e.v. mccollum's rule was, "eat what you want after you have eaten what you should." in 1952, time magazine called him dr. vitamin and noted that he "has done more than any other man to put vitamins back in the nation's daily diet." dr. mccollum was an advocate of the important contributions that could result from the collaborative approach of medically and biochemically oriented scientists. he demonstrated the relationship between nutritional deficiencies and clinical symptoms of disease. dr. mccollum was the first scientist to use a rat colony for nutrition research, a methodological innovation instrumental in his discovery of vitamins a and d. a strain of rats continues to bear his name.