Magnesium Assignment 2023 PDF

Magnesium Assignment  Magnesium - Magnesium is an essential element in biological systems, occurs typically as the Mg2+ ion. - Magnesium is the fourth most abundant mineral in the body and is the second-most abundant intracellular cation, it is essential to good...

Magnesium Assignment  Magnesium - Magnesium is an essential element in biological systems, occurs typically as the Mg2+ ion. - Magnesium is the fourth most abundant mineral in the body and is the second-most abundant intracellular cation, it is essential to good health. - Approximately 50% of total body magnesium is found in bone. The other half is found predominantly inside cells of body tissues and organs. - Only 1% of magnesium is found in blood, but the body works very hard to keep blood levels of magnesium constant. - Green vegetables such as spinach are good sources of magnesium, Some legumes (beans and peas), nuts and seeds, and whole, unrefined grains are also good sources of magnesium and “Tap water” or “hard water” can be a source of magnesium.  Magnesium ü300 enzyme systems are magnesium activated. üMost aspects of intracellular biochemistry are magnesium dependent, including glycolysis, oxidative metabolism and transmembrane transport of potassium and calcium. üThe electrical properties of cell membranes are affected by any reduction in the intracellular magnesium concentration. Examples of the Physiological Role of Magnesium  Functions - It is an essential mineral nutrient for life and is present in every cell type in every organism. For example, ATP must be bound to a magnesium ion in order to be biologically active. ATP is often actually Mg-ATP. - Similarly, magnesium plays a role in the stability of all polyphosphate compounds in the cells, including those associated with DNA and RNA synthesis. - It helps maintain normal muscle and nerve function, keeps heart rhythm steady, supports a healthy immune system, and keeps bones strong. - Magnesium also helps regulate blood sugar levels, promotes normal blood pressure, and is known to be involved in energy metabolism and protein synthesis. ü Magnesium influences the secretion of PTH by the parathyroid glands and severe hypomagnesaemia may cause hypoparathyroidism. Magnesium homeostasis üSince magnesium is an integral part of chlorophyll green vegetables are an important dietary source, as are cereals and animal meats. An average dietary intake is around 15mmol per day which generally meets the recommended dietary intake. üChildren and pregnant or lactating women have higher requirements. üAbout 30% of the dietary magnesium is absorbed from the small intestine and widely distributed to all metabolically active tissue. üHypermagnesaemia is uncommon but is occasionally seen in renal failure. üThe symptoms of hypomagnesaemia are very similar to those of hypocalcacmia: impaired neuromuscular function such as tetany, hyperirritability, tremor, convulsions and muscle weakness.  The serum levels of parathyroid hormone and magnesium depend on each other in a complex manner. The secretion of parathyroid hormone by the parathyroid is physiologically controlled by the serum calcium level, but magnesium can exert similar effects. While low levels of magnesium stimulate parathyroid hormone secretion, very low serum concentrations induce a paradoxical block. This block leads to clinically relevant hypocalcemia in severely hypomagnesiemic patients. The mechanism of this effect has recently been traced to an activation of the alpha-subunits of heterotrimeric G-proteins. This activation mimicks activation of the calcium sensing receptor and thus causes inhibition of parathyroid hormone secretion. 9  In addition to the effects of magnesium on parathyroid hormone secretion, parathyroid hormone in turn regulates magnesium homeostasis by modulating renal magnesium reabsorption. The distal convoluted tubule is of crucial importance for parathyroid hormone- regulated magnesium homeostasis 10 MAGNESIUM IMBALANCE  DEFINITION Hypomagnesemia is serum magnesium concentration < 1.8 mg/dL (< 0.70 mmol/L). Causes include inadequate magnesium intake and absorption or increased excretion due to hypercalcemia or medications such as furosemide. Clinical features are often due to accompanying hypokalemia and hypocalcemia and include lethargy, tremor, tetany, seizures, and arrhythmias. Treatment is with magnesium replacement.  Magnesium Deficiency ü Since magnesium is present in most common foodstuffs, low dietary intakes of magnesium is associated with general nutritional insufficiency. ü Magnesium deficiency can be expected as a result of: 1. Dietary insufficiency accompanied by intestinal malabsorption, severe vomiting, diarrhea or other causes of intestinal loss. 2. Osmotic diuresis such as occurs in diabetes mellitus. 3. Prolonged use of diuretic therapy especially when dietary intake has been marginal prolonged. 4. Nasogastric suction. 5. Cytotoxic drug therapy such as cisplatinum which impairs renal tubular reabsorption of magnesium 6. Treatment with the immunosuppressant drug; cyclosporin. CAUSES  SYMPTOMS Early signs of low magnesium include: nausea vomiting weakness decreased appetite As magnesium deficiency worsens, symptoms may include: numbness tingling muscle cramps seizures muscle spasticity personality changes abnormal heart rhythms MANAGEMENT  Renal Loss Causes of Magnesium Deficiency: Gastrointestinal Disorders Manifestations of Magnesium Depletion Laboratory diagnosis üMagnesium concentration of less than 0.7 mmo1/L in a serum specimen is evidence of marked intracellular depletion. However, intracellular magnesium depletion may exist where the serum magnesium concentration is within the reference range. Management üOral, IM and IV regimens have been proposed. üAdministration of magnesium salts, by whatever route is contraindicated when there is a significant degree of renal impairment. In these circumstances any supplementation must be monitored carefully to avoid toxic effects associated with hypermagnesaemia.  DEFINITION Hypermagnesemia is an electrolyte disorder in which there is a high level of magnesium in the blood. Hypermagnesemia is a serum magnesium concentration > 2.6 mg/dL (> 1.05 mmol/L)  CAUSES Most cases of hypermagnesemia occur in people who have kidney failure. Hypermagnesemia occurs because the process that keeps the levels of magnesium in the body at normal levels does not work properly in people with kidney dysfunction and end-stage liver disease.  Other causes of hypermagnesemia include: lithium therapy hypothyroidism Addison’s disease milk-alkali syndrome drugs containing magnesium, such as some laxatives and antacids familial hypocalciuric hypercalcemia  SYMPTOMS nausea vomiting neurological impairment abnormally low blood pressure (hypotension) flushing headache  MANAGEMENT The first step in treating hypermagnesemia is identifying and stopping the source of extra magnesium An intravenous (IV) calcium supply is then used to reduce symptoms such as impaired breathing, irregular heartbeat, and hypotension, as well as the neurological impact.  Intravenous calcium, diuretics, or water pills may also be used to help the body get rid of excess magnesium. People with renal dysfunction or those who have had a severe magnesium overdose may require dialysis if they are experiencing kidney failure, or if magnesium levels are still rising after treatment.