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Chapter 8 Minerals Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Objectives • Of the minerals discussed: – Identify at least two food sources of each mineral – State one or more functions of each mineral • Describe recommended method of avoiding mineral deficiencies Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Facts • Human body made up of specific chemical elements • Oxygen, carbon, hydrogen, and nitrogen make up 96 percent of body weight • Remaining elements and minerals represent 4 percent of body weight • Essential for good health Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Minerals • Inorganic elements necessary to build tissues, regulate body fluids, and assist in various body functions • Found in all body tissues • Do not provide energy by themselves – But contribute to production of energy (continues) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Minerals • Enriched foods – Foods to which nutrients have been added to improve nutritional value • Usually B vitamins and iron Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Classification • Major minerals – Required in amounts greater than 100 mg per day • Trace minerals – Required in amounts smaller than 100 mg per day Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Electrolytes • Ions – Electrically charged atoms • Resulting from mineral salts dissolved in water – Cations • Positively charged – Anions • Negatively charged – Must be balanced within body – Also known as electrolytes (continues) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Electrolytes • Maintain body’s fluid balance • Contribute to electrical balance • Assist in transmission of nerve impulses and contraction of muscles • Help regulate body’s acid-base balance Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Stop and Share • Consider the following question: – What is the best way to receive an adequate intake of minerals? (continues) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Stop and Share • Balanced diet – Only safe way to include minerals in amounts necessary to maintain health Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Toxicity • Occurs when concentrated forms of minerals taken regularly over time • Excessive amount of one mineral can lead to deficiency of another mineral • Changes in nearly all tissues may result • Concentrated minerals should be used only if prescribed Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Major Minerals • • • • • • • Calcium (Ca) Phosphorus (P) Potassium (K) Sodium (Na) Chloride (Cl) Magnesium (Mg) Sulfur (S) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Calcium • More in human body than any other mineral • In combination with phosphorus, gives strength and hardness to bones and teeth • Bones provide storage (continues) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Calcium • Necessary for the following: – – – – Normal nerve and muscle action Blood clotting Heart function Cell metabolism Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Calcium Regulation • Hormonal system regulates delivery to cells • Parathyroid glands release hormone telling kidneys to retrieve calcium before it is excreted when blood calcium levels drop (continues) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Calcium Regulation • Hormone works with calcitriol – Causing increased release of calcium from bones by stimulating activity of osteoclasts • Both actions increase blood calcium levels (continues) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Calcium Regulation • Every cell needs calcium • Normal blood calcium levels maintained even if intake poor • Bones become increasingly fragile as calcium withdrawn • Osteoporosis may result from years of low calcium intake (continues) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Calcium Regulation • Osteoblasts increase bone mass if blood calcium level high until age 30 to 35 • Bone mass remains stable in women with adequate consumption of calcium, phosphorus, and vitamin D – Until menopause Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Calcium Sources • Milk and milk products • Dark green leafy vegetables – Oxalic acid in some vegetables prevents calcium from being absorbed (continues) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Calcium Sources • Fiber intake of more than 35 g per day causes calcium to bind with phytates – Also limits absorption – Phytates • Phosphorus compounds found in some high-fiber cereals Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Calcium Absorption • Items that enhance absorption: – Vitamin D – Calcium-to-phosphorus ratio that includes no more phosphorus than calcium – Presence of lactose • Items that retard absorption: – Lack of weight-bearing exercise Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Calcium Requirements Age Amount 0 to 6 months 6 to 12 months 1 to 3 years 4 to 8 years 9 to 18 years 19 to 50 years 51 to 70+ years 210 mg 270 mg 500 mg 800 mg 1,300 mg 1,000 mg 1,200 mg (continues) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Calcium Requirements Age Amount Pregnant women: 14 to 18 years 1,300 mg 19 to 50 years Lactating women: 1,000 mg Same as non-lactating women of same age Source: Dietary Reference Intakes: The Essential Guide to Nutrient Requirements © 2006 by the National Academy of Sciences, Courtesy of the National Academies Press, Washington, D.C. Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Calcium Supplements • Calcium carbonate has highest concentration of bioavailable calcium • Absorbed most efficiently when consumed in doses of 500 mg • Check for United States Pharmacopeia (USP)approved products – Unlikely to contain lead Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Calcium Deficiency • Rickets results in poorly formed bone structure – Causes bowed legs, “pigeon breast,” enlarged wrists or ankles, and stunted growth • “Adult rickets” causes bones to become soft – Also known as osteomalacia (continues) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Calcium Deficiency • Osteoporosis causes brittle bones • Tetany results from insufficient calcium in blood – Characterized by involuntary muscle movement Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Calcium Excess • Excessive intake may do the following: – Cause constipation – Cause kidney stones – Inhibit absorption of iron and zinc Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Phosphorus • Constituent of all body cells • Stored in bones • Necessary for the following: – – – – Formation of strong, rigid bones and teeth Metabolism of carbohydrates, fats, and proteins Proper acid-base balance Effective action of several B vitamins Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Phosphorus Sources • Best sources: – Milk, cheese, meats, poultry, and fish • Other sources: – Cereals, legumes, nuts, and soft drinks Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Phosphorus Absorption • Increased in presence of vitamin D • Excessive use of antacids can negatively affect absorption Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Phosphorus Deficiency • Rare • Symptoms: – Bone demineralization – Fatigue – Anorexia Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Potassium • Found primarily in intracellular fluid • Essential with sodium for fluid balance and osmosis • Maintains fluid level within cell • Necessary for the following: – Transmitting nerve impulses and muscle contractions Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Potassium Sources • Fruits: – Especially melons, oranges, bananas, and peaches • Vegetables: – Brussels sprouts, mushrooms, potatoes, tomatoes, winter squash, lima beans, and carrots Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Potassium Deficiency • Hypokalemia • Caused by diarrhea, vomiting, diabetic acidosis, severe malnutrition, or excessive use of laxatives or diuretics • Symptoms: – Nausea, anorexia, fatigue, muscle weakness, and heart abnormalities Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Potassium Excess • Hyperkalemia • Caused by dehydration, renal failure, or excessive intake • Can result in cardiac failure Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Sodium • Primarily necessary for the following: – Control of fluid balance in body • Maintains acid-base balance • Participates in transmission of nerve impulses essential for normal muscle function Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Sodium Sources • Table salt contains 40 percent – One teaspoon contains 2,000 mg • Naturally available in animal foods • DRI of 1,500 mg • Tolerable upper limit of 5,800 mg – Easily exceeded by general population Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Sodium Deficiency • Caused by severe vomiting, diarrhea, and heavy perspiration – Leading to dehydration • Can upset acid-base balance – Causing acidosis or alkalosis Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Sodium Excess • May cause edema – Resulting in hypertension • Associated with hypertension and congestive heart failure • Treatment: – Sodium-restricted diet • Diets below 1 g rarely prescribed Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Chloride • Essential for the following: – Maintenance of fluid, electrolyte, and acid-base balance • Found in hydrochloric acid, cerebrospinal fluid, and muscle and nerve tissue • Helps blood carry carbon dioxide to lungs • Necessary during immune responses when WBCs attack foreign cells (continues) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Chloride • Found almost exclusively in table salt or in foods containing sodium chloride • Deficiency rare • Can occur with severe vomiting, diarrhea, excessive use of diuretics, and alkalosis Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Magnesium • • • • Vital to both hard and soft body tissues Essential for metabolism Regulates nerve and muscle function Plays role in blood-clotting process Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Magnesium Sources • Found primarily in plant foods • Green leafy vegetables, legumes, nuts, whole grains, some fruits (e.g., avocados, bananas), and milk in sufficient quantities Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Magnesium Deficiency • Unknown among people on normal diets • Symptoms: – Nausea and mental, emotional, and muscular disorders Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Sulfur • Necessary to all body tissue and for metabolism • Contributes to characteristic odor of burning hair and tissue • Component of some amino acids • Found in protein-rich foods • Both amount required by human body and deficiency unknown Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Trace Minerals • • • • • Iron (Fe) Iodine (I) Zinc (Zn) Selenium (Se) Copper (Cu) • • • • Manganese (Mn) Fluoride (F) Chromium (Cr) Molybdenum (Mo) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Iron • Delivers oxygen to body tissues • Component of hemoglobin • Component of myoglobin – Protein compound in muscles that provides oxygen to cells • Used by enzymes involved in making amino acids, hormones, and neurotransmitters Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Iron Sources • Heme iron: – Meat, poultry, and fish – Absorbed more than twice as efficiently as nonheme iron • Nonheme iron: – Whole-grain cereals, enriched grain products, vegetables, fruits, eggs, meat, fish, and poultry Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Iron Requirements • RDA doubles during pregnancy – Difficult to meet by diet alone – Iron supplement commonly prescribed • Increased requirements during infancy and teenage years • Vitamin C enhances absorption Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Iron Deficiency • Caused by insufficient intake, malabsorption, lack of stomach acid, or excessive blood loss • Iron-deficiency anemia – Most common nutrient deficiency worldwide • Symptoms: – Fatigue, weakness, irritability, shortness of breath, pale skin, and spoon-shaped fingernails Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Iron Excess • Hemochromatosis – Results from inborn error of metabolism that causes excessive absorption of iron – Untreated, can damage liver, spleen, and heart – To control iron buildup, must give blood on regular basis Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Iodine • Component of thyroid hormones, thyroxine (T4), and triiodothyronine (T3) • Necessary for the following: – Normal functioning of thyroid gland • Determines rate of metabolism • Sources: – Iodized salt, seafood, and some plant foods grown in soil bordering sea (continues) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Iodine • Increased requirements during pregnancy and lactation • Deficiencies: – Cause decrease in thyroxine and triiodothyronine – Gland grows, forming lump on neck • Goiter (continues) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Iodine • Myxedema – Condition of hypothyroidism in adults • Cretinism – Low thyroid in child – Physical and mental development delayed Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Zinc • Cofactor for more than 300 enzymes • Essential for the following: – – – – – Growth Wound-healing Taste acuity Glucose tolerance Mobilization of vitamin A within body (continues) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Zinc • Sources: – Meat, fish, eggs, dairy products, wheat germ, and legumes • Increased requirements during pregnancy and lactation • Deficiency symptoms: – Decreased appetite and taste acuity, delayed growth, dwarfism, hypogonadism, poor wound-healing, anemia, acne-like rash, and impaired immune response Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Selenium • Constituent of most body tissues • Concentrated in liver, kidneys, and heart • Component of enzyme that acts as antioxidant – Protects cells against oxidation – Spares vitamin E (continues) Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Selenium • Sources: – Seafood, kidney, liver, and muscle meats • High doses toxic – Causes vomiting, loss of hair and nails, and skin lesions Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Copper • In all tissues – Heaviest concentration in liver, kidneys, muscles, and brain • Helps with the following: – Formation of hemoglobin – Transportation of iron to bone marrow for RBC formation – Production of energy Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Copper Sources • Organ meats, shellfish, legumes, nuts, cocoa, whole-grain cereals, and human milk Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Copper Deficiency • Rare, but may occur in: – – – – – Malabsorption conditions Gross protein deficiency Premature infants Clients on long-term parenteral nutrition People taking excess zinc supplements • May cause anemia, bone demineralization, and impaired growth Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Copper Excess • Highly toxic • Wilson’s disease – Inherited condition causing accumulation of copper in liver, brain, kidneys, and cornea Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Manganese • Constituent of several enzymes involved in metabolism • Important in bone formation • Sources: – Whole grains, teas, vegetables, and fruits • Deficiency or toxicity from ingestion unknown • Inhalation linked to neurological problems Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Fluoride • Increases resistance to dental caries – May strengthen teeth and bones • Sources: – Fluoridated water, fish, and tea and commercially prepared foods with fluoridated water • Deficiency can result in increased tooth decay • Excess can cause permanent discoloration or mottling of children’s teeth Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Chromium • Associated with glucose and lipid metabolism • Levels decrease with age except in lungs – Where it accumulates • Sources: – Meat, mushrooms, nuts, yeast, organ meats, and wheat germ • Deficiency related to disturbances in glucose metabolism Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Molybdenum • Constituent of enzymes • Considered to play role in metabolism • Sources: – Milk, liver, legumes, and cereals • No deficiencies noted • Excess inhibits copper absorption Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Conclusion • Megadoses of minerals dangerous • Minerals necessary to promote growth and regulate body processes • Minerals originate in soil and water and ingested via food and drink • Deficiencies can result in severe conditions • Excess can be toxic Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.