Daily Vitamin C Consumption and Fatigability

Abstract: The increased prevalence of fatigue in persons with a low intake of vitamin C is mentioned only briefly in the literature. An analysis of the authors’ data on vitamin C intake and fatigability in 411 dentists and their wives revealed a negative relationship. The mean number of fatigue symptoms among the low users of vitamin C was double that among the relatively high users of vitamin C. The mean difference was statistically significant. 

 

A considerable body of literature is available concerning the relationship between vitamin C consumption and morbidity in terms of specific syndromes. Very little, however, has been reported about the possible relationship between vitamin C consumption and early nonspecific measures of ill health. There is also a paucity of information concerning fatigability as a measure of health status.

According to Crandon’s classic study¹ of experimental human scurvy, a progressive feeling of fatigue develops at the beginning of the third month. Although the capacity for anaerobic work (as measured by the hand ergograph) is undiminished during the scorbutic state, aerobic performance is significantly reduced.

From a study of 24 manual workers, Johnson et al² concluded that total deprivation of vitamin C for eight weeks had no effect on the physical efficiency of healthy young men who previously had been receiving an adequate diet. Moreover, a daily 75-mg dose of ascorbic acid added to the nutritionally satisfactory diet over a period of two months was of no benefit to manual workers with respect to physical vigor for hard work or efficiency in performing the work.

Gey and associates,³ in a study of 286 male United States Air Force officers, concluded that a daily supplement of 1000 mg of ascorbic acid had a negligible effect on endurance performance when compared to a placebo. The evaluation of performance was made by means of a 12-minute walk-run test before and after twelve weeks of training. They suggested, however, that the results might have been different if the subjects had been older or the physical activity had not included contact sports. They advocated double-blind studies to answer such questions and thus help to determine the true value of dietary supplements.

Statistical Study–Methods and Results

The vitamin C intake of 411 dentists and their wives was determined from the data on daily vitamin C consumption in a food-frequency questionnaire. The mean number of fatigue symptoms listed in answers to the seven questions comprising Section I of the Cornell Medical Index Health Questionnaire⁴ was designated the fatigability score. The relationship between the two variables was determined by calculating the fatigability score for different levels of vitamin C intake.

Results. The 81 subjects who consumed less than 100 mg of vitamin C per day reported a fatigability score averaging 0.81 ± 1.36, Conversely, the 330 subjects consuming more than 400 mg of vitamin C per day reported a fatigability score averaging 0.41 ± 1.00. The mean difference was statistically significant (t = 2.513; P <0.025).

This negative correlation might prove useful as a factor in the early detection and prevention of ill health.

 

References Cited:

1. Crandon J. H., Lund C. C., and Dill D. B.: “Experimental human scurvy,” New England J. Med. 223:353, 1940.
2. Johnson R. E., Darling R. C., Sargent F. et al: “Effects of variations in dietary vitamin C on the physical well being of manual workers,” J. Nutrit. 29:155, 1945.
3. Gey G. O., Cooper K. H., and Bottenberg R. A.: “Effect of ascorbic acid on endurance performance and athletic injury.” J. A. M. A. 211:105, 1970.
4. Brodman K., Erdmann A. J., and Wolff H. G.: Cornell Medical Index Health Questionnaire: Manual. New York, Cornell University Medical College, 1949.