Vitamin B12, or cobalamin, is used by every cell in the body. It is very important for DNA metabolism and several other functions. A lack of B12 can lead to the condition called pernicious anemia. This causes low red blood cell counts, fatigue, weakness and problems with the nerves. The vitamin helps to transfer and attach chemicals called methyl groups, which consist of a carbon and three hydrogen atoms, from one chemical to another. Since the vitamin is so important for health and is low in certain diseases, it has been synthesized for use.
Chemical Synthesis
Vitamin B12 is the most complicated, largest chemical structure of all the vitamins. Its synthesis was first described in 1973 by Robert Burns Woodward and Albert Eschenmoser. The synthesis involves creating two chemical rings and coupling them together, then the same with two other rings. All four are brought together to form the vitamin. The total reaction takes about 70 reactants, according to "Pure Applied Chemistry."
Biological Synthesis
Since chemical B12 synthesis takes many complicated steps and a lot of energy, it has a high cost of production. Therefore, companies manufacturing B12 use biological synthesis. Biological synthesis makes use of bacteria to synthesize the vitamin. Animals normally get all of their B12 ultimately from bacteria. Bacteria use it for similar functions as animals, to help transfer methyl groups between other chemicals. Bacterial enzymes synthesize the vitamin. Enzymes are special types of proteins that greatly increase the speed of chemical reactions. The species Propionibacterium shermanii and Pseudomonas denitrificans are commonly used to make vitamin B12 in manufacturing.
Over-the-Counter Supplements
Many foods, such as breakfast cereals, are fortified with vitamin B12. Oral pills, sublingual preparations, lozenges, tablets and skin patches are available as well. Most of these supplements are in the form of cyanocobalamin, which is converted into usable vitamin B12 by the body, according to the National Institutes of Health.
Prescription Medications
Prescription medications are available for those with pernicious anemia. These are typically administered by injection, usually into a muscle. Other prescription strength supplements are produced as well, such as a nasal gel.
References
- "Pure Applied Chemistry"; "The total synthesis of vitamin B12"; Robert Woodward; 1973
- "Encyclopedia of Microbiology, Second Edition"; Martin Alexander, Barry R. Bloom, David A. Hopwood, Roger Hull, et al.; 2000
- National Institues of Health: Office of Dietary Supplements: Dietary Supplement Fact Sheet: Vitamin B12
- "Robbins and Cotran Pathologic Basis of Disease"; Vinay Kumar et al; 8th Ed 2009
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