Minerals PDF

MINERALS R O S A D. D E V E R A , P H D, R N Minerals pertain to the elements in their simple inorganic form. In nutrition, they are commonly referred to as mineral elements or, in the case of those present or required in small amounts, they are known as trace elements or trace minerals. MINERAL...

MINERALS R O S A D. D E V E R A , P H D, R N Minerals pertain to the elements in their simple inorganic form. In nutrition, they are commonly referred to as mineral elements or, in the case of those present or required in small amounts, they are known as trace elements or trace minerals. MINERAL COMPOSITION OF THE BODY There are 21 mineral elements essential in nutrition. Calcium Phosphorus Potassium Sulfur Sodium Chlorine Magnesium Iron Zinc Selenium Manganese Copper Iodine Molybdenum Cobalt Chromium Fluorine Vanadium Nickel Tin Silicon GROUP 1: MAJOR MINERALS 1. Calcium a. Distribution 99% is present mostly in the bones and teeth and the remaining 1% is found in the soft tissues and body fluids and serves important functions unrelated to bone structure. b. Functions Calcium combines with phosphorus to form calcium phosphate, the hard material of the bones and teeth. Calcium participates in muscular contraction and relaxation. It promotes blood coagulation. It affects the transport function of cell membranes, possibly acting as a membrane stabilizer. Calcium is required in nerve transmission and regulation of heart beat. c. Utilization There are many factors which influence calcium absorption: c.1 Calcium absorption is better during periods of increased body needs such as in growth, pregnancy and lactation. The extent is about 60%. Also, when the intake is low, the body compensates by absorbing a high percentage. There is decreased absorption in old age. c.2 Vitamin D enhances the optimum absorption of calcium by increasing permeability of the intestinal membrane to calcium and by activating the active transport system. c.3 A low gastric pH (acidic) favors the absorption of calcium whereas hypochlorhydria (alkaline medium) causes the precipitation of the mineral. c.4. A normal protein diet does not have any effect on calcium absorption but high intakes of meat as in the diet of the Westerners increase the excretion of calcium in the urine even in lysine, arginine and serine increase the absorption by 50%. c.5 A high ratio of lactose to calcium is necessary for the formation of a soluble complex which can easily be transported to and possibly across the intestinal wall. c.6 The ratio of calcium to phosphorus is important in the absorption of both minerals in infants and a recommended level is a Ca:P ratio of 1.5:1. In adults, a ratio of 1:1 is necessary for better absorption. c.7 Oxalic and phytic acids interfere with the absorption of calcium. Oxalic acid present in several fruits and vegetables such as alagaw, kamias, kulitis, kutsarita, alasiman, unripe tamarind, tamarind leaves and spinach depresses calcium absorption by forming insoluble salts. Phytic acid in cereals as in wheat bread and oatmeal acts in the same manner as oxalic acid although in most cereals, phytase, an enzyme capable of splitting phytic acid to make it available for absorption, is present. c.8 Fats in excess may form insoluble soaps with calcium as evidenced by the presence of fatty acids, calcium and also fat-soluble vitamin D in the feces. This is especially observed in conditions where there is poor fat digestion as in sprue and steatorrhea. c.9 Anything that may cause an increase in GI motility like laxatives and foods high in bulk may reduce the rate of passage of food in the intestinal tract causing the decrease in the absorption of calcium. c.1 Lack of exercise may cause a loss of bone calcium and reduced ability to replace it. c.1 Mental stress or emotional instability has been found to decrease calcium absorption. c.1 Alcohol intake among alcoholics may cause decreased calcium absorption. c.1 Caffeine increases urinary calcium excretion. Approximately 1 cup of coffee can increase calcium excretion by 6 mg. d. Food sources kuhol cheese seaweed gamet bagoong malunggay leaves dried fish saluyot alakaak carabao’s milk biya dilis galunggong hipon, tagunton sardines susong pilipit dried ayungin talangka dried dilis silinyasi dried hibi milk, evaporated e. Effects of deficiency or excess e.1 Effects of deficiency Retarded growth Rickets Osteomalacia (adult rickets) in which a reduction in the mineral content of the bone is observed. Tetany caused by a reduction in circulating ioized calcium resulting in increased excitability of the nerve and uncontrolled reactions of muscle tissue. e.2 Effects of excess hypercalcemia e. Effects of deficiency or excess e.1 Effects of deficiency Retarded growth Rickets Osteomalacia (adult rickets) in which a reduction in the mineral content of the bone is observed. Tetany caused by a reduction in circulating ioized calcium resulting in increased excitability of the nerve and uncontrolled reactions of muscle tissue. e.2 Effects of excess hypercalcemia 2. MAGNESIUM a. Distribution About 50% of the magnesium in the body is present in the bones in combination with phosphate and calcium. b. Functions  It regulates blood phosphorus level.  It is necessary to promote the conduction of nerve impulses and to allow normal muscle contraction.  It may also increase the stability of calcium in the tooth enamel. c. Food sources Nuts Cocoa Peas Soybeans Sea foods Green plants Meat Wholegrains Milk Dried beans d. Effects of deficiency or excess Magnesium deficiency (hypomagnesemic) has been observed among infants and children suffering from kwashiorkor and diseases characterized by intestinal malabsorption, prolonged diarrhea or vomiting, and alcoholism; in persons maintained for long periods of time on magnesium-free fluids following surgery or diuretics; and in cases of hypercalcemia, diabetes, and acute renal failure with polyuria. 3. SODIUM a. Functions  Sodium is responsible for maintaining fluid balance.  It is also responsible for maintaining acid-base balance.  It allows the passage of materials like glucose through the cell wall and maintains normal muscle irritability and excitability. b. Food Sources Carrots Peas Celery Vetsin Beets Fish Sauce Soy Sauce Catsup Spinach c. Recommended Dietary Allowances Allowances and requirements for requirements for sodium have not been determined, but the amount should equal that of the body’s needs for growth; for losses in sweat and secretions, urine, and stools; and for non-sweat losses from the skin. d. Effects of deficiency or excess A deficiency of sodium (hyponatremia) can occur in dehydration as in heat exhaustion, especially following an intake of large amounts of H₂O, without providing additional salt; after surgical procedures with marked loss of blood; after marked diarrhea and vomiting; and after a long- term vigorous treatment with very restricted sodium diets. 4. POTASSIUM a. Functions  Potassium maintains fluid and electrolyte balance.  It plays a significant role in the activity of the skeletal and cardiac muscles.  It acts as a muscle relaxant in contrast to calcium which stimulates muscular contraction.  It is also important in carbohydrate and protein metabolism. b. Food sources Meat Fruit juice Legumes Dark green vegetables Milk Unrefined cereals Raw and dried fruits c. Recommended dietary allowance The diet should contain about 2-6 gm potassium so that a deficiency is usually unlikely in a healthy person. d. Effects of Deficiency or Excess Deficiency: Hypokalemia Abdominal Distension Apathy Muscular Weakness Mental Confusion Effects of Excess Hyperkalemia - Due to failure to excrete the potassium properly resulting in toxic levels. 5. PHOSPHORUS a.Functions Phosphorus is a component of bones and teeth. It is also a component of every cell. b. Food Sources Cheese Poultry Milk Fish Dairy Products Eggs Meat Dried beans