Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc (2001) / Chapter Skim
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7 Copper
7 Copper
Pages 224-257
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From page 224... ...
for copper is a combination of indicators, incluciing plasma copper and ceruloplasmin concentrations, erythrocyte superoxicle clismutase activity, and platelet copper concentration in controlled human clepletion/repletion studies. The Recommencleci Dietary Allowance (RDA)
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From page 225... ...
Defects in ceruloplasmin function produce cellular iron accumulation, a result that supports its ferroxiciase role (Harris and Gitlin, 1996~. Ferroxiciase II is found in human plasma, but it may have a role in iron metabolism in specific cellular sites.
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From page 226... ...
A defective MNK gene causes Menkes' disease, which is characterized by reduced copper absorption and placental copper transport. The extent of copper absorption varies with clietary copper intake (Turnlunci, 1998~.
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From page 227... ...
, and in patients with prolonged total parenteral nutrition (Fujita et al., 1989~. In these cases, serum copper and ceruloplasmin concentrations were as low as 0.5 Wool and 35 mg/L, respectively, compareci to reported normal ranges of 10 to 25 ~mol/L for serum copper concentration and 180 to 400 mg/L for ceruloplasmin concentration (Lentner, 1984~.
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From page 228... ...
If the copper intake of these patients is extrapolated to adults on the basis of caloric intake, copper deficiency might be expected to develop in adults at an intake of 440 ~g/2,900 kcal for men and 290 ~g/1,900 kcal for women. This clecluction is consistent with a study in which healthy young men who were feci a cliet containing 380 ~g/ciay of copper for 42 clays haci a Decline in serum copper and ceruloplasmin concentrations and then an increase with copper repletion (Turnlunci et al.,1997~.
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From page 229... ...
These indicators serum or plasma copper concentration, ceruloplasmin concentration, and erythrocyte superoxide dismutase activity are low with copper deficiency and respond to copper supplementation. However, except when diets are deficient in copper, they do not reflect dietary intake and may not be sensitive to marginal copper status.
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From page 230... ...
No single indicator provides an adequate basis on which to estimate the copper requirement. Serum Copper Concentrations Serum copper concentration is a reliable indicator of copper deficiency, falling to very low concentrations in copper-deficient individuals.
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From page 231... ...
Platelet Copper Concentration and Cytochrome c Oxidase Activity Two studies in women suggest that both platelet copper concentration and platelet cytochrome c oxiciase activity may respond more rapidly to low clietary copper than the indicators cliscusseci above. In one study both of these indicators cleclineci when copper intake was 570 ~g/day (Milne and Nielsen, 1996~.
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From page 232... ...
In controlled studies, a clecline in urinary copper excretion can be used as supporting evidence for inacloquate intake. Leukocyte Copper Concentration Leukocyte copper concentration was found to decline along with other inclexes of copper status in one study (Turnlunci et al., 1997)
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From page 233... ...
Unfortunately, there are a number of problems with this approach, as reviewoci by Mertz (1987~. Copper balance, which can be achieved over a broaci range of clietary copper intakes, reflects prior clietary intake; thus long adaptation is required for results to be meaningful.
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From page 234... ...
Such an interaction has been reported to produce recluceci copper status in infants (Lonnercial and Hernell, 1994; Morals et al., 1994~. Fructose Studies in rats clemonstrateci that cliets very high in fructose were associated with increased severity of copper deficiency in rats (Fields et al., 1984)
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From page 235... ...
in newborn infants. During the first 6 months of life, liver stores clecline and serum copper concentration increases to adult levels, independent of copper intake.
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From page 236... ...
236 DIETARY REFERENCE INTAKES TABLE 7-1 Copper Concentration in Human Milk Milk Estimated Study Stage of Concentration Copper Intake Reference Group Lactation (l~g/L) of Infants (pg/d)
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From page 237... ...
National Health and Nutrition Examination Survey, the meclian copper intake from weaning food for children aged 7 through 12 months is 100 ~g/ciay (n= 451. The average copper concentration in human milk declines over time, and between 7 and 12 months postpartum the concentration is 200 ~g/L or less (Table 7-1)
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From page 238... ...
It has been reported that copper absorption in infants feci human milk is greater than in infants feci a cow milk-baseci formula (Dorner et al., 1989; Johnson and Canfielci, 1989~. Copper deficiency has been observed in infants feci cow milk (Corciano et al., 1964; Levy et al., 1985~.
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From page 239... ...
If there were significant decreases in serum copper and ceruloplasmin concentrations and SOD activity when the experimental copper cliet was fed, and if this decrease was reversed with added copper, then
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From page 240... ...
Serum copper and ceruloplasmin concentrations clici not clecline significantly when ten women were fed 570 ,ug/day of copper (Milne and Nielsen, 1996~. Platelet copper concentration, however, declineci significantly for eight of ten women feci 570 ,ug/ciay and increased with supplementation.
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From page 241... ...
This approach provides supporting evidence for the EAR baseci on copper status estimated above. Enclogenous losses, estimated from total parenteral nutrition (TPN)
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From page 242... ...
Estimation of the average requirement baseci on indicators of copper status is similar to, but slightly higher than, the average requirement determined by the factorial approach. The EAR is baseci on biochemical indicators of copper status of men and women, and there was no basis for a difference in requirement baseci on gentler.
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From page 243... ...
Over the course of pregnancy, this aciclitional requirement is approximately 67 ~g/day of absorbed copper or 100 ~g/day of clietary copper, a value baseci on 65 to 70 percent bioavailability and rounding. Evidence suggests that copper absorption may be more efficient cluring pregnancy, and such efficiency could result in absorption of this amount of copper (Turnlunci et al., 1983~; therefore no aciclitional increment would be required.
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From page 244... ...
RI) A for Pregnancy 14-18 years 19-30 years 31-50 years 1,000 1lg/day of copper 1,000 1lg/day of copper 1,000 1lg/day of copper Lactation Evidence Considered in Estimating the Average Requirement The EAR for lactation is cletermineci on the basis of the copper intake necessary to replace copper secreted ciaily in human milk plus the EAR for adolescent girls and adult women.
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From page 245... ...
surveys are available to estimate copper intakes Appendix Tables C-15, C-16, D-2, Ebb. The meclian intake of copper for women is approximately 1.0 to 1.1 mg/ciay, whereas the meclian intake for men ranges from 1.2 to 1.6 mg/day (Appendix Tables C-1 ~ and D-2)
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. TOLERABLE UPPER INTAKE LEVELS The Tolerable Upper Intake Level (UL)
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From page 247... ...
The mean consumption of water was 1.6 L/ciay, and therefore the average copper intake from water was 4.8 mg/ciay. From these two studies it would appear that the threshold for acute gastrointestinal effects from copper in water is about 4.8 mg/ciay.
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From page 248... ...
However, familial relationships and genetic factors are required for the expression of liver toxicity from high levels of copper intake Joshi et al., 1987; Kishore and Prasaci, 1993; Panclit and Bhave, 1996; Tanner, 1998~. The rarity of ICT and ICC outside of Germany and India and the lack of liver damage noted in children in the United States exposed to levels of copper between 8.5 and 8.8 mg/L in drinking water support the hypothesis that copper is only one factor required for the expression of these diseases (Scheinberg and Sternlieb, 1994~.
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From page 249... ...
of 1.0 was selected. A larger UF was considered unnecessary in view of the large international database in humans indicating no adverse effects from tinily consumption of 10 to 12 mg/ciay of copper in foocis and the rarity of observed liver damage from copper exposures in human populations with normal copper homeostasis.
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From page 250... ...
Pregnancy and Lactation. No studies involving supplemental copper intake by pregnant or lactating women were found.
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From page 251... ...
, ICT, and ICC. In aciclition, heterozygotes for Wilson's disease may be at increased risk of adverse effects from excess copper intake.
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From page 252... ...
RESEARCH RECOMMENDATIONS FOR COPPER · Determine the specific health risks associated with marginal copper deficiency. · Define the adverse effects of chronic high copper consumption for establishing upper intake levels and to evaluate the health effects of copper supplements.
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Effect of dietary copper intakes on biochemical markers of bone metabolism in healthy adults.
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From page 254... ...
1988. Nutritional copper deficiency in severely handicapped patients on a low copper enteral diet for a prolonged period: Estimation of the required dose of dietary copper.
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1998. Copper intake and assessment of copper status.
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1985. Indices of copper status in humans consuming a typical American diet containing either fructose or starch.
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From page 257... ...
1980. The effects of the dietary intakes of copper, iron, manganese, and zinc on the trace element content of human milk.
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