In the year 1937, Rotter had suggested a skin-test for the estimation of the vitamin C nutrition of the body; in the year 1938 Portnoy and Wilkinson examined with some further and obtained similar results. Now, a small quantity of 2-6-di-chlorphenolindophenol was injected into the sole of each guinea-pig; the time of the complete decoloration of the dies was observed, and also the weight of the body was noted, both through the whole experiment. The feeding method was thus; Group I was feeded by the foundamental diets, that is vitamin C free diets, and group II was more added by the extract of the rhizome of Nelumbo nucifera, Gaertn. For summary, the weight of the body, in group I decreased distinctly; reversely in group II increased remarkably. From the point of view of the skin-test, in group I, the time of the complete decoloration prolonged remarkably, but in group II shortened more than the first.
So, conclusively: 1) Prolongation of the decoloration time in the skin-test, using 2-6-di-chlorphenolindophenol, appears to run parallel to the degree of the vitamin C content of tissues, though the other reducing substances in the skin, such as glutathione, may be concerned in decoloration phenomenon. 2) A decoloration time of less than 4 minutes indicates "Saturation", that of more than 10 minutes "Deficiency", while decoloration time of 5-10 minutes shows "Normal" content of vitamin C of the body.
This simple reaction may be of value as a advantage clinical test for vitamin C deficiency.