1619-1684

English physician who in 1645 provided the first scientific description of a vitamin D deficiency, or rickets. Whistler described the condition, wherein "the whole bony structure is as flexible as softened wax," in his Oxford doctoral dissertation, Inaugural Medical Disputation on the Children's Disease of the English Which the Inhabitants Idiomatically Call the Rickets. Five years later, in 1650, Francis Glisson (1597-1677) observed the same condition. Not until the early twentieth century would physicians be able to devise preventive measures against rickets.