- Vitamin B6 - Is a well known essential vitamin that can cause peripheral neuropathy in deficiency or excess. This should be limited to less than 200milligrams per day.
Vitamin A - Overdose occurs at 100,000 units/day and can present with fatigue, insomnia, painful bones and joints, bone growth abnormalities, hair loss, itchy skin, loss of appetite (anorexia), decreased blood clotting time, and risks of birth defects or abortions during pregnancy.
Vitmain D - Overdose occurs at 4000-10,000IU /day and can present with muscle weakness, joint pain, resorption of bone, calcification of soft tissues, loss of appetite, nausea and diarrhea.
Vitamin E & K - Have some studies that exhibit overdose, but with unknown upper limits are associated symptoms.