Vitamin B6 : Overdose...

Vitamin B6 is usually safe at intakes up to 200 mg per day in adults.

However, an excess of pyridoxine can cause neurological disorders, such as loss of sensation in legs and imbalance, (200 mg or more per day) over a long period of time.

Pyridoxine poisoning

Vitamin B6 toxicity can damage sensory nerves, leading to numbness in the hands and feet as well as difficulty walking. Symptoms of a pyridoxine overdose may include poor coordination, staggering, numbness, decreased sensation to touch, temperature, and vibration,; and tiredness for up to six months.