Organic micronutrients

Vitamins are organic micronutrients that the body cannot produce in amounts needed for good health. The highly polar nature of some vitamins renders them water-soluble. Nine... 

Vitamins are organic micronutrients that the body cannot produce in the amounts needed for good health. A number of vitamins have a high water solubility resulting from the highly polar nature of their molecules. All but one of the water-soluble vitamins are known to function as coenzymes in the body and are involved in many important metabolic processes. Fat-soluble vitamins have nonpolar molecular structures. As a result, they are insoluble in water but soluble in fat or other nonpolar solvents. Fat-soluble vitamins act somewhat like hormones in the body. Fat-soluble vitamins do not dissolve in water-based body fluids, so they are not excreted through the kidneys. Amounts in excess of bodily requirements are stored in body fat. Thus, it is much easier to produce toxic effects by overdosing with fat-soluble vitamins than with water-soluble vitamins. 

The term vitamin was derived from vitamine a word made up by the Polish scientist Casimir Funk from vital and amine , with the meaning amine of life . It was suggested in 1912 that the organic micronutrient food factors that prevent beriberi and perhaps other similar dietary-deficiency diseases might be chemical amines. This proved incorrect for the micronutrient class and the word was shortened to vitamin. Vitamins have been produced as commodity chemicals since the middle of the 20th century and are widely available as inexpensive synthetic multivitamin dietary supplements. They are classified by... 

The effect of a number of medium additions (organic micronutrients, metal ions, carbohydrates, lipids, nucleic acid derivatives) on the formation of riboflavin by microorganisms has been reviewed. 

Iron. As with copper, some dozen or more materials are used as fertilizer Hon sources. These include ferrous and ferric oxides and sulfides and ferrous ammonium phosphate [10101 -60-7] ferrous ammonium sulfate [10045-89-3] frits, and chelates. In many instances, organic chelates are more effective than inorganic materials. Recommended appHcation rates range widely according to both type of micronutrient used and crop. Quantities of Fe range from as low as 0.5 kg/hm as chelates for vegetables to as much as a few hundred kg/hm as ferrous sulfate for some grains. 

Zinc. Zinc, one of the most widely needed and used micronutrients, is appHed as sulfates (both basic and normal hydrates), carbonate, sulfide, phosphate, oxide, chelates, and other organic materials. Rates of Zn appHcation range from 0.2 to 22 kg/hm. ... 

Indicator plants generally have an offensive odor, which varies with the selenium concentration. Other vegetable matter grown on seleniferous soils may have a sufficiently high selenium content to be toxic when ingested by animals or humans. Apart from appearance in these seleniferous plants, selenium has been considered as a variable contaminant. Selenium is a necessary micronutrient in living organisms, needed by humans as well as animals (see Mineral NUTHiENTs). 

Vitamins aie specific organic compounds that are essential for normal metabolism. Many participate as cofactors or coen2ymes ia mammalian biochemical reactions. The common thread for the diverse chemical stmctures of the vitamins is that they ate micronutrients. Micronutrients are compounds that are requited ia only small amounts and are not synthesized by humans, either at all or, at least, ia sufficient quantity for metaboHc needs. Vitamins are obtained from the diet or as synthetic preparations used ia food fortification or supplements. 

Calcium is a macronutrient essential for all organisms. Chlorine is a micronutrient essential for higher (ie, seed) plants but not considered essential for mammals. Above certain levels chloride is toxic to plants and animals, thus when considering calcium chloride, potentially large concentrations of calcium ion can be tolerated, but at these concentrations the chloride ion becomes toxic. 

The use of foods by organisms is termed nutrition. The ability of an organism to use a particular food material depends upon its chemical composition and upon the metabolic pathways available to the organism. In addition to essential fiber, food includes the macronutrients—protein, carbohydrate, and lipid—and the micronutrients—including vitamins and minerals. 

F. J. Stevenson, Cycles of Soil Organic Carbon, Nitrogen, Phosphorous, Sulphur, Micronutrients, J. Wiley Sons, New York, 1986,... 

Y. Chen, Organic matter reactions involving micronutrients in soils and their effect on plants. Humic Substances in Terrestrial Ecosystems (A. Piccolo, ed.), Elsevier Sciences B. V., Amsterdam, 1996, p. 507. 

Sillanpaa M. Micronutrients and the Nutrient Status of Soils A Global Study. Rome Food and Agricultural Organization of the United Nations, 1982. 

Hajslova J, Schulzova V, Slanina P, Janne K, Hellenas KE and Andersson C (2005) Quality of organically and conventionally grown potatoes Four-year study of micronutrients, metals, secondary metabolites, enzymic browning and organoleptic properties . Food Additives and Contaminants, 22, 514—534. 

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