The vitamin has been reified. A chemical intangible originally defined as a unit of nutritive value, it was long ago reified into a pill. Now it is a pill; no one except a few precise scientists define it as anything else. Once the vitamin became a pill, it became real according to the precepts of American Cartesianism: I swallow it, therefore it is.

Reflections In A Jaundiced Eye (ed. 1990)