Vitamin B6 and Carpal Tunnel Syndrome

Over the past 20 years or so, a number of case reports and small studies have suggested that vitamin B6 deficiency might lead to carpal tunnel syndrome (CTS), a painful wrist condition usually linked to repetitive motion injuries. Some researchers believe vitamin B6 may be involved in CTS because of its important role in nerve function.

Although many doctors and CTS sufferers became B6 advocates, no controlled studies have tested the B5 theory. The first study to do so, involving 125 factory workers, found no connection between blood levels of the vitamin and wrist symptoms. Moreover, deficiency of vitamin B6 is rare, and too much of the vitamin can cause severe nerve damage. People with CTS who take the recommended mega-doses of B6 may be putting themselves at risk, since studies have shown that nerve damage can occur with doses as low as 200 milligrams per day.

Vitamin B6 and Premenstrual Syndrome
For years many women have taken vitamin B6 supplements to relieve premenstrual syndrome (PMS). However, in a recent review of 25 published studies, although B6 fared better than a placebo, researches found that there was not enough evidence to warrant a recommendation for using megadoses of B6 in the treatment of PMS. Furthermore, because of the potential for toxicity, the researches concluded that at the moment, there is no rational for giving vitamin B6 in doses greater than 100 milligrams per day. It may turn out that doses as low as 50 milligrams per day can relieve premenstrual symptoms.