I did a google scholar search of “zinc dialysis” and turned up an article from 1978:
Hypogeusia and zinc depletion in chronic dialysis patients.
by - Atkin-Thor E, Goddard BW, O’Nion J, Stephen RL, Kolff WJ..
The PubMed summary is:
Dialysis patients generally have a poor appetite, do not enjoy eating, and complain of food, particularly protein, as being disagreeable. Twenty dialysis patients with the above symptoms were tested for taste acuity, serum zinc (Zn), Zn concentrations in hair samples (intracellular Zn), and daily caloric intake. A double-blind, cross-over study was instituted using a Zn supplement and a placebo. After supplementation with Zn, taste acuity markedly improved in 95% of patients and Zn concentrations in hair increased in 85% of patients. The patients’ appetites were improved; the average caloric intake increased by 675 kcal/day, and intolerance to protein diminished. In addition 10 normal control subjects were studied pre- and post-Zn supplementation for fasting blood glucose, serum Zn levels, and hair Zn concentration. Side effects were noted, and these usually correlated with elevated serum Zn levels and were minimized or disappeared with decrease in dosage or cessation of therapy.
So I think zinc is somethng you should look at but it also sounds like one could get too much zinc so it should be monitored.