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Encyclopedia > Calcium
20 potassiumcalciumscandium
Mg

Ca

Sr
General
Name, symbol, number calcium, Ca, 20
Chemical series alkaline earth metals
Group, period, block 24, 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.) 1.55 g·cm−3
Liquid density at m.p. 1.378 g·cm−3
Melting point 1115 K
(842 °C, 1548 °F)
Boiling point 1757 K
(1484 °C, 2703 °F)
Heat of fusion 8.54 kJ·mol−1
Heat of vaporization 154.7 kJ·mol−1
Heat capacity (25 °C) 25.929 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 cubic face centered
Oxidation states 2
(strongly basic oxide)
Electronegativity 1.00 (Pauling scale)
Ionization energies
(more)
1st: 589.8 kJ·mol−1
2nd: 1145.4 kJ·mol−1
3rd: 4912.4 kJ·mol−1
Atomic radius 180 pm
Atomic radius (calc.) 194 pm
Covalent radius 174 pm
Miscellaneous
Magnetic ordering paramagnetic
Electrical resistivity (20 °C) 33.6 nΩ·m
Thermal conductivity (300 K) 201 W·m−1·K−1
Thermal expansion (25 °C) 22.3 µm·m−1·K−1
Speed of sound (thin rod) (20 °C) 3810 m/s
Young's modulus 20 GPa
Shear modulus 7.4 GPa
Bulk modulus 17 GPa
Poisson ratio 0.31
Mohs hardness 1.75
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 96.941% Ca is stable with 20 neutrons
41Ca syn 1.03×105 y ε - 41K
42Ca 0.647% Ca is stable with 22 neutrons
43Ca 0.135% Ca is stable with 23 neutrons
44Ca 2.086% Ca is stable with 24 neutrons
45Ca syn 162.7 d β- 0.258 45Sc
46Ca 0.004% >2.8×1015 y β-β-  ? 46Ti
47Ca syn 4.536 d β- 0.694, 1.99 47Sc
γ 1.297 -
48Ca 0.187% >4×1019 y β-β-  ? 48Ti
References
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Calcium (pronounced /ˈkælsiəm/) is the chemical element in the periodic table that has the symbol Ca and atomic number 20. It has an atomic mass of 40.078. Calcium is a soft grey alkaline earth metal, and is the fifth most abundant element in the Earth's crust. It is essential for living organisms, particularly in cell physiology, and is the most common metal in many animals. Look up calcium in Wiktionary, the free dictionary. ... General Name, symbol, number potassium, K, 19 Chemical series alkali metals Group, period, block 1, 4, s Appearance silvery white Standard atomic weight 39. ... General Name, Symbol, Number scandium, Sc, 21 Chemical series transition metals Group, Period, Block 3, 4, d Appearance silvery white Atomic mass 44. ... General Name, symbol, number magnesium, Mg, 12 Chemical series alkaline earth metals Group, period, block 2, 3, s Appearance silvery white solid at room temp Standard atomic weight 24. ... General Name, Symbol, Number strontium, Sr, 38 Chemical series alkaline earth metals Group, Period, Block 2, 5, s Appearance silvery white metallic Standard atomic weight 87. ... Calcium table image created for Wikipedia by Schnee on June 25, 2003, 9:51 UTC. Licensed under the terms of the GNU FDL. File links The following pages link to this file: Calcium User:Femto/elements e3 Categories: GFDL images ... This is a standard display of the periodic table of the elements. ... An extended periodic table was suggested by Glenn T. Seaborg in 1969. ... This is a list of chemical elements, sorted by name and color coded according to type of element. ... Categories: Chemical elements ... sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex... The alkaline earth metals are a series of elements comprising Group 2 (IUPAC style) of the periodic table: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba) and radium (Ra). ... A group, also known as a family, is a vertical column in the periodic table of the chemical elements. ... 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 alkaline earth metals are the series of elements in Group 2 of the periodic table: beryllium, magnesium, calcium, strontium, barium and radium (not always considered due to its very short half-life). ... A period 4 element is one of the chemical elements in the fourth row (or period) of the periodic table of the elements. ... The s-block of the periodic table of elements consists of the first two groups: the alkali metals and alkaline earth metals, plus hydrogen. ... Color is an important part of the visual arts. ... Calcium sample. ... The atomic mass (ma) is the mass of an atom at rest, most often expressed in unified atomic mass units. ... To help compare different orders of magnitude, the following list describes various mass levels between 10−36 kg and 1053 kg. ... Hydrogen = 1 List of Elements in Atomic Number Order. ... Electron atomic and molecular orbitals In atomic physics and quantum chemistry, the electron configuration is the arrangement of electrons in an atom, molecule, or other physical structure (, a crystal). ... General Name, symbol, number argon, Ar, 18 Chemical series noble gases Group, period, block 18, 3, p Appearance colorless Standard atomic weight 39. ... For other uses, see Electron (disambiguation). ... Example of a sodium electron shell model An electron shell, also known as a main energy level, is a group of atomic orbitals with the same value of the principal quantum number n. ... 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 (i. ... For other uses, see Solid (disambiguation). ... For other uses, see Density (disambiguation). ... For other uses, see Room temperature (disambiguation). ... For other uses, see Density (disambiguation). ... The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. ... The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. ... For other uses, see Kelvin (disambiguation). ... Celsius is, or relates to, the Celsius temperature scale (previously known as the centigrade scale). ... For other uses, see Fahrenheit (disambiguation). ... Italic text This article is about the boiling point of liquids. ... For other uses, see Kelvin (disambiguation). ... Celsius is, or relates to, the Celsius temperature scale (previously known as the centigrade scale). ... For other uses, see Fahrenheit (disambiguation). ... Standard enthalpy change of fusion of period three. ... Kilojoule per mole are an SI derived unit of energy per amount of material, where energy is measured in units of 1000 joules, and the amount of material is measured in mole units. ... The heat of vaporization is a physical property of substances. ... Kilojoule per mole are an SI derived unit of energy per amount of material, where energy is measured in units of 1000 joules, and the amount of material is measured in mole units. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Vapor pressure is the pressure of a vapor in equilibrium with its non-vapor phases. ... Enargite crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... The oxidation number of an element in a molecule or complex is the charge that it would have if all the ligands (basically, atoms that donate electrons) were removed along with the electron pairs that were shared with the central atom[1]. It means that the oxidation number is the... Acids and bases: Acid-base extraction Acid-base reaction Acid dissociation constant Acidity function Buffer solutions pH Proton affinity Self-ionization of water Acids: Lewis acids Mineral acids Organic acids Strong acids Superacids Weak acids Bases: Lewis bases Organic bases Strong bases Superbases Non-nucleophilic bases Weak bases edit In... Electronegativity is a measure of the ability of an atom or molecule to attract electrons in the context of a chemical bond. ... The ionization energy (IE) of an atom or of a molecule is the energy required to strip it of an electron. ... These tables list the ionization energy in kJ/mol necessary to remove an electron from a neutral atom (first energy), respectively from a singly, doubly, etc. ... Kilojoule per mole are an SI derived unit of energy per amount of material, where energy is measured in units of 1000 joules, and the amount of material is measured in mole units. ... Atomic radius: Ionic radius Covalent radius Metallic radius van der Waals radius edit Atomic radius, and more generally the size of an atom, is not a precisely defined physical quantity, nor is it constant in all circumstances. ... You have big harry skanky balls ... One picometre is defined as 1x10-12 metres, in standard units. ... You have big harry skanky balls ... Atomic radius: Ionic radius Covalent radius Metallic radius van der Waals radius edit The covalent radius, rcov, is a measure of the size of atom which forms part of a covalent bond. ... You have big harry skanky balls ... For other senses of this word, see magnetism (disambiguation). ... Simple Illustration of a paramagnetic probe made up from miniature magnets. ... // Headline text POOP!! Danny Hornsby (also known as Gnome) is a measure indicating how strongly a Gnome can opposes the flow of electric current. ... K value redirects here. ... During heat transfer, the energy that is stored in the intermolecular bonds between atoms changes. ... This page is about the physical speed of sound waves in a medium. ... Metre per second (U.S. spelling: meter per second) is an SI derived unit of both speed (scalar) and velocity (vector), defined by distance in metres divided by time in seconds. ... In solid mechanics, Youngs modulus (E) is a measure of the stiffness of a given material. ... In materials science, shear modulus, G, or sometimes S or μ, sometimes referred to as the modulus of rigidity, is defined as the ratio of shear stress to the shear strain:[1] where = shear stress; force acts on area ; = shear strain; length changes by amount . ... The bulk modulus (K) of a substance essentially measures the substances resistance to uniform compression. ... Figure 1: Rectangular specimen subject to compression, with Poissons ratio circa 0. ... 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. ... The Brinell scale characterises 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. ... Calcium (Ca) Standard atomic mass: 40. ... For other uses, see Isotope (disambiguation). ... Natural abundance refers to the prevalence of different isotopes of an element as found in nature. ... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ... Radioactive decay is the process in which an unstable atomic nucleus loses energy by emitting radiation in the form of particles or electromagnetic waves. ... The decay energy is the energy released by a nuclear decay. ... The electronvolt (symbol eV) is a unit of energy. ... In nuclear physics, a decay product, also known as a daughter product, is a nuclide resulting from the radioactive decay of a parent or precursor nuclide. ... Stable isotopes are chemical isotopes that are not radioactive. ... This article or section does not adequately cite its references or sources. ... 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 a very short period of time. ... To help compare orders of magnitude of different times this page lists times between 32 000 years and 320 000 years (1012 seconds—a terasecond—and 1013 seconds). ... Electron capture is a decay mode for isotopes that will occur when there are too many protons in the nucleus of an atom, and there isnt enough energy to emit a positron; however, it continues to be a viable decay mode for radioactive isotopes that can decay by positron... General Name, symbol, number potassium, K, 19 Chemical series alkali metals Group, period, block 1, 4, s Appearance silvery white Standard atomic weight 39. ... Stable isotopes are chemical isotopes that are not radioactive. ... This article or section does not adequately cite its references or sources. ... Stable isotopes are chemical isotopes that are not radioactive. ... This article or section does not adequately cite its references or sources. ... Stable isotopes are chemical isotopes that are not radioactive. ... This article or section does not adequately cite its references or sources. ... 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 a very short period of time. ... 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 (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. ... General Name, Symbol, Number scandium, Sc, 21 Chemical series transition metals Group, Period, Block 3, 4, d Appearance silvery white Atomic mass 44. ... To help compare orders of magnitude of different times, this page lists times longer than 1019 seconds (317 billion years) See also times of other orders of magnitude. ... In the process of beta decay unstable nuclei decay by converting a neutron in the nucleus to a proton and emitting an electron and anti-neutrino. ... General Name, symbol, number titanium, Ti, 22 Chemical series transition metals Group, period, block 4, 4, d Appearance silvery metallic Standard atomic weight 47. ... 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 a very short period of time. ... To help compare orders of magnitude of different times this page lists times between 105 seconds and 106 seconds (27. ... In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. ... General Name, Symbol, Number scandium, Sc, 21 Chemical series transition metals Group, Period, Block 3, 4, d Appearance silvery white Atomic mass 44. ... This article is about electromagnetic radiation. ... To help compare orders of magnitude of different times, this page lists times longer than 1019 seconds (317 billion years) See also times of other orders of magnitude. ... In the process of beta decay unstable nuclei decay by converting a neutron in the nucleus to a proton and emitting an electron and anti-neutrino. ... General Name, symbol, number titanium, Ti, 22 Chemical series transition metals Group, period, block 4, 4, d Appearance silvery metallic Standard atomic weight 47. ... Recommended values for many properties of the elements, together with various references, are collected on these data pages. ... The periodic table of the chemical elements A chemical element, or element, is a type of atom that is defined by its atomic number; that is, by the number of protons in its nucleus. ... The Periodic Table redirects here. ... See also: List of elements by atomic number In chemistry and physics, the atomic number (also known as the proton number) is the number of protons found in the nucleus of an atom. ... The alkaline earth metals are a series of elements comprising Group 2 (IUPAC style) of the periodic table: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba) and radium (Ra). ... This article is about Earth as a planet. ... Life on Earth redirects here. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... 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Contents

Notable characteristics

Calcium is a rather soft (though harder than lead), gray, metallic element that can be extracted by electrolysis from fused calcium chloride.[1] It burns with an orange flame and forms a white nitride coating when exposed to air. It reacts with water, displacing a hydrogen atom from the structure, then forming calcium hydroxide. In chemistry and manufacturing, electrolysis is a method of separating chemically bonded elements and compounds by passing an electric current through them. ... R-phrases S-phrases , , Related Compounds Other anions calcium fluoride calcium bromide calcium iodide Other cations magnesium chloride strontium chloride Supplementary data page Structure and properties n, εr, etc. ... Definition The nitride ion is very very gay and retarded A nitride (compound) is a compound that has nitrogen with more electropositive elements. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... It has been suggested that Portlandite be merged into this article or section. ...


The most abundant isotope, 40Ca, has a nucleus of 20 protons and 20 neutrons. Its electron configuration is 2 electrons in the K shell (principal quantum number 1), 8 in the L shell (principal quantum number 2), 8 in the M shell (principal quantum number 3), and 2 in the N shell (principal quantum number 4). The outer shell is the valence shell, with 2 electrons in the lone 4s orbital, the 3d orbitals being empty. For other uses, see Proton (disambiguation). ... This article or section does not adequately cite its references or sources. ... Electron atomic and molecular orbitals In atomic physics and quantum chemistry, the electron configuration is the arrangement of electrons in an atom, molecule, or other physical structure (, a crystal). ... For other uses, see Electron (disambiguation). ...


Occurrence

Calcium is not naturally found in its elemental state. Calcium occurs most commonly in sedimentary rocks in the minerals calcite, dolomite and gypsum. It occurs in igneous and metamorphic rocks chiefly in the silicate minerals: plagioclase, amphiboles, pyroxenes and garnets. Two types of sedimentary rock: limey shale overlaid by limestone. ... Doubly refracting Calcite from Iceberg claim, Dixon, New Mexico. ... For other uses, see Dolomite (disambiguation). ... It has been suggested that Selenite be merged into this article or section. ... Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. ... Metamorphic rock is the result of the transformation of a pre-existing rock type, the protolith, in a process called metamorphism, which means change in form, derived from the Greek words meta, change, and morphe, form. The protolith is subjected to extreme heat (>150 degrees Celsius) and pressure causing profound... The silicate minerals make up the largest and most important class of rock-forming minerals. ... Lunar Ferroan Anorthosite #60025 (Plagioclase Feldspar). ... For the logical fallacy, see Amphibology. ... Figure 1:Mantle-peridotite xenolith with green peridot olivine and black pyroxene crystals from San Carlos Indian Reservation, Gila Co. ... Garnet is a group of minerals that have been used since the Bronze Age as gemstones and abrasives. ...


See also Calcium minerals.


Applications

Some uses are:

A reducing agent (also called a reductant or reducer) is the element or a compound in a redox (reduction-oxidation) reaction (see electrochemistry) that reduces another species. ... General Name, symbol, number uranium, U, 92 Chemical series actinides Group, period, block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Standard atomic weight 238. ... General Name, Symbol, Number zirconium, Zr, 40 Chemical series transition metals Group, Period, Block 4, 5, d Appearance silvery white Standard atomic weight 91. ... General Name, Symbol, Number thorium, Th, 90 Chemical series Actinides Group, Period, Block n/a, 7, f Appearance silvery white Standard atomic weight 232. ... For other uses, see Iron (disambiguation). ... An alloy is a homogeneous hybrid of two or more elements, at least one of which is a metal, and where the resulting material has metallic properties. ... Aluminum redirects here. ... General Name, symbol, number beryllium, Be, 4 Chemical series alkaline earth metals Group, period, block 2, 2, s Appearance white-gray metallic Standard atomic weight 9. ... Copper has played a significant part in the history of mankind, which has used the easily accessible uncompounded metal for nearly 10,000 years. ... This article is about the metal. ... General Name, symbol, number magnesium, Mg, 12 Chemical series alkaline earth metals Group, period, block 2, 3, s Appearance silvery white solid at room temp Standard atomic weight 24. ... For other uses, see Cement (disambiguation). ... Mortar holding weathered bricks. ... For other uses, see Construction (disambiguation). ...

Calcium compounds

Calcium carbonate is a chemical compound, with the chemical formula CaCO3. ... For other uses, see Cement (disambiguation). ... Agricultural lime is a soil additive made from pulverized limestone or chalk. ... For other uses, see Limestone (disambiguation). ... Toothpaste is a paste used, almost always in conjunction with a toothbrush, to clean teeth. ... It has been suggested that Portlandite be merged into this article or section. ... Lime water is the common name for saturated calcium hydroxide solution. ... Calcium arsenate (Ca3(AsO4)2) is a chemical compound. ... It has been suggested that ovicide be merged into this article or section. ... Calcium carbide is a chemical compound with the chemical formula CaC2. ... Acetylene (systematic name: ethyne) is a hydrocarbon belonging to the group of alkynes. ... This article is about portable open fires. ... Welding is a fabrication process that joins materials, usually metals or thermoplastics, by causing coalescence. ... For other uses, see Plastic (disambiguation). ... R-phrases S-phrases , , Related Compounds Other anions calcium fluoride calcium bromide calcium iodide Other cations magnesium chloride strontium chloride Supplementary data page Structure and properties n, εr, etc. ... This article is about water ice. ... Look up dust in Wiktionary, the free dictionary. ... This article is about the construction material. ... For other uses, see Tomato (disambiguation). ... “Car” and “Cars” redirect here. ... Firestone tire This article is about pneumatic tires. ... Food additives are substances added to food to preserve flavor or improve its taste and appearance. ... Retinol (Vitamin A) For the record label, see Vitamin Records A vitamin is an organic compound required in tiny amounts for essential metabolic reactions in a living organism. ... Calcium hypochlorite is a chemical compound with formula Ca(ClO)2. ... For the 2003 film, see Swimming Pool (film). ... This is an article about antimicrobial agents. ... This article is about the chemical whitener. ... Roll-on deodorant Rexona Degree brand Stick deodorant Deodorants (Deodourants) are substances applied to the body, most frequently the underarms, to reduce the 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. ... A Fungicide is one of three main methods of pest control- chemical control of fungi in this case. ... For other uses, see Textile (disambiguation). ... Calcium phosphate is the name given to a family of minerals containing calcium ions (Ca2+) together with orthophosphates (PO43-), metaphosphates or pyrophosphates (P2O74-) and occasionally hydrogen or hydroxide ions. ... For other uses, see Animal (disambiguation). ... Spreading manure, an organic fertilizer Fertilizers (also spelled fertilisers) are compounds given to plants to promote growth; they are usually applied either via the soil, for uptake by plant roots, or by foliar feeding, for uptake through leaves. ... Dough Dough is a paste made out of any cereals (grains) or leguminous crops by grinding with small amount of water. ... Typical divisions Ascomycota (sac fungi) Saccharomycotina (true yeasts) Taphrinomycotina Schizosaccharomycetes (fission yeasts) Basidiomycota (club fungi) Urediniomycetes Sporidiales Yeasts are a growth form of eukaryotic microorganisms classified in the kingdom Fungi, with approximately 1,500 species described. ... This article is about the material. ... Calcium phosphide is a chemical that has uses in incendiary bombs. ... For other uses, see Fireworks (disambiguation). ... Rat poisons are a category of pest control chemicals intended to kill rats. ... The torpedo, historically called a locomotive torpedo, is a self-propelled explosive projectile weapon, launched above or below the water surface, propelled underwater toward a target, and designed to detonate on contact or in proximity to a target. ... A World War I-era parachute flare dropped from aircraft for illumination. ... Calcium stearate is a non-toxic stabilizer and lubricant. ... candle wax This page is about the substance. ... For other uses, see Crayon (disambiguation). ... For other uses, see Cement (disambiguation). ... For other uses, see Plastic (disambiguation). ... Make-up redirects here. ... Food additives are substances added to food to preserve flavor or improve its taste and appearance. ... For other uses, see Paint (disambiguation). ... Calcium sulphate is a common laboratory and industrial chemical. ... Scheelite is a calcium tungstate mineral with the chemical formula CaWO4. ... For other uses, see Paint (disambiguation). ... A compact fluorescent lamp A fluorescent lamp is a type of electric lamp that excites argon and mercury vapor to create luminescence. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz...

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. Prominent among these are the H-line at 3968.5 Å and the K line at 3933.7 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. Measurement of periodic variations of these active regions can also be used to deduce the rotation periods of these stars.[2] Sol redirects here. ... 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 with the nearby frequencies. ... An angstrom, angström, or Ã¥ngström (symbol Ã…) is a unit of length. ... The chromosphere (literally, color sphere) is a thin layer of the Suns atmosphere just above the photosphere, roughly 10,000 kilometers deep (approximating to, if a little less than, the diameter of the Earth). ...


History

Calcium (Latin calx, meaning "limestone") was known as early as the first century when the Ancient Romans prepared lime as calcium oxide. It was not isolated until 1808 in England when Sir Humphry Davy electrolyzed a mixture of lime and mercuric oxide. Davy was trying to isolate calcium; when he heard that Berzelius and Pontin prepared calcium amalgam by electrolyzing lime in mercury, he tried it himself. He worked with electrolysis throughout his life and also discovered/isolated magnesium, strontium and barium. For other uses, see Latin (disambiguation). ... Ancient Rome was a civilization that grew from a small agricultural community founded on the Italian Peninsula circa the 9th century BC to a massive empire straddling the Mediterranean Sea. ... Calcium oxide (CaO), commonly known as lime, quicklime or burnt lime, is a widely used chemical compound. ... For other uses, see England (disambiguation). ... Sir Humphry Davy, 1st Baronet, FRS (17 December 1778 – 29 May 1829) was a British chemist and physicist. ... In chemistry and manufacturing, electrolysis is a method of separating chemically bonded elements and compounds by passing an electric current through them. ... General Name, symbol, number magnesium, Mg, 12 Chemical series alkaline earth metals Group, period, block 2, 3, s Appearance silvery white solid at room temp Standard atomic weight 24. ... General Name, Symbol, Number strontium, Sr, 38 Chemical series alkaline earth metals Group, Period, Block 2, 5, s Appearance silvery white metallic Standard atomic weight 87. ... For other uses, see Barium (disambiguation). ...


Other compounds include Calcium carbonate (CaCO3), one of the common compounds of calcium. 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. Calcium carbonate is a chemical compound, with the chemical formula CaCO3. ...


Compounds

Calcium, combined with phosphate to form hydroxylapatite, is the mineral portion of human and animal bones and teeth. The mineral portion of some corals can also be transformed into hydroxylapatite. A phosphate, in inorganic chemistry, is a salt of phosphoric acid. ... Hydroxylapatite is a naturally occurring form of calcium apatite with the formula Ca5(PO4)3(OH), but is usually written Ca10(PO4)6(OH)2 to denote that the crystal unit cell comprises two molecules. ... Extant Subclasses and Orders Alcyonaria    Alcyonacea    Helioporacea Zoantharia    Antipatharia    Corallimorpharia    Scleractinia    Zoanthidea [1][2]  See Anthozoa for details For other uses, see Coral (disambiguation). ...


Calcium oxide (lime) is used in many chemical refinery processes and is made by heating and carefully adding water to limestone. When lime is mixed with sand, it hardens into a mortar and is turned into plaster by carbon dioxide uptake. Mixed with other compounds, lime forms an important part of Portland cement. Calcium oxide (CaO), commonly known as lime, quicklime or burnt lime, is a widely used chemical compound. ... For other uses, see Limestone (disambiguation). ... Mortar holding weathered bricks. ... This article is about the building material. ... Carbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. ... Sampling fast set Portland cement Portland cement is the most common type of cement in general usage, as it is a basic ingredient of concrete, mortar and plaster. ...


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. Other important calcium compounds are nitrate, sulfide, chloride, carbide, cyanamide, and hypochlorite. For other uses, see Limestone (disambiguation). ... Ball-and-stick model of the carbonate ion, CO32− For other meanings, see Carbonate (disambiguation) In chemistry, a carbonate is a salt or ester of carbonic acid. ... Water droplet coming out of the central canal of a stalactite A stalactite (Greek stalaktites, (Σταλακτίτης), from the word for drip and meaning that which drips) is a type of speleothem(secondary mineral) that hangs from the ceiling or wall of limestone caves. ... The Witchs Finger in the Carlsbad Caverns A stalagmite (from the Greek stalagma (Σταλαγμίτης), drop or drip) is a type of speleothem that rises from the floor of a limestone cave due to the dripping of mineralized solutions and the deposition of calcium carbonate. ... The hardness of the water results in a calcification Hard water is water that has a high mineral content (contrast with soft water), usually consisting of calcium (Ca2+) and magnesium (Mg2+) ions, and possibly including other dissolved metals, bicarbonates, and sulfates. ... Calcium nitrate, also called Norgessalpeter (Norwegian saltpeter) and Kalksalpeter, is a white coloured soluble salt with the formula Ca(NO3)2. ... Calcium sulfide is the chemical compound with the formula CaS. This white material crystallizes in cubes, with the rock salt structure. ... R-phrases S-phrases , , Related Compounds Other anions calcium fluoride calcium bromide calcium iodide Other cations magnesium chloride strontium chloride Supplementary data page Structure and properties n, εr, etc. ... Calcium carbide is a chemical compound with the chemical formula CaC2. ... CaCN2 Calcium compound. ... Calcium hypochlorite is a chemical compound with formula Ca(ClO)2. ...


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. It also has a cosmogenic isotope, radioactive 41Ca, which has a half-life of 103,000 years. Unlike cosmogenic isotopes that are produced in the atmosphere, 41Ca is produced by neutron activation of 40Ca. 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. Calcium (Ca) Standard atomic mass: 40. ... For other uses, see Isotope (disambiguation). ... Calcium 48 is a rare isotope of calcium. ... Cosmogenic isotopes are rare radioactive isotopes created when cosmic radiation interacts with an atomic nucleus. ... Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles. ... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ... Cosmogenic isotopes are rare radioactive isotopes created when cosmic radiation interacts with an atomic nucleus. ... Air redirects here. ... This article or section does not adequately cite its references or sources. ...


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. Techniques using mass spectrometry and a double spike isotope dilution have been used for K-Ca age dating. Potassium-argon or K-Ar dating is a method used by archaeologists and geologists to ascertain the date of ancient mineral deposits. ... This article includes a list of works cited but its sources remain unclear because it lacks in-text citations. ... Mass spectrometry (previously called mass spectroscopy (deprecated)[1] or informally, mass-spec and MS) is an analytical technique used to measure the mass-to-charge ratio of ions. ... General Name, symbol, number potassium, K, 19 Chemical series alkali metals Group, period, block 1, 4, s Appearance silvery white Standard atomic weight 39. ...


Nutrition

Recommended Adequate Intake by the IOM for Calcium:[3]
Age Calcium (mg/day)
0–6 months 210
7–12 months 270
1–3 years 500
4–8 years 800
9–18 years 1300
19–50 years 1000
51+ years 1200

Calcium is an important component of a healthy diet. A deficit can affect bone and tooth formation, while overretention can cause hypercalcemia (elevated levels of calcium in the blood), impaired kidney function and decreased absorption of other minerals.[4] 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.[5] Vitamin D is needed to absorb calcium. Dairy products, such as milk and cheese, are a well-known source of calcium. 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 dairy products. Others, such as vegans, avoid dairy products for ethical and health reasons. Fortunately, many other 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; amaranth; collard greens; okra; rutabaga; broccoli; dandelion leaves; kale; sardines; and fortified products such as orange juice and soy milk. The calcium content of most foods can be found in the USDA National Nutrient Database.[6] A good source of calcium is eggshell, which can be ground into a powder and mixed into food or a glass of water.[7] Maintaining a healthy diet is the practice of making choices about what to eat with the intent of improving or maintaining good health. ... Vitamin D is a fat soluble vitamin that contributes to the maintenance of normal levels of calcium and phosphorus in the bloodstream. ... Dairy products are generally defined as foodstuffs produced from milk. ... Lactose intolerance is the name given to the condition (found in the majority of humans) in which lactase, an enzyme needed for proper metabolization of lactose, is not produced in adulthood. ... This article is about the dietary lifestyle, Vegan can also mean relating to vega, especially the star Vega, as in astronomical references to the Vegan system, or Science Fiction references to aliens from that system. ... Seaweed covered rocks in the UK Phycologists consider seaweed to refer any of a large number of marine benthic algae that are multicellular, macrothallic (large-bodied), and thus differentiated from most algae that tend towards microscopic size (Smith, 1944). ... Families Alariaceae Chordaceae Laminariaceae Lessoniaceae Phyllariaceae Pseudochordaceae Percentages are relative to US recommendations for adults. ... Binomial name (Harvey) Suringar, 1873 Wakame ), Undaria pinnatifida, is a type of edible kelp. ... Hijiki or hiziki (Japanese: 鹿尾菜 or 羊栖菜) (Sargassaceae), is a type of edible seaweed commonly found on rocky coastlines. ... Binomial name (Mill. ... Binomial name Sesamum indicum 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. ... This article is on the plant. ... Orange blossoms and oranges on tree For other uses of orange, see orange (disambiguation) The Orange Citrus x sinensis is a Citrus tree, and the fruits of this tree. ... For other uses, see Amaranth (disambiguation). ... Collards, also called collard greens or borekale (Brassica oleracea Acephala Group), are various loose-leafed cultivars of the cabbage plant. ... Binomial name (L.) Moench Okra (American English: , British English ), also known as ladys finger[1], bhindi and gumbo, is a flowering plant valued for its edible green fruits. ... Binomial name Brassica napobrassica Mill. ... Broccoli is a plant of the Cabbage family, Brassicaceae (formerly Cruciferae). ... For other uses, see Dandelion (disambiguation). ... Kale or Borecole is a form of cabbage (Brassica oleracea Acephala Group), green in color, in which the central leaves do not form a head. ... Sardines in the Pacific An open Sardines can Sardines on a plate grilled Sardines For the hide and seek-like game, see Hide and seek. ... A can of Yeos soy milk, poured into a glass Greek Café Frappé prepared with soy milk, topped with additional cinnamon 1 l (2. ...


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 osteoporosis, in which the bone deteriorates and there is an increased risk of fractures. Calcium has also been found to assist in the production of lymphatic fluids. Osteoporosis is a disease of bone - leading to an increased risk of fracture. ... In mammals including humans, the lymphatic vessels (or lymphatics) are a network of thin tubes that branch, like blood vessels, into tissues throughout the body. ...


For more information about calcium in living nature, see calcium in biology and calcium metabolism. Calcium plays a vital role in the anatomy, physiology and biochemistry of organisms and of the cell, particularly in signal transduction pathways. ... Calcium metabolism or calcium homeostasis is the mechanism by which the body maintains adequate calcium levels. ...


Dietary calcium supplements

Calcium supplements are used to prevent and to treat calcium deficiencies. There are conflicting recommendations about when to take calcium supplements. However, most experts agree that no more than 500 mg should be taken at a time because the percent of calcium absorbed decreases as the amount of calcium in the supplement increases.[3] It is recommended to spread doses throughout the day, with the last dose near bedtime. Recommended daily calcium intake varies from 1000 to 1500 mg, depending upon the stage of life.


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. 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.[8] The Fred Hutchinson Cancer Research Center is an institution in the Cascade neighborhood of Seattle, Washington engaged in scientific research towards the prevention and treatment of cancer. ...

  • Calcium carbonate is the most common and least expensive calcium supplement. It can be difficult to digest and causes gas in some people. Taking magnesium with it can help to prevent constipation. Calcium carbonate is 40% elemental calcium. 1000 mg will provide 400 mg of calcium. It is recommended to take this supplement with food to aid in absorption. In some calcium supplements based on calcium carbonate, vitamin D is added to aid in absorption. Vitamin D is needed for the absorption of calcium from the stomach and for the functioning of calcium in the body.[9][10]
  • Calcium citrate is more easily absorbed (bioavailability is 2.5 times higher than calcium carbonate), easier to digest 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. It is easily absorbed and is less likely to cause constipation and gas than either.
  • Calcium lactate and calcium aspartate are both more difficult to digest and are more expensive than calcium carbonate
  • Calcium chelates have been chemically bonded with an agent that the body recognizes as food. This form is generally known to be better absorbed by the human body than all other forms of calcium due to the bond.

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. Dicalcium malate (chelated with malic acid) is a newer form of a true calcium chelate. It contains a high amount of elemental calcium (30%). Calcium carbonate is a chemical compound, with the chemical formula CaCO3. ... Vitamin D is a fat soluble vitamin that contributes to the maintenance of normal levels of calcium and phosphorus in the bloodstream. ... Calcium citrate is the calcium salt of citric acid. ... In pharmacology, bioavailability is used to describe the fraction of an administered dose of unchanged drug that reaches the systemic circulation, one of the principal pharmacokinetic properties of drugs. ... Calcium phosphate is the name given to a family of minerals containing calcium ions (Ca2+) together with orthophosphates (PO43-), metaphosphates or pyrophosphates (P2O74-) and occasionally hydrogen or hydroxide ions. ... Calcium lactate is a white crystalline salt made by the action of lactic acid on calcium carbonate; used in foods (as a baking powder) and given medicinally. ... Aspartic acid (Asp, D), also known as aspartate, the name of its anion, is one of the 20 natural proteinogenic amino acids which are the building blocks of proteins. ... Chelation (from Greek χηλή, chelè, meaning claw) is the process of reversible binding (complexation) of a ligand - the chelant, chelator, chelating agent, sequestering agent, or complexing agent - to a metal ion, forming a metal complex, the chelate. ... Overview of the citric acid cycle The citric acid cycle (also known as the tricarboxylic acid cycle, the TCA cycle, or the Krebs cycle, after Hans Adolf Krebs who identified the cycle) is a series of chemical reactions of central importance in all living cells that use oxygen as part...


Do calcium supplements prevent fractures due to osteoporosis?

Randomized controlled trials found both positive[11][12] and negative[13][14][15][16] benefit. The different results may be explained by doses of calcium and underlying rates of calcium supplementation in the control groups.[17] A randomized controlled trial (RCT) is a form of clinical trial, or scientific procedure used in the testing of the efficacy of medicine, used because of its record of reliability. ...


Do calcium supplements prevent cancer?

A meta-analysis[12] by the international Cochrane Collaboration of two randomized controlled trials[18][19]found that calcium "might contribute to a moderate degree to the prevention of adenomatous colonic polyps". A meta-analysis is a statistical practice of combining the results of a number of studies. ... The Cochrane Collaboration developed in response to Archie Cochranes call for systematic, up-to-date reviews (currently known as systematic reviews) of all relevant randomized clinical trials of health care. ... A randomized controlled trial (RCT) is a form of clinical trial, or scientific procedure used in the testing of the efficacy of medicine, used because of its record of reliability. ... A polyp can be defined as lining of mucosa which projects out in a mushroom shape. ...


More recent studies were conflicting:

A randomized controlled trial (RCT) is a form of clinical trial, or scientific procedure used in the testing of the efficacy of medicines or medical procedures. ... A randomized controlled trial (RCT) is a form of clinical trial, or scientific procedure used in the testing of the efficacy of medicines or medical procedures. ... In statistics and mathematical epidemiology, relative risk (RR) of an event associated with the exposure is a ratio of probability of outcome of interest in exposed group versus treatment group. ... It has been suggested that this article or section be merged with Cohort (statistics). ...

See also

Calcium metabolism or calcium homeostasis is the mechanism by which the body maintains adequate calcium levels. ... Calcium plays a vital role in the anatomy, physiology and biochemistry of organisms and of the cell, particularly in signal transduction pathways. ... Disorders of calcium metabolism occur when the body has too little or too much calcium. ...

Notes

  1. ^ Pauling, Linus General Chemistry p. 627, 1970 ed. Dover Publications
  2. ^ Staff (1995). H-K Project. Mount Wilson Observatory. Retrieved on 2006-08-10.
  3. ^ a b Dietary Supplement Fact Sheet: Calcium
  4. ^ Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D and Fluoride. Washington DC: The National Academies Press, 1997
  5. ^ Curhan G, Willett WC, Rimm E, Stampher MJ. A prospective study of dietary calcium and other nutrients and the risk of symptomatic kidney stones. N Engl J Med 1993;328:833-8
  6. ^ USDA National Nutrient Database
  7. ^ Anne Schaafsma, Gerard M Beelen (1999). "Eggshell powder, a comparable or better source of calcium than purified calcium carbonate: piglet studies". Journal of the Science of Food and Agriculture 79 (12): 1596-1600. 
  8. ^ Anne Harding. Calcium May Help With Weight Loss. Retrieved on 2007-07-10.
  9. ^ drugs.com article about Calcium with Vitamin D. Retrieved on 2006-08-23.
  10. ^ Caltro. Retrieved on 2006-08-23.
  11. ^ Dawson-Hughes B, Harris SS, Krall EA, Dallal GE (1997). "Effect of calcium and vitamin D supplementation on bone density in men and women 65 years of age or older". N. Engl. J. Med. 337 (10): 670–6. PMID 9278463. 
  12. ^ a b Weingarten MA, Zalmanovici A, Yaphe J (2005). "Dietary calcium supplementation for preventing colorectal cancer and adenomatous polyps". Cochrane database of systematic reviews (Online) (3): CD003548. doi:10.1002/14651858.CD003548.pub3. PMID 16034903. 
  13. ^ Jackson RD, LaCroix AZ, Gass M, et al (2006). "Calcium plus vitamin D supplementation and the risk of fractures". N. Engl. J. Med. 354 (7): 669–83. doi:10.1056/NEJMoa055218. PMID 16481635. 
  14. ^ Grant AM, Avenell A, Campbell MK, et al (2005). "Oral vitamin D3 and calcium for secondary prevention of low-trauma fractures in elderly people (Randomised Evaluation of Calcium Or vitamin D, RECORD): a randomised placebo-controlled trial". Lancet 365 (9471): 1621–8. doi:10.1016/S0140-6736(05)63013-9. PMID 15885294. 
  15. ^ Porthouse J, Cockayne S, King C, et al (2005). "Randomised controlled trial of calcium and supplementation with cholecalciferol (vitamin D3) for prevention of fractures in primary care". BMJ 330 (7498): 1003. doi:10.1136/bmj.330.7498.1003. PMID 15860827. 
  16. ^ Prince RL, Devine A, Dhaliwal SS, Dick IM (2006). "Effects of calcium supplementation on clinical fracture and bone structure: results of a 5-year, double-blind, placebo-controlled trial in elderly women". Arch. Intern. Med. 166 (8): 869–75. doi:10.1001/archinte.166.8.869. PMID 16636212. 
  17. ^ Fletcher RH (2006). "Calcium plus vitamin D did not prevent hip fracture or colorectal cancer in postmenopausal women". ACP J. Club 145 (1): 4–5. PMID 16813354. 
  18. ^ Baron JA, Beach M, Mandel JS, et al (1999). "Calcium supplements for the prevention of colorectal adenomas. Calcium Polyp Prevention Study Group". N. Engl. J. Med. 340 (2): 101–7. PMID 9887161. 
  19. ^ Bonithon-Kopp C, Kronborg O, Giacosa A, Räth U, Faivre J (2000). "Calcium and fibre supplementation in prevention of colorectal adenoma recurrence: a randomised intervention trial. European Cancer Prevention Organisation Study Group". Lancet 356 (9238): 1300–6. PMID 11073017. 
  20. ^ Wactawski-Wende J, Kotchen JM, Anderson GL, et al (2006). "Calcium plus vitamin D supplementation and the risk of colorectal cancer". N. Engl. J. Med. 354 (7): 684–96. doi:10.1056/NEJMoa055222. PMID 16481636. 
  21. ^ Lappe JM, Travers-Gustafson D, Davies KM, Recker RR, Heaney RP (2007). "Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial". Am. J. Clin. Nutr. 85 (6): 1586–91. PMID 17556697. 
  22. ^ Lin J, Manson JE, Lee IM, Cook NR, Buring JE, Zhang SM (2007). "Intakes of calcium and vitamin d and breast cancer risk in women". Arch. Intern. Med. 167 (10): 1050–9. doi:10.1001/archinte.167.10.1050. PMID 17533208. 

Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 222nd day of the year (223rd in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 191st day of the year (192nd in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... {| style=float:right; |- | |- | |} is the 235th day of the year (236th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... {| style=float:right; |- | |- | |} is the 235th day of the year (236th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ...

References

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

External links

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►Calcium Facts - Learn the Truth (1960 words)
Calcium is thought to allow the bones to not be broken down for their materials and also to give the bones more calcium in order for them to fully reach their genetic potential.
In a study that substantiates this, increasing the amount of calcium ingested from 80% of the RDA to 110% of the RDA in adolescent girls significantly increased the amount of total body bone as well as the density of the spine.
Calcium carbonate and the premenstrual syndrome: effects on premenstrual and menstrual symptoms.
Calcium (1270 words)
The major minerals (calcium, magnesium, phosphorus, sodium, chloride and potassium) are needed in the greatest quantities or are present in large amounts in the body.
During pregnancy and breast feeding women in the USA are now advised to have 1,400mg calcium daily and American men and women over the age of 50 years are advised to increased their calcium intake towards 1,500mg because the intestinal absorption of calcium declines with age.
Although the calcium intake of adult vegans tends to be lower than the recommended optimum, it is close to the Estimated Average Requirement.
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