What does too much zinc from fixodent do to someone?

Possible neurologiic: Though not proven it is thought to cause possible neurologic damage.

Zinc Overdose: Studies have linked the overinjestion of zinc adhesives to neurological damage and blood abnormalities. Specifically numbness or tingling in extemities, loss of balance leading to difficulty in walking normally, headaches and pain, blurred vision, loss of muscle co-ordination. If used properly, fixodent is safe. The amounts of zinc required to cause these problems is pretty large.