Calcium nutritional importance

Both lipases and lipoxygenases are present in the bran and the germ. Phytases are nutritionally important as they liberate the phosphorus, of which approximately 70% is in the kernel bound to phytin. Phytin blocks the intestinal absorption of both iron and calcium. Phytase is also present in yeast, which is why leavened bread is nutritionally superior to unleavened bread. There have been concerns about the incidence of rickets among those of South Asian origin who eat chapattis, live in the UK, and have a tendency to keep their skin covered up from the sun. 

Adequate calcium nutrition during childhood and adolescence is thought to bean important deterrent to osteoporosis in later life. A one-year study of 149 girls (8 years old) revealed the effects of consuming a typical diet (900 mg Ca/day) or a diet supplemented with an additional 850 mg Ca/day Bonjour el al, 1997). The Ca supplement was supplied by specially prepared biscuits, juices, and candy bars (rather thar pills) to assure compliance. To view some of the data, the density at the femoral diaphysis increased by 5% (unsupplemented) and by 6% (plus calcium) during the 1-ycar period. The density at the lumbar spine increased by 4% (unsupplemented) and by 4% (plus calcium). The data dernonstrated a dear and definite increase in bone density at some sites, but not at others. This study, as well as others Johnston et al., 1992), tend to show that caicium supplements to children can benefit bones of the appendicular skeleton, but not the axial skeleton. The appendicular skeleton includes the pelvis, arm bones, and leg bones. The axial skeleton includes the skull, vertebra, ribs, and sternum. 

In general, milk and dairy products (particularly Swiss-type cheeses), certain fruits (kiwi, oranges) and vegetables (broccoli, dried beans) as well as processed food such as chocolate exceed others such as meat, poultry or pasta in their relevance for optimal calcium nutrition (Tables 2.3-2 and 2.3-3). Since consumption of mineral water, which can contain relatively high amounts of calcium (Table 2.3-2), is increasing in industrialized countries, it becomes more and more important as a calcium source. 

Calcium. Soil minerals are a main source of calcium for plants, thus nutrient deficiency of this element in plants is rare. Calcium, in the form of pulverized limestone [1317-65-3] or dolomite [17069-72-6] frequendy is appHed to acidic soils to counteract the acidity and thus improve crop growth. Such liming incidentally ensures an adequate supply of available calcium for plant nutrition. Although pH correction is important for agriculture, and liming agents often are sold by fertilizer distributors, this function is not one of fertilizer manufacture. 

Chlorine. Nearly all chlorine compounds are readily soluble in water. As a result, the major reservoir for this element in Figure 1 is the ocean (5). Chloride, as noted earHer, is naturally present at low levels in rain and snow, especially over and near the oceans. Widespread increases in chloride concentration in mnoff in much of the United States can be attributed to the extensive use of sodium chloride and calcium chloride for deicing of streets and highways. Ref. 19 points out the importance of the increased use of deicing salt as a cause of increased chloride concentrations in streams of the northeastern United States and the role of this factor in the chloride trends in Lake Ontario. Increases in chloride concentration also can occur as a result of disposal of sewage, oil field brines, and various kinds of industrial waste. Thus, chloride concentration trends also can be considered as an index of the alternation of streamwater chemistry by human development in the industrialized sections of the world. Although chlorine is an essential element for animal nutrition, it is of less importance for other life forms. 

Four of the main-group cations are essential in human nutrition (Table A). Of these, the most important is Ca2+. About 90% of the calcium in the body is found in bones and teeth, largely in the form of hydroxyapatite, CatOH)2 - SCa PO. Calcium ions in bones and teeth exchange readily with those in the blood about 0.6 g of Ca2+ enters and leaves your bones every day. In a normal adult this exchange is in balance, but in elderly people, particularly women, there is sometimes a net loss of bone calcium, leading to the disease known as osteoporosis. 

It is important that children have proper nutrition and eat a balanced diet of foods that supply adequate amounts of vitamins and minerals, especially calcium and iron. Good nutrition lowers the amount of swallowed lead that passes to the bloodstream and also may lower some of the toxic effects of lead. 

Milk is an excellent source of calcium, phosphorus, riboflavin (vitamin B2), thiamine (vitamin Bl) and vitamin B12, and a valuable source of folate, niacin, magnesium and zinc (Food Standards Agency, 2002). In particular, dairy products are an important source of calcium, which is vital for maintaining optimal bone health in humans (Prentice, 2004). The vitamins and minerals it provides are all bioavailable (i.e. available for absorption and use by the body) and thus milk consumption in humans increases the chances of achieving nutritional recommendations for daily vitamins and mineral intake (Bellew et al., 2000). 

The importance of dietary or endogenously synthesized vitamin D has long been recognized as a primary factor influencing the bioavailability of calcium. Some of the most exciting biochemical-nutritional research in recent years has been devoted to determining the mechanisms involved in vitamin D-calcium interactions. This research has been well reviewed in other publications. The objective of the symposium upon which this book is based was to review some of the other lesser-known dietary factors that appear to have an impact on the bioavailability of calcium. 

The position of calcium, from the standpoint of its importance in nutrition and the likelihood that diets may be deficient in it, is regarded as probably unequaled by any other element. 

It is well recognized that interrelations exist. How much sodium one needs depends upon his potassium intake his calcium needs are determined in part by his phosphate intake his need for a specific amino acid may be determined in part by the amount of the other amino acids that he gets (they can interfere with each other s utilization). Only by further experimentation can we determine how important antagonisms and other interrelations are in human nutrition. If highly important, they will seriously complicate the picture but will not change its basic outlines. 

The importance of nutrition in the dental caries problem is reviewed in 90 pages by Shaw.22 Although we have indicated that metabolic peculiarities in the area of mineral metabolism seem "most likely to be pertinent" to the dental caries problem (p. 218), it does not follow that interest should be restricted to this field. Because teeth are organic structures produced as the result of metabolic processes, there is not a single vitamin, amino acid, or other nutrient factor which may not be implicated in the disease. Probably many different deficiencies are involved in the production of the sum total of all caries existing in all individuals. Much evidence, of course, has been found to indicate the importance of calcium, phosphorus, and vitamin D, but other items may also be very important. 

The importance of the calcium ion in human physiology is reflected by the emphasis placed on this element in human nutrition, which is important throughout life. When we are young and growing rapidly, adequate dietary calcium is required... 

The calcium ion is a key factor in human nutrition. It has an important structural role in bone and teeth and is a regulatory factor in many aspects of metabolism. 

Osteoporosis The mainstays of prevention and management of osteoporosis are estrogen and calcium exercise and nutrition may be important adjuncts. 

Of the seven macro mineral elements required by dairy cattle, five can be considered fertilizer elements (potassium, calcium, phosphorus, magnesium, and sulfur), but sodium and chloride are both toxic lo plants at high concentrations and present practical problems in areas with saline soils. High salt intakes have also been shown lo increase udder edema in heifers. Because of the importance of chloride in nutrition and mclabolisni. research is needed to define the chloride requirements of lactating cows and clarify mineral relationships, especially between chloride and potassium plus sodium-... 

D-Pantolactone (Figure 6.3.1) is an important intermediate in the production of d-pantothenic acid, also called vitamin B5. Deficiency of pantothenic acid can result in symptoms such as pathological changes of the skin and mucosa, disorders in the gastrointestinal tract and nervous system, organ changes, and hormonal disorders. Pantothenic acid is used mainly in feed for chicken and pigs and also as a vitamin supply in human nutrition. Its commercial form, the calcium salt, is produced worldwide on a multi-thousand ton scale. 

Calcium needs and metabolism have become an important nutrition issue due to the increased prevalence of osteoporosis. Osteoporosis is a disease of fragility of major bones such as the pelvis, femur, and spine caused by an age-related loss of bone minerals. As discussed in Chapter 7, calcium intake and physical activity may favorably affeot the calcium content of bones and delay the onset of osteoporosis. 

Ratter and coworkers placed due emphasis on the influence of high calcium levels in the soil on the cerrado vegetation when they concluded that the floristic composition and phytosociological parameters of cerradoes and cerrados on more fertile soils can be quite different from those on dystrophic soils (Ratter 1971, 1992, Ratter et al. 1977, 1978). Many species occur only on dystrophic soils, others only on mesotrophic soils. Even when species indifferent to soil fertility occur in different communities their relative importance can vary to a great extent (Araujo and Haridasan 1988). Nutritional adaptations of such species and communities have received very little attention for any useful discussion at a community or ecosystem level (Haridasan 1992). 

The remaining inorganic nutrients are fascinating from a biochemical standpoint, but tend not to be of roubnc importance in clinical nutrition or medicine. Assessment of nutritional status for a number of the inorganic nutrients involves the direct analysis for the nutrient, that is, in scrum, rather than a functional lest. For example, dearly defined levels of potassium and calcium are closely tied with human health. But suitable functional tests have not been devised. 

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