[Effects of high level Zn intake on metabolism in man].
OBJECTIVE
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.


METHODS
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.


RESULTS
(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.


CONCLUSIONS
When healthy men received 50 mg Zn supplement per day, it might interfere Zn, Cu and lipids metabolism and inhibit antioxidation process.
Xiang
Youzhang
Y
Shandong Institute for Prevention & Treatment of Endemic Disease, Jinan 250014, China.
Yang
Xiaoxia
X
Bian
Jianchao
J
Wang
Lin
L
D000293:Adolescent; D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage*; D003300:Copper / Q000378:metabolism*; D019587:Dietary Supplements; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects*; D008054:Lipid Peroxides / Q000097:blood; D008055:Lipids / Q000097:blood*; D008297:Male; D012424:Rural Population; D013482:Superoxide Dismutase / Q000097:blood; D015032:Zinc / Q000008:administration & dosage* / Q000378:metabolism
D000975:Antioxidants; D008054:Lipid Peroxides; D008055:Lipids; D003300:Copper; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D015032:Zinc