Vitamin P – Do Certain Polyphenolic IMPS Have a Vital Function?

Abstract

Abbreviations used: IMPS, invalid/improbable/interfering metabolic panaceas; PAC, proanthocyanidins; OPAC, oligomeric proanthocyanidins. AbstractIn the 1930s, it was discovered that the ability of synthetic Vitamin C to treat scurvy was inferior to plant extracts containing Vitamin C. This observation led to the proposal of Vitamin P (permeability), as an essential phytochemical dietary nutrient. Subsequent attempts to isolate and characterize Vitamin P led to confusing and sometimes irreproducible results. Over the years several flavonoids and coumarins have been identified as having Vitamin P-like activity.Essentially all of these Vitamin P candidates were recently identified as IMPs (Invalid/Improbable/Interfering Metabolic Panaceas) in a NAPRALERT meta analysis. While the historic inability to define a single compound and specific mode of action led to general skepticism about the Vitamin P proposition, the more logical conclusion is that several abundant and metabolically labile plant constituents fill this essential role in human nutrition. This review of 100+ years of multilingual Vitamin P and C literature provides the rationales for this conclusion.