It is easy to think
that one person discovered a vitamin on a Thursday just before lunch. It makes
history so much easier to re-tell. In the case of vitamin A, the process of
discovery spanned 130 years, starting in 1816 when a French physiologist
Francois Magendie fed dogs a poor diet and found they died in a similar fashion
as malnourished infants, and ending with its manufacture in 1946.
Milk gave the clue
Through a series of
experiments in the late 19th century it was clear that milk
contained something that was important to life. Giving animals the separate
components of milk – lactose, protein, fat and salts – could not sustain life,
yet whole milk could.
This was the time when
the dogma dictated that life needed only protein, fats and carbohydrates, and
some minerals like iron, so finding there was more to nutrition and life was
surprising. What was this mystical component in milk?
Dietetic factors
Biochemist Frederick
Hopkins in 1906 proposed that there were “unsuspected dietetic factors” in food
that accounted for conditions such as scurvy and rickets. We now know they were
caused by a lack of vitamins C and D respectively.
At this time it was
also assumed that all fats were the same, yet different fats had a different
ability to support life. If animals were given the fat extracted from eggs or
milk, or simply as butter, they lived but if the fat came only from lard or
olive oil they died. The fat-soluble substance in butter and egg yolk actually
contained vitamins A, D and E, all of which were yet to be identified.
Then things began to fall into place and clever people
started finding a range of vitamins. Hopkins was awarded the Nobel prize in
1929 (along with Christiaan Eijkman) for “the discovery of the vitamins”, and in
his acceptance speech he acknowledged the work of those who went before.
Scientists behaving badly
Then the bunfight
began. Elmer McCollum from the University of Wisconsin claimed that he had
discovered vitamin A in 1913 because he had worked out it was a fat-soluble
compound, despite others having determined that fact in the preceding 20 years.
McCollum would continue to claim that he was the one
to find vitamin A, yet was unable to get any backers. He attacked rivals,
sabotaged research, stole colleagues research notebooks, so it was no surprise
that he wasn’t nominated for a Nobel Prize.
It took until 1937 before we knew the structure of
vitamin A and until 1946 before it was first manufactured, completing the
process of discovery.
Vitamin A not the first vitamin
You would assume that
vitamin A was the first vitamin found, then isolated in a laboratory and
declared to the world. Not so. That was vitamin B, now known as vitamin B1 or
thiamine, first isolated in 1912 by Casimir Funk who said that thiamine was a
“vital amine” and coined the term “vitamine”. Now both vitamine and thiamine
have lost that last “e”. As long time readers will know, Popeye consumed spinach for its vitamin A content, not for its iron. Well, for
the beta-carotene content really, but back in 1932 we didn’t know that
beta-carotene became vitamin A in the body.
During the second half
of the 20th century, vitamins were given almost god-like status,
with most of the claims and beliefs being disproven. We were swallowing
mountains of vitamin C in the hope it stopped the common cold (it didn’t), and
we hoped a multivitamin would reduce stress and perk us up (not that easy,
sorry). OK, the B vitamin folate as a supplement for expectant Mums can help
reduce the risk of spinal deformities in the foetus, so it wasn’t all bad news.
What does it all mean?
The science of vitamins
is a very young science and there is much more to discover. Although small
amounts of vitamins are needed to avoid disease, we are not clear on the amount
needed to prolong life or prevent a disease. One genuine concern is that although
vitamins are considered “natural” we love to take them in amounts not found in
nature. Could years of taking vitamin supplements become a health problem in
the future? There is some evidence that says “Yes” and other evidence that says
“No problem”.
Reference:
Semba RD. On the
‘discovery’ of vitamin A. Annals of Nutrition & Metabolism 2012; 61:
192-198
