Deficiencies as PD cause/Zinc
Zinc is a metallic chemical element with the symbol Zn and atomic number 30. Credit for its discovery in 1746 is normally given to the German chemist Andreas Sigismund Marggraf.
It has been shown to be an important dietary supplement  quoted below.
"Zinc is involved in numerous aspects of cellular metabolism. It is required for the catalytic activity of approximately 100 enzymes and it plays a role in immune function, protein synthesis, wound healing, DNA synthesis, and cell division. Zinc also supports normal growth and development during pregnancy, childhood, and adolescence and is required for a proper sense of taste and smell. A daily intake of zinc is required to maintain a steady state because the body has no specialized zinc storage system."
"Zinc deficiency is characterized by growth retardation, loss of appetite, and impaired immune function. In more severe cases, zinc deficiency causes hair loss, diarrhea, delayed sexual maturation, impotence, hypogonadism in males, and eye and skin lesions. Weight loss, delayed healing of wounds, taste abnormalities, and mental lethargy can also occur."
Jimenez-Jimenez et al  measured zinc and copper in serum levels for 32 (Zn) and 39 (Cu) PD patients, with their spouses as controls. Their conclusions state:-
"These values did not correlate with age in the control group. These results suggest that serum levels of zinc and copper do not play any role as risk factors for PD."
Jimenez-Jimenex et al  compared Cerebral Spinal Fluid and serum levels of iron, copper, manganese, and zinc, measured by atomic absorption spectrophotometry, in 37 patients with Parkinson's disease (PD) and 37 matched controls. The CSF levels of zinc were significantly decreased in PD patients as compared with the controls.
Forsleff et al  applied a novel oral zinc tally test (ZTT) used to assess the zinc status of 100 PD patients and 25 controls. Patients with PD showed a significantly decreased zinc status as compared to controls. Their conclusions state:-
" PD status is positively correlated with self-reported vision problems, and olfactory and taste loss. Further study of the role of zinc in the development and treatment of PD is warranted."
Forte et al  assessed:-
"whether hair could be a reliable marker of possible changes, calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), silicon (Si) and zinc (Zn) were determined in hair from 81 patients affected by PD and 17 age-matched controls."
Results indicated significantly lower levels of Fe in the hair of patients (p=0.018) compared with controls. Ca and Mg levels were slightly lower while Zn levels were higher in patients, although these differences were not significant; neither were variations in Cu and Si. Ca and Mg were at least 1.5 times higher in females than in males in both controls and patients. In addition, Ca correlated positively with Mg in both groups and in both sexes (p-value always less than 0.03), and negatively with age in patients (p<0.01). Finally, element levels did not correlate with either the duration or the severity of the disease or with anti-Parkinson treatment
Brewer et al 
"evaluated zinc status in 29 patients with Alzheimer's disease, 30 patients with Parkinson's disease, and 29 age- and sex-matched controls. Results showed a significantly lower blood zinc in patients with Alzheimer's and patients with Parkinson's than in controls. Urine zinc excretion, normalized to urine creatinine excretion, was not significantly different in either patient group compared to controls. These patients are probably zinc deficient because of nutritional inadequacy."
Saini & Schaffner  found that PD mutated fruit flies fed on a zinc-enhanced diet had:-
"a higher frequency of reaching adulthood, extended lifespan and improved motoric abilities."
Low zinc and Parkinson's Disease
- National Institutes of Health, Diet Supplement Fact Sheet. http://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/
- Jiménez-Jiménez FJ,; Fernández-Calle, P.; Martínez-Vanaclocha, M.; Herrero, E.; Molina, J.A.; Vázquez, A. and Codoceo, R. (1992) J. Neurol. Sci. 112(1-2) 30-33. Serum levels of zinc and copper in patients with Parkinson's disease. http://www.ncbi.nlm.nih.gov/pubmed/1469436.
- Jiménez-Jiménez, F.J.; Molina, J.A.; Aguilar, M.V.; Meseguer, I.; Mateos-Vega, CJ.; González-Muñoz, M.J.; de Bustos, F.; Martínez,;-Salio; A. Ortí-Pareja, M.; Zurdo M. and Martínez-Para, M.C. (1998) J Neural. Transm.;105(4-5):497-505. Cerebrospinal fluid levels of transition metals in patients with Parkinson's disease. http://www.ncbi.nlm.nih.gov/pubmed/9720977
- Forsleff, L.; Schauss, A.G.; Bier, I.D. and Stuart, S. J. (1998)Altern. Complement. Med. 5(1):57-64. Evidence of functional zinc deficiency in Parkinson's disease. http://www.ncbi.nlm.nih.gov/pubmed/10100031
- Forte, Giovanni; Alimonti, Alessandro; Violante, Nicola; Di Gregorio, Marco; Senofonte, Oreste; Petrucci, Francesco; Sancesario, Guiseppe, and Bocca, Beatrice. Forte, Giovanni; Alimonti, Alessandro; Violante, Nicola; Di Gregorio, Marco; Senofonte, Oreste; Petrucci, Francesco; Sancesario, Guiseppe, and Bocca, Beatrice. (2005) Calcium, copper, iron, magnesium, silicon and zinc content of hair in Parkinson's disease. Journal of Trace Elements in Medicine and Biology 19 (2-3) 195-220 http://www.sciencedirect.com/science/article/pii/S0946672X05000970
- Brewer. G.J.; Kanzer, S.H.; Zimmerman, E.A.; Molho, E.S.; Celmins, D.F.; Heckman, S.M. and Dick, R. (2010) Am. J. Alzheimers Di.s Other Demen. 25(7):572-575. Subclinical zinc deficiency in Alzheimer's disease and Parkinson's disease. http://www.ncbi.nlm.nih.gov/pubmed?term=Subclinical%20Zinc%20Deficiency%20in%20Alzheimer%E2%80%99s%20Disease%20and%20Parkinson%E2%80%99s%20Diseasehttp://www.springerlink.com/content/k46292348p0726mp/
- Saini, Nidhi and Schaffner, Walter (2010) Biogical Chemistry. 391 (5), 513–518. Zinc supplement greatly improves the condition of parkin mutant Drosophila. http://www.reference-global.com/doi/abs/10.1515/BC.2010.052