title: Zinc, copper, and nitrogen balances during bed rest and fluoride supplementation in healthy adult males.
abstract: The effects of bed rest and fluoride supplementation on zinc, copper, and nitrogen balances and Zn and Cu serum levels were measured in 15 healthy males. Subjects aged 19-54 y remained on a metabolic research ward for 10 wk. During weeks 1-5, subjects were ambulatory. During wks 6-10 they remained in continuous bed rest. During weeks 3-10 nine subjects received 10 or 20 mg F/d as sodium fluoride. Daily urine and weekly fecal composites were made and biweekly fasting blood samples were taken. Dietary intakes were 1.40 +/- 0.17 mg Cu/d (22.0 +/- 2.7 mumol Cu/d), 10.82 +/- 0.49 mg Zn/d (165.6 +/- 7.6 mumol Zn/d), and 14.27 +/- 0.23 g N/d (1019 +/- 16 mmol N/d). Bed rest increased urinary Zn and N excretions and fecal Zn excretions and decreased Zn balance (p less than 0.05) whereas Cu balance was unchanged. During bed rest, F supplementation increased Zn and N balances compared with untreated control subjects (p less than 0.05). These results are compatible with bone and muscle atrophy during bed rest and increased bone formation with F supplementation.
authors.affiliation: Medical Sciences Division, NASA Johnson Space Center, Houston, TX 77058.
authors.forename: J M
authors.initials: JM
authors.lastname: Krebs
authors.forename: V S
authors.initials: VS
authors.lastname: Schneider
authors.forename: A D
authors.initials: AD
authors.lastname: LeBlanc
mesh_terms: D000328:Adult; D001510:Bed Rest; D001842:Bone and Bones / Q000378:metabolism; D003300:Copper / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D012969:Sodium Fluoride / Q000008:administration & dosage*; D013997:Time Factors; D015032:Zinc / Q000378:metabolism*
chemical_list: D003300:Copper; D012969:Sodium Fluoride; D015032:Zinc; D009584:Nitrogen