Discovering Vitamin B12

The active ingredient in liver was not isolated until 1948 by the chemists Karl A. Folkers of the United States and Alexander R. Todd of Great Britain. The substance was a cobalamin called vitamin B12. It could also be injected directly into muscle, making it possible to treat pernicious anemia more easily.

The chemical structure of the molecule was determined by Dorothy Crowfoot Hodgkin and her team in 1956, based on crystallographic data. Eventually, methods of producing the vitamin in large quantities from bacteria cultures were developed in the 1950s, and these led to the modern form of treatment for the disease (the above from [6]). It is a large protein of molecular weight 1355.5 (ie 1 Molecular Weight (mol) =6.022*10²³ (Avogadro’s constant) molecules of vitamin B₁₂ would weigh 1,355.5g if it could be isolated in pure form – see the table on comparing weight concentration with mol concentration in Diagnosis)

More on vitamin B₁₂ can be found on this page.

Citations

1.            Chanarin, I., The Megaloblastic Anaemias. 3rd ed. 1986, Oxford: Blackwell Scientific Publications.

2.            Addison, T., Anaemia: disease of the supra-renal capsules. London Medical Gazette 1849. 43: p. 517-518.

3.            Biermer, A., Über eine Form von progressiver perniciöser Anämie. Correspondenz-Blatt Schw. Ärzte., 1872. 2: p. 15-17.

4.            Russell, J.S.R., F.E. Batten, and J. Collier, Subacute Combined Degeneration of the Spinal Cord. Brain, 1900. 23: p. 39-110.

5.            Minot, G.R. and W.P. Murphy, Treatment of pernicious anemia by a special diet. 1926. Yale J Biol Med, 2001. 74(5): p. 341-53.

6.            Wikipedia. Vitamin B12. [web page] 2009  [cited 2009 2 Oct]; Description of Vitamin B12 (cobalamin) including description of discovery of cure for Pernicious anaemia and structure of B12]. Available from: http://en.wikipedia.org/wiki/Vitamin_B12.