According to this article: Vitamin B6 Toxicity
An Overview of Vitamin B6 Toxicity
Vitamin B6 (pyridoxine) is a water-soluble vitamin. Although people tend to think of water-soluble vitamins as being non-toxic, vitamin B6 can actually cause significant toxicity. Although vitamin B6 side effects may sometimes be seen even with normal doses, toxicity usually occurs with high doses.
What Are the Signs?
The classic sign of vitamin B6 toxicity is peripheral neuropathy (nerve problems in the hands and feet). This can cause unusual and unexplained sensations, such as numbness, tingling "pins and needles" feelings, *****ing, or burning. These sensations may sometimes affect the area around the mouth as well. If left untreated, the nerve damage can cause difficulty sensing vibrations and sensing the position of the limbs. As you might imagine, this can cause significant coordination problems.
The nerve problems due to vitamin B6 toxicity are often reversible once the vitamin is stopped. However, very high doses (especially if taken chronically) can cause permanent damage.