Author
Nielsen, Forrest - Frosty | |
Davis, Cindy | |
MILNE, DAVID - 5450-10-00 |
Submitted to: North Dakota Academy of Science Proceedings
Publication Type: Proceedings Publication Acceptance Date: 3/20/2000 Publication Date: 5/1/2000 Citation: Nielsen, F.H., Davis, C.D., Milne, D.B. 2000. Low dietary zinc and copper negatively affect plasma and urine. Proceedings of North Dakota Academy of Science. v.54. p. 39. Interpretive Summary: Although low dietary calcium receives the most recognition for increasing the risk of becoming osteoporotic, there are a number of other possible nutrients whose lack could increase the susceptibility to osteoporosis; these include zinc and copper. Supplementation of both zinc and copper have been associated with conserving bone density or preventing spinal bone loss in postmenopausal women. Thus, the effects of low dietary zinc and copper on some indicators used to assess bone health were determined in 23 postmenopausal women housed in a metabolic ward. The combination of low dietary zinc and copper caused some changes that could be considered unfavorable because they have been associated with decreased bone density and increased hip fractures. Low dietary copper without regard to dietary zinc, and low dietary zinc without regard to dietary copper, each also had effects that indicate that these two elements are important for good bone health. Thus, the findings suggest that low dietary zinc or low dietary copper, and especially the combination of low dietary zinc and copper, may be important factors in the incidence of osteoporosis. Technical Abstract: Although low dietary calcium receives the most recognition for increasing the risk of becoming osteoporotic, there are a number of other possible nutrients whose lack could increase the susceptibility to osteoporosis; these include zinc and copper. Supplementation of both zinc and copper have been associated with conserving bone density or preventing spinal bone loss in postmenopausal women. Thus, the effects of low dietary zinc and copper on some variables used to assess bone health were determined in 23 postmenopausal women housed in a metabolic ward. After a 10-day equilibration period, 10 women were fed a diet containing l mg of copper per 2000 kcal and 13 women were fed 3 mg of copper per 2000 kcal for the remainder of the study. The diet for both groups contained 3 mg of zinc per 2000 kcal for 90 days after the first equilibration period, and 53 mg per day for the last 90 days of the study after another 10-day equilibration period. Both plasma osteocalcin and urinary calcium excretion were increased by the combination of low dietary zinc and copper. These changes could be considered unfavorable because they have been associated with decreased bone density and increased hip fractures. Low dietary copper decreased plasma ionized calcium and low dietary zinc decreased urinary N-telopeptide excretion; these changes also indicate that copper and zinc are important to good bone health. Thus, the findings suggest that low dietary zinc or low dietary copper, and especially the combination of low dietary copper and zinc, may be important factors in the incidence of osteoporosis. |