Vitamin D became classified as a vitamin through a historical accident.
It was in 1919/20 that Sir Edward Mellanby, working with dogs raised
exclusively indoors, devised a diet that allowed him to unequivocally
establish that their bone disease, rickets was caused by a deficiency of
a trace component present in the diet.
The transformation of
the vitamin D precursor (7-dehydrocholesterol) by UVB has been
discovered in 1923 by Harry Goldblatt and Katherine Soames, research
that was later developed by Alfred Fabian Hess and Mildred Weinstock.
Harry
Goldblatt (1891-1977) was an American pathologist whose research and experiments on
renovascular hypertension were an important contribution to
understanding and treating this disease. He was born in Iowa, the son of
Phillip and Jennie Spitz Goldblatt. He grew up in Canada, received a
B.A. from McGill University, and graduated from its medical school in
1916.
During the course of extensive nutritional research, in
1923 Harry Goldblatt and Katherine Soames clearly identified that when a
precursor of vitamin D in the skin (7-dehydrocholesterol) was
irradiated with sunlight or ultraviolet light, a substance equivalent to
the fat-soluble vitamin was produced.
Goldblatt and Soames
irradiated rat livers that had been excised from rachitic rats with
ultraviolet light and found that when the irradiated tissue was ground
and fed to other rachitic rats, there was a remission of the D
deficiency, whereas the livers from unirradiated rats were not.
Research of Vitamin D by Harry Goldblatt