Roger Williams' work on biochemical individuality influenced the understanding of nutrition's importance.

“And one of the fathers of the thinking in functional medicine was Roger Williams, who discovered pantothenic acid, or vitamin B5. He wrote a book called biochemical individuality. And actually, his book was the one that got me interested in college, because I lived with a nutrition PhD student who was talking about, basically, the gut flora of cows, which he was studying to understand fiber and the microbiome. And he gave me a book called nutrition against disease by Roger Williams. And this is, like, in 1980. And I read it, and I was like, oh, wow, nutrition is such an important thing.”