Ratio zinc supplementation

Direct measurement of DNA and protein synthesis in experimental animals suggest that in zinc deficiency protein synthesis is adversely affected (, ). Our own data on human subjects in these experiments show that the total protein, total collagen, and RNA-DNA ratio Increased as a result of zinc supplementation. The activity of deoxythymidine kinase was not measurable during the zinc restriction phase but became 70% of normal level after supplementation with zinc for 3 months. Similar data have been published for experimental animals. Thus, our data show that deoxythymidine kinase in human subjects also is a zinc-dependent enzyme, and an adverse effect of zinc deficiency on this enzyme may be responsible for decreased protein synthesis. Our studies do not rule out an adverse effect of zinc deficiency on protein catabolism. Further studies are required to establish the effect of zinc restriction on protein catabolism. 

From these results, it is evident that supplementation of the diet containing mixed infant cereal resulted in a body weight gain better than and a femur zinc value comparable to that observed before in weanling rats fed a diet containing 12 pg/g zinc from zinc sulphate (7). The zinc supplementation reduced the phytate/zinc molar ratio of the diet from 10 to 5. 

Taper e al. (39) from the same laboratory as the aforementioned geriatric study, found no significant effect of dietary zinc levels when they studied 18 young women of childbearing age. Dietary copper intake was 2.0 mg day with 0.86 mg from food and 1.14 mg as supplement. Foodstuffs provided 5.63 mg of zinc, and total daily Intakes were adjusted to 8 mg (N = 7), 16 mg (N = 6) and 24 mg (N = 5). The experimental details of the supplementation with zinc and copper salts were not provided. The dietary Zn/Cu ratios were 4.0, 8.0, and 12.0 respectively the mean fecal excretion (mean SD) for the respective diets was 2.01 + 0.15, 2.10 + 0.14 and 2.02 + 0.23, respectively. Neither the fecal outputs nor the derivative apparent retention values differed significantly one from another. 

The other potential area of significance for excessive Fe/Zn ratios Is In the formulation of vltamln-mlneral supplements. We found that, In the 1977 Physician s Desk Reference (55), of 21 such products specifying both zinc and Iron content, only 3 had a Fe/Zn ratio less than 3.0 (50). In the 1981 PDR (56), of 18 such products, 6 had a Fe/Zn ratio of less than 3.0 (Table IV). 

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