A Rapid and Simple Lingual Ascorbic Acid Test

By W.M. Ringsdorf Jr.and E. Cheraskin

Summary: Dr. Royal Lee and other early nutritionists maintained that ascorbic acid is only one of the many components constituting the natural vitamin C complex—and not necessarily the functional one at that. On the other hand, ascorbic acid serves as a useful biomarker for determining the level of vitamin C complex in the body. Acknowledging that subclinical vitamin C deficiency is common, the authors outline a fast and inexpensive method of determining plasma and intradermal levels of vitamin C in an individual. From GP, journal of the American Academy of General Practice, 1962. Lee Foundation for Nutritional Research reprint 124.

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A Rapid and Simple Lingual Ascorbic Acid Test

There is general agreement that classical scurvy is now rare. However, in the opinion of some authorities, marginal vitamin C deficiency states are not infrequent. Unfortunately, these subtle problems cannot be detected by clinical examination. The present blood and urine tests for vitamin C status are cumbersome, expensive, and difficult to obtain. Thus, a simple tool to detect the marginally deficient vitamin C patient is needed. This report outlines a simple procedure that involves timing the decolorization of a minim of dye deposited on the dorsum of the dried tongue.

As far as we can determine, only one attempt of this type has been reported. Giza and Weclawowicz studied children, adults, and guinea pigs. They deposited one minim of a 0.06 percent solution of dichlorophenolindophenol on the dried dorsal surface of the protruded tongue. In their opinion the results compared favorably with blood vitamin C levels and urinary ascorbic acid excretion.


We studied 100 white adult males and females. All determinations were performed postprandially. One minim of a N/300 2,6-dichlorophenolindophenol solution was deposited through a 25-gauge needle on the dried dorsum of the protruded tongue. The number of seconds required for decolorization was determined by a stopwatch (Figure 1).

Immediately upon completion of the procedure, the test was repeated to establish its reproducibility. In only one instance was the second test shorter than the first and then only by one second. The largest group of second tests (32 percent) differed from the first test by three seconds. Practically all of the differences (98 percent) were less than eight seconds.

Figure 1A. Deposition of one minim of N/300 2:6 dichlorophenolindophenol solution.

Figure 1B. The dye begins to disappear at 2 seconds.

Figure 1C. At 10 seconds the dye is rapidly being decolorized.

Figure 1D. At 16.5 seconds the dye solution has completely vanished.

At each visit the plasma ascorbic acid level was also determined. Also at each session, the intradermal ascorbic acid decolorization test time was measured. In this manner the study permitted an evaluation and comparison of the lingual time versus the plasma ascorbic acid level and the lingual time versus the intradermal time in seventy-five subjects.


Figure 2 describes the relationship of the plasma ascorbic acid to the first lingual test. The groups of lingual scores are shown on the abscissa. The mean plasma ascorbic acid values are depicted on the ordinate. This shows quite clearly a progressive decline in mean plasma ascorbic acid with an increase in lingual time. The number of subjects is shown at each point in parentheses. The highest plasma ascorbic acid values are associated with the shortest lingual test times.

Figure 2. Relationship of lingual scores to plasma ascorbic acid level.

Figure 3 summarizes the relationship of the intradermal time (in minutes) to the first lingual test (in seconds). The lingual time group values are shown on the abscissa. The mean intradermal test time scores are plotted on the ordinate. Also included at each point, in parentheses, is the number of subjects. This figure quite definitely demonstrates a progressive increase in mean intradermal time in parallel with an increase in lingual time.

It appears, within the limits of this study, that the lingual time measures whatever is being measured by the plasma ascorbic acid level and the intradermal time. Furthermore, this procedure is carried out in seconds, as contrasted with minutes for the intradermal time and hours for the plasma level.

Figure 3. Relationship of lingual time and intradermal time.

This investigation was supported in part by trainee ship grant 2G-15 from the Epidemiology and Biometry Section, USPHS, and grant A-2899 from the National Institute of Arthritis and Metabolic Diseases.

By W.M. Ringsdorf Jr., DMD, and E. Cheraskin, MD, DMD. Section on Oral Medicine, University of Alabama Medical Center, Birmingham, Alabama. Reprinted by the Lee Foundation for Nutritional Research from GP, Volume XXV, Number 6, June 1962, published by the American Academy of General Practice.

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