Normal levels of trace elements in human blood plasma or serum

Even though brass, a zinc-copper alloy, had been known for centuries, metallic zinc was not isolated in Europe until 1509. The metal was then named zinken because of its superficial similarity to tin (German-zinn) (Wootton, 1910). Zinc (atomic number 30; atomic weight 65 37) has a completed d subshell with 2 s electrons and the divalent cation is the only naturally occurring oxidation state. This relative stability, its ability to co-ordinate 4 or occasionally 6 ligands, and its capacity to act as a Lewis acid are probably fundamental to zinc's biological role. The biological importance of zinc was first discovered when Raulin (1869) demonstrated that it was necessary for the growth of Aspergillus niger. Subsequently, the ubiquitous distribution of zinc in nature was appreciated and the essentiality of zinc for higher plants (Maze, 1914) and animals (Todd et al., 1934) was established. In man the medicinal use of calamine (zinc carbonate) is first recorded in Papyrus Ebers of 1550 BC (Ebers, 1937) but it was not until 1939 that it was suggested that zinc deficiency might contribute to the clinical manifestations of human vitamin deficiency syndromes such as beriberi (Eggleton, 1939). The first human zinc deficiency syndrome was identified in the early 1960s in malnourished adolescent boys in Iran and Egypt (Halsted et al., 1972). A more profound deficiency state became apparent when Moyanhan and Barnes (1973) showed that treatment with zinc induced a complete and rapid clinical remission in a patient with acrodermatitis enteropathica.

https://adc.bmj.com/content/archdischild/54/12/909.full.pdf

Current status of zinc in health and disease states

Reversal of uræmic impotence by zinc

The purpose of the present paper is to provide a rationale for zinc supplementation as a potential therapeutic agent in critically ill patients by describing its role in health and disease, conducting a systematic review of current randomized trials in critical care, considering optimum route and dose of administration, and making recommendations for future research. Normal zinc homeostasis is required for a functional immune system, adequate antioxidant capacity, glucose homeostasis, and wound healing. In addition, zinc is a required cofactor for many enzymes, transcription factors, and replication factors. In non-critically ill patients, zinc supplementation has been associated with an improvement in markers of immune function. In critically ill patients, only 4 randomized trials have examined the effect of zinc supplementation on clinical outcomes. When all 4 studies were aggregated, zinc supplementation was associated with a nonsignificant reduction in mortality (relative risk = 0.63, 95% confidence intervals 0.25-1.59, P = .33) and length of stay in intensive care (-0.35 days, -0.85 to 0.15; P = .17). Thus, because of the paucity of clinical data, there is inadequate evidence to recommend the routine use of high-dose zinc supplementation in the critically ill. A first step would be to determine the optimal dose that has a maximal positive effect on underlying inflammatory, immunologic, and metabolic processes yet is safe and tolerated by critically ill patients. Subsequently, large, rigorously designed, randomized trials are required to elucidate the efficacy of such doses of zinc supplementation in this patient population.

Zinc supplementation in critically ill patients: a key pharmaconutrient?

(1977). Zinc in Human Nutrition. CRC Critical Reviews in Clinical Laboratory Sciences: Vol. 8, No. 1, pp. 1-80.

Zinc in human nutrition.

A country patient on home haemodialysis suffered acute nausea, vomiting, and fever during dialyses when she used water stored in a galvanized tank. She subsequently was found to have severe anaemia with raised plasma and erythrocyte zinc concentrations. Intercurrent hospital haemodialyses and subsequent home dialyses with deionized water were symptom-free. Experimental haemodialyses of dogs against small concentrations of zinc showed a disproportionate rise in plasma zinc and possible uptake of zinc by the liver.

https://www.bmj.com/content/bmj/4/5836/331.full.pdf

Eileen D. M. Gallery

Papers

Acute Zinc Toxicity in Haemodialysis