Effects of high level Zn intake on metabolism in man
Xiang, Y.; Yang, X.; Bian, J.; Wang, L.
Wei Sheng Yan Jiu 33(6): 727-731
2004
ISSN/ISBN: 1000-8020 PMID: 15727190 Document Number: 570189
To observe the effects of high level Zn intake on zinc (Zn) copper (Cu), lipids metabolism and antioxidation function in man so as to provide scientific basis for Zn supplementation. 40 rural healthy men were chosen and tablets of 50 mg Zn (as 0.2 g of zinc glucose) per day was taken by them for eight weeks. All subjects were checked up for five times: at week 0, 2, 4, 8 during the period of Zn supplementation and at week 12 and their serum, RBC, hair, and 24h-urine were collected for assays at the same time. (1) Zn contents in serum, RBC and hair increased significantly after 2 to 4 weeks supplementation and decreased at 4 weeks after stopping supplementation, but they were still higher than those before supplementation. Zn contents in 24h-urine increased significantly after supplementation and decreased at 4 weeks after stopping supplementation to the same level as before supplementation. (2) Cu contents in serum, RBC and hair increased significantly after 4 weeks supplementation and decreased at 4 weeks after stopping supplementation. Cu contents in 24h-urine did not change significantly during experiment. (3) RBC superoxide dismutase (SOD) activities were decreased persistently after 2 weeks supplementation and were not recovered at 4 weeks after stopping supplementation. RBC glutathione peroxidase (GPX) activities increased significantly after 4 weeks supplementation. The content of lipid peroxide (LPO) increased significantly after 2 weeks supplementation. (4) Total cholesterol (TC), triglyceride (TG), Low density lipoprotein cholesterol (LDL-C) and apolipoprotein B100 (ApoB100) increased significantly, high density lipoprotein cholesterol (HLD-C) and apolipoprotein A1 (ApoA1) decreased after supplementation. When healthy men received 50 mg Zn supplement per day, it might interfere Zn, Cu and lipids metabolism and inhibit antioxidation process.