Mineral (nutrient)

In the context of nutrition, a mineral is a chemical element required as an essential nutrient by organisms to perform functions necessary for life.[1][2] However, the four major structural elements in the human body by weight (oxygen, hydrogen, carbon, and nitrogen), are usually not included in lists of major nutrient minerals (nitrogen is considered a "mineral" for plants, as it often is included in fertilizers). These four elements compose about 96% of the weight of the human body, and major minerals (macrominerals) and minor minerals (also called trace elements) compose the remainder.

Minerals, as elements, cannot be synthesized biochemically by living organisms.[3] Plants get minerals from soil.[3] Most of the minerals in a human diet come from eating plants and animals or from drinking water.[3] As a group, minerals are one of the four groups of essential nutrients, the others of which are vitamins, essential fatty acids, and essential amino acids.[4] The five major minerals in the human body are calcium, phosphorus, potassium, sodium, and magnesium.[1] All of the remaining elements in a human body are called "trace elements". The trace elements that have a specific biochemical function in the human body are sulfur, iron, chlorine, cobalt, copper, zinc, manganese, molybdenum, iodine and selenium.[5]

Most chemical elements that are ingested by organisms are in the form of simple compounds. Plants absorb dissolved elements in soils, which are subsequently ingested by the herbivores and omnivores that eat them, and the elements move up the food chain. Larger organisms may also consume soil (geophagia) or use mineral resources, such as salt licks, to obtain limited minerals unavailable through other dietary sources.

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 other species 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. Minerals are used by animals and microorganisms for the process of mineralizing structures, called "biomineralization", used to construct bones, seashells, eggshells, exoskeletons and mollusc shells.[6]

Essential chemical elements for humans

At least twenty chemical elements are known to be required to support human biochemical processes by serving structural and functional roles as well as electrolytes.[7] However, as many as twenty-nine elements in total are suggested to be used by mammals, as inferred by biochemical and uptake studies.[8]

Oxygen, hydrogen, carbon and nitrogen are the most abundant elements in the body by weight and make up about 96% of the weight of a human body. Calcium makes up 920 to 1200 grams of adult body weight, with 99% of it contained in bones and teeth. This is about 1.5% of body weight.[1] Phosphorus occurs in amounts of about 2/3 of calcium, and makes up about 1% of a person's body weight.[9] The other major minerals (potassium, sodium, chlorine, sulfur and magnesium) make up only about 0.85% of the weight of the body. Together these eleven chemical elements (H, C, N, O, Ca, P, K, Na, Cl, S, Mg) make up 99.85% of the body. The remaining ~18 ultratrace minerals comprise just 0.15% of the body, or about a gram in total for the average person.[10]

Differences exist opinion about the essential nature of various ultratrace elements in humans (and other mammals), even based on the same data. For example, there is no scientific consensus on whether chromium is an essential trace element in man. The United States and Japan designate chromium as an essential nutrient,[11][12] but the European Food Safety Authority (EFSA), representing the European Union, reviewed the question in 2014 and does not agree.[13]

Most of the known and suggested mineral nutrients are of relatively low atomic weight, and are reasonably common on land, or for sodium and iodine, in the ocean:

Nutritional elements in the periodic table
H   He
Li Be   B C N O F Ne
Na Mg   Al Si P S Cl Ar
K Ca Sc   Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y   Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac ** Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
 
  * Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
  ** Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
  Quantity elements
  Essential trace elements
  Deemed essential trace element by U.S., not by European Union
  Suggested function from deprivation effects or active metabolic handling, but no clearly-identified biochemical function in humans
  Limited circumstantial evidence for trace benefits or biological action in mammals
  No evidence for biological action in mammals, but essential in some lower organisms.
(In the case of lanthanum, the definition of an essential nutrient as being indispensable and irreplaceable is not completely applicable due to the extreme similarity of the lanthanides. Thus Ce, Pr, and Nd may be substituted for La without ill effects for organisms using La, and the smaller Sm, Eu, and Gd may also be similarly substituted but cause slower growth.)

Roles in biological processes

Dietary element RDA (US) [mg][14] UL (US and EU) [mg][15][16][17] Category High nutrient density
dietary sources
Term for deficiency Term for excess
Potassium 4700 NE; NE A systemic electrolyte and is essential in coregulating ATP with sodium Sweet potato, tomato, potato, beans, lentils, dairy products, seafood, banana, prune, carrot, orange[18] hypokalemia hyperkalemia
Chlorine 2300 3600; NE Needed for production of hydrochloric acid in the stomach and in cellular pump functions Table salt (sodium chloride) is the main dietary source. hypochloremia hyperchloremia
Sodium 1500 2300; NE A systemic electrolyte and is essential in coregulating ATP with potassium Table salt (sodium chloride, the main source), sea vegetables, milk, and spinach. hyponatremia hypernatremia
Calcium 1200 2500; 2500 Needed for muscle, heart and digestive system health, builds bone, supports synthesis and function of blood cells Dairy products, eggs, canned fish with bones (salmon, sardines), green leafy vegetables, nuts, seeds, tofu, thyme, oregano, dill, cinnamon.[19] hypocalcaemia hypercalcaemia
Phosphorus 700 4000; 4000 A component of bones (see apatite), cells, in energy processing, in DNA and ATP (as phosphate) and many other functions Red meat, dairy foods, fish, poultry, bread, rice, oats.[20][21] In biological contexts, usually seen as phosphate[22] hypophosphatemia hyperphosphatemia
Magnesium 420 350; 250 Required for processing ATP and for bones Spinach, legumes, nuts, seeds, whole grains, peanut butter, avocado[23] hypomagnesemia,
magnesium deficiency
hypermagnesemia
Iron 18 45; NE Required for many proteins and enzymes, notably hemoglobin to prevent anemia Meat, seafood, nuts, beans, dark chocolate[24] iron deficiency iron overload disorder
Zinc 11 40; 25 Pervasive and required for several enzymes such as carboxypeptidase, liver alcohol dehydrogenase, and carbonic anhydrase Oysters*, red meat, poultry, nuts, whole grains, dairy products[25] zinc deficiency zinc toxicity
Manganese 2.3 11; NE A cofactor in enzyme functions Grains, legumes, seeds, nuts, leafy vegetables, tea, coffee[26] manganese deficiency manganism
Copper 0.9 10; 5 Required component of many redox enzymes, including cytochrome c oxidase Liver, seafood, oysters, nuts, seeds; some: whole grains, legumes[26] copper deficiency copper toxicity
Iodine 0.150 1.1; 0.6 Required for synthesis of thyroid hormones, thyroxine and triiodothyronine and to prevent goiter: Seaweed (kelp or kombu)*, grains, eggs, iodized salt[27] iodine deficiency iodism Hyperthyroidism[28]
Chromium 0.035 NE; NE Involved in glucose and lipid metabolism, although its mechanisms of action in the body and the amounts needed for optimal health are not well-defined[29][30] Broccoli, grape juice (especially red), meat, whole grain products[31] Chromium deficiency Chromium toxicity
Molybdenum 0.045 2; 0.6 The oxidases xanthine oxidase, aldehyde oxidase, and sulfite oxidase[32] Legumes, whole grains, nuts[26] molybdenum deficiency molybdenum toxicity[33]
Selenium 0.055 0.4; 0.3 Essential to activity of antioxidant enzymes like glutathione peroxidase Brazil nuts, seafoods, organ meats, meats, grains, dairy products, eggs[34] selenium deficiency selenosis
Cobalt none NE; NE Required in the synthesis of vitamin B12, but because bacteria are required to synthesize the vitamin, it is usually considered part of vitamin B12 which comes from eating animals and animal-sourced foods (eggs...) Cobalt poisoning

RDA = Recommended Dietary Allowance; UL = Tolerable upper intake level; Figures shown are for adults age 31-50, male or female neither pregnant nor lactating

* One serving of seaweed exceeds the US UL of 1100 μg but not the 3000 μg UL set by Japan.[35]

Blood concentrations of minerals

Minerals are present in a healthy human being's blood at certain mass and molar concentrations. The figure below presents the concentrations of each of the chemical elements discussed in this article, from center-right to the right. Depending on the concentrations, some are in upper part of the picture, while others are in the lower part. The figure includes the relative values of other constituents of blood such as hormones. In the figure, minerals are color highlighted in purple.

Reference ranges for blood tests, sorted logarithmically by mass above the scale and by molarity below. (A separate printable image is available for mass and molarity)
Reference ranges for blood tests, sorted logarithmically by mass above the scale and by molarity below. (A separate printable image is available for mass and molarity)

Dietary nutrition

Dietitians may recommend that minerals are best supplied by ingesting specific foods rich with the chemical element(s) of interest. The elements may be naturally present in the food (e.g., calcium in dairy milk) or added to the food (e.g., orange juice fortified with calcium; iodized salt fortified with iodine). Dietary supplements can be formulated to contain several different chemical elements (as compounds), a combination of vitamins and/or other chemical compounds, or a single element (as a compound or mixture of compounds), such as calcium (calcium carbonate, calcium citrate) or magnesium (magnesium oxide), or iron (ferrous sulfate, iron bis-glycinate).

The dietary focus on chemical elements derives from an interest in supporting the biochemical reactions of metabolism with the required elemental components.[36] Appropriate intake levels of certain chemical elements have been demonstrated to be required to maintain optimal health. Diet can meet all the body's chemical element requirements, although supplements can be used when some recommendations are not adequately met by the diet. An example would be a diet low in dairy products, and hence not meeting the recommendation for calcium.

Elements considered possibly essential but not confirmed

Many ultratrace elements have been suggested as essential, but such claims have usually not been confirmed. Definitive evidence for efficacy comes from the characterization of a biomolecule containing the element with an identifiable and testable function.[5] One problem with identifying efficacy is that some elements are innocuous at low concentrations and are pervasive (examples: silicon and nickel in solid and dust), so proof of efficacy is lacking because deficiencies are difficult to reproduce.[36] Ultratrace elements of some minerals such as silicon and boron are known to have a role but the exact biochemical nature is unknown, and others such as arsenic are suspected to have a role in health, but with weaker evidence.[5]

Element Description Excess
Bromine Possibly important to basement membrane architecture and tissue development, as a needed catalyst to make collagen IV.[37] bromism
Arsenic Essential in rat, hamster, goat and chicken models, but no biochemical mechanism known in humans.[38] arsenic poisoning
Nickel Nickel is an essential component of several enzymes, including urease and hydrogenase.[39] Although not required by humans, some are thought to be required by gut bacteria, such as urease required by some varieties of Bifidobacterium.[40] In humans, nickel may be a cofactor or structural component of certain metalloenzymes involved in hydrolysis, redox rections, and gene expression. Nickel deficiency depressed growth in goats, pigs, and sheep, and diminished circulating thyroid hormone concentration in rats.[41] Nickel toxicity
Fluorine Fluorine (as fluoride) is not considered an essential element because humans do not require it for growth or to sustain life. Research indicates that the primary dental benefit from fluoride occurs at the surface from topical exposure.[42][43] Of the minerals in this table, fluoride is the only one for which the U.S. Institute of Medicine has established an Adequate Intake.[44] Fluoride poisoning
Boron Boron is an essential plant nutrient, required primarily for maintaining the integrity of cell walls.[45][46][47] Boron has been shown to be essential to complete the life cycle in representatives of all phylogenetic kingdoms, including the model species Danio rerio (zebrafish) and Xenopus laevis (African clawed frog).[39][48] In animals, supplemental boron has been shown to reduce calcium excretion and activate vitamin D.[49] Nontoxic
Lithium It is not known whether lithium has a physiological role in any species,[50] but nutritional studies in mammals have indicated its importance to health, leading to a suggestion that it be classed as an essential trace element. Lithium toxicity
Strontium Strontium has been found to be involved in the utilization of calcium in the body. It has promoting action on calcium uptake into bone at moderate dietary strontium levels, but a rachitogenic (rickets-producing) action at higher dietary levels.[51] Rachitogenic (causing Rickets)
Other Silicon and vanadium have established, albeit specialized, biochemical roles as structural or functional cofactors in other organisms, and are possibly, even probably, used by mammals (including humans). By contrast, tungsten, lanthanum, and cadmium have specialized biochemical uses in certain lower organisms, but these elements appear not to be utilized by humans.[8] Other elements considered to be possibly essential include aluminium, germanium, lead, rubidium, and tin.[39][52][53] Multiple

Mineral ecology

Minerals can be bioengineered by bacteria which act on metals to catalyze mineral dissolution and precipitation.[54] Mineral nutrients are recycled by bacteria distributed throughout soils, oceans, freshwater, groundwater, and glacier meltwater systems worldwide.[54][55] Bacteria absorb dissolved organic matter containing minerals as they scavenge phytoplankton blooms.[55] Mineral nutrients cycle through this marine food chain, from bacteria and phytoplankton to flagellates and zooplankton, which are then eaten by other marine life.[54][55] In terrestrial ecosystems, fungi have similar roles as bacteria, mobilizing minerals from matter inaccessible by other organisms, then transporting the acquired nutrients to local ecosystems.[56][57]

See also

References

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Further reading

  • Humphry Bowen (1966) Trace Elements in Biochemistry. Academic Press.
  • Humphrey Bowen (1979) Environmental Chemistry of the Elements. Academic Press, ISBN 0-12-120450-2.

External links

Calcifuge

A calcifuge is a plant that does not tolerate alkaline (basic) soil. The word is derived from the Latin 'to flee from chalk'. These plants are also described as ericaceous, as the prototypical calcifuge is the genus Erica (heaths). It is not the presence of carbonate or hydroxide ions per se that these plants cannot tolerate, but the fact that under alkaline conditions, iron becomes less soluble. Consequently, calcifuges grown on alkaline soils often develop the symptoms of iron deficiency, i.e. interveinal chlorosis of new growth. There are many horticultural plants which are calcifuges, most of which require an 'ericaceous' compost with a low pH, composed principally of Sphagnum moss peat.

A plant that thrives in lime-rich soils is known as a calcicole.

Calcium/cholecalciferol

Calcium/cholecalciferol is a combination of a calcium salt (usually calcium carbonate) and vitamin D3 (cholecalciferol), available under many brand names and in many forms such as chewable tablets, coated tablets, and effervescent tablets. It is used to prevent and treat lack of calcium and vitamin D in the elderly, as well as adjunctive therapy for osteoporosis.

Dietary Reference Intake

The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the Institute of Medicine (IOM) of the National Academies (United States). It was introduced in 1997 in order to broaden the existing guidelines known as Recommended Dietary Allowances (RDAs, see below). The DRI values differ from those used in nutrition labeling on food and dietary supplement products in the U.S. and Canada, which uses Reference Daily Intakes (RDIs) and Daily Values (%DV) which were based on outdated RDAs from 1968 but were updated as of 2016.

Ecosystem

An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the system through photosynthesis and is incorporated into plant tissue. By feeding on plants and on one-another, animals play an important role in the movement of matter and energy through the system. They also influence the quantity of plant and microbial biomass present. By breaking down dead organic matter, decomposers release carbon back to the atmosphere and facilitate nutrient cycling by converting nutrients stored in dead biomass back to a form that can be readily used by plants and other microbes.Ecosystems are controlled by external and internal factors. External factors such as climate, the parent material which forms the soil and topography, control the overall structure of an ecosystem, but are not themselves influenced by the ecosystem.Ecosystems are dynamic entities—they are subject to periodic disturbances and are in the process of recovering from some past disturbance. Ecosystems in similar environments that are located in different parts of the world can end up doing things very differently simply because they have different pools of species present. Internal factors not only control ecosystem processes but are also controlled by them and are often subject to feedback loops.Resource inputs are generally controlled by external processes like climate and parent material. Resource availability within the ecosystem is controlled by internal factors like decomposition, root competition or shading. Although humans operate within ecosystems, their cumulative effects are large enough to influence external factors like climate.Biodiversity affects ecosystem functioning, as do the processes of disturbance and succession. Ecosystems provide a variety of goods and services upon which people depend.

Food fortification

Food fortification or enrichment is the process of adding micronutrients (essential trace elements and vitamins) to food. It can be carried out by food manufacturers, or by governments as a public health policy which aims to reduce the number of people with dietary deficiencies within a population. The predominant diet within a region can lack particular nutrients due to the local soil or from inherent deficiencies within the staple foods; addition of micronutrients to staples and condiments can prevent large-scale deficiency diseases in these cases.As defined by the World Health Organization (WHO) and the Food and Agricultural Organization of the United Nations (FAO), fortification refers to "the practice of deliberately increasing the content of an essential micronutrient, ie. vitamins and minerals (including trace elements) in a food, so as to improve the nutritional quality of the food supply and to provide a public health benefit with minimal risk to health", whereas enrichment is defined as "synonymous with fortification and refers to the addition of micronutrients to a food which are lost during processing".Food fortification has been identified as the second strategy of four by the WHO and FAO to begin decreasing the incidence of nutrient deficiencies at the global level. As outlined by the FAO, the most commonly fortified foods are cereals and cereal-based products; milk and dairy products; fats and oils; accessory food items; tea and other beverages; and infant formulas. Undernutrition and nutrient deficiency is estimated globally to cause the deaths of between 3 and 5 million people per year.

Green Revolution

The Green Revolution, or Third Agricultural Revolution, is a set of research and technology transfer initiatives occurring between 1950 and the late 1960s, that increased agricultural production worldwide, particularly in the developing world, beginning most markedly in the late 1960s. The initiatives resulted in the adoption of new technologies, including high-yielding varieties (HYVs) of cereals, especially dwarf wheats and rices, in association with chemical fertilizers and agro-chemicals, and with controlled water-supply (usually involving irrigation) and new methods of cultivation, including mechanization. All of these together were seen as a 'package of practices' to supersede 'traditional' technology and to be adopted as a whole.Both the Ford Foundation and the Rockefeller Foundation were heavily involved.

One key leader was Norman Borlaug, the "Father of the Green Revolution", who received the Nobel Peace Prize in 1970. He is credited with saving over a billion people from starvation. The basic approach was the development of high-yielding varieties of cereal grains, expansion of irrigation infrastructure, modernization of management techniques, distribution of hybridized seeds, synthetic fertilizers, and pesticides to farmers.

The term "Green Revolution" was first used in a speech on 8 March 1968 by the administrator of the U.S. Agency for International Development (USAID), William S. Gaud, who noted the spread of the new technologies: "These and other developments in the field of agriculture contain the makings of a new revolution. It is not a violent Red Revolution like that of the Soviets, nor is it a White Revolution like that of the Shah of Iran. I call it the Green Revolution."

Hydroponics

Hydroponics is a subset of hydroculture, which is a method of growing plants without soil by using mineral nutrient solutions in a water solvent. Terrestrial plants may be grown with only their roots exposed to the mineral solution, or the roots may be supported by an inert medium, such as perlite or gravel.

The nutrients used in hydroponic systems can come from an array of different sources; these can include, but are not limited to, byproduct from fish waste, duck manure, or purchased chemical fertilisers.

Iodine

Iodine is a chemical element with symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a lustrous, purple-black non-metallic solid at standard conditions that melts to form a deep violet liquid at 114 degrees Celsius, and boils to a violet gas at 184 degrees Celsius. The element was discovered by the French chemist Bernard Courtois in 1811. It was named two years later by Joseph Louis Gay-Lussac from this property, after the Greek ἰώδης "violet-coloured".

Iodine occurs in many oxidation states, including iodide (I−), iodate (IO−3), and the various periodate anions. It is the least abundant of the stable halogens, being the sixty-first most abundant element. It is the heaviest essential mineral nutrient. Iodine is essential in the synthesis of thyroid hormones. Iodine deficiency affects about two billion people and is the leading preventable cause of intellectual disabilities.

The dominant producers of iodine today are Chile and Japan. Iodine and its compounds are primarily used in nutrition. Due to its high atomic number and ease of attachment to organic compounds, it has also found favour as a non-toxic radiocontrast material. Because of the specificity of its uptake by the human body, radioactive isotopes of iodine can also be used to treat thyroid cancer. Iodine is also used as a catalyst in the industrial production of acetic acid and some polymers.

List of apple diseases

This article is a list of diseases of apples (Malus × domestica).

Magnesium in biology

Magnesium is an essential element in biological systems. Magnesium occurs typically as the Mg2+ ion. It is an essential mineral nutrient (i.e., element) for life and is present in every cell type in every organism. For example, ATP (adenosine triphosphate), the main source of energy in cells, must bind to a magnesium ion in order to be biologically active. What is called ATP is often actually Mg-ATP. As such, magnesium plays a role in the stability of all polyphosphate compounds in the cells, including those associated with the synthesis of DNA and RNA.

Over 300 enzymes require the presence of magnesium ions for their catalytic action, including all enzymes utilizing or synthesizing ATP, or those that use other nucleotides to synthesize DNA and RNA. [cite needed]

In plants, magnesium is necessary for synthesis of chlorophyll and photosynthesis.

Mineral absorption

In plants and animals, mineral absorption, also called mineral uptake is the way in which minerals enter the cellular material, typically following the same pathway as water. In plants, the entrance portal for mineral uptake is usually through the roots. Some mineral ions diffuse in-between the cells. In contrast to water, some minerals are actively taken up by plant cells. Mineral nutrient concentration in roots may be 10,000 times more than in surrounding soil. During transport throughout a plant, minerals can exit xylem and enter cells that require them. Mineral ions cross plasma membranes by a chemiosmotic mechanism. Plants absorb minerals in ionic form: nitrate (NO3−), phosphate (HPO4−) and potassium ions (K+); all have difficulty crossing a charged plasma membrane.

It has long been known plants expend energy to actively take up and concentrate mineral ions. Proton pump hydrolyzes adenosine triphosphate (ATP) to transport H+ ions out of cell; this sets up an electrochemical gradient that causes positive ions to flow into cells.

Negative ions are carried across the plasma membrane in conjunction with H+ ions as H+ ions diffuse down their concentration gradient.

Natural foods

Natural foods and all natural foods are widely used terms in food labeling and marketing with a variety of definitions, most of which are vague. The term is often assumed to imply foods that are not processed and whose ingredients are all natural products (in the chemist's sense of that term), thus conveying an appeal to nature. But the lack of standards in most jurisdictions means that the term assures nothing. In some countries, the term "natural" is defined and enforced. In others, such as the United States, it is not enforced.

Nutrient

A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excreted by cells to create non-cellular structures, such as hair, scales, feathers, or exoskeletons. Some nutrients can be metabolically converted to smaller molecules in the process of releasing energy, such as for carbohydrates, lipids, proteins, and fermentation products (ethanol or vinegar), leading to end-products of water and carbon dioxide. All organisms require water. Essential nutrients for animals are the energy sources, some of the amino acids that are combined to create proteins, a subset of fatty acids, vitamins and certain minerals. Plants require more diverse minerals absorbed through roots, plus carbon dioxide and oxygen absorbed through leaves. Fungi live on dead or living organic matter and meet nutrient needs from their host.

Different types of organism have different essential nutrients. Ascorbic acid (vitamin C) is essential, meaning it must be consumed in sufficient amounts, to humans and some other animal species, but not to all animals and not to plants, which are able to synthesize it. Nutrients may be organic or inorganic: organic compounds include most compounds containing carbon, while all other chemicals are inorganic. Inorganic nutrients include nutrients such as iron, selenium, and zinc, while organic nutrients include, among many others, energy-providing compounds and vitamins.

A classification used primarily to describe nutrient needs of animals divides nutrients into macronutrients and micronutrients. Consumed in relatively large amounts (grams or ounces), macronutrients (carbohydrates, fats, proteins, water) are used primarily to generate energy or to incorporate into tissues for growth and repair. Micronutrients are needed in smaller amounts (milligrams or micrograms); they have subtle biochemical and physiological roles in cellular processes, like vascular functions or nerve conduction. Inadequate amounts of essential nutrients, or diseases that interfere with absorption, result in a deficiency state that compromises growth, survival and reproduction. Consumer advisories for dietary nutrient intakes, such as the United States Dietary Reference Intake, are based on deficiency outcomes and provide macronutrient and micronutrient guides for both lower and upper limits of intake. In many countries, macronutrients and micronutrients in significant content are required by regulations to be displayed on food product labels. Nutrients in larger quantities than the body needs may have harmful effects. Edible plants also contain thousands of compounds generally called phytochemicals which have unknown effects on disease or health, including a diverse class with non-nutrient status called polyphenols, which remain poorly understood as of 2017.

Plant nutrients consist of more than a dozen minerals absorbed through roots, plus carbon dioxide and oxygen absorbed or released through leaves. All organisms obtain all their nutrients from the surrounding environment.

Nutrient cycle

A nutrient cycle (or ecological recycling) is the movement and exchange of organic and inorganic matter back into the production of matter. Energy flow is a unidirectional and noncyclic pathway, whereas the movement of mineral nutrients is cyclic. Mineral cycles include the carbon cycle, sulfur cycle, nitrogen cycle, water cycle, phosphorus cycle, oxygen cycle, among others that continually recycle along with other mineral nutrients into productive ecological nutrition.

Plant nutrition

Plant nutrition is the study of the chemical elements and compounds necessary for plant growth, plant metabolism and their external supply. In 1972, Emanuel Epstein defined two criteria for an element to be essential for plant growth:

in its absence the plant is unable to complete a normal life cycle.

or that the element is part of some essential plant constituent or metabolite.This is in accordance with Justus von Liebig's law of the minimum. The essential plant nutrients include carbon, oxygen and hydrogen which are absorbed from the air, whereas other nutrients including nitrogen are typically obtained from the soil (exceptions include some parasitic or carnivorous plants).

There are seventeen most important nutrients for plants. Plants must obtain the following mineral nutrients from their growing medium:-

the macronutrients: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sulfur (S), magnesium (Mg), carbon (C), oxygen(O), hydrogen (H)

the micronutrients (or trace minerals): iron (Fe), boron (B), chlorine (Cl), manganese (Mn), zinc (Zn), copper (Cu), molybdenum (Mo), nickel (Ni)These elements stay beneath soil as salts, so plants consume these elements as ions. The macronutrients are consumed in larger quantities; hydrogen, oxygen, nitrogen and carbon contribute to over 95% of a plants' entire biomass on a dry matter weight basis. Micronutrients are present in plant tissue in quantities measured in parts per million, ranging from 0.1 to 200 ppm, or less than 0.02% dry weight.Most soil conditions across the world can provide plants adapted to that climate and soil with sufficient nutrition for a complete life cycle, without the addition of nutrients as fertilizer. However, if the soil is cropped it is necessary to artificially modify soil fertility through the addition of fertilizer to promote vigorous growth and increase or sustain yield. This is done because, even with adequate water and light, nutrient deficiency can limit growth and crop yield.

Plant physiology

Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. Closely related fields include plant morphology (structure of plants), plant ecology (interactions with the environment), phytochemistry (biochemistry of plants), cell biology, genetics, biophysics and molecular biology.

Fundamental processes such as photosynthesis, respiration, plant nutrition, plant hormone functions, tropisms, nastic movements, photoperiodism, photomorphogenesis, circadian rhythms, environmental stress physiology, seed germination, dormancy and stomata function and transpiration, both parts of plant water relations, are studied by plant physiologists.

Root pressure

Root pressure is the transverse osmotic pressure within the cells of a root system that causes sap to rise through a plant stem to the leaves.Root pressure occurs in the xylem of some vascular plants when the soil moisture level is high either at night or when transpiration is low during the day. When transpiration is high, xylem sap is usually under tension, rather than under pressure, due to transpirational pull. At night in some plants, root pressure causes guttation or exudation of drops of xylem sap from the tips or edges of leaves. Root pressure is studied by removing the shoot of a plant near the soil level. Xylem sap will exude from the cut stem for hours or days due to root pressure. If a pressure gauge is attached to the cut stem, the root pressure can be measured.

Root pressure is caused by active distribution of mineral nutrient ions into the root xylem. Without transpiration to carry the ions up the stem, they accumulate in the root xylem and lower the water potential. Water then diffuses from the soil into the root xylem due to osmosis. Root pressure is caused by this accumulation of water in the xylem pushing on the rigid cells. Root pressure provides a force, which pushes water up the stem, but it is not enough to account for the movement of water to leaves at the top of the tallest trees. The maximum root pressure measured in some plants can raise water only to 6.87 meters, and the tallest trees are over 100 meters tall.

Santalum lanceolatum

Santalum lanceolatum is an Australian tree of the family Santalaceae. It is commonly known as desert quandong, northern sandalwood, sandalwood, or true sandalwood and in some areas as burdardu. The mature height of this plant is variable, from 1 to 7 m. The flowers are green, white, and cream, appearing between January and October. The species has a distribution throughout central Australia, becoming scattered or unusual in more southern regions.

St. Paul, Arkansas

St. Paul is a town in southern Madison County, Arkansas, United States. The population was 113 at the 2010 census. It is on the edge of the Northwest Arkansas region.

St. Paul was platted in 1887 when the railroad was extended to that point.

Types
Vitamins and
chemical elements ("minerals")
Other common ingredients
Related articles
Mineral supplements (A12)
Major
Trace
Ultratrace

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