Carpal Tunnel Syndrome: A Vitamin B(6) Deficiency?


Carpal tunnel syndrome is a complex of symptoms thought to result from the compression of the median nerve as it passes through the wrist, producing pain, burning and/or tingling in the fingers and hand.

Based on research they have conducted in the past 10 years, Dr. John Ellis and his colleagues believe that it is often caused by a long-term vitamin B( 6) deficiency.(17) They have frequently found carpal tunnel syndrome to be responsive to increased dietary vitamin B( 6).

In 1973, Dr. Ellis and Dr. J. Presley summarized many clinical studies showing that increased dietary vitamin B( 6) was of clinical benefit to patients with carpal tunnel syndrome.( 8) However, none of these early studies used blood chemistry tests to prove that these patients were vitamin B( 6)-deficient.

In 1975 and 1976 Dr. Takeo Kishi and colleagues developed an extremely sensitive method for determining vitamin B( 6) status in humans.( 9, 10) This method required the assay of erythrocyte glutamic oxaloacetic transaminase (EGOT) activity in the absence, and then in the presence, of the coenzyme pyridoxal 5'-phosphate (the active form of vitamin B( 6)). A large differential between the two EGOT activity tests would indicate a lack of adequate vitamin B( 6) to saturate the enzyme and keep it busy. In short, the assay determines how much the specific activity of EGOT is being limited by the absence of adequate vitamin B( 6).

Later, Dr. Junichi Azuma and co-workers used this assay to reveal an apparent vitamin B( 6) deficiency in typical "healthy" individuals who served as controls in vitamin B( 6) deficiency studies.( 11)

From 1976 through 1983, Dr. Ellis, Dr. Karl Folkers and their research teams published multiple studies utilizing this assay procedure.( 1-7) They clearly demonstrated a vitamin B( 6) deficiency in patients with carpal tunnel syndrome, which was diagnosed both by clinical examination and electrical conduction data.

When these carpal tunnel syndrome patients were given vitamin B( 6), EGOT specific activity would normalize within several weeks. Baseline EGOT activity also increased, suggesting that increased dietary vitamin B( 6) also stimulated EGOT production.

However, nine to 12 weeks or longer might be required before symptoms improved, depending upon the severity of the carpal tunnel syndrome. Improvement of the clinical picture occurred with such consistency that the doctors conducting double-blind crossover trials with placebos were able to determine which patients were receiving added dietary vitamin B( 6).( 7)

Further Studies

To provide further evidence, Dr. Folkers' team conducted electromyographic studies.( 12) They had some difficulty in limiting the variables for these studies so that the results would be statistically significant. Specifically, the temperature of the hands had to be the same at the different test times for the data to be of value. This double-blind study involved six patients with carpal tunnel syndrome who also had demonstrable vitamin B( 6) deficiencies, and it found: "In all patients taking pyridoxine, decreases in the motor latency and increases in the conduction velocity of the median nerve were observed. It is well known that the most sensitive electrodiagnostic measurements for confirming the presence of the carpal tunnel syndrome are the distal sensory and motor latency periods."( 12)

The researchers in one study concluded that no relationship exists between carpal tunnel syndrome and vitamin B( 6) deficiency.( 13, 14) However, these studies contained significant flaws. The severity of several cases of carpal tunnel syndrome improved with increased dietary vitamin B( 6).( 13) The authors attributed these improvements to a placebo effect, even though this study was not placebo-controlled. The tables indicate that the EGOT-specific activity doubled in most of the patients while taking vitamin B( 6). This observation was not addressed in the text, even though Ellis considers this to be the basis for diagnosing a vitamin B( 6) deficiency. Finally, Dr. Ellis and his colleagues indicate that pyridoxine should be tried for at least 12 weeks. An unspecified number of the six subjects in this trial were under care for only nine weeks.

The work of Dr. Ellis and Dr. Folkers has been confirmed in a case study reported by Dr. Arne Hamfelt.( 15) In the late 1960s, Dr. Hamfelt had developed a direct method for assaying serum pyridoxal phosphate, the active form of vitamin B( 6). In this report, Dr. Hamfelt found that a patient who was surgically treated for carpal tunnel syndrome was indeed vitamin B( 6) deficient.

Why the long period of time for clinical response to increased dietary vitamin B( 6)? Even though the biochemical deficiency is controlled in two to four weeks, it apparently takes considerably longer for the over 50 vitamin B( 6) dependent enzyme systems to gear up for optimal function.


( 1) Carpal tunnel syndrome appears to be the result of a long-term primary vitamin B( 6) deficiency.

( 2) Carpal tunnel syndrome patients should be evaluated regarding their vitamin B( 6) status by EGOT-specific activity and percent deficiency.

( 3) Carpal tunnel syndrome is often responsive to long-term dietary management, wherein the diet is supplemented with vitamin B( 6).

(1.) Ellis, J.M., Kishi, T., Azuma, J., and Folkers, K., "Vitamin B6 Deficiency in Patients With a Clinical Syndrome Including the Carpal Tunnel Defect; Biochemical and Clinical Response to Therapy With Pyridoxine," Research Communications in Chemical Pathology and Pharmacology, 13:743-757, April, 1976.

(2.) Ellis, J.M., Azuma, J., Watanabe, T., Folkers, K., Lowell, J.R., Hurst, G.A., Ahn, C.H., Shuford, E.H., and Ulrich R.F., "Survey and New Data on Treatment With Pyridoxine of Patients Having a Clinical Syndrome Including the Carpal Tunnel and Other Defects," Research Communication in Chemical Pathology and Pharmacology, 17:165-177, May, 1977.

(3.) Folkers, K., Ellis, J., Watanabe, T., Saji, S., and Kaji, M., "Biochemical Evidence for a Deficiency of Vitamin B6 in the Carpal Tunnel Syndrome Based on a Crossover Clinical Study," Proceedings of the National Academy of Science. 75:3410-3412, July, 1978.

(4.) Ellis, J., Folkers, K., Watanabe, T., Kaji, M., Saji, S., Caldwell, J.W., Temple, C.A., and Wood, F.S., "Clinical Results of a Crossover Treatment With Pyridoxine and Placebo of the Carpal Tunnel Syndrome," The American Journal of Clinical Nutrition, 32:2040-2046, Oct., 1979.

(5.) Shizukuishi, S., Nishii, S., Ellis, J., and Folkers, K., "The Carpal Tunnel Syndrome as a Probable Primary Deficiency of Vitamin B6 Rather Than a Deficiency of a Dependency State," Biochemical and Biophysical Research Communications. 95:1126-1130, Aug. 14, 1980.

(6.) Ellis, J., Folders, K., Levy, M., Takemura, K., Shizukuishi, S., Ulrich, R., and Harrison, P., "Therapy With Vitamin B6 With and Without Surgery for Treatment of Patients Having the Idiopathic Carpal Tunnel Syndrome," Research Communications in Chemical Pathology and Pharmacology, 33:331-334, Aug., 1981.

(7.) Ellis, J.M., Folders, K., Levy, M., Shizukuishi, S., Lewandowski, J., Nishii, S., Schubert, H.A., and Ulrich, R., "Response of Vitamin B6 Deficiency and the Carpal Tunnel Syndrome to Pyridoxine," Proceedings of the National Academy of Science, USA, 79:7494-7498, Dec., 1982.

(8.) Ellis, J.M., and Presley, J., Vitamin B6: The Doctor's Report, New York: Harper and Row, 1973.

(9.) Kishi, H., Kishi, T., Williams, R.H., and Folkers, K., "Human Deficiencies of Vitamin B(6): I. Studies on Parameters of the Assay of the Glutamic Oxaloacetic Transaminase by the CAS Principle," Research Communications in Chemical Pathology and Pharmacology, 12:557-569, 1975.

(10.) Kishi, H., and Folkers, K., "Improved and Effective Assays of the Glutamic Oxaloacetic Transaminase by the Coenzyme-Apoenzyme System (CAS) Principle," Journal of Nutritional Science and Vitaminology, 22:225-234, 1976.

(11.) Azuma, J., Kishi, T., Williams, R.H., and Folkers, K., "Apparent Deficiency of Vitamin B6 in Typical Individuals Who Commonly Serve as Normal Controls," Research Communications in Chemical Pathology and Pharmacology, 14:343-348, 1976.

(12.) Wolaniuk, A., Vadhanavikit, S., and Folkers, K., "Electromyographic Data Differentiate Patients With the Carpal Tunnel Syndrome When Double Blindly Treated With Pyroxidine and Placebo," Research Communications in Chemical Pathology and Pharmacology. 41:501511. Sept., 1983.

(13.) Smith, G.P., Rudge, P.J., and Peters, T.J., "Biochemical Studies of Pyridoxal and Pyridoxal Phosphate Status and Therapeutic Trial of Pyridoxine in Patients with Carpal Tunnel Syndrome," Annals of Neurology. 15:104-107, Jan., 1984.

(14.) McCann, V.J., and Davis, R.E., "Carpal Tunnel Syndrome, Diabetes and Pyridoxal," Australian and New Zealand Journal of Medicine, 8:638-640, Dec., 1978.

(15.) Hamfelt, A., "Carpal Tunnel Syndrome and Vitamin B(6) Deficiency," (letter), Clinical Chemistry, 28:721, 1982.

Life University.


By Laurence Johansen

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