When I did my hair mineral analysis test the results came back worse than those with Lyme disease or severly autistic children. Probably the worst the naturopath saw. POIS is BAD. [!]
Talking about Zinc... I tried it, but of course not for long enough. Maybe for a week is the longest I've gone since I didn't wanted to risk copper deficiency and serious heart conditions associated with it. I used Zinc Chelate, but wondered if there's a better form? I might give it another go, let's say a month.
PS. You should take B6 with Zinc.
If your hair test was that bad, how do you know it's not Mercury related? Andy Cutler says that pregnancy, mercury and lactating woman are the only 3 things that can cause deranged mineral transport, which is according to him very likely if your hair test is messed up.