Also known as Cobalamin, Cyanocobalamin, Hydroxycobalamin, Adenosylcobalamin, Methylcobalamin

Vitamin B12 1
The molecular structure of vitamin B12 (cobalamin), the most complex of all known vitamins, was announced in 1955 by several scientists, including British biochemists A. R. Todd and Dorothy Hodgkin . In 1973 the vitamin was reported to have been synthesized by organic chemists. Vitamin B12 and closely related cobalamins are necessary for folic acid to fulfill its role; both are involved in the synthesis of proteins. American physicians G. R. Minot and W. P. Murphy in 1926 fed large amounts of liver to patients with pernicious anemia and cured them; the curative substance in this case was probably vitamin B12 . However, pernicious anemia in humans is caused not by a vitamin B12 deficiency in the diet but rather the absence of a substance called the intrinsic factor, ordinarily secreted by the stomach and responsible for facilitating the absorption of B12 from the intestine. When a person's body cannot produce the intrinsic factor, the standard treatment today is to inject vitamin B12 directly into the bloodstream. Minot and Murphy's therapy worked because the liver they fed their patients contained such large quantities of B12 that sufficient amounts of the vitamin were absorbed without the assistance of the intrinsic factor. Inadequate absorption of B12 causes pernicious anemia, nervous system degeneration, and amenorrhea. The only site of cobalamin synthesis in nature appears to be in microorganisms; neither animals nor higher plants are capable of making these vitamin B12 derivatives. Nevertheless, such animal tissues as the liver, kidney, and heart of ruminants contain relatively large quantities of vitamin B12 ; the vitamin stored in these organs was originally produced by the bacteria in the ruminant gut. Bivalves (clams or oysters), which siphon microorganisms from the sea, are also good sources. Plants, on the other hand, are poor sources of vitamin B12 . The recommended daily dietary allowance for adults is 3 micrograms.

What is Vitamin B12? 6
Vitamin B12 (also called cobalamin) was the last vitamin to be identified, and has since become one of the most popular, having been attributed a wide range of crucial roles. The body stores significant levels of it in the liver, but these reserves can fall sharply after age 50, leading to vitamin B12 deficiency. Deficiency can be offset with supplementation, or one may opt to increase their intake of fish, eggs, and meats, which are all good natural sources.

How can it benefit you? 6
Vitamin B12 deficiency can lead to serious symptoms including nerve damage, weakening of the muscles, depression, failing memory (people with Alzheimer’s often have low levels of it), fatigue, anemia, and stunted growth in children.

This vitamin is crucial for the formation and regeneration of red blood cells, the body’s manufacture of DNA and RNA (our cell’s genetic material), and the proper functioning of nerves. Moreover, vitamin B12 works synergistically with other vitamins (namely folic acid) to lower homocysteine levels. Having elevated homocysteine levels is one of the most important markers for risk of heart disease, and can lead to heart attacks.

Other functions and benefits include its role as an oxygen carrier, metabolizing fat, alleviating neurological disorders, and boosting the immune system.

Precautions 6
There is no known toxicity to Vitamin B12. Any excess the body needs is excreted in urine.

Opinion 6
Even though vitamin B12 can be stored in large amounts by the body, some estimates by experts believe as many as 20% of older people may have a deficiency. Therefore, we believe middle-aged to older people should especially consider this vitamin as part of their dietary regimen. In addition, vegetarians may also harbor vitamin B12 deficiency because the highest sources come from animal products.

Tips on Choosing a Supplement 6



Vitamin B12 needs to be taken with folic acid because they work synergistically. The important mineral calcium, moreover, cannot be absorbed by the body in its absence. Therefore, we suggest, in general, you take your vitamin B12 as a part of a comprehensive, scientifically balanced formula, unless you have a specific reason to want a higher dosage for therapeutic purposes.


Functions: 9



Cellular functions

Transfer of 1-carbon fragments (methyl)

Synthesis of amino acids and fatty acids

Biosynthesis of purines, choline methionine, etc.

Mutase reactions

cofactor in carbon transfer in nucleic acid metabolism

Development of red blood cells

"Extrinsic factor" to prevent pernicious anemia

Nerve system maintenance


Deficiency symptoms: 9



Anemia

Weakness

Fatigue

Neurological lesions

Nerve degeneration

Sprue

Red-sore tongue


What is Vitamin B12? 5
Vitamin B12 is part of a group of vitamins called B complex. There are eight B vitamins all together and they were at one time thought to be just one vitamin. Research has shown that they are indeed all slightly different in structure.

The other seven B vitamins that make up B Complex are:





Pyridoxine

Folic acid

Riboflavin

Biotin

Pantothenic Acid

Niacin

Thiamine


They share similar characteristics; they are all water-soluble, they are all essential in enabling the body to use energy from food and they are all vital for the production of normal tissue.

Vitamin B12 is a water-soluble vitamin and was actually the last of the B vitamins to be discovered in 1948. It has a bright red molecule at its centre, hence the other name it is known by "cobalamin."

Where is it found? 5
It is found animal produce and in micro-organisms like yeast. Its richest source is found in liver but all the following provide a good source too: eggs, fish, cheese, kidney and there are lesser amounts in milk.

Why is it needed? 5
Vitamin B12 is necessary if the body is to continue to produce red blood cells. A deficiency in vitamin B12 can lead to pernicious anaemia, which is when the body is unable to produce normal red cells and produces cells that are abnormally large and elliptical in shape. Other abnormalities are also present.

Vitamin B12 also assists in the manufacture of chemical compounds that ensure growth and function of the spinal cord and nerves.

What happens if you are deficient? 5
This vitamin is stored in the liver, kidney and other body tissues. Most people get enough B12 from their diet and it is found that the most common reason for deficiency is due to the body's inability to absorb this vitamin. This inability is due to a variety of reasons including low amounts of stomach acid, overgrowths of bacteria or coeliac disease.

People who don't eat animal produce - vegans - may be at risk of becoming deficient. It is common for alcoholics to be deficient too.

Deficiency can lead to pernicious anaemia; neurological damage due deterioration of the fatty sheaths that cover the nerves resulting in pins and needles in feet and hands, heart disease, muscle weakness, confusion, loss of memory and depression or mental functioning disorders, changes in mood, hallucinations, inflamed tongue.

Vitamin B12 also assists in the manufacture of chemical compounds that ensure growth and function of the spinal cord and nerves.

Added to: 5
Cereals, especially cornflakes

What conditions has it been used to treat? 5
Beri beri is treated with B12. It has been used to boost low spirits and boost memory in those with Alzheimer’s disease. It has been shown to prevent memory loss in the elderly.

Primary:



Heart disease prevention (in conjunction with folic acid and B6).

Conditions affecting nervous system: nerve pain, ringing in the ear (tinnitus), numbness and tingling.

Depression

Confusion

Mood changes

Alzheimer's disease

Multiple sclerosis


Secondary:



Asthma

Fatigue

Hepatitis

Insomnia

Epilepsy

Infertility


How much is normally taken? 5
The RDA for Vitamin B12 is 2 mcg a day.

For anxiety between 100-500 mcg have been supplemented a day and for pernicious anaemia up to 2,000 mcg for the first month is given with a reduced dosage of 1,000 mcg there after.

Are there any contraindications or side effects? 5
There are no known side-effects.

Great read REX...........