Electrolytes & trace minerals

[Jhanananda]

Making the connection between chromium deficiency and diabetes has brought my attention to sources of electrolytes & trace minerals.

Common salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in its natural form as a crystalline mineral is known as rock salt or halite. Salt is present in vast quantities in seawater, where it is the main mineral constituent. The open ocean has about 35 grams (1.2 oz) of solids per litre, a salinity of 3.5%.

Salt is essential for human life, and saltiness is one of the basic human tastes. The tissues of animals contain larger quantities of salt than do plant tissues. Salt is one of the oldest and most ubiquitous food seasonings, and salting is an important method of food preservation.

Some of the earliest evidence of salt processing dates to around 8,000 years ago, when people living in an area in what is now known as the country of Romania were boiling spring water to extract the salts; a salt-works in China dates to approximately the same period. Salt was also prized by the ancient Hebrews, the Greeks, the Romans, the Byzantines, the Hittites, Egyptians, and the Indians. Salt became an important article of trade and was transported by boat across the Mediterranean Sea, along specially built salt roads, and across the Sahara in camel caravans. The scarcity and universal need for salt has led nations to go to war over salt and use it to raise tax revenues. Salt is also used in religious ceremonies and has other cultural significance.

Salt is processed from salt mines, or by the evaporation of seawater (sea salt) or mineral-rich spring water in shallow pools. Its major industrial products are caustic soda and chlorine, and is used in many industrial processes including the manufacture of polyvinyl chloride, plastics, paper pulp and many other products. Of the annual global production of around two hundred million tonnes of salt, only about 6% is used for human consumption. Other uses include water conditioning processes, deicing highways, and agricultural use. Edible salt is sold in forms such as sea salt and table salt which usually contains an anti-caking agent and may be iodised to prevent iodine deficiency. As well as its use in cooking and at the table, salt is present in many processed foods.

Sodium is an essential nutrient for human health via its role as an electrolyte and osmotic solute.[1][2][3] Excessive salt consumption can increase the risk of cardiovascular diseases, such as hypertension, in children and adults. Such health effects of salt have long been studied. Accordingly, numerous world health associations and experts in developed countries recommend reducing consumption of popular salty foods.[3][4] The World Health Organization recommends that adults should consume less than 2,000 mg of sodium, equivalent to 5 grams of salt per day.[5]

History
Humans have always tended to build communities either around sources of salt, or where they can trade for it.

All through history the availability of salt has been pivotal to civilization. The word "salary" comes from the Latin word for salt because the Roman Legions were sometimes paid in salt, which was quite literally worth its weight in gold. In Britain, the suffix "-wich" in a placename means it was once a source of salt, as in Sandwich and Norwich. The Natron Valley was a key region that supported the Egyptian Empire to its north, because it supplied it with a kind of salt that came to be called by its name, natron.

Even before this, what is now thought to have been the first city in Europe is Solnitsata, in Bulgaria, which was a salt mine, providing the area now known as the Balkans with salt since 5400 BC.[6] Even the name Solnisata means "salt works".

While people have used canning and artificial refrigeration 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.[7] A very ancient salt-works operation has been discovered at the Poiana Slatinei archaeological site next to a salt spring in Lunca, Neamț County, Romania. Evidence indicates that Neolithic people of the Precucuteni Culture were boiling the salt-laden spring water through the process of briquetage to extract the salt as far back as 6050 BC.[8] 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.[9] The harvest of salt from the surface of Xiechi Lake near Yuncheng in Shanxi, China, dates back to at least 6000 BC, making it one of the oldest verifiable saltworks.[10]

There is more salt in animal tissues such as meat, blood and milk, than there is in plant tissues.[11] Nomads who subsist on their flocks and herds do not eat salt with their food, but agriculturalists, feeding mainly on cereals and vegetable matter, need to supplement their diet with salt.[12] With the spread of civilization, salt became one of the world's main trading commodities. It was of high value to the ancient Hebrews, the Greeks, the Romans, the Byzantines, the Hittites and other peoples of antiquity. In the Middle East, salt was used to ceremonially seal an agreement, and the ancient Hebrews made a "covenant of salt" with God and sprinkled salt on their offerings to show their trust in him.[13] An ancient practice in time of war was salting the earth: scattering salt around in a defeated city in order to prevent plant growth. The Bible tells the story of King Abimelech who was ordered by God to do this at Shechem,[14] and various texts claim that the Roman general Scipio Aemilianus Africanus ploughed over and sowed the city of Carthage with salt after it was defeated in the Third Punic War (146 BC).[15]

The word salad literally means "salted", and comes from the ancient Roman practice of salting leaf vegetables.

Chemistry
Salt is mostly sodium chloride, the ionic compound with the formula NaCl, representing equal proportions of sodium and chlorine. Sea salt and freshly mined salt (much of which is sea salt from prehistoric seas) also contain small amounts of trace elements (which in these small amounts are generally good for plant and animal health). Mined salt is often refined in the production of table salt; it is dissolved in water, purified via precipitation of other minerals out of solution, and re-evaporated. During this same refining process it is often also iodized. Salt crystals are translucent and cubic in shape; they normally appear white but impurities may give them a blue or purple tinge. The molar mass of salt is 58.443 g/mol, its melting point is 801 °C (1,474 °F) and its boiling point 1,465 °C (2,669 °F). Its density is 2.17 grams per cubic centimetre and it is readily soluble in water. When dissolved in water it separates into Na+ and Cl− ions and the solubility is 359 grams per litre.[27] From cold solutions, salt crystallises as the dihydrate NaCl·2H2O. Solutions of sodium chloride have very different properties from those of pure water; the freezing point is −21.12 °C (−6.02 °F) for 23.31 wt% of salt, and the boiling point of saturated salt solution is around 108.7 °C (227.7 °F).

Table salt is a refined salt containing about 97 to 99 percent sodium chloride.

Usually, anticaking agents such as sodium aluminosilicate or magnesium carbonate are added to make it free-flowing. Iodized salt, containing potassium iodide, is widely available.

Fortified table salt

Some table salt sold for consumption contain additives which address a variety of health concerns, especially in the developing world. The identities and amounts of additives vary widely from country to country. Iodine is an important micronutrient for humans, and a deficiency of the element can cause lowered production of thyroxine (hypothyroidism) and enlargement of the thyroid gland (endemic goitre) in adults or cretinism in children.[35] Iodized salt has been used to correct these conditions since 1924[36] and consists of table salt mixed with a minute amount of potassium iodide, sodium iodide or sodium iodate. A small amount of dextrose may also be added to stabilize the iodine.[37] Iodine deficiency affects about two billion people around the world and is the leading preventable cause of mental retardation.[38] Iodized table salt has significantly reduced disorders of iodine deficiency in countries where it is used.

In "doubly fortified salt", both iodide and iron salts are added. The latter alleviates iron deficiency anaemia, which interferes with the mental development of an estimated 40% of infants in the developing world. A typical iron source is ferrous fumarate.[45] Another additive, especially important for pregnant women, is folic acid (vitamin B9), which gives the table salt a yellow color. Folic acid helps prevent neural tube defects and anaemia, which affect young mothers, especially in developing countries.[45]

A lack of fluorine in the diet is the cause of a greatly increased incidence of dental caries.[46] Fluoride salts can be added to table salt with the goal of reducing tooth decay, especially in countries that have not benefited from fluoridated toothpastes and fluoridated water. The practice is more common in some European countries where water fluoridation is not carried out. In France, 35% of the table salt sold contains added sodium fluoride.

Other kinds

Unrefined sea salt contains small amounts of magnesium and calcium halides and sulfates, traces of algal products, salt-resistant bacteria and sediment particles. The calcium and magnesium salts confer a faintly bitter overtone, and they make unrefined sea salt hygroscopic (i.e., it gradually absorbs moisture from air if stored uncovered). Algal products contribute a mildly "fishy" or "sea-air" odour, the latter from organobromine compounds. Sediments, the proportion of which varies with the source, give the salt a dull grey appearance. Since taste and aroma compounds are often detectable by humans in minute concentrations, sea salt may have a more complex flavor than pure sodium chloride when sprinkled on top of food. When salt is added during cooking however, these flavors would likely be overwhelmed by those of the food ingredients.[47] The refined salt industry cites scientific studies saying that raw sea and rock salts do not contain enough iodine salts to prevent iodine deficiency diseases.

Different natural salts have different mineralities depending on their source, giving each one a unique flavour. Fleur de sel, a natural sea salt from the surface of evaporating brine in salt pans, has a unique flavour varying with the region from which it is produced. In traditional Korean cuisine, so-called "bamboo salt" is prepared by roasting salt[49] in a bamboo container plugged with mud at both ends. This product absorbs minerals from the bamboo and the mud, and has been claimed to increase the anticlastogenic and antimutagenic properties of doenjang (a fermented bean paste).[50]

Kosher salt, though refined, contains no iodine and has a much larger grain size than most refined salts. This can give it different properties when used in cooking, and can be useful for preparing kosher meat. Some kosher salt has been certified to meet kosher requirements by a hechsher, but this is not true for all products labelled as kosher salt.[51]

Pickling salt is ultrafine to speed dissolving to make brine. Gourmet salts may be used for specific tastes.

Salt in food

Salt is present in most foods, but in naturally occurring foodstuffs such as meats, vegetables and fruit, it is present in very small quantities. It is often added to processed foods (such as canned foods and especially salted foods, pickled foods, and snack foods or other convenience foods), where it functions as both a preservative and a flavoring. Dairy salt is used in the preparation of butter and cheese products.[52] Before the advent of electrically powered refrigeration, salting was one of the main methods of food preservation. Thus, herring contains 67 mg sodium per 100 g, while kipper, its preserved form, contains 990 mg. Similarly, pork typically contains 63 mg while bacon contains 1,480 mg, and potatoes contain 7 mg but potato crisps 800 mg per 100 g.[11] The main sources of salt in the diet, apart from direct use of sodium chloride, are bread and cereal products, meat products and milk and dairy products.[11]

In many East Asian cultures, salt is not traditionally used as a condiment.[53] In its place, condiments such as soy sauce, fish sauce and oyster sauce 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.

Sodium consumption and health
Main article: Health effects of salt

Table salt is made up of just under 40% sodium by weight, so a 6 g serving (1 teaspoon) contains about 2,300 mg of sodium.[55] Sodium serves a vital purpose in the human body: via its role as an electrolyte, it helps nerves and muscles to function correctly, and it is one factor involved in the osmotic regulation of water content in body organs (fluid balance).[56] Most of the sodium in the Western diet comes from salt.[3] The habitual salt intake in many Western countries is about 10 g per day, and it is higher than that in many countries in Eastern Europe and Asia.[57] The high level of sodium in many processed foods has a major impact on the total amount consumed.[58] In the United States, 75% of the sodium eaten comes from processed and restaurant foods, 11% from cooking and table use and the rest from what is found naturally in foodstuffs.[59]

Because consuming too much salt increases risk of cardiovascular diseases,[3] health organizations generally recommend that people reduce their dietary intake of salt.[3][60][61][62] High salt intake is associated with a greater risk of stroke, total cardiovascular disease and kidney disease.[2][57] A reduction in sodium intake by 1,000 mg per day may reduce cardiovascular disease by about 30 percent.[1][3] In adults and children with no acute illness, a decrease in the intake of sodium from the typical high levels reduces blood pressure.[61][63] A low salt diet results in a greater improvement in blood pressure in people with hypertension.[64][65]

The World Health Organization recommends that adults should consume less than 2,000 mg of sodium (which is contained in 5 g of salt) per day.[60] Guidelines by the United States recommend that people with hypertension, African Americans, and middle-aged and older adults should limit consumption to no more than 1,500 mg of sodium per day and meet the potassium recommendation of 4,700 mg/day with a healthy diet of fruits and vegetables.[3][66]

While reduction of salt intake to less than 2,300 mg per day is recommended by developed countries,[3] one review recommended that salt intake be no less than 1,200 mg (contained in 3 g) per day, as it is an essential nutrient required from the diet.[61] Another review indicated that reducing sodium intake to lower than 2,300 mg per day may not be beneficial.[2]

One of the two most prominent dietary risks for disability in the world is eating too much salt.

[Jhanananda]

Electrolyte
An electrolyte is a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water. The dissolved electrolyte separates into cations and anions, which disperse uniformly through the solvent. Electrically, such a solution is neutral. If an electrical potential (voltage) is applied to such a solution, the cations of the solution are drawn to the electrode that has an abundance of electrons, while the anions are drawn to the electrode that has a deficit of electrons. The movement of anions and cations in opposite directions within the solution amounts to a current. This includes most soluble salts, acids, and bases. Some gases, such as hydrogen chloride, under conditions of high temperature or low pressure can also function as electrolytes. Electrolyte solutions can also result from the dissolution of some biological (e.g., DNA, polypeptides) and synthetic polymers (e.g., polystyrene sulfonate), termed "polyelectrolytes", which contain charged functional groups. A substance that dissociates into ions in solution acquires the capacity to conduct electricity. Sodium, potassium, chloride, calcium, magnesium, and phosphate are examples of electrolytes, informally known as "lytes".

In medicine, electrolyte replacement is needed when a patient has prolonged vomiting or diarrhea, and as a response to strenuous athletic activity. Commercial electrolyte solutions are available, particularly for sick children (oral rehydration solutions) and athletes (sports drinks). Electrolyte monitoring is important in the treatment of anorexia and bulimia.

Physiological importance
See also: Water–electrolyte imbalance

In physiology, the primary ions of electrolytes are sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), chloride (Cl−), hydrogen phosphate (HPO42−), and hydrogen carbonate (HCO3−). The electric charge symbols of plus (+) and minus (−) indicate that the substance is ionic in nature and has an imbalanced distribution of electrons, the result of chemical dissociation. Sodium is the main electrolyte found in extracellular fluid and potassium is the main intracellular electrolyte; both are involved in fluid balance and blood pressure control.

All known higher lifeforms require a subtle and complex electrolyte balance between the intracellular and extracellular environments. In particular, the maintenance of precise osmotic gradients of electrolytes is important. Such gradients affect and regulate the hydration of the body as well as blood pH, and are critical for nerve and muscle function. Various mechanisms exist in living species that keep the concentrations of different electrolytes under tight control.

Both muscle tissue and neurons are considered electric tissues of the body. Muscles and neurons are activated by electrolyte activity between the extracellular fluid or interstitial fluid, and intracellular fluid. Electrolytes may enter or leave the cell membrane through specialized protein structures embedded in the plasma membrane called "ion channels". For example, muscle contraction is dependent upon the presence of calcium (Ca2+), sodium (Na+), and potassium (K+). Without sufficient levels of these key electrolytes, muscle weakness or severe muscle contractions may occur.

Electrolyte balance is maintained by oral, or in emergencies, intravenous (IV) intake of electrolyte-containing substances, and is regulated by hormones, in general with the kidneys flushing out excess levels. In humans, electrolyte homeostasis is regulated by hormones such as antidiuretic hormones, aldosterone and parathyroid hormones. Serious electrolyte disturbances, such as dehydration and overhydration, may lead to cardiac and neurological complications and, unless they are rapidly resolved, will result in a medical emergency.

[Jhanananda]

Mineral (nutrient)
A mineral is a chemical element required as an essential nutrient by organisms, other than carbon, hydrogen, nitrogen, oxygen and sulfur present in common organic molecules. The remaining elements are classed as minerals in the four groups of essential nutrients (the others are vitamins, essential fatty acids, and essential amino acids).[1][2]

The first six most-common major chemical elements (sometimes known as "major minerals") in order of abundance in the human body include calcium, phosphorus, potassium, sodium, chlorine, and magnesium. Calcium and phosphorus, as skeletal minerals comprising about 1.6 kg of an adult, make up 99% of the mass of the body along with the four non-mineral elements carbon, hydrogen, oxygen, and nitrogen. The last four major mineral elements (potassium, sodium, chlorine and magnesium) make up only about 0.85% of the weight of the body. Together these 11 chemical elements make up 99.85% of the body.

All of the remaining functional elements in a human body are sometimes known as "trace elements." All of the trace elements together total less than 10 grams, less than the weight of the least common major mineral, magnesium. The trace elements necessary for mammalian life include iron, cobalt, copper, zinc, manganese, molybdenum, iodine, and selenium. Because inorganic mineral content of foods do not form volatile combustion products, nutrition analysis methods involving combustion may report the total mineral content of food as "crude ash".

Over twenty minerals are necessary for mammals, and several more for various other types of life. The total number of chemical elements that are absolutely needed is not known for any organism. Ultratrace elements of some minerals such as silicon and boron are known to clearly have a role but the exact biochemical nature is unknown, and others such as arsenic and chromium are suspected to have a role in health, but with weaker evidence. Bromine has recently been found to have a biochemical role in the body in the synthesis of collagen, but these findings have not yet been confirmed.

Most chemical elements that are ingested by organisms are in the form of simple compounds. Larger chemical compounds of elements need to be broken down for absorption. Plants absorb dissolved elements in soils, which are subsequently picked up by the herbivores that eat them, and the elements move up the food chain. Larger organisms may also consume soil (geophagia) and visit salt licks to obtain limiting minerals they are unable to acquire through other components of their diet.

Bacteria and fungi play an essential role in the weathering of primary elements that results in the release of nutrients for their own nutrition and for the nutrition of others in the ecological food chain. One element, cobalt, is available for use by animals only after having been processed into complex molecules (e.g., vitamin B12) by bacteria. Scientists are only recently starting to appreciate the magnitude and role that microorganisms have in the global cycling and formation of biominerals.

The above link also provides 3 really useful charts: Minerals that play important roles in biological processes, which list the mineral and it function in the body, along with known conditions due to deficiency, or over abundance of the mineral; Blood concentrations of minerals; and Elements considered possibly essential but not confirmed.

[Jhanananda]

Trace Minerals Charts.  I found none of them provided the quantitative measurement that I was looking for.

Vitamins Study Guide Trace Minerals Chart

Complementary Therapists Dietary Minerals

Merck Manuals Mineral Deficiency and Toxicity

Merck Manuals Guidelines for Daily Intake of Minerals

[Jhanananda]

This morning I Googled "electrolyte loss due to sweat" and found this article Sweat rate and sodium loss during work in the heat, by Graham P Bates1 and Veronica S Millercorresponding author, and Published online 2008 Jan 29.

Abstract
Objective

Significant and poorly documented electrolyte losses result from prolonged sweating. This study aimed to quantify likely sodium losses during work in heat.
Methods

Male subjects exercised in an environmental chamber on two consecutive days in both winter and summer. Sweat collecting devices were attached to the upper arms and legs.
Results

Sweat rates were higher and sodium concentrations were lower in the summer (acclimatised) than the winter (unacclimatised) trials. Sweat sodium concentration was reduced on the second day in summer but not winter. Regional differences were found in both seasons.
Conclusion

The difference between days in summer probably reflects short-term acclimation. The difference between seasons reflects acclimatisation. The data predict average sodium (Na) losses over a work shift of 4.8–6 g, equivalent to 10–15 g salt (NaCl). Losses are potentially greater in unacclimatised individuals.

Fluid and electrolyte losses resulting from prolonged sweating must be replaced to prevent imbalance in body fluids, however guidelines for this replacement are often conflicting.

This study provides important information for occupational health practitioners by quantifying the likely sodium losses over a work shift and providing recommendations for replacement.

We can use these numbers to calculate the loss rate of trace minerals due to sweating.  However, 10-15g of salt lost each day is 3 times as much salt as is recommended by the AMA.  Therefore, people who live physically active lives must consume 10-15g of salt per day to keep up with their loss of sodium and other important electrolytes.