October 30, 2012

History of the Discovery of Vitamin B6

Pellagra and the B Vitamins:

Pellagra is one of the earliest described clinical syndromes.  A syndrome is a “cluster of symptoms” that characterize a particular disease.

Pellagra probably originated in Northern Italy where it was named "Pelle Agra" (Pelle = skin; Agra = sour).

The Four Ds:

Pellagra has been called "The Syndrome of The "Four D's": Diarrhea, Dermatitis, Dementia and Death.  Outbreaks occurred mainly in areas where maize was the main food crop; hence it was widely believed that maize itself carried some kind of “toxin.”

It transpired that Pellagra was related to the processing of maize (leading to deficiency of an essential nutrient), rather than to the maize itself.

By the early 1900s, Pellagra had reached epidemic proportions in the Southern United States.  In 1926, Goldberger showed that a balanced diet, or at least a small amount of Brewer's Yeast, could prevent the condition.  In the 1930s, Elvehjem showed that the vitamin Niacin (Vitamin B3) was curative, at least in dogs.

Rats:

The first report of a "Pellagra-like" condition in rats (called Acrodynia) was made in 1926.  Although it was not initially recognized as such, this later proved to be the result of a vitamin B6 deficiency due to a diet consisting mainly of alcohol-extracted cornmeal.  Gyorgy later identified vitamin B6 as the specific component that prevented the condition. For further details, the interested reader is referred to:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1263399/pdf/biochemj01064-0134.pdf

Shortly afterwards, several independent laboratories isolated the nutritionally active material, called “pyridoxine”.

Pyridoxine/Vitamin B6:

The chemistry of Vitamin B6 (pyridoxine) is very complex; a detailed description is beyond the scope of this Blog.  Suffice to say that an adequate dietary intake of B6 is needed to allow for synthesis of its “coenzyme” forms (specific types of the vitamin needed by the body to assist with the chemical breakdown/metabolism of various compounds).

Many enzymes in the body use vitamin Bas a “catalyst” for various reactions.  In this Blog, we will focus entirely on the role of B6 in the breakdown of 'homocysteine.'

Homocysteine:

Before discussing Bfurther however, we have just one last historical journey to undertake ..

Check back soon for the “History of the Discovery of Homocysteine…” 

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