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Minerals in Detail
Chemical Details | Description | Industrial Applications |
In Nature | Health Impacts | Daily Intake
CALCIUM
Calcium - chemical details
| Symbol | Ca |
| Atomic number | 20 |
| Atomic mass | 40.08 g.mol-1 |
| Electronegativity | 1.0 (according to Pauling) |
| Density | 1.6 g.cm-3 at 20°C |
| Melting point | 840 °C |
| Boiling point | 1484 °C |
| Vanderwaals radius | 0.197 nm |
| Ionic radius | 0.099 nm |
| Isotopes | 10 |
| Electronic configuration | [ Ar ] 4s2 |
| Energy of first ionisation | 589.6 kJ.mol-1 |
| Energy of second ionisation | 1145 kJ.mol-1 |
| Standard potential | - 2.87 V |
| Discovered | 1808 - Sir Humphrey Davy |
Chemical Details | Description | Industrial Applications |
In Nature | Health Impacts | Daily Intake
Calcium - Description
The chemical element Calcium is the fifth element and the third most abundant metal in the earth’s crust. The metal is trimorphic, harder than sodium, but
softer than aluminium. Just like beryllium and aluminium, and unlike the alkaline metals, it doesn’t cause skin-burns. It is less chemically reactive than
alkaline metals and than the other alkaline-earth metals.
Calcium ions dissolved in water form deposits in pipes and boilers - water like this with "too
much" calcium or magnesium is called hard water. In contact with air, calcium develops an oxide and nitride coating, which protects it from further corrosion.
It burns in the air at a high temperature to produce nitride.
The natural carbonates are the most abundant calcium minerals. Iceland spar and calcite are
essentially pure carbonate forms, whilst marble is an impure form and much more compact. Although calcium carbonate is normally insoluble in water, it does
dissolve if the water contains carbon, reacting to form bicarbonate. This fact explains cave formations (stalactites and stalagmites), where the lime stone
deposits have been in contact with (and transported by) acidic water. Calcium is sometimes also referred to as lime.
Chemical Details | Description | Industrial Applications |
In Nature | Health Impacts | Daily Intake
Calcium - Industrial applications
Calcium is used in an enormous number of industrial applications, from alloy formation to deoxidising to whitening powder to concrete. For details on
industrial applications and impact on the environment see www.lenntech.com/Periodic-chart-elements/Ca-en.htm
Chemical Details | Description | Industrial Applications |
In Nature | Health Impacts | Daily Intake
Calcium - In natural form
Calcium compounds account for 3.64% of the earth’s crust. The distribution of calcium is very wide; it is found in almost every soil in the world. Calcium
cannot be found alone in nature. Calcium is found mostly as limestone, gypsum and fluorite. Stalagmites and stalactites contain calcium carbonate. Seawater
contains 0.15% of calcium chloride. Calcium is essential for the life of plants and animals.
Calcium is always present in every plant, as it is essential for its growth. It is contained in the soft tissue, and in fluids within the tissue. For animals
it is present in the skeleton, teeth, in egg shells, in coral, etc. All vertebrates’ bones contain calcium in the form of calcium fluoride, calcium carbonate
and calcium phosphate.
Chemical Details | Description | Industrial Applications |
In Nature | Health Impacts | Daily Intake
Calcium - Impact on health
Calcium is the most abundant metal in the human body. It is the main constituent of bones and teeth, and it has keys metabolic functions. It is an essential
component for the preservation of the human skeleton and teeth. It also assists the functions of nerves and muscles. Though many people do not realise it,
there is an intense biological activity inside our bones. They are being renewed constantly by new tissue replacing old. During childhood and adolescence,
there’s more production of new tissue than destruction of the old, but somewhere around the 30 or 35 years of age, the process is inverted and we start to
lose more tissue than what we can replace.
The main source of dietary calcium is from milk and milk products, but it is also derived from vegetables (spinach, cauliflower), nuts and beans.
A lack of calcium is one of the main causes of osteoporosis. Osteoporosis is a disease where the bones become extremely porous, are easily fractured, and
heal slowly. It occurs especially but not exclusively in women, particularly following menopause (the period marked by the natural and permanent cessation of
menstruation, occurring usually between the ages of 45 and 55. During that period the body stops producing estrogen, the hormone that preserves the osseous
mass - among other things). Osteoporosis can often lead to curvature of the spine from vertebral collapse.
Evidence suggests that we need a daily intake of 1,000 milligrams of calcium in order to preserve the osseous mass in normal conditions. This is both for men
and pre-menopausal women. The recommended daily intake rises to 1,500 during and after menopause. Calcium works together with magnesium to create new osseous
mass. Calcium should be taken together with magnesium in a 2:1 rate, that is to say, if you ingest 1000 mg of calcium, you should also take 500 mg of
magnesium. Some magnesium sources in the diet are seafood, whole-grains, nuts, beans, wheat oats, seeds and green vegetables.
Other important measures to prevent osteoporosis are:
Doing regular exercise (at least three times a week)
Taking adequate amounts of manganese, folic acid, vitamin B6, vitamin B12, omega 3 (it aids calcium absorption and stimulates new osseous mass production) and vitamin D (it aids calcium absorption in the small intestine)
Not abusing of sugar, saturated grease and animal proteins
Not abusing of alcohol, caffeine, nor gaseous drinks
Not smoking
Other triggers for osteoporosis are hereditary factors and stress.
The use of more than 2,5 grams of calcium per day without a medical necessity can lead to the development of kidney stones and sclerosis of kidneys and blood vessels.
Chemical Details | Description | Industrial Applications |
In Nature | Health Impacts | Daily Intake
Calcium - Recommended daily & maximum intake
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Risk free |
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intake? |
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Food sources? |
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Result of overdose? |
| Age Group |
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RDA |
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Limit |
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Infants
0-6 mo
7-12 mo
Children
1-3 y
4-8 y
Males
9-13 y
14-18 y
19-30 y
31-50 y
50-70 y
> 70 y
Females
9-13 y
14-18 y
19-30 y
31-50 y
50-70 y
> 70 y
Pregnancy
< 19 y
19-30 y
31+ y
Lactation
< 19 y
19-30 y
31+ y |
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(mg/d)
210
270
500
800
1,300
1,300
1,000
1,000
1,200
1,200
1,300
1,300
1,000
1,000
1,200
1,200
1.300
1,000
1,000
1,300
1,000
1,000 |
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(mg/d)
ND
ND
2,500
2,500
2,500
2,500
2,500
2,500
2,500
2,500
2,500
2,500
2,500
2,500
2,500
2,500
2,500
2,500
2,500
2,500
2,500
2,500 |
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Broccoli
Calcium-set tofu
Cheese
Chinese cabbage
Corn tortillas
Kale
Milk
Yoghurt
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Kidney stones, hypercalcemia, milk alkali syndrome, and renal insufficiency
The use of more than 2,5 grams of calcium per day without a medical necessity can lead
to the development of kidney stones and sclerosis of kidneys and blood vessels. |
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Explanations:
ND = Not determinable. There is either insufficient data on adverse effects and/or concern with the body's ability to handle excess amounts. In most
instances it is wise not to supplement for this particular element, but to rely on diet to provide sufficient quantities.
RDA = Recommended Dietary Allowance. May be used as a goal for daily intake. RDAs are set at a level that should meet the needs of 97-98% of all individuals.1, 2, 3, 4
Limit = The maximum level of daily nutrient intake from all sources that is highly likely to pose no risk of adverse effects.1, 2, 3, 4
References:
- Standing Committee on the Scientific Evaluation of Dietary Reference Intakes (1997). Dietary Reference Intakes for Calcium, Phosphorous, Magnesium, Vitamin D, and Fluoride.Food and Nutrition Board: Institute of Medicine.
- Standing Committee on the Scientific Evaluation of Dietary Reference Intakes (1998). Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6,
Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline.Food and Nutrition Board: Institute of Medicine.
- Standing Committee on the Scientific Evaluation of Dietary Reference Intakes (2000). Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids.Food and Nutrition Board: Institute of Medicine.
- Standing Committee on the Scientific Evaluation of Dietary Reference Intakes (2001). Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc.Food and Nutrition Board: Institute of Medicine.
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