Copper daily intake

There have been numerous reports of possible allergic reactions to mercury and mercury salts and to the mercury, silver and copper in dental amalgam as well as to amalgam corrosion products Studies of the release of mercury by amalgams into distilled water, saline and artificial saliva tend to be conflicting and contradictory but, overall, the data indicate that mercury release drops with time due to film formation and is less than the acceptable daily intake for mercury in food . Further, while metallic mercury can sensitise, sensitisation of patients to mercury by dental amalgam appears to be a rare occurrence. Nevertheless, there is a growing trend to develop polymer-based posterior restorative materials in order to eliminate the use of mercury in dentistry. 

Copper is an essential trace element. It is required in the diet because it is the metal cofactor for a variety of enzymes (see Table 50—5). Copper accepts and donates electrons and is involved in reactions involving dismu-tation, hydroxylation, and oxygenation. However, excess copper can cause problems because it can oxidize proteins and hpids, bind to nucleic acids, and enhance the production of free radicals. It is thus important to have mechanisms that will maintain the amount of copper in the body within normal hmits. The body of the normal adult contains about 100 mg of copper, located mostly in bone, liver, kidney, and muscle. The daily intake of copper is about 2—A mg, with about 50% being absorbed in the stomach and upper small intestine and the remainder excreted in the feces. Copper is carried to the liver bound to albumin, taken up by liver cells, and part of it is excreted in the bile. Copper also leaves the liver attached to ceruloplasmin, which is synthesized in that organ. 

J. P. Buchet, R. Lauwerys, A. Vandevoorde, J. M. Pycke, Oral daily intake of cadmium, lead, manganese, copper, chromium, mercury, calcium, zinc, and arsenic in Belgium duplicate meal study, Food Chem. Toxicol., 21 (1983), 19-24. 

Taper e al. (39) from the same laboratory as the aforementioned geriatric study, found no significant effect of dietary zinc levels when they studied 18 young women of childbearing age. Dietary copper intake was 2.0 mg day with 0.86 mg from food and 1.14 mg as supplement. Foodstuffs provided 5.63 mg of zinc, and total daily Intakes were adjusted to 8 mg (N = 7), 16 mg (N = 6) and 24 mg (N = 5). The experimental details of the supplementation with zinc and copper salts were not provided. The dietary Zn/Cu ratios were 4.0, 8.0, and 12.0 respectively the mean fecal excretion (mean SD) for the respective diets was 2.01 + 0.15, 2.10 + 0.14 and 2.02 + 0.23, respectively. Neither the fecal outputs nor the derivative apparent retention values differed significantly one from another. 

Implications for Human Nutrition. The human studies cited have examined the effect of zinc on copper uptake, and evidence suggests that Zn/Cu ratios of greater than 10 1 can produce a nutritional impact. The source of the discrepancies among the three metabolic studies reviewed is not immediately evident. One possibility would be a different susceptibility to copper malabsorption at different ages. Another might have to do with the actual Zn/Cu ratios in those meals which provided the bulk of the daily Intake of the two minerals or with their chemical forms. Studies in which all of the copper and zinc are derived from natural foodstuffs would complement the foregoing human studies in this area. 

Stable isotopes of iron zinc and copper have been given to subjects in a variety of studies at our Center Standard doses were 4 nig Fe> 4 mg Zn and 2 mg of Cu for adult subjects Isotopes were fed in a single dose in juice at breakfast or in Trutol (a flavored glucose solution) While doses of this size are not truly tracer doses they are in the physiological range of intake Recommended daily intakes are 10 mg Fe 15 mg Zn and 2- 3 mg Cu for adult males (11) Table II shows the average absorption values obtained from subjects who were consuming diets adequate in all minerals and other dietary components ... 

Copper The daily intake from food is 0.8—2.0 mg it is released into the portal vein via copper-transporting ATPase. The transport of copper, which is toxic in its free form, is effected by the binding to ceruloplasmin, albumin and transcuprin. Copper is bound to reduced glutathione and metallothionein in the hepatocytes and distributed to various organelles or incorporated into enzymes. The biological effects of copper are manifold and essential for some cellular functions, (s. p. 50) Copper is toxic not only in its free form, but also in cases of overload (e. g. cirrhosis in childhood due to the consumption of water from copper pipes). Copper homoe-ostasis is regulated via biliary excretion (normal value about 1.2-2.0 mg/day), so that the normal value in serum is 75-130 fg/dl. (321, 323, 370, 383, 386) (s. p. 102)... 

Daily intakes of copper and other essential minerals are estimated and can be found as part of the Food and Drug Administration s Total Diet Study. 

One study showed that, in full-term infants, manganese is absorbed from breast milk and cow s milk formulas that were either unsupplemented or supplemented with iron, copper, zinc, and iodine (Domer et al. 1989). Manganese intake was greater in the formula-fed infants than in the breast-fed infants due to the higher manganese content of the formula. However, breast-fed infants retained more of their daily intake of... 

Although bile may serve as the major excretory vehicle for excess copper, significant but lesser amounts of copper are lost via hair, stratum corneum, finger- and toe-nails, sweat and urine as end-products of metabolism. These losses point out the need for compensating daily intake and absorption to replenish this essential metalloelement. 

Unfortunately, there are no modern-day uses of copper complexes for this purpose. It is likely that copper complexes representing less than the amounts of copper recommended as safe daily intakes will eventually be found to be useful in successfully treating human seizure states. 

Overexposure to zinc by food, water, and air commonly poses no risk to the general population. Long-term administration of zinc (100-150 mg per day) to patients to promote wound healing is usually well tolerated, but anemia may be induced in case of low copper status. This effect is readily reversible, however. Using a safety factor of 10 this means that an additional zinc intake of 10-15 mg per day does not constitute a health hazard (US ERA 1980). The provisional maximum tolerable daily intake for man has been estimated at 0.3 to 1.0 mg Znkg body weight (WHO 1983). 

Sharrett AR, Carter AP, Orheim RM and Feinlieb M (1982a) Daily intake of lead, cadmium, copper, and zinc from drinking water the Seattle study of trace metal exposure. Environ Res 28 456-475. 

Hunt CD and Meacham SL (2001) Aluminum, boron, calcium, copper, iron, magnesium, manganese, molybdenum, phosphorus, potassium, sodium, and zinc concentrations in common Western foods and estimated daily intakes by infants toddlers and male and female adolescents, adults, and seniors in the United States. J Am Diet Assoc 101 1058-1060. 

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