Vitamin B6 is a water-soluble vitamin that can result in nerve
damage when too much is taken in the form of supplements. B6 is
found naturally in most grains such as flax and wheat. Many
vitamin supplements and diet pills also contain more than the
daily requirements of vitamin B6. B6 toxicity, also known as B6
overdose, is rare and most doctors are unfamiliar with it. It's
becoming more common as manufacturers are adding B6 supplements
to many vitamins and fortifying cereals. Symptoms commonly
include a feeling of pins and needles, like nails being driven
into you, generally in your hands and feet or anywhere else in
your body where you've sustained nerve damage in the past.
However, instead of pain, symptoms may include numbness. Either
is refered to as neuropathy. Anytime you eat foods with certain
forms of vitamin B in them (B1, B3, B6), your symptoms worsen
for many hours. B6 toxicity is usually reversible by avoiding
foods with vitamin B in them for 6 months to 3 years.