Mineral metabolism excess

Calcium carbonate(eg, Turns, Os-Cal) is less soluble and reacts more slowly than sodium bicarbonate with HC1 to form carbon dioxide and CaCl2. Like sodium bicarbonate, calcium carbonate may cause belching or metabolic alkalosis. Calcium carbonate is used for a number of other indications apart from its antacid properties (see Chapter 42 Agents That Affect Bone Mineral Homeostasis). Excessive doses of either sodium bicarbonate or calcium carbonate with calcium-containing dairy products can lead to hypercalcemia, renal insufficiency, and metabolic alkalosis (milk-alkali syndrome). 

Some copper compounds have been used therapeutically in the past. Small quantities of copper salts enhance the physiological utilization of iron and are thus often present in hemopoietic formulations. Copper chloride and copper sulfate are used in parenteral nutrition solutions. The artificial radioactive copper isotope Cu has been used in mineral metabolic studies. Excess accumulation of copper can occur due to an abnormality of ceruloplasmin and causes Wilson s disease and Menkes disease, which are both characterized by copper accumulation (SEDA-22, 244) (9). 

Ketosis— The most common causes of this condition— which is characterized by an excess of ketones in the blood— are (1) diabetes (2) diets high in fat and protein, but low in carbohydrate (3) fevers and (4) starvation. A mild ketosis in normally healthy people is usually not dangerous, unless it occurs regularly over a long period of time, flien, it may lead to such problems as (1) excessive urinary loss of sodium and water (2) acidosis which provokes the loss of calcium from bone, and potassium from muscle and (3) the accumulation of uric acid (a waste product of protein metabolism) in the blood, and sometimes in the soft tissues where it causes damage and pain (the latter disorder is commonly called gout). Uric acid buildup is usually treated with alkalizers to prevent the formation of kidney stones. However, the alkalizers may cause other alterations in mineral metabolism. 

Stress and Trauma. Many types of stresses and traumas (the term used for sudden shocks, injuries, or wounds to the body) may alter various aspects of mineral metabolism. The reactions of the body to various types of stresses and traumas are similar because (1) such stresses as the deprivation of food or water, extremes of heat or cold, or emotional upsets may damage the body tissues in ways which are similar to the effects of trauma and (2) most traumas provoke substantial increases in the secretion of stress hormones by the pituitary and adrenal glands. The prolonged secretion of abnormally high levels of stress hormones may lead to excessive losses of potassium, phosphorus, calcium, magnesium, and zinc in the urine. Usually, such conditions are accompanied by greater than normal... 

In the event of dietary Ca abundance, Ca in excess of adequate circulating concentrations is deposited in the skeleton. This occurs to the extent of the body s ability to store Ca, and any excess beyond this threshold is excreted. Accrual of Ca into bone is governed by such factors as dietary intake (including the absorption, bioavailability, utilization of nutrients and minerals, and other dietary constituents that influence absorption or retention), calciotropic hormones, genetic potential, lifestyle factors, life stage, general health, and the adaptive response to physical/mechanical stimuli within the constraints of metabolic economy. 

In agriculture, excesses or deficiencies of essential and beneficial elements (Epstein, 1972 Hewitt and Smith, 1975 Webber, 1981) have profound effects on the health and hence the yields of plants. Chlorosis is often the visible deficiency symptom (Kabata-Pendias and Pendias, 1984). However, disturbances of metabolic processes and consequent losses of biomass production may occur before deficiency symptoms are recognised. Thus the analysis of plants for mineral and nutrient status is particularly important in agriculture. The agricultural agencies of many countries publish recommended analytical methods (for example, HMSO, 1986). 

Q7 Calcium is present in both intracellular fluid (ICF) and ECF, but the concentration in the ECF is twice as high as that in the ICF. Calcium is found in both ionized and bound forms, and Ca2+ homeostasis is mainly controlled by parathyroid hormone, which increases absorption of calcium in the intestine and reabsorption in the nephron. Calcitonin also affects ECF calcium concentration by promoting renal excretion when there is an excess of calcium in the body. The normal kidney filters and reabsorbs most of the filtered calcium however, in renal disease this is reduced and blood calcium decreases. Calcium and phosphate imbalance can occur in patients with renal failure, leading to osteomalacia (defective mineralization of bone). Osteomalacia is mainly due to reduced production of 1,25-dihydroxycholecalciferol, an active form of vitamin D metabolized in the kidney. Deficiency of 1,25-dihydroxycholecalciferol reduces the absorption of calcium salts by the intestine. 

For instance, urea, the product of protein digestion from which the term urine is derived, must be removed. Other waste products of metabolism must be removed. Any toxins produced by bacteria must be removed. Any drug residue or other unusable material must be removed. Any excess hormone must be removed. Glucose, on the other hand, should not be eliminated and proteins should not be secreted. Vitamins need to be saved, as does calcium and a certain amount of sodium and other minerals. However, water must be regulated. Too much water in the blood would be bad because if blood were too dilute, then not enough nutrients would be transported to the cell. If blood had too little water, then the physical process of pumping the blood around would be... 

Excessive zinc interferes with iron and copper metabolism the latter leads to copper-deficiency anemia. Salts of strong mineral acids are corrosive to skin and intestine. 

These effects are related to rapid metabolism of the sugar and can be prevented if the sugar is metabolized slowly. Trichoderma viride will produce as much cellulase on cellobiose as it does on cellulose if its metabolism is slowed by (1) suboptimum temperature and aeration, (2) deficiencies of mineral nutrients such as calcium, magnesium, or trace metals, or (3) excess of a mineral such as cobalt (23). 

Generally, nutrient deficiencies or excesses are caused by soil properties, fertilizer application, interactions between mineral elements during uptake and metabolism, and intrinsic factors of plants and crops with intensive nutrient responses. The rules of these element-specific influences were given by Bergmann (1992). 

Minerals, like vitamins, have adverse effects if ingested in excessive amonnts. Problems associated with dietary excesses or deficiencies of minerals are described in snbseqnent chapters in conjunction with their normal metabolic functions. 

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