Zinc Deficiency Effects

Zinc deficiency effects have been produced experimentally in freshwater sponges at <0.65 pg Zn/L (Francis and Harrison 1988), in rainbow trout fed diets containing <15 mg Zn/kg FW (Spry et al. 1988), in certain species of marine algae at <0.7 pg Zn/L (Vymazal 1986), and in certain species of marine invertebrates at <6.5 pg Zn/L (Clapper et al. 1985a, 1985b) or <34 mg Zn/kg DW whole organism (White and Rainbow 1985). Zinc deficiency in natural aquatic ecosystems has not yet been credibly documented. 

The balance between excess and insufficient zinc is important. Zinc deficiency occurs in many species of plants and animals, with severe adverse effects on all stages of growth, development, reproduction, and survival. In humans, zinc deficiency is associated with delayed sexual maturation in adolescent males poor growth in children impaired growth of hair, skin, and bones disrupted Vitamin A metabolism and abnormal taste acuity, hormone metabolism, and immune function. Severe zinc deficiency effects in mammals are usually prevented by diets containing >30 mg Zn/kg DW ration. Zinc deficiency effects are reported in aquatic organisms at nominal concentrations between 0.65 and 6.5 pg Zn/L of medium, and in piscine diets at <15 mg Zn/kg FW ration. Avian diets should contain >25 mg Zn/kg DW ration for prevention of zinc deficiency effects, and <178 mg Zn/kg DW for prevention of marginal sublethal effects. 

Bird diets, in mg Znflcg DW feed, should contain 25.0-38.0 to prevent zinc deficiency effects, 93.0-120.0 for adequate to optimi growth, <178.0 to prevent marginal sublethal effects, and <2000.0 to prevent the death of... 

Bushnell PJ, Levin ED. 1983. Effects of zinc deficiency on lead toxicity in rats. Neurobehav Toxicol Teratol 5 283-288. 

Sublethal effects in birds are similar to those in other species and include growth retardation, anemia, renal effects, and testicular damage (Hammons et al. 1978 Di Giulio et al. 1984 Blus et al. 1993). However, harmful damage effects were observed at higher concentrations when compared to aquatic biota. For example, Japanese quail (Coturnix japonica) fed 75 mg Cd/kg diet developed bone marrow hypoplasia, anemia, and hypertrophy of both heart ventricles at 6 weeks (Richardson et al. 1974). In zinc-deficient diets, effects were especially pronounced and included all of the signs mentioned plus testicular hypoplasia. A similar pattern was evident in cadmium-stressed quail on an iron-deficient diet. In all tests, 1% ascorbic acid in the diet prevented cadmium-induced effects in Japanese quail (Richardson et al. 1974). In studies with Japanese quail at environmentally relevant concentrations of 10 pg Cd/kg B W daily (for 4 days, administered per os), absorbed cadmium was transported in blood in a form that enhanced deposition in the kidney less than 0.7% of the total administered dose was recovered from liver plus kidneys plus duodenum (Scheuhammer 1988). 

An endemic zinc deficiency syndrome among young men has been reported from Iran and Egypt, and is characterized by retarded growth, infantile testes, delayed sexual maturation, mental lethargy, anemia, reduced concentration of zinc in plasma and red cells, enlarged liver and spleen, and hyperpigmentation oral supplementation of 30 mg Zn daily had a prompt beneficial effect (Prasad 1979 Elinder 1986). 

No effect on growth, survival, or feed conversion. Zinc accumulated in tissue metallothioneins, especially in liver and kidney levels normal after 5 days on zinc-deficient diet (Oh et al. 1979). 

Bettger, W.J. 1989. The effect of dietary zinc deficiency on erythrocyte-free and membrane-bound amino acids in the rat. Nutr. Res. 9 911-919. 

Blamberg, D.L., U.B. Blackwood, W.C. Supplee, and G.F. Combs. 1960. Effect of zinc deficiency in hens on hatchability and embryonic development. Proc. Soc. Exper. Biol. Med. 104 217-220. 

Casey, C.E. and K.M. Hambidge. 1980. Epidemiological aspects of human zinc deficiency. Pages 1-27 in J.O. Nriagu (ed.). Zinc in the Environment. Part II Health Effects. John Wiley, NY. 

Devineau, J. and C. Amiard Triquet 1985. Patterns of bioaccumulation of an essential trace element (zinc) and a pollutant metal (cadmium) in larvae of the prawn Palaemon serratus. Mar. Biol. 86 139-143. Dib, A., J.P Clavel, and J.P. Carreau. 1989. Effects of gamma-linolenic acid supplementation on lipid composition of liver microsomal membranes. I. Pregnant rats fed a zinc-deficient diet and those fed a balanced one. Jour. Clin. Biochem. Nutr. 6 95-102. 

Mansour, M.M.S., N.M. El-Malkh, and E.M.I. El-Zayat. 1989. Effect of dietary zinc deficiency on serum and testicular total protein contents in male albino rats. Jour. Drug Res. (Egypt) 18 131-142. 

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