On November 15, 1967, American biochemist Elmer McCollum passed away. McCollum is known for his work on the influence of diet on health. Together with Marguerite Davis McCollum discovered the first vitamin, named A, in 1913. He also helped to discover vitamin B and vitamin D and worked out the effect of trace elements in the diet.
In 1903, Elmer McCollum graduated from the University of Kansas. He secured a scholarship to Yale University in 1904, and wrote his thesis on pyrimidines. McCollum got his Ph.D. from Yale in two years. He remained for another year as a postdoctoral researcher working with Thomas Osborne and Lafayette Mendel on plant protein and diet. Then Mendel found a position for McCollum at the University of Wisconsin–Madison, not in his preferred organic chemistry, but as an instructor in agricultural chemistry.
At Wisconsin, Elmer McCollum was assigned to analyze cow feed and the animal’s milk, blood, feces, and urine for the famous single-grain experiment. Back then, chemists were trying to create the perfect foods for farm animals. McCollum continued to search for a breakthrough in human and animal nutrition. He determined that he must find out what was lacking in the animals’ purified diets, and that he needed to experiment on animals with a short life span, finally deciding on rats.
He began working with Marguerite Davis who helped McCollum develop “the biological method for the analysis of food”, and she co-authored a number of papers. Among them was “The Necessity Of Certain Lipins In The Diet During Growth” in 1913. They fed rats pure casein, carbohydrates, with a little agar-agar and a mixture of six or seven salts. They substituted lard or olive oil for some of the carbohydrates for a group of rats. For 70 to 120 days, their rats grew, and then they stopped growing. They still appeared to be healthy, except the females did not have enough milk to nourish their young. They successfully restored about thirty rats to normality, after these rats had reached the stage of growth suspension, by adding a small amount of extracts of egg or butter. Their paper included charts for five rats, illustrating their weights over time compared to a normal growth curve, meant to show McCollum and Davis’s “almost invariable success in inducing a resumption of growth after complete suspension for a time”. One chart showed their results with a fat-free diet. They became convinced that without a substance in the egg or butter extract, rats could not grow, even though they appeared to be healthy.
The scientists concluded that rats stoped growing until they are fed certain “ether extracts of egg or of butter”, and that “there are certain accessory articles in certain food-stuffs which are essential for normal growth for extended periods”. They also found this food factor in extracts of alfalfa leaves and in organ meats. This substance that McCollum called “factor A,” was later called vitamin A.
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