Trace elements intake with diet

Selenium has been recognized as an essential trace element in the diets of man and animals for many years (1) Another strong indication of its essentiality is the fact that it is an essential component of the enzyme glutathione peroxidase (2) Recently, scientists from the People s Republic of China demonstrated that Keshan disease (a cardiomyopathy in children) was correlated with low dietary selenium Intakes ( ) and could largely be prevented with supplementation Similarly, poor selenium nutrition in patients receiving total parenteral nutrition has been linked to muscular discomfort (4) and cardiomyopathy ( ) ... 

Trace Element Intake of Adults with Mixed and Ovolactovegetarian Diets... 

Tab. 4.9 Trace element intake of adults with mixed and ovolactovegetarian diets as a function of gender and type of diet...

Tab. 4.13 Trace element intake of adults with mixed diet determined by the duplicate portion technique and calculated by the basket method...

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. 

The aims of the food-monitoring programme 1998-2003 were (i) to monitor the content and changes over time of trace elements in food sold on the Danish market and (ii) to estimate the intake of trace elements with the entire diet and also to evaluate if any associated health consequences were likely to occur. 

Infant formulas are supplemented with Mn and other trace elements in the form of inorganic salts. Whether these supplemented minerals have different bioavailabilities from their counterparts found naturally in human milk or bovine milk has not been extensively investigated. Chan and associates previously reported that Mn was bound to different molecules in human milk, bovine milk and infant formula (12). Inadequate or excessive intake of Mn has severe effects especially during infancy (1,13). It is therefore important to evaluate the bioavailability of Mn in different milk diets. To achieve this aim, suckling rats and everted intestinal sacs derived from these animals were used as systems to study the absorption of Mn from rat milk, human milk, bovine milk and infant formula. Effect of age on Mn absorption in suckling rat pups from various milk diets was also investigated. Some of the data presented in this article have been reported previously (14-17). 

Vitamins In particular, water-soluble vitamins have to be provided in adequate quantities. With a carbohydrate diet and alcoholic liver disease, the daily requirement is higher. A daily intake of multivitamins, best combined with trace elements and minerals, is recommended. As a rule, liposoluble vitamins are best administered by parenteral route due to inadequate absorption. The therapeutic significance of zinc (s. pp 50, 99) should always be borne in mind. (34, 153, 155,169)... 

This discussion examines the recent progress of nutritional trace element research and its implications for trace element analysis. Elements recently identified as essential are present in low concentrations for which analytical methods are not yet reliable. Biological availability of trace elements depends on chemical form and on interactions with other inorganic and organic constituents of the diet. Therefore, information on elemental species is required, in addition to quantitative data. Finally, the demonstration of essential functions of trace elements previously known only for their toxicity necessitates establishing safe ranges of intake, free from danger of chronic toxicity but sufficient to meet human needs. 

The net intake can be also be estimated by using exogenous and endogenous labeling of representative diet with radio or stable isotopes of the trace element under investigation. These research methods can give valuable insights as to the bioavadability of nutrients and the efficiency of uptake by the intestinal tract from particular diets. ... 

Diets that are low in protein, zinc, selenium, vitamin Bg, and fat may collectively depress immune function. This type of diet may be associated with either a low-caloric-intake diet or low-fat, low-meat-products diet. Zinc is an essential trace element for many biological functions, including immune functions. Indeed, zinc is required for the biological activity of a thymic hormone, called thymulin in its zinc-bound form, and is important for the maturation and differentiation of T-cells. With advancing age, zinc, thymic functions, and peripheral immune efficiency show a progressive decline. Supplementing zinc in old age restores immune efficiency. 

The trace element concentration of dietary dry matter consumed is a good indicator of the trace element supply of humans with mixed or vegetarian diets. The trace element concentration of the consumed dry matter does not vary with dry matter intake, which is influenced by gender, age, season and eating habits (Anke et al. 1997a). 

Rohrig B, Anke M and Drobner C (1996) Investigation of copper intake with the duplicate portion method in relation oftime and kind of diet. In Pais I, ed. International Trace Element Symposium Budapest, pp. 171 -178, St. Istvan University, Budapest, Hungary. 

Rohrig B, Anke M, Drobner C, Jaritz M and Holzinger S (1998) Zinc intake of German adults with mixed and vegetarian diets. Trace Elements and Electrolytes, 15 81-86. 

Schafer U, Anke M and Seifert M (2001) Manganese intake of adults with mixed and vegetarian diets and of breast-feeding and not breast-feeding women determined with the duplicate portion technique. In Ermidou S, and Pollet S, eds. 3 International Symposium on Trace Elements in Human New Perspectives, pp. 248 -262. Moro-giannis Achamai, Greece. 

Metallic arsenic is a grey brittle metal, and it is known as one of the most deadly poisons, and it is one of the few compounds (besides vinyl chloride) that causes the rare liver cancer angiosarcoma, but it is still thought of as an essential (trace) element for some animals and for humans, with a necessary intake of 0.01 mg per day, most probably due to the special metabolism of certain amino acids (chickens and rats fed with an arsenic free diet are found to have their growth inhibited). It is claimed that arsenic in small doses stimulates the metabolism and boosts the formation of red blood cells. In fact, its derivatives can be used illegally as a dopant for racehorses and even to fatten poultry and pigs. 

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