Submitted to: International Society For Trace Elements Research In Humans
Publication Type: Abstract only
Publication Acceptance Date: 9/15/2001
Publication Date: 10/1/2001
Citation: Nielsen, F.H., Milne, D.B., Klevay, L.M., Davis, C.D. 2001. Zinc deprivation alters variables of oxidative metabolism and bone turnover, with some alterations modified by dietary copper, in postmenopausal women [abstract]. Journal of Trace Elements in Experimental Medicine. v.14. p.286-287. Interpretive Summary:
Technical Abstract: A study was conducted to ascertain the effects of moderately deficient and excessive intakes of zinc (Zn) in post-menopausal women fed about 1 or 3 mg copper (Cu)/day. After an equilibration period where dietary Cu was 2 mg and Zn was 9 mg per 2000 kcal, 9 women fed 1 mg Cu/day and 12 women fed 3 mg Cu/d were placed on a basal diet providing 3 mg Zn/2000 kcal for 90 days, then placed on another 10 days of equilibration diet before being fed the basal diet supplemented with 50 mg Zn/day for 90 days. Erythrocyte superoxide dismutase (ESOD) activity was significantly lower at the end of the high than the end of low dietary Zn period. On the other hand, extracellular superoxide dismutase (ECSOD) activity was significantly higher at the end of the high than the end of the low dietary Zn period. Both ESOD and ECSOD activities decreased during the low Zn dietary period in the women fed 1 mg Cu/day and increased during the same period in the women fed 3 mg Cu/day. Whole blood glutathione concentration and erythrocyte glutathione peroxidase activity were lower during the high than during the low dietary Zn period. Plasma osteocalcin concentration was increased by the combination of low dietary Zn and Cu. Urinary calcium excretion also was highest when both dietary Cu and Zn were low. Urinary N-telopeptide excretion was higher with high dietary Zn than with low dietary Zn. The findings indicate that low dietary Zn, especially when dietary Cu is not luxuriant but near the new U.S. Recommended Dietary Allowance, alters oxidative metabolism and indicators of bone remodeling. Some of the alterations perhaps were indicators of undesirable biochemical or physiological changes.