Neurological Impact of Zinc Excess and Zinc Deficiency

Zinc is an essential mineral that can cause pathological effects whether in excess or deficiency. Zinc
is a component for over 250 enzymes and is required for cell growth, cell division, and cell function.
Zinc is found in muscle and bones, with the prostrate, liver, skin, and kidney having detectable levels
of zinc. However, zinc present in excess or deficiency can cause significant pathology in patients that
include deleterious effects neurologically. Zinc in excess in vivo can cause focal neuronal pathology,
while zinc deficiency can bring about mental lethargy, neuropsychiatric disorders, and reduced nerve
conduction. Zinc is assimilated within the body by oral ingestion, dermal exposure, and pulmonary
inhalation. Although not generally viewed as a cause of cancer, studies suggest that zinc is
associated with progression of prostate malignancy. Toxic levels of zinc have been shown to induce
lethargy, neurotoxicity, and gliotoxicity. High levels of zinc causes neuronal death in cortical cell tissue
culture. Zinc is known to accumulate following the death of neurons in global ischemia. Therefore,
zinc deficiency or excess is of significant clinical concern. Endogenous zinc is known to have
important involvement within cytotoxic activity within individual cells. Zinc excess is shown to induce
lethargy and focal neuronal reduction. Zinc deficiency has been shown to induce lethargy,
neurosensory pathology, neuropsychiatric disorders, and reduction of nerve conduction. Oral
ingestion of toxic levels of zinc will produce symptoms of dizziness and lethargy. The inhalation of zinc
can bring about shaking, fatigue, and fever. Although zinc acts as a neuromodulator, endogenous zinc
can be a potent and rapid neurotoxin. At 300 μM levels, zinc will extensively destroy cortical cells in
tissue culture. Neurons exposed to zinc will initiate apoptosis. The activity of zinc in the human body
has significant implications for normal health. Zinc in excess or deficit will cause pathological
conditions which should be rapidly diagnosed by clinicians. Further study of the biological activity of
zinc is warranted.