Nutritional Influences on Illness: Carpal Tunnel Syndrome

Nutritional Influences on Illness: Carpal Tunnel Syndrome

One of the most common neuropathies in clinical practice, carpal tunnel syndrome (CTS) most frequently affects women between the ages of 40 and 60. The carpal tunnel is a small cavity between the carpal bones through which the median nerve runs on its way to the hand and fingers. The syndrome, caused by pressure on the nerve, is associated with repetitive wrist motions such as typing. It is marked by pain and paresthesias ("pins and needles"), impaired finger flexion, finger edema, weakness of hand grip, and other symptoms.

Standard treatment consists of wrist splints, steroid injections, and anti-inflammatory drugs. Often these treatments fail, and patients then undergo surgical decompression of the median nerve.

While medications and surgery may sometimes be necessary, many times the syndrome can be successfully treated with simple nutritional supplementation. John Ellis, a practicing physician, is the person who is primarily responsible for discovering the efficacy of vitamin B6 in the treatment of this syndrome. Ellis finds that at least 85% of patients respond to doses that are usually between 50 mg and 200 mg daily. He notes that improvement starts in a few weeks, with complete cure occurring in 8 to 12 weeks.( 1)

In our society, vitamin B6 intake is frequently inadequate for our metabolic needs.( 2) Ellis believes that CTS patients are often B6-deficient. When he elevated vitamin B6 nutriture (EGOT activity) in 4 patients just prior to surgical decompression, he found a B6 deficiency in all four.( 3)

A subsequent study, reported in the Archives of Surgery, confirmed his impression. Pyridoxal phosphate levels in 6 normals were found to be two and one-half times those of 8 CTS patients, a difference that was statistically significant. These results so impressed the investigators that they suggested that "part of the total work-up of patients with CTS should include a nutritional evaluation, in particular, a determination of vitamin B6 status."( 4)

A good number of studies have investigated Ellis' belief in the efficacy of vitamin B6 supplementation. However, their sample sizes have been small and the results mixed.( 5) It may be that at least two sub-groups of patients are responders. Responders who show objective evidence of healing may have a combination of vitamin B6 deficiency and electrophysiologic evidence of neuropathy,( 6) while responders who fail to show objective improvement may experience pain relief due to the vitamin's anti-nociceptive (pain-relieving) effect.( 7, 8)

Dietary vitamin B6 is in the form of pyridoxine. After ingestion, the vitamin is converted to pyridoxal-5'-phosphate, its active form. For various reasons, some people have difficulty in accomplishing this conversion; this is one reason why supplementation with pyridoxal-5'-phosphate (usually at one-tenth the dosage of pyridoxine) is preferable to supplementation with pyridoxine. Another reason is that long-term supplementation with higher doses of pyridoxine (usually at least 2 grams daily but occasionally much lower doses) can cause a sensory neuropathy.

The liver's ability to phosphorylate pyridoxine apparently is limited; thus, when its dosage exceeds the liver's capacity, pyridoxine levels become excessively elevated. Theoretically, these high levels could be directly neurotoxic; alternatively they could compete with pyridoxal-5'-phosphate for binding sites, causing it to become relatively deficient.( 9) Too much supplemental pyridoxine could therefore foster a neuropathy by creating a deficiency of the active form of the very same vitamin it was supposed to supplement!

Carpal tunnel syndrome may also be caused by a deficiency of riboflavin. After conversion to pyridoxine-5'-phosphate, a riboflavin-dependent enzyme is needed to activate the vitamin by converting it to pyridoxal-5'-phosphate; thus a riboflavin deficiency may result in inadequate vitamin B6 activity even though B6 dietary intake is adequate.( 10) This is a good example of why knowledgeable practitioners like to prescribe vitamin B complex whenever supplementation with a single B vitamin is indicated.( 11)

Doctor Werbach cautions that the nutritional treatment of illness should be supervised by physicians or practitioners whose training prepares them to recognize serious illness and to integrate nutritional interventions safely into the treatment plan.

Next Month: Cervical Dysplasia

(1.) Ellis JM, Folkers K. Clinical aspects of treatment of carpal tunnel syndrome with vitamin B6. Ann NY Acad Sci 585:302-20, 1990.

(2.) Rall L, Meydani S. Vitamin B6 and immune competence. Nutr Rev 51:217-25, 1993.

(3.) Ellis J. et al. Therapy with vitamin B6 with and without surgery for treatment of patients having the idiopathic carpel tunnel syndrome. Res Comm Chem Pathol Pharmacol 33(2):331, 1981.

(4.) Fuhr JE. et al. Vitamin B6 levels in patients with carpal tunnel syndrome. Arch Surg. 124:1329-30, 1989.

(5.) Werbach MR. Carpal tunnel syndrome. Nutritional Influences on Illness. Second Edition. Tarzana, California, Third Line Press 1993.

(6.) Byers CM. et al. Pyridoxine metabolism and carpal tunnel syndrome with and without peripheral neuopathy. Arch Phys Med Rehabil 65(11):712-16, 1984.

(7.) Bernstein AL. Vitamin B6 in neurology. Ann NY Acad Sci 585:250-60,1990.

(8.) Zimmerman M. et al. Antinociceptive properties of pyridoxine. Neurophysiological and behavioral findings. Ann NY Acad Sci 585:219-30, 1990.

(9.) Parry CJ, Bredesen DE. Sensory neuropathy with low-dose pyridoxine. Neurology 35:1466-8, 1985.

(10.) Folkers K, Ellis J. Successful therapy with vitamin B6 and vitamin B2 of the carpal tunnel syndrome and need for determination of the RDAs for vitamins B6 and B2 for disease states. Ann NY Acad Sci 585:295-301, 1990.

(11.) Sauberlich HE. Interactions of thiamine, riboflavin and other B-vitamins. Ann NY Acad Sci 355:80-97, 1980.

Reprinted with permission from the International Journal of Alternative and Complementary Medicine, Green Library, 9 Rickett St., Fulham, London SW6 1RU, United Kingdom.

Carpal tunnel syndrome is only one of 87 different illnesses covered in Doctor Werbach's internationally acclaimed Nutritional Influences on Illness, now in its second edition. A free brochure describing all of his books is available from Third Line Press, Inc., 4751 Viviana Drive, Tarzana CA 91356. Telephone 818-996-0076; fax 818-774-1575; e-mail:

Townsend Letter for Doctors & Patients.


By Melvyn R. Werbach

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