How can I take zinc A? I can't eat the raw metal can I?
Found this which is a bit worrying:
"The figure below summarizes the key aspects of the mechanisms possibly explaining Zn’s potential to induce brain cell death.
Does this now mean we should be aware of our daily Zn intake to protect our brain?
Most probably not. Although Zn toxicity (here especially peripheral symptoms) has been described in individuals repeatedly consuming more than 50 mg per day, the blood brain barrier, which regulates Zn homeostasis of the brain, is comparatively impermeable to changes in the concentration of blood metal ions. This does, of course, not mean that one cannot deplete the brain of Zn when significantly cutting down oral Zn intake.
In terms of neurodegeneration, for example Alzheimer’s disease, current believe is that the toxic effects of Zn are due to disruption of the brain endogenous Zn homeostasis, a hypothesis which is supported by studies in neuronal-specific Zn-transporter knockout mice."