a salt of Phosphoric acid. Hydroxylapatite, also called hydroxyapatite, is a Mineral. It is a naturally occurring form of calcium Apatite with the formula Ca5(PO43(OH The mineral portion of some corals can also be transformed into hydroxylapatite. Corals are Marine organisms from the class Anthozoa and exist as small Sea anemone –like Polyps typically in colonies of many

Calcium oxide (lime) is used in many chemical refinery processes and is made by heating and carefully adding water to limestone. Calcium oxide ( CaO) commonly known as burnt lime, lime or quicklime, is a widely used Chemical compound. Limestone is a Sedimentary rock composed largely of the Mineral Calcite ( Calcium carbonate: CaCO3 When lime is mixed with sand, it hardens into a mortar and is turned into plaster by carbon dioxide uptake. Mortar is a workable paste formed by mixture of Cement, Water and fine aggregate Masonry to bind construction blocks together and fill the gaps between The term plaster can refer to plaster of Paris Lime plaster, or Cement plaster. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Mixed with other compounds, lime forms an important part of Portland cement. Portland cement is the most common type of Cement in general usage in many parts of the world as it is a basic ingredient of Concrete, mortar, Stucco

Calcium carbonate (CaCO₃) is one of the common compounds of calcium. Calcium carbonate is a Chemical compound with the Chemical formula Ca[[Carbon C]] O 3 It is heated to form quicklime (CaO), which is then added to water (H₂O). This forms another material known as slaked lime (Ca(OH)₂), which is an inexpensive base material used throughout the chemical industry. Chalk, marble, and limestone are all forms of calcium carbonate.

When water percolates through limestone or other soluble carbonate rocks, it partially dissolves part of the rock and causes cave formation and characteristic stalactites and stalagmites and also forms hard water. Limestone is a Sedimentary rock composed largely of the Mineral Calcite ( Calcium carbonate: CaCO3 In Chemistry, a carbonate is a salt or Ester of Carbonic acid. A stalactite ( Greek stalaktites, (Σταλακτίτης from the word for "drip" and meaning "that which drips" is a type of Speleothem A stalagmite (from the Greek stalagma ("Σταλαγμίτης" "drop" or "drip" is a Hard water is the type of Water that has high Mineral content (in contrast with Soft water) Other important calcium compounds are calcium nitrate, calcium sulfide, calcium chloride, calcium carbide, calcium cyanamide and calcium hypochlorite. Calcium nitrate, also called Norgessalpeter (Norwegian saltpeter is the Inorganic compound with the formula Ca(NO32 Calcium sulfide is the Chemical compound with the formula CaS Calcium chloride (CaCl2 is an ionic compound of Calcium and Chlorine. Calcium carbide is a Chemical compound with the Chemical formula of Ca[[Carbide C2]] Calcium cyanamide or CaCN2 is a Calcium compound used as Fertiliser, first synthesized in 1898 by Adolph Frank and Nikodem Caro Calcium hypochlorite is a Chemical compound with formula (2 It is widely used for Water treatment and as a Bleaching agent (bleaching

Isotopes

Main article: Isotopes of calcium

Calcium has four stable isotopes (⁴⁰Ca and ⁴²Ca through ⁴⁴Ca), plus two more isotopes (⁴⁶Ca and ⁴⁸Ca) that have such long half-lives that for all practical purposes they can be considered stable. Calcium ( Ca) has four stable Isotopes (40Ca and 42Ca through 44Ca plus two more isotopes (46Ca and 48Ca Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides Calcium-48 is a rare isotope of calcium containing 20 Protons and 28 Neutrons It makes up 0 It also has a cosmogenic isotope, radioactive ⁴¹Ca, which has a half-life of 103,000 years. Environmental Radioactivity is the study of radioactive materials in the Human environment. Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. Half-Life (computer-game page here It's already listed in the disambiguation page Unlike cosmogenic isotopes that are produced in the atmosphere, ⁴¹Ca is produced by neutron activation of ⁴⁰Ca. Environmental Radioactivity is the study of radioactive materials in the Human environment. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. Most of its production is in the upper metre or so of the soil column, where the cosmogenic neutron flux is still sufficiently strong. ⁴¹Ca has received much attention in stellar studies because it decays to ⁴¹K, a critical indicator of solar-system anomalies.

97% of naturally occurring calcium is in the form of ⁴⁰Ca. ⁴⁰Ca is one of the daughter products of ⁴⁰K decay, along with ⁴⁰Ar. While K-Ar dating has been used extensively in the geological sciences, the prevalence of ⁴⁰Ca in nature has impeded its use in dating. Potassium-argon dating or K-Ar dating is a Radiometric dating method used in Geochronology and Archeology. Geology (from Greek γη gê, "earth" and λόγος Logos, "speech" lit Techniques using mass spectrometry and a double spike isotope dilution have been used for K-Ca age dating. Mass spectrometry is an analytical technique that identifies the chemical composition of a compound or sample based on the Mass-to-charge ratio of charged particles Potassium (pəˈtæsiəm is a Chemical element. It has the symbol K (kalium from qalīy Atomic number 19 and Atomic mass 39

The most abundant isotope, ⁴⁰Ca, has a nucleus of 20 protons and 20 neutrons. The proton ( Greek πρῶτον / proton "first" is a Subatomic particle with an Electric charge of one positive This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. This is the heaviest stable isotope of any element which has equal numbers of protons and neutrons. In supernova explosions, calcium is formed from the reaction of carbon with various numbers of alpha particles (helium nuclei), until the most common calcium isotope (containing 10 helium nuclei) has been synthesized.

Nutrition

Main articles: calcium in biology and calcium metabolism

Calcium is an important component of a healthy diet. Calcium (Ca2+ plays a vital role in the Anatomy, Physiology and Biochemistry of Organisms and of the cell, particularly Calcium metabolism or calcium homeostasis is the mechanism by which the body maintains adequate Calcium levels A healthy diet is one that is arrived at with the intent of improving or maintaining optimal Health. Calcium is essential for the normal growth and maintenance of bones and teeth, and calcium requirements must be met throughout life. Long-term calcium deficiency can lead to rickets and poor blood clotting and in case of a menopausal woman, it can lead to osteoporosis, in which the bone deteriorates and there is an increased risk of fractures. Osteoporosis is a Disease of Bone that leads to an increased risk of fracture. While a lifelong deficit can affect bone and tooth formation, over-retention can cause hypercalcemia (elevated levels of calcium in the blood), impaired kidney function and decreased absorption of other minerals. ^[6] High calcium intakes or high calcium absorption were previously thought to contribute to the development of kidney stones. However, more recent studies show that high dietary calcium intakes actually decrease the risk for kidney stones. ^[7] Vitamin D is needed to absorb calcium. Vitamin D is a group of fat-soluble Prohormones, the two major forms of which are vitamin D2 (or Ergocalciferol) and vitamin D3 (or

Dairy products, such as milk and cheese, are a well-known source of calcium. Dairy products are generally defined as Foodstuffs produced from Milk. However, some individuals are allergic to dairy products and even more people, particularly those of non Indo-European descent, are lactose-intolerant, leaving them unable to consume non-fermented dairy products in quantities larger than about half a liter per serving. Lactose intolerance is the inability to metabolize Lactose, a sugar found in Milk and other Dairy products because the required enzyme Others, such as vegans, avoid dairy products for ethical and health reasons. Fortunately, many good sources of calcium exist. These include seaweeds such as kelp, wakame and hijiki; nuts and seeds (like almonds and sesame); blackstrap molasses; beans; oranges; figs; quinoa; amaranth; collard greens; okra; rutabaga; broccoli; dandelion leaves; kale; and fortified products such as orange juice and soy milk. Seaweed is a loose colloquial term encompassing macroscopic Multicellular, benthic marine Algae. Kelp are large Seaweeds ( Algae) belonging to the Brown algae and classified in the order Laminariales Undaria pinnatifida, is a type of edible Kelp. History in the West In 1867 the word "wakame" first appeared in an English-language publication ( Sargassum fusiforme, syn. Hizikia fusiformis) is a brown sea vegetable growing wild on rocky coastlines around Japan, Korea, and China The Almond ( Prunus dulcis, syn Prunus amygdalus Batsch Amygdalus communis L Sesame ( Sesamum indicum) is a Flowering plant in the genus Sesamum. Molasses or Treacle is a thick Syrup by-product from the processing of the Sugarcane or Sugar beet into Sugar. Bean is a common name for large plant Seeds of several genera of the family Fabaceae (formerly Leguminosae used for human food or animal An orange —specifically the sweet orange —is the Citrus fruit Citrus sinensis ( syn Ficus is a Genus of about 850 Species of woody Trees Shrubs Vines Epiphytes and hemi-epiphytes in the family For the town with a similar name see Quinua Peru. "Quinoa" is also a title of a 1992 music album by Tangerine Dream. Amaranthus, collectively known as amaranth or pigweed, is a cosmopolitan genus of herbs Collards, also called borekale (from the Dutch boerenkool (farmers' kale are various loose-leafed Cultivars of Brassica oleracea ( Acephala Okra ( American English:, British English,) also known as lady's finger, bhindi ( Hindustani) and gumbo, is a The swede, (yellow turnip, swedish turnip or rutabaga ( Brassica napobrassica, or Brassica napus var Broccoli is a plant of the Cabbage family Brassicaceae (formerly Cruciferae Kale or Borecole is a form of Cabbage ( Brassica oleracea Acephala Group) green in color in which the central leaves do not Soy milk (also called soya milk, soybean milk, or soy juice) and sometimes referred to as soy drink/beverage is a beverage made from (However, calcium fortified orange juice often contains vitamin D3 derived from lanolin, and is thus unacceptable for vegans. Cholecalciferol is a form of Vitamin D, also called vitamin D3. Lanolin, also called Adeps Lanae, wool wax, wool fat, anhydrous wool fat or wool grease, is a greasy yellow substance secreted by ^[8] ) An overlooked source of calcium is eggshell, which can be ground into a powder and mixed into food or a glass of water. ^[9][10][11] Cultivated vegetables generally have less calcium than wild plants. ^[12]

The calcium content of most foods can be found in the USDA National Nutrient Database. ^[13]

Dietary calcium supplements

500 milligram calcium supplements made from calcium carbonate

Calcium supplements are used to prevent and to treat calcium deficiencies. Calcium carbonate is a Chemical compound with the Chemical formula Ca[[Carbon C]] O 3 Most experts recommend that supplements be taken with food and that no more than 600 mg should be taken at a time because the percent of calcium absorbed decreases as the amount of calcium in the supplement increases. ^[5] It is recommended to spread doses throughout the day. Recommended daily calcium intake for adults ranges from 1000 to 1500 mg. It is recommended to take supplements with food to aid in absorption.

Vitamin D is added to some calcium supplements. Vitamin D is a group of fat-soluble Prohormones, the two major forms of which are vitamin D2 (or Ergocalciferol) and vitamin D3 (or Vitamin D is not necessary, but it might be beneficial if the person has low vitamin D status. Proper vitamin D status is important because vitamin D is converted to a hormone in the body which then induces the synthesis of intestinal proteins responsible for calcium absorption. ^[14]

• The absorption of calcium from most food and commonly-used dietary supplements is very similar. ^[15] This is contrary to what many calcium supplement manufacturers claim in their promotional materials.
• Milk is an excellent source of dietary calcium because it has a high concentration of calcium and the calcium in milk is excellently absorbed. Milk is an opaque white liquid produced by the Mammary glands of female Mammals (including Monotremes. ^[16]
• Calcium carbonate is the most common and least expensive calcium supplement. Calcium carbonate is a Chemical compound with the Chemical formula Ca[[Carbon C]] O 3 It should be taken with food. The absorption of calcium from calcium carbonate is similar to the absorption of calcium from milk. ^[17] While most people digest calcium carbonate very well, some might develop gastrointestinal discomfort or gas. Taking magnesium with it can help to avoid constipation. Calcium carbonate is 40% elemental calcium. 1000 mg will provide 400 mg of calcium. However, supplement labels will usually indicate how much calcium is present in each serving, not how much calcium carbonate is present.
• Antacids, such as Tums, frequently contain calcium carbonate, and are a very commonly-used, inexpensive calcium supplement. An antacid is any substance generally a base or Basic salt, which counteracts stomach acidity.
• Coral Calcium is a salt of calcium derived from fossilized coral reefs. Coral Calcium is a Salt of Calcium derived from Fossilized Coral reefs Living coral reefs are endangered and cannot be harvested without significant Coral calcium is composed of calcium carbonate and trace minerals.
• Calcium citrate can be taken without food and is the supplement of choice for individuals with achlorhydria or who are taking histamine-2 blockers or protein-pump inhibitors. Calcium citrate is the Calcium salt of Citric acid. It is commonly used as a Food additive ( E333) usually as a Preservative ^[18] It is more easily digested and absorbed than calcium carbonate if taken on empty stomach and less likely to cause constipation and gas than calcium carbonate. It also has a lower risk of contributing to the formation of kidney stones. Calcium citrate is about 21% elemental calcium. 1000 mg will provide 210 mg of calcium. It is more expensive than calcium carbonate and more of it must be taken to get the same amount of calcium.
• Calcium phosphate costs more than calcium carbonate, but less than calcium citrate. Calcium phosphate is the name given to a family of Minerals containing Calcium Ions (Ca2+ together with orthophosphates (PO43- It is easily absorbed and is less likely to cause constipation and gas than either.
• Calcium lactate has similar absorption as calcium carbonate^[19], but is more expensive. Calcium lactate is a white crystalline Salt made by the action of Lactic acid on Calcium carbonate. Calcium lactate and calcium gluconate are less concentrated forms of calcium and are not practical oral supplements. ^[18]
• Calcium chelates are synthetic calcium compunds, with calcium bound to an organic molecule, such as malate, aspartate, or fumarate. Chelation is the binding or complexation of a bi- or multidentate Ligand. These forms of calcium may be better absorbed on an empty stomach. However, in general they are absorbed similarly to calcium carbonate and other common calcium supplements when taken with food. ^[20] The 'chelate' mimics the action that natural food performs by keeping the calcium soluble in the intestine. Thus, on an empty stomach, in some individuals, chelates might theoretically be absorbed better.
• Microcrystalline hydroxyapatite (MH) is marketed as a calcium supplement, and has in some randomized trials been found to be more effective than calcium carbonate. Hydroxylapatite, also called hydroxyapatite, is a Mineral. It is a naturally occurring form of calcium Apatite with the formula Ca5(PO43(OH
• Orange juice with calcium added is a good dietary source for persons who have lactose intolerance. Orange juice is a Fruit juice obtained by squeezing pressing or otherwise crushing the interior of an orange. Lactose intolerance is the inability to metabolize Lactose, a sugar found in Milk and other Dairy products because the required enzyme

The National Nutritional Food Association — NNFA (Newport Beach, Calif. ) defines a chelate very specifically, and several criteria must be met in order for chelation to actually occur. Some of the claimed "chelates" on the market are the various Krebs (Citric Acid) Cycle chelates, such as citrate, malate, and aspartate. The citric acid cycle, also known as the tricarboxylic acid cycle ( TCA cycle) or the Krebs cycle, (or rarely the Szent-Györgyi–Krebs cycle Dicalcium malate (chelated with malic acid) is a newer form of a true calcium chelate. It contains a high amount of elemental calcium (30%).

In July 2006, a report citing research from Fred Hutchinson Cancer Research Center in Seattle, Washington claimed that women in their 50s gained 5 pounds less in a period of 10 years by taking more than 500 mg of calcium supplements than those who did not. Nobel Prize Recipients The Hutchinson Center is home to three recipients of the Nobel Prize in physiology or medicine. However, the doctor in charge of the study, Dr. Alejandro J. Gonzalez also noted it would be "going out on a limb" to suggest calcium supplements as a weight-limiting aid. ^[21]

Prevention of fractures due to osteoporosis

Such studies often do not test calcium alone, but rather combinations of calcium and vitamin D. Randomized controlled trials found both positive^[22][23] and negative^{[24][25][26][27]} effects. A randomized controlled trial (RCT is a type of scientific Experiment most commonly used in testing the Efficacy or Effectiveness of Healthcare The different results may be explained by doses of calcium and underlying rates of calcium supplementation in the control groups. ^[28] However, it is clear that increasing the intake of calcium promotes deposition of calcium in the bones, where it is of more benefit in preventing the compression fractures resulting from the osteoporotic thinning of the dendritic web of the bodies of the vertebrae, than it is at preventing the more serious cortical bone fractures which happen at hip and wrist. Dendrites (from Greek δένδρον déndron, “tree” are the branched projections of a Neuron that act to conduct the electrochemical

Prevention of cancer?

A meta-analysis^[23] by the international Cochrane Collaboration of two randomized controlled trials^[29][30]found that calcium "might contribute to a moderate degree to the prevention of adenomatous colonic polyps". In Statistics, a meta-analysis combines the results of several studies that address a set of related research hypotheses The Cochrane Collaboration is a group of over 11500 volunteers in more than 90 countries who apply a rigorous systematic process to review the effects of interventions tested in biomedical A randomized controlled trial (RCT is a type of scientific Experiment most commonly used in testing the Efficacy or Effectiveness of Healthcare A colonic polyp is a polyp found in the colon A polyp can be defined as lining of mucosa which projects out in a mushroom shape

More recent studies were conflicting, and one which was positive for effect (Lappe, et al. ) did control for a possible anti-carcinogenic effect of vitamin D, which was found to be an independent positive influence from calcium-alone on cancer risk (see second study below) ^[31]. Vitamin D is a group of fat-soluble Prohormones, the two major forms of which are vitamin D2 (or Ergocalciferol) and vitamin D3 (or

• A randomized controlled trial found that 1000 mg of elemental calcium and 400 IU of vitamin D₃ had no effect on colorectal cancer^[32]
• A randomized controlled trial found that 1400–1500 mg supplemental calcium and 1100 IU vitamin D₃ reduced aggregated cancers with a relative risk of 0. A randomized controlled trial (RCT is a type of scientific Experiment most commonly used in testing the Efficacy or Effectiveness of Healthcare A randomized controlled trial (RCT is a type of scientific Experiment most commonly used in testing the Efficacy or Effectiveness of Healthcare In Statistics and mathematical Epidemiology, relative risk (RR is the risk of an event (or of developing a disease relative to exposure 402. ^[33]
• An observational cohort study found that high calcium and vitamin D intake was associated with "lower risk of developing premenopausal breast cancer. A cohort study or panel study is a form of Longitudinal study used in Medicine and Social science. "^[34]

See also

• Calcium metabolism
• Calcium in biology
• Calcium compounds
• Disorders of calcium metabolism

Notes

References

• Rebecca J. Donatelle. Health, The Basics. 6th ed. San Francisco: Pearson Education, Inc. 2005.

External links

• WebElements.com — Calcium
• USDA National Nutrient Database, Calcium content of selected foods