The optimal levels of vitamin C intake in human individuals have been disputed ever since the isolation of the vitamin (1). On the one hand, the Food and Nutrition Board has set the recommended daily dietary allowances for vitamin C at 40 mg for children, 45-60 mg for adolescents, and 55-60 mg for adults. On the other hand, there are strong suggestions that the optimal levels of intake for the well-being of human individuals may be far above the recommended daily dietary allowances (1-3). Certainly optimal levels could also vary greatly from individual to individual (3, 4). It seems that a simple and rapid method for estimating how much vitamin C an individual needs would be highly desirable. Methods. This report presents results of an attempt to apply the lingual ascorbic acid test reported by Giza and Weclawowicz (5), and also studied extensively by Cheraskin and Ringsdorf (6-8). Volunteers, 47 in number, were recruited from staff members and students at the University of Texas. They were asked to follow their usual dietary habits except to avoid any ascorbic acid supplementation for 3 days prior to the tests. The tests were done in the early mornings under overnight fasting conditions. The technique was as described by Cheraskin and Ringsdorf with the modification of applying the 2,6-dichlorophenolindo-phenol reagent with a micropipette to obtain accurate drops of 0.01 ml in volume. The initial decolorization times of the 47 volunteers ranged from 8-65 sec. In three other volunteers, not included in the study, the droplet of reagent remained as such on the tongue and would not spread. Volunteers showing a long decolorization time (longer than 10 sec) were given ascorbic acid supplementations at graded levels: 500, 1,000, and 2,000; 3,000 and 4,000 mg if necessary, to decrease the decolorization time.