Minerals, dietary requirements

The essential mineral nutrients are classified either as principal elements or as trace and ultratrace elements. The distinction between these groups is the relative amounts ia the dietary requirement (see Table 1). 

Biochemistry is important in many fields of science in addition to medicine. For instance, biochemists investigate food by studying molecules such as vitamins, amino acids, fatty acids, various minerals, and water, all of which are dietary requirements for healthy nutrition. They also explain how these nutrients are absorbed by the body and what they do in the cells. For example, the question of how the body derives energy from dietary fats and oils involves a series of biochemical reactions explained by the biochemistry of the metabolic pathways. 

Determination of human requirements for dietary trace minerals necessarily includes knowledge of the factors which affect the availability of minerals for absorption Interactions of dietary minerals with organic constituents of the diet and with other minerals are complex Careful study of mineral absorption in human subjects is required to delineate dietary requirements and the factors which affect them ... 

Carbohydrate nutrition is different in nature from the nutrition of amino acids, fats, vitamins, and minerals. Humans have no dietary requirement for any specific type of carbohydrate. All carbohydrates of the body can be synthesized from dietary glucose or fructose, the major sugars in the diet. The body stores sugar in the form of glycogen, a polysaccharide composed of glucose units. 

Other Dietary Requirements In addition to providing energy, the diet provides precursors for the biosynthesis of compounds necessary for cellular and tissue structure, function, and survival. Among these precursors are the essential fatty acids and essential amino acids (those that the body needs but cannot synthesize). The diet must also supply vitamins, minerals, and water. 

Xanthine oxidase uses molybdenum for electron transfer to Oj. This enzyme accounts for the human dietary requirement for molybdenum, which is classified as a trace mineral. 

Iron, whether in the form Fe(II) or Fe(III), is usually found in the body in association with proteins. Little or no iron can be found free in the blood. Because iron-containing proteins are ubiquitous, there is a dietary requirement for this mineral. Severe deficits can lead to iron-deficiency anemia. 

Vitamins and minerals are required for the body to function properly. Each day we need to eat a balanced diet that supplies us with the sufficient amount of vitamins and minerals to remain healthy. Our diet should contain grains, vegetables, fruits, milk, meat and beans. The portion of each varies depending on our age and gender. The USDA Web site publishes the Recommended Dietary Allowance (RDA) for daily dose requirement of each vitamin. 

The number of different minerals necessary to maintain good health is still unknown to science. While dietary deficiencies of only a few minerals such as iron or iodine can be linked directly to disease, some authorities claim that as many as 60 elements are necessary for optimum longevity and quality of life in humans. What has become more widely recognized is that a number of minerals are required by the body, and deficiencies in these minerals may not produce obvious... 

Mineral Content of Edible Tree Nuts in Relation to Dietary Requirements and in the Context of Other Foods Abundant in the Same Minerals... 

The net requirement of a mineral element for maintenance plus growth is calculated as the sum of the endogenous losses and the quantity retained. To determine the dietary requirement, the net requirement is divided by an average value for availability. For example, a 300 kg heifer gaining 0.5 kg/day might have an endogenous calcium loss of 5.0 g/day and be retaining 6.0 g/day. Its net calcium requirement would therefore be 11.0 g/day. For an animal of this type, the availability of calcium is predicted to be about 0.68 and the daily calcium requirement would be calculated as 11.0/0.68 = 16.0 g/day. 

Net mineral requirements for maintenance and growth are calculated from endogenous losses and the mineral content of body tissues. They are then translated into dietary requirements using appropriate availability factors. 

The mineral composition of mare s milk varies with stage of lactation. For the purpose of estimating dietary requirements, the following values are acceptable ... 

Cobalt, copper, molybdenum, iodine, iron, manganese, nickel, selenium, and zinc are sometimes provided to mminants. Mineral deficiency or toxicity in sheep, especially copper and selenium, is a common example of dietary mineral imbalance (21). Other elements may be required for optimal mminant performance (22). ExceUent reviews of trace elements are available (5,22). 

The amount of each element required in daily dietary intake varies with the individual bioavailabihty of the mineral nutrient. BioavailabiUty depends both on body need as deterrnined by absorption and excretion patterns of the element and by general solubiUty, and on the absence of substances that may cause formation of iasoluble products, eg, calcium phosphate, Ca2(P0 2- some cases, additional requirements exist either for transport of substances or for uptake or binding. For example, calcium-binding proteias are iavolved ia calcium transport an intrinsic factor is needed for vitamin cobalt,... 

Thus the requirement for the use of man-made drugs and dietary additives as veterinary medicines for the treatment of farmed animals is considerable and worth about 100 million pounds sterling annually in the UK ( 104 million in 1994j io jjjg investment in dietary additives such as vitamins, trace minerals, coccidiostats, pigmenters, enzymes and other probiotics to feed compounders in the UK is worth about 110 million, assuming an addition rate of 2.5 kg per tonne and a cost of approximately 3% of the total concentrate dietary cost (calculated from MAFF data, 1995). ° These data can be increased by a factor of about 10 when the compound feed produced within Europe is considered. 

Polymeric formulas typically have low osmolality of 300 to 500 mOsm/kg. These formulas also usually supply essential vitamins and minerals in amounts similar to the Adequate Intakes or Recommended Dietary Allowances for these nutrients when the formula is delivered in amounts adequate to meet the macronutrient requirements of most patients. Many polymeric formulas are inexpensive relative to oligomeric formulas. Most polymeric formulas are lactose-free and gluten-free, as are most modern tube feeding products. Products designed to be used as oral supplements generally are polymeric and often have sucrose or other simple sugars added to improve taste. 

The concept of bioavailability was developed to explain the difference between the total amount of mineral in a food and the amount which was used by the individual consuming the food. Over the past sixty years or more, there have been numerous studies related to dietary calcium requirements and bioavailability (1,2). As a result, much is known about non-calcium food components which influence the absorption and utilization of dietary calcium under experimental conditions. What now is lacking is a detailed knowledge of how these factors interact with calcium under normal conditions of ingestion in meals. 

While the dog is a carnivore, it is able to adapt to an omnivorous diet. Requirements for dietary sources of energy, amino acids, glucose precursors, fatty acids, minerals, vitamins, and water have been established based on recommendations by the National Research Council (NRC, 1985). Adult beagles maintained in a laboratory environment function well with one feeding of standard laboratory chow per day. In safety assessment testing, however, some compounds may induce serious dietary deficiencies through induced loss of appetite, malabsorption, or vomiting, and, in these cases, it may be advisable to provide a dietary supplement. 

In view of the reported growing importance ascribed to folic acid deficiency in the prevention of various disease conditions, such as neural tube defects, megaloblastic anemia, colon cancer, and colorectal cancer, a dissolution requirement is specified for folic acid when it is present in multivitamin-mineral combination products. Currently, the dissolution standard required in the official articles of dietary supplements (including vitamin-mineral combination products) places folic acid outside the index vitamin hierarchy. Therefore, a mandatory dissolution test for folic acid is required that is independent of and in addition to the mandatory index vitamin test for multivitamin preparations containing folic acid. 

The development and maintenance of healthy bone depends in part on an adequate supply of dietary calcium. Although phosphate is absolutely required for the mineralization of bone, it is abundant in the diet. If one gets enongh to eat, one gets enough phosphate. The same is not necessarily trne for calcinm and many people snpplement their diet with a preparation of calcium, frequently calcinm glnconate or calcium citrate. More follows below about the chemistry of bone when we get to a consideration of calcium. 

Resorption of the required mineral substances from food usually depends on the body s requirements, and in several cases also on the composition of the diet. One example of dietary influence is calcium (see p. 342). Its resorption as Ca is promoted by lactate and citrate, but phosphate, oxalic acid, and phytol inhibit calcium uptake from food due to complex formation and the production of insoluble salts. 

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