Elmer Verner McCollum (March 3, 1879 – November 15, 1967) was born and
raised in Kansas and attended the University of Kansas. His studies were
initially directed toward medicine, but he eventually decided that
chemistry better captured his interests, and he completed his work for a
Masters degree in chemistry at Kansas. He was accepted into the Ph.D.
program at the Sheffield Scientific School at Yale.
Contrary to
the dogma that all fats had similar nutritional value, in 1913, Elmer
McCollum and his associate Marguerite Davis at Wisconsin showed butter
and egg yolk were not equivalent to lard and olive oil in supporting the
growth and survival of rats. The growth-supporting ‘accessory factor’
became known as ‘fat-soluble A’ in 1918 and then ‘vitamin A’ in 1920.
“Fat-soluble
A” was first believed to be a single vitamin capable of curing
xerophthalmia and rickets. Cod-liver oil was first used as a
therapeutic agent in the 1770s. McCollum showed that cod-liver oil
aerated at the temperature of boiling water for 12 to 20 hr retained its
antirachitic activity in rats, but was ineffective against
xerophthalmia. In addition, these properties were unequally distributed
in certain foods. Apparently, two separate factors were involved.
The factor effective against rickets later was named vitamin D.
The
discovery of vitamin A by McCollum and Davis in 1913 ushered in the era
of accessory food substances culminating in the achievement of that
goal. It included the discovery of vitamin D and its production in skin
caused by ultraviolet light. This was followed by a description of its
actions at the physiological level that resulted in a healthy skeleton
and beyond.
In 1915 McCollum and Davis had found that
when water oralcohol extractions of wheat germ or rice polishing
were added, polished rice was greatly improved in nutritional
quality. These experiments constituted the basis for their
discovery that the anti-beriberi factor, necessary to relieve
polyneuritis in pigeons, was necessary for rats and that there
were apparently only two unidentified nutrients necessary for
such animals.
They proposed the term fat-soluble A and
water-soluble B, respectively, to designate the two unidentified
nutrients. The isolation of B1was achieved in 1926 by Dutch scientists
in Java using small “rice birds” fed on washed white rice supplemented
with cod liver oil for their assays.
History of science is devoted to the history of science, medicine and technology from earliest times to the present day. Histories of science were originally written by practicing and retired scientists, starting primarily with William Whewell, as a way to communicate the virtues of science to the public.
Tuesday, December 22, 2020
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