The start of the second World War was breaking news when Ruth Flinn Harrell conducted her first investigations into what she called "superfeeding." Her 1942 Columbia University doctoral thesis, "Effect of Added Thiamine on Learning," was published by the university in 1943 and would be followed by "Further Effects of Added Thiamine on Learning and Other Processes" in 1947. Her research was not about enriched or fortified foods; "added" meant "provided by supplement tablets." In a 1946 Journal of Nutrition article, Dr. Harrell stated that "a liberal thiamine intake improved a number of mental and physical skills of orphanage children." One reporter wrote, "An experiment was conducted by Dr. Ruth Flinn Harrell which involved 104 children from nine to nineteen years of age. Half of the children were given a vitamin B₁ (thiamine) pill each day, and the other half received a placebo. The test lasted 6 weeks. It was found by a series of tests that the group that was given the vitamin gained one-fourth more in learning ability than did the other group." By 1956, Harrell had investigated "The Effect of Mothers' Diets on the Intelligence of Offspring," finding that "supplementation of the pregnant and lactating mothers' diet by vitamins increased the intelligence quotients of their offspring at three and four years of age."

Early in 1981, Harrell and colleagues published a study in Proceedings of the National Academy of Sciences showing that high doses of vitamins improved intelligence and educational performance in learning disabled children, including those with Down syndrome. Dr. Harrell, who had been investigating vitamin effects on learning for forty years, had at last succeeded in focusing much-needed public attention on the role of nutrition in learning disabilities.

—Saul AW. The Pioneering Work of Ruth Flinn Harrell, Champion of Children. J Orthomolecular Med, 2004. Vol 19, No 1, p 21-26.