Cobalamin or vitamin B₁₂ is a chemical compound that is also known as cyanocobalamine. It is needed for nerve cells and red blood cells, and to make DNA. It is an organometallic compound with a trivalent cobalt ion bound inside a corrin ring. Its chemical structure was determined by Dorothy Crowfoot Hodgkin. Vitamins are organic chemicals that a given living organism requires in trace quantities for good health, but which the organism cannot synthesize, and therefore must obtain from its diet. ... A chemical compound is a chemical substance formed from two or more elements, with a fixed ratio determining the composition. ... Neurons (also called nerve cells) are the primary cells of the nervous system. ... Human red blood cells Red blood cells are the most common type of blood cell and are the vertebrate bodys principal means of delivering oxygen to body tissues via the blood. ... DNA replication Deoxyribonucleic acid (DNA) is a nucleic acid which is capable of carrying genetic instructions for the biological development of all cellular forms of life and many viruses. ... An organometallic compound is partially characterized by the presence of one or more metal-carbon bonds, in which the carbon involved would, apart from the metal-carbon bond, be otherwise considered a part of an organic compound. ... General Name, Symbol, Number cobalt, Co, 27 Chemical series transition metals Group, Period, Block 9 , 4, d Density, Hardness 8. ... A corrin is a polyaromatic ring related to the porphyrin ring in hemoglobin, consisting of 4 pyrrole subunits, joined on opposite sides by a C-CH3 methylene link, on one side by a C-H methylene link, and with the two of the pyrroles joined directly. ... Analytical chemistry is the analysis of material samples to gain an understanding of their chemical composition and structure. ... Dorothy Crowfoot Hodgkin OM (May 12, 1910–July 29, 1994) was a British scientist, born Dorothy Mary Crowfoot in Cairo. ...

History as a treatment for anemia

Vitamin B₁₂ deficiency is the cause of several forms of anemia. The treatment for this disease was first devised by William Murphy who bled dogs to make them anemic and then fed them various substances to see what (if anything) would make them healthy again. He discovered that ingesting large amounts of liver seemed to cure the disease. George Minot and George Whipple then set about to chemically isolate the curative substance and ultimately were able to isolate vitamin B₁₂ from the liver. For this, all three shared the 1934 Nobel Prize in Medicine. Anemia ( American English) or anaemia ( Commonwealth English), which literally means without blood, is a lack of red blood cells and/or hemoglobin. ... See William Beverly Murphy for the food businessman. ... George Richards Minot (December 2, 1885 (Boston, Massachusetts, U.S.A.) - February 25, 1950) won the 1934 Nobel Prize in Physiology or Medicine with William P. Murphy and George H. Whipple for their work in the study of anemia. ... George Hoyt Whipple (August 28, 1878 - February 1, 1976) was one of three recipients in 1934 of the Nobel Prize in physiology or medicine for their work on liver therapy in cases of anemia. ... 1934 was a common year starting on Monday (link will take you to calendar). ... List of Nobel Prize laureates in Physiology or Medicine from 1901 to the present day. ...

Deprivation

Vitamin B₁₂ is mostly absorbed in the terminal ileum. The production of intrinsic factor in the stomach is vital to absorption of this vitamin. Megaloblastic anemia can result from inadequate intake of vitamin B₁₂, inadequate production of intrinsic factor (pernicious anemia), disorders of the terminal ileum resulting in malabsorption, or by competition for available B₁₂ (such as fish tapeworms or bacteria present in blind loop syndrome). Neurological signs of B₁₂ deficiency, which can occur without accompanying hematologic abnormalities, include demyelination and irreversible nerve cell death. Symptoms include numbness or tingling of the extremities and an ataxic gait. In anatomy of the digestive system, the ileum (not to be confused with the ilium, a pelvic bone), is the final section of the small intestine. ... Intrinsic factor is a glycoprotein produced by the parietal cells of the stomach. ... In anatomy, the stomach (in ancient Greek στομάχι) is an organ in the alimentary canal used to digest food. ... Megaloblastic anemia is anemia resulting from a deficiency of vitamin B12 and folic acid. ... Pernicious anemia refers to a type of autoimmune anemia. ... Tapeworm can mean: Tapeworm, parasitic flatworms that live as adults in the digestive tracts of vertebrates. ... In neuroscience, myelin is an electrically insulating fatty layer that surrounds the axons of many neurons, especially those in the peripheral nervous system. ... Paresthesia (paraesthesia in British) is a sensation of tingling, pricking, or numbness of the skin with no apparent physical cause, more generally known as the feeling of pins and needles. ...

The American Psychiatric Association's American Journal of Psychiatry has published studies showing a relationship between depression levels and deficient vitamin B₁₂ blood levels in elderly people in 2000 [1] (http://ajp.psychiatryonline.org/cgi/content/abstract/157/5/715) and 2002 [2] (http://ajp.psychiatryonline.org/cgi/content/abstract/159/12/2099). The American Psychiatric Association is a professional American and international physicians who are trained in psychiatry. ... In ordinary conversation, nearly any mood with some element of sadness may be called depressed. However, for depression to be termed clinical depression it must reach criteria which are generally accepted by clinicians; it is more than just a temporary state of sadness. ... 2000 is a leap year starting on Saturday of the Gregorian calendar. ... 2002 is a common year starting on Tuesday of the Gregorian calendar. ...

Inadequate intake can be overcome with oral B12 supplements or modification of diet. However, the (not uncommon) lack of intrinsic factor, leading to inadequate absorption, is typically unresponsive to oral supplementation. In such cases intramuscular injection of ~1mg of methylcobalimin about monthly can overcome the consequent pernicious anemia. The Shillings test can determine whether symptoms of B12 deficiency are caused by lack of intrinsic factor.

Sources

In nature, B₁₂ is solely produced by bacteria found in animals (including humans), so that dirt could actually be considered a natural source of B₁₂. While vegetarians usually get enough B₁₂ through dairy products or eggs, it can sometimes be lacking in those following vegan diet who do not make an effort to find B₁₂ enriched foodstuffs, like enriched cereals, soy-based products or yeast extract. Claimed sources of B12 that have been shown through direct studies of vegans to be inadequate include spirulina (an algae), nori (a seaweed), barley grass, and human gut bacteria. Several studies of vegans on raw food diets show that raw food offers no special protection against B12 deficiency either. Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus_Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... For animals adapted to eat primarily plants, sometimes referred to as vegetarian animals, see Herbivore. ... Dairy products are generally defined as foodstuffs produced from milk. ... Bird and fish eggs are common food sources. ... This article is about the dietary lifestyle, Vegan can also mean relating to vega, especially the star Vega, as in astronomical references to the Vegan system, or Science Fiction references to aliens from that system. ... Cereal crops are mostly grasses cultivated for their edible seeds (actually a fruit called a grain, technically a caryopsis). ... Binomial name Glycine max Soybeans (US) or soya beans (UK) (Glycine max) are a high-protein legume (Family Fabaceae) grown as food for both humans and livestock. ... Yeast extract is the common name for yeast autolysates, that is, concentrations of yeast cells that are allowed to die and break up, so that the yeasts digestive enzymes break their proteins down into simpler compounds. ... Species Spirulina corakiana Spirulina crispum Spirulina labyrinthiformis Spirulina laxa Spirulina laxissima Spirulina major Spirulina meneghiniana Spirulina nordstedtii Spirulina princeps Spirulina subsalsa Spirulina subtilissima Spirulina platensis Spirulina tenerrima Spirulina weissii Spirulina is a genus of filamentous cyanobacteria (commonly called blue-green algae), with a coil-like shape. ... The algae (singular is alga) comprise several different groups of living things that produce energy through photosynthesis. ... Nori (海苔) is a Japanese term used to refer to edible varieties of seaweed in the various species of the red alga Porphyra, including most notably and . ... Seaweed covered rocks in the UK Phycologists consider seaweed to refer any of a large number of marine benthic algae that are multicellular, macrothallic (large-bodied), and thus differentiated from most algae that tend towards microscopic size (Smith, 1944). ...

Other uses

Vitamin B₁₂ is a popular substance for use in diluting (or cutting) methamphetamine. Methamphetamine is a synthetic stimulant drug which induces a strong feeling of euphoria and is highly addictive. ...

External links

• http://ods.od.nih.gov/factsheets/cc/vitb12.html
• Vitamin B12 information (http://www.talkwellness.org/vitaminb12.html)
• Sources of Vitamin B12 in a raw food diet (http://www.1st-in-raw-food-diet.com/vitamin-b12.html)
• http://www.vegansociety.com/html/food/nutrition/b12/