DeForest Clinton Jarvis (March 15, 1881 – August 18, 1966) was an American physician from Vermont. He is best known for his writings on the subject of folk medicine. He recommended a mixture of whole apple cider vinegar and honey (variously called "switchel" or "honegar") as a health tonic and promoted an alkaline diet; both practices which are still promulgated by various naturopaths. He also advocated the consumption of kelp, fish, corn, and apples, and warned against white flour, white sugar, and processed foods.

Jarvis was born in Plattsburg, New York into a fifth-generation Vermont family and grew up in Burlington, Vermont. His parents were George Jarvis and Abbie Vincent. He graduated from the University of Vermont Medical College in 1904, and began practicing medicine in Barre, Vermont in 1909.

Jarvis's 1958 book Folk Medicine: A Vermont Doctor's Guide to Good Health was on the New York Times Best Seller list for two years, ultimately selling over one million copies, more than 245,000 copies in a single year, and was still in print as of 2002.

Wrote one reviewer, "Pliny, the ancient Roman originator of the doctrine of signatures, used honey and vinegar to cleanse the system and promote good health. D. C. Jarvis, M.D. in Folk Medicine has re-popularized the use of honey and apple cider vinegar in modern times."

More recently, modern science has begun to revisit some of his claims about vinegar, particularly with respect to diabetes, weight loss and insulin resistance.

He died at the Girouard Nursing Home in South Barre, Vermont, at the age of 85.

His hobbies included making jewelry and playing the cello, and he managed a children's orchestra for 22 years.

After his death in 1966, Jarvis's office was dismantled and shipped to the Shelburne Museum, where it was reconstructed and is still displayed, as an example of a small-town Vermont doctor's office.

-- Wikipedia