Edible salt - AbsoluteAstronomy.com

Salt, also known as table salt, or rock salt, is a mineral

Mineral

A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...

that is composed primarily of sodium chloride

Sodium chloride

Sodium chloride, also known as salt, common salt, table salt or halite, is an inorganic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...

(NaCl), a chemical compound belonging to the larger class of ionic salts. It is essential for animal

Animal

Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...

life in small quantities, but is harmful to animals and plants in excess. Salt is one of the oldest, most ubiquitous food seasonings and salting

Salting (food)

Salting is the preservation of food with dry edible salt. It is related to pickling . It is one of the oldest methods of preserving food, and two historically significant salt-cured foods are dried and salted cod and salt-cured meat.Salting is used because most bacteria, fungi and other potentially...

is an important method of food preservation

Food preservation

Food preservation is the process of treating and handling food to stop or slow down spoilage and thus allow for longer storage....

. The taste

Taste

Taste is one of the traditional five senses. It refers to the ability to detect the flavor of substances such as food, certain minerals, and poisons, etc....

of salt (saltiness) is one of the basic human tastes.

Salt for human consumption is produced in different forms: unrefined salt (such as sea salt

Sea salt

Sea salt, salt obtained by the evaporation of seawater, is used in cooking and cosmetics. It is historically called bay salt or solar salt...

), refined salt (table salt), and iodized salt. It is a crystalline solid, white, pale pink or light gray in color, normally obtained from sea water or rock deposits. Edible rock salts may be slightly grayish in color because of mineral content.

Chloride

Chloride

The chloride ion is formed when the element chlorine, a halogen, picks up one electron to form an anion Cl−. The salts of hydrochloric acid HCl contain chloride ions and can also be called chlorides. The chloride ion, and its salts such as sodium chloride, are very soluble in water...

and sodium

Sodium

Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...

ions, the two major components of salt, are needed by all known living creatures in small quantities. Salt is involved in regulating the water

Water

Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

content (fluid balance

Fluid balance

Fluid balance is the concept of human homeostasis that the amount of fluid lost from the body is equal to the amount of fluid taken in. Euvolemia is the state of normal body fluid volume. Water is necessary for all life on Earth...

) of the body. The sodium ion itself is used for electrical signaling in the nervous system. Because of its importance to survival, salt has often been considered a valuable commodity during human history. However, as salt consumption has increased during modern times, scientists have become aware of the health risks associated with too much salt intake, including high blood pressure

Hypertension

Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...

. Therefore health authorities have recommended limitations of dietary sodium. The United States Department of Health and Human Services

United States Department of Health and Human Services

The United States Department of Health and Human Services is a Cabinet department of the United States government with the goal of protecting the health of all Americans and providing essential human services. Its motto is "Improving the health, safety, and well-being of America"...

recommends that individuals consume no more than 1500–2300 mg of sodium (3750–5750 mg of salt) per day depending on age.

History

While people have used canning

Canning

Canning is a method of preserving food in which the food contents are processed and sealed in an airtight container. Canning provides a typical shelf life ranging from one to five years, although under specific circumstances a freeze-dried canned product, such as canned, dried lentils, can last as...

and artificial refrigeration

Refrigeration

Refrigeration is a process in which work is done to move heat from one location to another. This work is traditionally done by mechanical work, but can also be done by magnetism, laser or other means...

to preserve food for the last hundred years or so, salt has been the best-known food preservative, especially for meat, for many thousands of years. A very ancient saltworks operation has been discovered at the Poiana Slatinei archaeological site next to a salt spring in Lunca

Vânatori-Neamt

Vânători-Neamţ is a commune in Neamţ County, Romania. It is composed of four villages: Lunca, Mânăstirea Neamţ, Nemţişor and Vânători-Neamţ....

, Neamţ County

Neamt County

Neamț is a county of Romania, in the historic region of Moldavia, with the county seat at Piatra Neamț. It has three communes, Bicaz-Chei, Bicazu Ardelean and Dămuc in Transylvania.-Demographics:...

, Romania

Romania

Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

. Evidence indicates that Neolithic

Neolithic

The Neolithic Age, Era, or Period, or New Stone Age, was a period in the development of human technology, beginning about 9500 BC in some parts of the Middle East, and later in other parts of the world. It is traditionally considered as the last part of the Stone Age...

people of the Precucuteni Culture were boiling the salt-laden spring water through the process of briquetage

Briquetage

Briquetage is the name for a coarse ceramic material used to make evaporation vessels and supporting pillars used in extracting salt from seawater. Thick-walled saltpans were filled with saltwater and heated from below until the water had boiled away and salt was left behind...

to extract the salt as far back as 6050 BC. The salt extracted from this operation may have had a direct correlation to the rapid growth of this society's population soon after its initial production began. The harvest of salt from the surface of Xiechi Lake

Xiechi Lake

Xiechi Lake is the largest natural lake in Shanxi in Northern China. It is a saline lake....

near Yuncheng in Shanxi

Shanxi

' is a province in Northern China. Its one-character abbreviation is "晋" , after the state of Jin that existed here during the Spring and Autumn Period....

, China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

dates back to at least 6000 BC, making it one of the oldest verifiable saltworks.

Salt was included among funereal offerings found in ancient Egypt

Ancient Egypt

Ancient Egypt was an ancient civilization of Northeastern Africa, concentrated along the lower reaches of the Nile River in what is now the modern country of Egypt. Egyptian civilization coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first pharaoh...

ian tombs from the third millennium BC, as were salted birds and salt fish. From about 2800 BC, the Egyptians began exporting salt fish to the Phoenicia

Phoenicia

Phoenicia , was an ancient civilization in Canaan which covered most of the western, coastal part of the Fertile Crescent. Several major Phoenician cities were built on the coastline of the Mediterranean. It was an enterprising maritime trading culture that spread across the Mediterranean from 1550...

ns in return for Lebanon cedar

Lebanon Cedar

Cedrus libani is a species of cedar native to the mountains of the Mediterranean region.There are two distinct types that are considered to be different subspecies or varieties. Lebanon cedar or Cedar of Lebanon Cedrus libani is a species of cedar native to the mountains of the Mediterranean...

, glass, and the dye Tyrian purple

Tyrian purple

Tyrian purple , also known as royal purple, imperial purple or imperial dye, is a purple-red natural dye, which is extracted from sea snails, and which was possibly first produced by the ancient Phoenicians...

; the Phoenicia

Phoenicia

ns traded Egyptian salt fish and salt from North Africa

North Africa

North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...

throughout their Mediterranean trade empire.

Along the Sahara

Sahara

The Sahara is the world's second largest desert, after Antarctica. At over , it covers most of Northern Africa, making it almost as large as Europe or the United States. The Sahara stretches from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean...

, the Tuareg maintain routes especially for the transport of salt by Azalai

Azalai

The Azalai is a semi annual salt caravan route practiced by Tuareg traders in the Sahara desert, or the act of traveling with a caravan along that route.- History :...

(salt caravans). In 1960, the caravans still transported some 15,000 tons of salt, but this trade has now declined to roughly a third of this figure.

Salzburg

Salzburg

-Population development:In 1935, the population significantly increased when Salzburg absorbed adjacent municipalities. After World War II, numerous refugees found a new home in the city. New residential space was created for American soldiers of the postwar Occupation, and could be used for...

, Hallstatt

Hallstatt

Hallstatt, Upper Austria is a village in the Salzkammergut, a region in Austria. It is located near the Hallstätter See . At the 2001 census it had 946 inhabitants...

, and Hallein

Hallein

Hallein is a historic town in the Austrian state of Salzburg, the capital of the Hallein district. It is located in the Tennengau region south of the City of Salzburg, along the Salzach river in the shadow of the Untersberg massif, near the border with Germany. With a population of c...

lie on the river Salzach in central Austria

Austria

Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

, within a radius of no more than 17 kilometres. Salzach

Salzach

The Salzach is a river in Austria and Germany. It is a right tributary of the Inn and is 225 kilometres in length.The river's name is derived from the German word Salz, meaning "salt". Until the 19th century shipping of salt down the river was an important part of the local economy...

literally means "salt water" and Salzburg

Salzburg

"salt city", both taking their names from the German

German language

German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....

word for salt, .

Hallstatt

Hallstatt culture

The Hallstatt culture was the predominant Central European culture from the 8th to 6th centuries BC , developing out of the Urnfield culture of the 12th century BC and followed in much of Central Europe by the La Tène culture.By the 6th century BC, the Hallstatt culture extended for some...

gave its name to the Celt

Celt

The Celts were a diverse group of tribal societies in Iron Age and Roman-era Europe who spoke Celtic languages.The earliest archaeological culture commonly accepted as Celtic, or rather Proto-Celtic, was the central European Hallstatt culture , named for the rich grave finds in Hallstatt, Austria....

ic archaeological culture

Archaeological culture

An archaeological culture is a recurring assemblage of artifacts from a specific time and place, which are thought to constitute the material culture remains of a particular past human society. The connection between the artifacts is based on archaeologists' understanding and interpretation and...

that began mining for salt in the area in around 800 BC. Around 400 BC, the Hallstatt Celts, who had heretofore mined

Salt mine

A salt mine is a mining operation involved in the extraction of rock salt or halite from evaporite deposits.-Occurrence:Areas known for their salt mines include Kilroot near Carrickfergus, Northern Ireland ; Khewra and Warcha in Pakistan; Tuzla in Bosnia; Wieliczka and Bochnia in Poland A salt mine...

for salt, began open pan salt making

Open pan salt making

In Europe virtually all domestic salt is obtained by solution mining of underground salt formations although some is still obtained by the solar evaporation of sea water. Salt is extracted from the Brine using vacuum pans, where brine is heated in a partial vacuum in order to lower the boiling...

. During the first millennium BC, Celtic communities grew rich trading salt and salted meat

Salt-cured meat

Salt-cured meat or salted meat, for example bacon and kippered herring, is meat or fish preserved or cured with salt. Salting, either with dry salt or brine, was the only widely available method of preserving meat until the 19th century...

to Ancient Greece

Ancient Greece

Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...

and Ancient Rome

Ancient Rome

Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....

in exchange for wine and other luxuries.

The word salary
Salary
A salary is a form of periodic payment from an employer to an employee, which may be specified in an employment contract. It is contrasted with piece wages, where each job, hour or other unit is paid separately, rather than on a periodic basis....

originates from which referred to the money paid to the Roman Army

Roman army

The Roman army is the generic term for the terrestrial armed forces deployed by the kingdom of Rome , the Roman Republic , the Roman Empire and its successor, the Byzantine empire...

's soldiers for the purchase of salt. The word salad literally means "salted," and comes from the ancient Roman

Ancient Rome

practice of salting leaf vegetable

Leaf vegetable

Leaf vegetables, also called potherbs, green vegetables, greens, leafy greens or salad greens, are plant leaves eaten as a vegetable, sometimes accompanied by tender petioles and shoots...

s.

Mahatma Gandhi

Mahatma Gandhi

Mohandas Karamchand Gandhi , pronounced . 2 October 1869 – 30 January 1948) was the pre-eminent political and ideological leader of India during the Indian independence movement...

led at least 100,000 people on the "Dandi March" or "Salt Satyagraha

Salt Satyagraha

The Salt March, also known as the Salt Satyagrahah began with the Dandi March on March 12, 1930, and was an important part of the Indian independence movement. It was a campaign of tax resistance and nonviolent protest against the British salt monopoly in colonial India, and triggered the wider...

", in which protesters made their own salt from the sea, which was illegal under British rule, as it avoided paying the "salt tax

History of the British salt tax in India

Taxation of salt has occurred in India since the earliest times. However, this tax was greatly increased when the British East India Company began to establish its rule over provinces in India. In 1835, special taxes were imposed on Indian salt to facilitate its import. This paid huge dividends for...

". This civil disobedience

Civil disobedience

Civil disobedience is the active, professed refusal to obey certain laws, demands, and commands of a government, or of an occupying international power. Civil disobedience is commonly, though not always, defined as being nonviolent resistance. It is one form of civil resistance...

inspired millions of common people, and elevated the Indian independence movement

Indian independence movement

The term Indian independence movement encompasses a wide area of political organisations, philosophies, and movements which had the common aim of ending first British East India Company rule, and then British imperial authority, in parts of South Asia...

from an elitist struggle to a national struggle.

Unrefined salt

Different natural salts have different mineralities, giving each one a unique flavor. Fleur de sel

Fleur de sel

Fleur de sel is a hand-harvested sea salt collected by workers who scrape only the top layer of salt before it sinks to the bottom of large salt pans...

, a natural sea salt from the surface of evaporating brine in salt pans, has a unique flavor varying from region to region. In traditional Korean cuisine, so-called "bamboo salt

Jukyeom

Jukyeom is a Korean folk remedy consisting of bamboo salt. Sea salt is stuffed into bamboo tubes, and the ends plugged with mud; the assembly is roasted one or more times. The trace elements in the mud and bamboo are thought to make this form of salt more healthy...

" is prepared by roasting salt in a bamboo

Bamboo

Bamboo is a group of perennial evergreens in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Giant bamboos are the largest members of the grass family....

container plugged with mud at both ends. This product absorbs minerals from the bamboo and the mud, and has been shown to increase the anticlastogenic

Clastogen

A clastogen is a material that can cause breaks in chromosomes, leading to sections of the chromosome being deleted, added, or rearranged. This is a form of mutagenesis, and can lead to carcinogenesis, as cells that are not killed by the clastogenic effect may become cancerous...

and antimutagenic

Mutagen

In genetics, a mutagen is a physical or chemical agent that changes the genetic material, usually DNA, of an organism and thus increases the frequency of mutations above the natural background level. As many mutations cause cancer, mutagens are therefore also likely to be carcinogens...

properties of doenjang

Doenjang

Doenjang is a traditional Korean fermented soybean paste. Its name literally means "thick paste" in Korean.-Production:...

.

Completely raw sea salt is bitter because of magnesium and calcium compounds, and thus is rarely eaten. The refined salt industry cites scientific studies saying that raw sea and rock salts do not contain enough iodine

Iodine

Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....

salts to prevent iodine deficiency diseases

Iodine deficiency

Iodine is an essential trace element; the thyroid hormones thyroxine and triiodotyronine contain iodine. In areas where there is little iodine in the diet—typically remote inlandareas where no marine foods are eaten—iodine deficiency gives rise to...

.

Unrefined sea salts are also commonly used as ingredients in bathing additives and cosmetic

Cosmetics

Cosmetics are substances used to enhance the appearance or odor of the human body. Cosmetics include skin-care creams, lotions, powders, perfumes, lipsticks, fingernail and toe nail polish, eye and facial makeup, towelettes, permanent waves, colored contact lenses, hair colors, hair sprays and...

products. One example is bath salts

Bath salts

The term bath salts refers to a range of water-soluble, usually inorganic solid products designed to be added to a bath. They are said to improve cleaning, improve the experience of bathing, and serve as a vehicle for cosmetic agents...

, which uses sea salt

Sea salt

Sea salt, salt obtained by the evaporation of seawater, is used in cooking and cosmetics. It is historically called bay salt or solar salt...

as its main ingredient and combined with other ingredients used for its healing and therapeutic effects.

Refined salt

Refined

Refining

Refining is the process of purification of a substance or a form. The term is usually used of a natural resource that is almost in a usable form, but which is more useful in its pure form. For instance, most types of natural petroleum will burn straight from the ground, but it will burn poorly...

salt, which is most widely used presently, is mainly sodium chloride. Food grade salt accounts for only a small part of salt production in industrialized countries

Developed country

A developed country is a country that has a high level of development according to some criteria. Which criteria, and which countries are classified as being developed, is a contentious issue...

(3% in Europe) although worldwide, food uses account for 17.5% of salt production. The majority is sold for industrial use. Salt has great commercial value because it is a necessary ingredient in many manufacturing processes. A few common examples include: the production of pulp and paper, setting dyes in textiles and fabrics, and the making of soaps and detergents.

The manufacture and use of salt is one of the oldest chemical industries. Salt can be obtained by evaporation of sea water, usually in shallow basins warmed by sunlight

Sunlight

Sunlight, in the broad sense, is the total frequency spectrum of electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the Earth's atmosphere, and solar radiation is obvious as daylight when the Sun is above the horizon.When the direct solar radiation is not blocked...

; salt so obtained was formerly called bay salt, and is now often called sea salt or solar salt. Rock salt deposits are formed by the evaporation of ancient salt lakes, and may be mined

Mining

Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...

conventionally or through the injection of water. Injected water dissolves the salt, and the brine

Brine

Brine is water, saturated or nearly saturated with salt .Brine is used to preserve vegetables, fruit, fish, and meat, in a process known as brining . Brine is also commonly used to age Halloumi and Feta cheeses, or for pickling foodstuffs, as a means of preserving them...

solution can be pumped to the surface where the salt is collected.
After the raw salt is obtained, it is refined to purify it and improve its storage and handling characteristics. Purification usually involves recrystallization. In recrystallization, a brine solution is treated with chemicals that precipitate most impurities (largely magnesium and calcium salts). Multiple stages of evaporation are then used to collect pure sodium chloride crystals, which are kiln

Kiln

A kiln is a thermally insulated chamber, or oven, in which a controlled temperature regime is produced. Uses include the hardening, burning or drying of materials...

-dried.

Table salt

In Western cuisines, salt is used in cooking, and also made available to diners in salt shakers on the table.

Table salt is refined salt, which contains about 97% to 99% sodium chloride

Sodium chloride

. It usually contains substances that make it free-flowing (anticaking agents) such as sodium silicoaluminate

Sodium silicoaluminate

Sodium aluminosilicate is an acid salt comprising sodium, aluminium, silicon and oxygen. These include synthetic amorphous sodium aluminosilicate, a few naturally occurring minerals and synthetic zeolites...

or magnesium carbonate. Some people also add a desiccant

Desiccant

A desiccant is a hygroscopic substance that induces or sustains a state of dryness in its local vicinity in a moderately well-sealed container....

, such as a few grains of uncooked rice

Rice

Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...

, or a saltine cracker

Saltine cracker

A saltine or soda cracker is a thin, usually square cracker made from white flour, shortening, yeast, and baking soda, with most varieties lightly sprinkled with coarse salt. It has perforations throughout its surface, to allow steam to escape for uniform rising, and along the edges, as individual...

in salt shakers to absorb extra moisture and help break up clumps when anticaking agents are not enough.
Table salt has a particle density

Particle density

The particle density or true density of a particulate solid or powder, is the density of the particles that make up the powder, in contrast to the bulk density, which measures the average density of a large volume of the powder in a specific medium .The particle density is a relatively well-defined...

of 2.165 g/cm, and a bulk density

Bulk density

Bulk density is a property of powders, granules and other "divided" solids, especially used in reference to mineral components , chemical substances, ingredients, foodstuff or any other masses of corpuscular or particulate matter. It is defined as the mass of many particles of the material...

(dry, ASTM D 632 gradation) of about 1.154 g/cm.

Additives in table salt

Most table salt sold for consumption contains a variety of additives, which address a variety of health concerns, especially in the developing world. The amounts of additives vary widely from country to country.

Iodine and iodide

Iodine-containing compounds are added to table salt. Iodine deficiency affects about two billion people and is the leading preventable cause of mental retardation

Mental retardation

Mental retardation is a generalized disorder appearing before adulthood, characterized by significantly impaired cognitive functioning and deficits in two or more adaptive behaviors...

. The practice began in 1924. Iodized salt is thus table salt mixed with a minute amount of potassium iodide

Potassium iodide

Potassium iodide is an inorganic compound with the chemical formula KI. This white salt is the most commercially significant iodide compound, with approximately 37,000 tons produced in 1985. It is less hygroscopic than sodium iodide, making it easier to work with...

, sodium iodide

Sodium iodide

Sodium iodide is a white, crystalline salt with chemical formula NaI used in radiation detection, treatment of iodine deficiency, and as a reactant in the Finkelstein reaction.-Uses:Sodium iodide is commonly used to treat and prevent iodine deficiency....

, or sodium iodate

Sodium iodate

Sodium iodate is the sodium salt of iodic acid. Sodium iodate is an oxidizing agent and as such it can cause fires upon contact with combustible materials or reducing agents.-Preparation:...

. Iodized salt is used to help reduce the incidence of iodine deficiency

Iodine deficiency

in humans. Iodine deficiency commonly leads to thyroid

Thyroid

The thyroid gland or simply, the thyroid , in vertebrate anatomy, is one of the largest endocrine glands. The thyroid gland is found in the neck, below the thyroid cartilage...

gland problems, specifically endemic goiter

Goitre

A goitre or goiter , is a swelling in the thyroid gland, which can lead to a swelling of the neck or larynx...

, a disease characterized by a swelling of the thyroid gland, usually resulting in a bulbous protrusion on the neck. Iodized table salt has significantly reduced disorders of iodine deficiency

Iodine deficiency

in countries where it is used. Iodine is important to prevent the insufficient production of thyroid hormone

Thyroid hormone

The thyroid hormones, thyroxine and triiodothyronine , are tyrosine-based hormones produced by the thyroid gland primarily responsible for regulation of metabolism. An important component in the synthesis of thyroid hormones is iodine. The major form of thyroid hormone in the blood is thyroxine ,...

s (hypothyroidism

Hypothyroidism

Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone.Iodine deficiency is the most common cause of hypothyroidism worldwide but it can be caused by other causes such as several conditions of the thyroid gland or, less commonly, the pituitary gland or...

), which can cause goitre

Goitre

A goitre or goiter , is a swelling in the thyroid gland, which can lead to a swelling of the neck or larynx...

, cretinism

Cretinism

Cretinism is a condition of severely stunted physical and mental growth due to untreated congenital deficiency of thyroid hormones usually due to maternal hypothyroidism.-Etymology and use of cretin:...

in children, and myxedema

Myxedema

Myxedema describes a specific form of cutaneous and dermal edema secondary to increased deposition of connective tissue components in subcutaneous tissue as seen in various forms of hypothyroidism and Graves' disease. It is more common in women than in men...

in adults.

The amount of iodine and the specific iodine compound added to salt varies from country to country. In the United States, the Food and Drug Administration

Food and Drug Administration

The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...

recommends [21 CFR 101.9 (c)(8)(iv)] 150 micrograms of iodine per day for both men and women. US iodized salt contains 46–77 ppm (parts per million), whereas in the UK the iodine content of iodized salt is recommended to be 10–22 ppm. Today, iodized salt is more common in the United States, Australia and New Zealand than in the United Kingdom.

Fluoride

Especially in countries that have not benefited from fluoridated toothpastes and fluoridated water, fluoride

Fluoride

Fluoride is the anion F−, the reduced form of fluorine when as an ion and when bonded to another element. Both organofluorine compounds and inorganic fluorine containing compounds are called fluorides. Fluoride, like other halides, is a monovalent ion . Its compounds often have properties that are...

salts are added to table salt. The practice is more common in some European countries, where water fluoridation

Water fluoridation

Water fluoridation is the controlled addition of fluoride to a public water supply to reduce tooth decay. Fluoridated water has fluoride at a level that is effective for preventing cavities; this can occur naturally or by adding fluoride...

is not practiced. In France, 35% of sold table salt contains sodium fluoride

Sodium fluoride

Sodium fluoride is an inorganic chemical compound with the formula NaF. A colorless solid, it is a source of the fluoride ion in diverse applications. Sodium fluoride is less expensive and less hygroscopic than the related salt potassium fluoride....

Anti-caking agents

Sodium ferrocyanide

Sodium ferrocyanide is the sodium salt of the coordination compound of formula [Fe6]4-. It is a yellow crystalline solid that is soluble in water and insoluble in alcohol. Despite the presence of the cyanide ligands, sodium ferrocyanide is not especially toxic because the cyanides are tightly...

, also known as yellow prussiate of soda, is sometimes added to salt as an anticaking agent. The additive is considered safe for human consumption. Such anti-caking agents have been added since at least 1911 when magnesium carbonate

Magnesium carbonate

Magnesium carbonate, MgCO3, is a white solid that occurs in nature as a mineral. Several hydrated and basic forms of magnesium carbonate also exist as minerals...

was first added to salt to make it flow more freely. The safety of sodium ferrocyanide as a food additive was found to be provisionally acceptable by the Committee on Toxicity

Committee on Toxicity

The Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment is a UK independent scientific committee that provides advice to the Food Standards Agency, the Department of Health and other Government Departments and Agencies on matters concerning the toxicity of...

in 1988. Some other anticaking agents include tricalcium phosphate

Tricalcium phosphate

Tricalcium phosphate is a calcium salt of phosphoric acid with the chemical formula Ca32. It is also known as tribasic calcium phosphate or "bone ash" ....

, calcium

Calcium carbonate

Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...

or magnesium carbonate

Magnesium carbonate

Magnesium carbonate, MgCO3, is a white solid that occurs in nature as a mineral. Several hydrated and basic forms of magnesium carbonate also exist as minerals...

s, fatty acid

Fatty acid

In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...

salts (acid salt

Acid salt

Acid salt is a somewhat obscure term for a class of salts formed by the partial neutralization of diprotic or polyprotic acids. Because the parent acid is only partially neutralized, one or more replaceable hydrogen atoms remain. Typical acid salts have one or more alkali metal ions as well as one...

s), magnesium oxide

Magnesium oxide

Magnesium oxide , or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium . It has an empirical formula of and consists of a lattice of Mg2+ ions and O2– ions held together by ionic bonds...

, silicon dioxide

Silicon dioxide

The chemical compound silicon dioxide, also known as silica , is an oxide of silicon with the chemical formula '. It has been known for its hardness since antiquity...

, calcium silicate

Calcium silicate

Calcium silicate is the chemical compound Ca2SiO4, also known as calcium orthosilicate and sometimes formulated 2CaO.SiO2. It is one of group of compounds obtained by reacting calcium oxide and silica in various ratios e.g. 3CaO.SiO2, Ca3SiO5; 2CaO.SiO2, Ca2SiO4; 3CaO.2SiO2, Ca3Si2O7 and...

, sodium aluminosilicate, and calcium aluminosilicate

Calcium aluminosilicate

Calcium aluminosilicate, an aluminosilicate compound with calcium cations, most typically has formula CaAl2Si2O8.As a food additive, it is sometimes designated "E556"....

. Both the European Union and the United States Food and Drug Administration

Food and Drug Administration

The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...

(FDA) permitted the use of aluminum in the latter two compounds.

Iron

In "doubly fortified salt", both iodide and iron salts are added. This additive alleviates iron deficiency anemia

Iron deficiency anemia

Iron-deficiency anemia is a common anemia that occurs when iron loss occurs, and/or the dietary intake or absorption of iron is insufficient...

, which interferes with the mental development of an estimated 40% of infants in the developing world. A typical iron source is ferrous fumarate

Iron(II) fumarate

Iron fumarate, also known as ferrous fumarate, is the iron salt of fumaric acid, occurring as a reddish-orange powder, used to supplement iron intake. It has the chemical formula 424...

Other additives

Another additive, especially important for pregnant

Pregnancy

Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...

women, is folic acid

Folic acid

Folic acid and folate , as well as pteroyl-L-glutamic acid, pteroyl-L-glutamate, and pteroylmonoglutamic acid are forms of the water-soluble vitamin B9...

(vitamin B₉), which gives the table salt a yellow color. Folic acid helps prevent neural tube defects (NTDs) and anemia, which affect young mothers, especially in developing countries.

In Canada, at least one brand (Windsor Salt

Canadian Salt Company

Founded in 1893, in Windsor, Ontario, with three employees of the Canadian Pacific Railway Company and was originally named The Windsor Salt Company. Within a few years, the operation was sold and became The Canadian Salt Company, Limited...

) contains inverted sugar syrup

Inverted sugar syrup

Inverted or invert sugar syrup is a mixture of glucose and fructose; it is obtained by splitting sucrose into these two components. Compared with its precursor, sucrose, inverted sugar is sweeter and its products tend to remain more moist and are less prone to crystallisation...

Salty condiments

In many East Asian cultures, salt is not traditionally used as a condiment. In its place, condiments such as soy sauce

Soy sauce

Soy sauce is a condiment produced by fermenting soybeans with Aspergillus oryzae or Aspergillus sojae molds, along with water and salt...

, fish sauce

Fish sauce

Fish sauce is a condiment that is derived from fish that have been allowed to ferment. It is an essential ingredient in many curries and sauces. Fish sauce is a staple ingredient in numerous cultures in Southeast Asia and the coastal regions of East Asia, and features heavily in Thai and Vietnamese...

and oyster sauce

Oyster sauce

Oyster sauce describes a number of sauces made by cooking oysters. The most common in modern use is a viscous dark brown condiment made from sugar, salt and water thickened with cornstarch, flavoured with a little oyster essence or extract and some versions may be darkened with caramel, though high...

tend to have a high sodium content and fill a similar role to table salt in western cultures. They are most often used for cooking rather than as table condiments.

Health effects

Acute effects

Too much or too little salt in the diet can lead to muscle cramps

Cramp

Cramps are unpleasant, often painful sensations caused by muscle contraction or over shortening. Common causes of skeletal muscle cramps include muscle fatigue, low sodium, and low potassium...

, dizziness

Dizziness

Dizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....

, or electrolyte disturbance

Electrolyte disturbance

Electrolytes play a vital role in maintaining homeostasis within the body. They help to regulate myocardial and neurological function, fluid balance, oxygen delivery, acid-base balance and much more. Electrolyte imbalances can develop by the following mechanisms: excessive ingestion; diminished...

, which can cause neurological problems, or death. Drinking too much water, with insufficient salt intake, puts a person at risk of water intoxication

Water intoxication

Water intoxication, also known as water poisoning, is a potentially fatal disturbance in brain functions that results when the normal balance of electrolytes in the body is pushed outside of safe limits by over-consumption of water....

(hyponatremia

Hyponatremia

Hyponatremia is an electrolyte disturbance in which the sodium concentration in the serum is lower than normal. In the vast majority of cases, hyponatremia occurs as a result of excess body water diluting the serum sodium and is not due to sodium deficiency. Sodium is the dominant extracellular...

). Salt is sometimes used as a health aid, such as in treatment of dysautonomia

Dysautonomia

Dysautonomia is a broad term that describes any disease or malfunction of the autonomic nervous system. This includes postural orthostatic tachycardia syndrome , inappropriate sinus tachycardia , vasovagal syncope, mitral valve prolapse dysautonomia, pure autonomic failure, neurocardiogenic...

.

Death can occur by ingestion of large amounts of salt in a short time (about 1 g per kg of body weight). Deaths have also resulted from attempted use of salt solutions as emetics, forced salt intake, and accidental confusion of salt with sugar in child food.

Long-term effects

The effect of salt consumption on long term health outcomes is controversial. Salt reduction appears to have little or no effect on mortality and its effect on morbidity is unknown. Some associations include:

Stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...

and cardiovascular disease
Cardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...

.
High blood pressure
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...

: Evidence shows an association between salt intakes and blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...

among different populations and age range in adults. Reduced salt intake also results in a small reduction in blood pressure.
Left ventricular hypertrophy
Left ventricular hypertrophy
Left ventricular hypertrophy is the thickening of the myocardium of the left ventricle of the heart.-Causes:While ventricular hypertrophy occurs naturally as a reaction to aerobic exercise and strength training, it is most frequently referred to as a pathological reaction to cardiovascular...

(cardiac enlargement): "Evidence suggests that high salt intake causes left ventricular hypertrophy, a strong risk factor
Risk factor
In epidemiology, a risk factor is a variable associated with an increased risk of disease or infection. Sometimes, determinant is also used, being a variable associated with either increased or decreased risk.-Correlation vs causation:...

for cardiovascular disease, independently of blood pressure effects." "...there is accumulating evidence that high salt intake predicts left ventricular hypertrophy." Excessive salt (sodium) intake, combined with an inadequate intake of water, can cause hypernatremia
Hypernatremia
Hypernatremia or hypernatraemia is an electrolyte disturbance that is defined by an elevated sodium level in the blood. Hypernatremia is generally not caused by an excess of sodium, but rather by a relative deficit of free water in the body...

. It can exacerbate renal disease.
Edema
Edema
Edema or oedema ; both words from the Greek , oídēma "swelling"), formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid beneath the skin or in one or more cavities of the body that produces swelling...

: A decrease in salt intake has been suggested to treat edema (fluid retention).
Stomach cancer
Stomach cancer
Gastric cancer, commonly referred to as stomach cancer, can develop in any part of the stomach and may spread throughout the stomach and to other organs; particularly the esophagus, lungs, lymph nodes, and the liver...

is associated with high levels of sodium, "but the evidence does not generally relate to foods typically consumed in the UK." However, in Japan, salt consumption is higher.

The Cochrane Collaboration found that "a modest and long term reduction in population salt intake [...] would result in a lower population blood pressure, and a reduction in strokes, heart attacks and heart failure. Furthermore, our study is consistent with the fact that the lower the salt intake, the lower the blood pressure." Some isolated cultures, such as the Yanomami in South America, have been found to consume little salt and are still capable of regular activity. This may indicate an adaptation of humans to low levels of sodium that originated in the predominantly vegetarian diet

Vegetarianism

Vegetarianism encompasses the practice of following plant-based diets , with or without the inclusion of dairy products or eggs, and with the exclusion of meat...

of human primate ancestors.

The risk for disease due to insufficient or excessive salt intake varies because of biochemical individuality. Some have asserted that while the risks of consuming too much salt are real, the risks have been exaggerated for most people, or that the studies done on the consumption of salt can be interpreted in many different ways. There have also been recent scientific debates upon whether 'excess' sodium in our diet has any adverse effect at all on healthy individuals and whether the last 50 years of scientific research that strongly correlates salt intake and hypertension might just be a well intentioned misinterpretation of the scientific data.

Pathophysiology

Sodium

is one of the primary electrolyte

Electrolyte

In chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....

s in the body. All four cationic electrolytes (sodium, potassium, magnesium, and calcium) are available in unrefined salt, as are other vital minerals needed for optimal bodily function.

Recommended intake

Recommended intakes of salt are usually expressed in terms of sodium intake. Salt (as sodium chloride) contains 39.3% of sodium by weight.

Country	Description	Sodium intake mg per day	Salt intake mg per day	Authority	Remarks
United Kingdom	The Reference Nutrient Intake Dietary Reference Values In the United Kingdom, the Department of Health published the Dietary Reference Values for Food Energy and Nutrients for the United Kingdom. This records Dietary Reference Values which recommended nutritional intakes for the UK population... (RNI) defined for a typical adult	RNI: 1600	RNI: 4000	Scientific Advisory Committee on Nutrition (SACN) (2003)	However, average adult intake is two and a half times the RNI. SACN states, "The target salt intakes set for adults and children do not represent ideal or optimum consumption levels, but achievable population goals." The Food Safety Authority of Ireland Republic of Ireland Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,... endorses the UK targets.
Canada	An Adequate Intake (AI) and Upper Limit (UL) recommended for persons aged 9 years or more.	AI: 1200–1500 UL: 2200–2300	AI: 3000–3750 UL: 5500–5750	Health Canada Health Canada Health Canada is the department of the government of Canada with responsibility for national public health.The current Minister of Health is Leona Aglukkaq, a Conservative Member of Parliament appointed to the position by Prime Minister Stephen Harper.-Branches, regions and agencies:Health Canada... (2005)
Australia and New Zealand	An Adequate Intake (AI) and an Upper Level of intake (UL) defined for adults	AI: 460–920 UL: 2300	AI: 1150–2300 UL: 5750	NHMRC (2006)	Not able to define a recommended dietary intake (RDI)
United States	An Upper Limit (UL) defined for adults. A different upper limit defined for the special group comprising people over 51 years of age, African Americans and people with hypertension, diabetes, or chronic kidney disease (regardless of age).	UL: 2300 UL for special group: 1500	UL: 5750 UL for special group: 3750	Department of Agriculture and Department of Health and Human Services (2010)	The Food and Drug Administration Food and Drug Administration The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments... itself does not make a recommendation, but refers readers to the dietary guidelines given by this authority.

A 2009 meta-analysis

Meta-analysis

In statistics, a meta-analysis combines the results of several studies that address a set of related research hypotheses. In its simplest form, this is normally by identification of a common measure of effect size, for which a weighted average might be the output of a meta-analyses. Here the...

found that the sodium consumption of 19,151 individuals from 33 countries fit into the narrow range of 2,700 to 4,900 mg/day. The small range across many cultures, together with animal studies, suggest that sodium intake is tightly controlled by feedback loops in the body, making recommendations to reduce sodium consumption below 2,700 mg/day potentially futile.

Labeling

UK: The Food Standards Agency

Food Standards Agency

The Food Standards Agency is a non-ministerial government department of the Government of the United Kingdom. It is responsible for protecting public health in relation to food throughout the United Kingdom and is led by a board appointed to act in the public interest...

defines the level of salt in foods as follows: "High is more than 1.5 g salt per 100 g (or 0.6 g sodium). Low is 0.3 g salt or less per 100 g (or 0.1 g sodium). If the amount of salt per 100 g is in between these figures, then that is a medium level of salt." In the UK, foods produced by some supermarkets and manufacturers have ‘traffic light’ colors on the front of the pack: Red (High), Amber (Medium), or Green (Low).

USA: The FDA Food Labeling Guide stipulates whether a food can be labeled as "free." "low," or "reduced/less" in respect of sodium. When other health claims are made about a food (e.g., low in fat, calories, etc.), a disclosure statement is required if the food exceeds 480 mg of sodium per 'serving.'

Normal salt itself contains 40 g of sodium per 100 g of salt.

Campaigns

In 2004, Britain's Food Standards Agency

Food Standards Agency

started a public health

Public health

Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals" . It is concerned with threats to health based on population health...

campaign called "Salt – Watch it", which recommends no more than 6g of salt per day; it features a character called Sid the Slug

Sid the Slug

Sid the Slug is an advertising character employed by the Food Standards Agency in the United Kingdom as the face of the "Salt - Watch it" campaign to warn the public of the risks of excessive salt consumption....

and was criticised by the Salt Manufacturers Association (SMA). The Advertising Standards Authority

Advertising Standards Authority (United Kingdom)

The Advertising Standards Authority is the self-regulatory organisation of the advertising industry in the United Kingdom. The ASA is a non-statutory organisation and so cannot interpret or enforce legislation. However, its code of advertising practice broadly reflects legislation in many instances...

did not uphold the SMA complaint in its adjudication. In March 2007, the FSA launched the third phase of their campaign with the slogan "Salt. Is your food full of it?" fronted by comedienne Jenny Eclair.

The University of Tasmania's Menzies Research Institute maintains a website to educate people about the problems of a salt-laden diet.

Consensus Action on Salt and Health (CASH) established in 1996, actively campaigns to raise awareness of the harmful health effects of salt. The 2008 focus includes raising awareness of high levels of salt hidden in sweet foods and marketed towards children.

In January 2010, New York City

New York City

New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...

launched the National Salt Reduction Initiative, modeled after an initiative in the United Kingdom. The campaign calls on food makers to voluntarily reduce the amount of sodium in their foods, from 20 percent in peanut butter to a 40 percent reduction in canned vegetables, with an overall goal of reducing sodium in packaged and restaurant foods by 25 percent by 2015.

A number of major food producers have pledged to reduce the sodium content of their food. The Wall Street Journal reported that Pepsi

Pepsi

Pepsi is a carbonated soft drink that is produced and manufactured by PepsiCo...

is developing a “designer salt” that’s slightly more powdery than the salt it regularly uses. The company hopes this new form of salt will cut sodium levels by 25 percent in its Lay’s potato chips.
Nestlé's

Nestlé

Nestlé S.A. is the world's largest food and nutrition company. Founded and headquartered in Vevey, Switzerland, Nestlé originated in a 1905 merger of the Anglo-Swiss Milk Company, established in 1867 by brothers George Page and Charles Page, and Farine Lactée Henri Nestlé, founded in 1866 by Henri...

prepared foods company, which produces frozen meals, announced that it will reduce sodium in its foods by 10% by 2015.
General Mills

General Mills

General Mills, Inc. is an American Fortune 500 corporation, primarily concerned with food products, which is headquartered in Golden Valley, Minnesota, a suburb of Minneapolis. The company markets many well-known brands, such as Betty Crocker, Yoplait, Colombo, Totinos, Jeno's, Pillsbury, Green...

announced that it will reduce the sodium content of 40 percent of its foods by about 20 percent by 2015.

Taxation of sodium has been proposed as a method of decreasing sodium intake and thereby improving health in countries like the United States where typical salt consumption is high.

The Salt Institute, a salt industry body, is active in promoting the use of salt, and questioning or opposing restrictions on salt intake.

Salt substitutes

Salt intake can be reduced by simply reducing the quantity of salty foods in a diet, without recourse to salt substitutes. Salt substitutes have a taste similar to table salt and contain mostly potassium chloride

Potassium chloride

The chemical compound potassium chloride is a metal halide salt composed of potassium and chlorine. In its pure state, it is odorless and has a white or colorless vitreous crystal appearance, with a crystal structure that cleaves easily in three directions. Potassium chloride crystals are...

, which will increase potassium

Potassium

Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...

intake. Excess potassium intake can cause hyperkalemia

Hyperkalemia

Hyperkalemia refers to the condition in which the concentration of the electrolyte potassium in the blood is elevated...

. Various diseases and medications may decrease the body's excretion of potassium, thereby increasing the risk of hyperkalemia. Those who have kidney failure

Renal failure

Renal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...

, heart failure or diabetes should seek medical advice before using a salt substitute. One manufacturer, LoSalt, has issued an advisory statement that those taking the following prescription drugs should not use a salt substitute: amiloride

Amiloride

Amiloride is a potassium-sparing diuretic, first approved for use in 1967 , used in the management of hypertension and congestive heart failure. Amiloride was also tested as treatment of cystic fibrosis, but it was revealed inefficient in vivo due to it's short time of action, therefore...

, triamterene, Dytac, spironolactone

Spironolactone

Spironolactone , commonly referred to as simply spiro, is a diuretic and is used as an antiandrogen.It is a synthetic 17-lactone drug that is a renal competitive aldosterone antagonist in a class of pharmaceuticals called...

(Aldactone), and eplerenone

Eplerenone

Eplerenone is an aldosterone antagonist used as an adjunct in the management of chronic heart failure. It is similar to the diuretic spironolactone, though it may be more specific for the mineralocorticoid receptor and is specifically marketed for reducing cardiovascular risk in patients...

(Inspra).

Low salt diets

Diets

Dieting

Dieting is the practice of eating food in a regulated fashion to achieve or maintain a controlled weight. In most cases dieting is used in combination with physical exercise to lose weight in those who are overweight or obese. Some athletes, however, follow a diet to gain weight...

low in salt are mainly low sodium diet

Low sodium diet

A low sodium diet is a diet that includes no more than 1,500 to 2,400 mgs of sodium per day. People who follow a vigorous or moderate exercise schedule are usually advised to limit their sodium intake to 3,000 mg per day and those with moderate to severe heart failure are usually advised to...

s, that is, diets that specifically aim to lower intake of sodium, potentially including salt substitutes replacing sodium with other components. For those monitoring sodium intake, it is noteworthy that sea salt has the same sodium content as table salt.

Production

Salt is produced by evaporation of seawater

Sea salt

Sea salt, salt obtained by the evaporation of seawater, is used in cooking and cosmetics. It is historically called bay salt or solar salt...

or brine

Brine

from other sources, such as brine wells and salt lake

Salt lake

A salt lake or saline lake is a landlocked body of water which has a concentration of salts and other dissolved minerals significantly higher than most lakes . In some cases, salt lakes have a higher concentration of salt than sea water, but such lakes would also be termed hypersaline lakes...

s, and by mining

Salt mine

rock salt, called halite

Halite

Halite , commonly known as rock salt, is the mineral form of sodium chloride . Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pink, red, orange, yellow or gray depending on the amount and type of impurities...

.

In 2002, total world production (of sodium chloride in general, not just table salt) was estimated at 210 million tonne

Tonne

The tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...

s, the top five producers being the United States (40.3 million tonnes), China (32.9), Germany (17.7), India (14.5), and Canada (12.3).

Non-dietary uses and occurrences

Apart from its use in table salt in the diet, sodium chloride

Sodium chloride

is a major industrial chemical. It occurs widely, being the main saline component of the ocean

Ocean

An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...

s, and plays a role in formation of clouds.

Usage in religion

In the Hebrew Bible

Hebrew Bible

The Hebrew Bible is a term used by biblical scholars outside of Judaism to refer to the Tanakh , a canonical collection of Jewish texts, and the common textual antecedent of the several canonical editions of the Christian Old Testament...

, thirty-five verses mention salt

Salt in the Bible

The role of salt in the Bible is relevant to understanding Hebrew society during the Old Testament and New Testament periods. Salt is a necessity of life and was a mineral that was used since ancient times in many cultures as a seasoning, a preservative, a disinfectant, a component of ceremonial...

, one of which being the story of Lot's wife, who, according to the legend, was turned into a pillar of salt when she looked back at the cities of Sodom and Gomorrah

Sodom and Gomorrah

Sodom and Gomorrah were cities mentioned in the Book of Genesis and later expounded upon throughout the Hebrew Bible, the New Testament and Deuterocanonical sources....

(Genesis 19:26) as they were destroyed. When King Abimelech

Abimelech

Abimelech was a common name of the Philistine kings.Abimelech was most prominently the name of a king of Gerar who is mentioned in two of the three wife-sister narratives in Genesis...

destroyed the city of Shechem

Shechem

Shechem was a Canaanite city mentioned in the Amarna letters, and is mentioned in the Hebrew Bible as an Israelite city of the tribe of Manasseh and the first capital of the Kingdom of Israel...

, he is said to have "sown salt

Salting the earth

Salting the earth, or sowing with salt, is the ritual of spreading salt on conquered cities to symbolize a curse on its re-inhabitation. It originated as a practice in the ancient Near East and became a well-established folkloric motif in the Middle Ages.-Destroying cities:The custom of purifying...

on it," probably as a curse on anyone who would re-inhabit it. (Judges 9:45) The Book of Job contains the first mention of salt as a condiment. "Can that which is unsavory be eaten without salt? or is there any taste in the white of an egg?" (Job 6:6)

In the Christian New Testament

New Testament

The New Testament is the second major division of the Christian biblical canon, the first such division being the much longer Old Testament....

, six verses mention salt. In the Sermon on the Mount

Sermon on the Mount

The Sermon on the Mount is a collection of sayings and teachings of Jesus, which emphasizes his moral teaching found in the Gospel of Matthew...

, Jesus

Jesus

Jesus of Nazareth , commonly referred to as Jesus Christ or simply as Jesus or Christ, is the central figure of Christianity...

referred to his followers as the "salt of the earth

Salt and Light

Salt and light are metaphors used by Jesus in the Sermon on the Mount, one of the main teachings of Jesus on morality and discipleship. These metaphors in Matthew 5:13-16 immediately follow the Beatitudes and refer to expectations from the disciples....

". The apostle Paul also encouraged Christians to "let your conversation be always full of grace, seasoned with salt" (Colossians 4:6).

In one of the Hadith

Hadith

The term Hadīth is used to denote a saying or an act or tacit approval or criticism ascribed either validly or invalidly to the Islamic prophet Muhammad....

recorded in Sunan Ibn Majah, Prophet Muhammad

Muhammad

Muhammad |ligature]] at U+FDF4 ;Arabic pronunciation varies regionally; the first vowel ranges from ~~; the second and the last vowel: ~~~. There are dialects which have no stress. In Egypt, it is pronounced not in religious contexts...

is reported to have said that: "Salt is the master of your food. God sent down four blessings from the sky – fire

Fire

Fire is the rapid oxidation of a material in the chemical process of combustion, releasing heat, light, and various reaction products. Slower oxidative processes like rusting or digestion are not included by this definition....

, water

Water

, iron

Iron

Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...

and salt"

Salt is mandatory in the rite of the Tridentine Mass

Tridentine Mass

The Tridentine Mass is the form of the Roman Rite Mass contained in the typical editions of the Roman Missal that were published from 1570 to 1962. It was the most widely celebrated Mass liturgy in the world until the introduction of the Mass of Paul VI in December 1969...

. Salt is used in the third item (which includes an Exorcism

Exorcism

Exorcism is the religious practice of evicting demons or other spiritual entities from a person or place which they are believed to have possessed...

) of the Celtic Consecration (cf. Gallican Rite

Gallican rite

The Gallican Rite is a historical sub-grouping of the Roman Catholic liturgy in western Europe; it is not a single rite but actually a family of rites within the Western Rite which comprised the majority use of most of Christianity in western Europe for the greater part of the 1st millennium AD...

) that is employed in the consecration of a church. Salt may be added to the water "where it is customary" in the Roman Catholic rite of Holy water

Holy water

Holy water is water that, in Catholicism, Anglicanism, Eastern Orthodoxy, Lutheranism, Oriental Orthodoxy, and some other churches, has been sanctified by a priest for the purpose of baptism, the blessing of persons, places, and objects; or as a means of repelling evil.The use for baptism and...

.

Salt is considered to be a very auspicious substance in Hinduism

Hinduism

Hinduism is the predominant and indigenous religious tradition of the Indian Subcontinent. Hinduism is known to its followers as , amongst many other expressions...

, and is used in particular religious ceremonies like housewarmings and weddings.

Salt is considered to be very auspicious substance in Jainism too. Devotees offer raw rice and a pinch of salt before the deity to signify their devotion equivalent to the importance of salt among others signified by raw rice.

In Judaism

Judaism

Judaism ) is the "religion, philosophy, and way of life" of the Jewish people...

, it is recommended to have either a salty bread or to add salt to the bread if this bread is unsalted when doing Kiddush

Kiddush

Kiddush , literally, "sanctification," is a blessing recited over wine or grape juice to sanctify the Shabbat and Jewish holidays.-Significance:...

for Shabbat

Shabbat

Shabbat is the seventh day of the Jewish week and a day of rest in Judaism. Shabbat is observed from a few minutes before sunset on Friday evening until a few minutes after when one would expect to be able to see three stars in the sky on Saturday night. The exact times, therefore, differ from...

. It is customary to spread some salt over the bread or to dip the bread in a little salt when passing the bread around the table after the Kiddush. To preserve the covenant between their people and God, Jews dip the Sabbath bread in salt.

In Wicca

Wicca

Wicca , is a modern Pagan religious movement. Developing in England in the first half of the 20th century, Wicca was popularised in the 1950s and early 1960s by a Wiccan High Priest named Gerald Gardner, who at the time called it the "witch cult" and "witchcraft," and its adherents "the Wica."...

, salt is symbolic of the element Earth. It is also believed to cleanse an area of harmful or negative energies. A dish of salt and a dish of water are almost always present on an altar

Altar

An altar is any structure upon which offerings such as sacrifices are made for religious purposes. Altars are usually found at shrines, and they can be located in temples, churches and other places of worship...

. The salt is mixed with the water to consecrate it, in effect producing holy water. This mixture is used in a wide variety of rituals and ceremonies.

In the native Japanese religion Shinto

Shinto

or Shintoism, also kami-no-michi, is the indigenous spirituality of Japan and the Japanese people. It is a set of practices, to be carried out diligently, to establish a connection between present day Japan and its ancient past. Shinto practices were first recorded and codified in the written...

, salt is used for ritual purification

Ritual purification

Ritual purification is a feature of many religions. The aim of these rituals is to remove specifically defined uncleanliness prior to a particular type of activity, and especially prior to the worship of a deity...

of locations and people (harae

Harae

Harae or harai is the general term for rituals of purification in Shinto. Harae is one of four essential elements involved in a Shinto ceremony . The purpose is the purification of pollution or sins and uncleanness . These concepts include bad luck and disease as well as guilt in the English sense...

, specifically shubatsu), such as in sumo wrestling, and small piles of salt called or are placed in dishes by the entrance of establishments for the two-fold purposes of warding off evil and attracting patrons.

In Aztec

Aztec

The Aztec people were certain ethnic groups of central Mexico, particularly those groups who spoke the Nahuatl language and who dominated large parts of Mesoamerica in the 14th, 15th and 16th centuries, a period referred to as the late post-classic period in Mesoamerican chronology.Aztec is the...

mythology, Huixtocihuatl

Huixtocihuatl

In Aztec mythology, Huixtocihuatl was a fertility goddess who presided over salt and salt water. Her younger brother was Tlaloc, and the rain gods, the Tlaloques are her sisters, or, in some sources, the children of Tlaloc...

was a fertility goddess who presided over salt and salt water.

The ancient Egyptians, Greeks and Romans invoked their gods with offerings of salt and water. Some think this to be the origin of Holy Water

Holy Water

Holy Water is the ninth studio album by hard rock band Bad Company, and their third with Brian Howe in place of Paul Rodgers as lead vocalist, released in June 1990. The singles on the album all received moderate radio airplay. These included "Holy Water", "Boys Cry Tough", "Walk Through Fire", and...

in the Christian faith.

External links

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History

Unrefined salt

Refined salt

Table salt

Additives in table salt

Iodine and iodide

Fluoride

Anti-caking agents

Iron

Other additives

Salty condiments

Health effects

Acute effects

Long-term effects

Pathophysiology

Recommended intake

Labeling

Campaigns

Salt substitutes

Low salt diets

Production

Non-dietary uses and occurrences

Usage in religion

See also

External links