Author
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NIELSEN, FORREST - 5450-10-00 |
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Milne, David |
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Submitted to: Recommended Dietary Allowances Workshop
Publication Type: Abstract Only Publication Acceptance Date: 9/1/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: The consequence of Mg deprivation when dietary Cu was marginal or adequate was investigated in two experiments with healthy postmenopausal women fed a diet of mixed western foods. The diet provided about 1.5 mg Cu/day in exp. 1 and 2.4 mg Cu/day in exp. 2. A depletion-repletion design was used in exp. 1 with about 104 mg Mg/day fed for 78 days, then about 308 mg Mg/day was fed for 57 days. A double-blind random cross over design was used in exp. 2 where the basal diet providing about 104 mg Mg/day plus a placebo, and the basal diet plus a 200 mg/day Mg supplement, each were fed for 72 days. The Mg deprivation decreased urinary magnesium excretion and erythrocyte membrane Mg concentration, and induced non-positive Mg balance in both experiments. Total serum cholesterol was lower during Mg depletion than repletion; LDL-cholesterol was similarly affected. APO-A1 lipoprotein was lower during Mg depletion than repletion in exp. 2; it was not measured in exp. 1. Mg deprivation also made Ca balance more positive in both experiments. Urinary Ca was not increased in exp. 1 (probably because of marginal Cu intake), but was increased in exp. 2 when Mg was supplemented. In exp. 1 calcitonin was significantly lower during Mg depletion than repletion; the difference only approached significance in exp. 2. In exp. 1, the Mg supplementation decreased Cu balance from 0.22 to 0.04 mg/day (P<0.0001). In exp. 2, there was a significant diet x sequence interaction affecting Cu balance. The findings show that low dietary intakes of Mg affect some indices used to assess changes in cardiovascular and bone health, and that Mg intake affects Cu metabolism in postmenopausal women. |
