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Focus on Pharmacology Essentials for Health Professionals Jahangir Moini, MD, MPH Chapter 8 Nutritional Aspects of Pharmacology Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Nutrition • Nutrition: how the body takes in and uses food and other sources of nutrients for growth and repair of tissues • A five-part process: intake, digestion, absorption, metabolism, elimination Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Nutrients • Nutrient: element or compound from diet that supports normal metabolism, growth, reproduction, or other functions – Essential nutrient: needed by body for normal functioning – Nonessential nutrient: can be synthesized by body from other compounds; may also be derived from diet Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Seven Nutrients • • • • • • • Proteins Fatty acids (also called lipids or fats) Carbohydrates Fiber Vitamins Minerals Water Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Macronutrients • Needed by body in large amounts for energy – Carbohydrates – Fats – Proteins – Macrominerals (dietary minerals needed in high quantities: grams) – Water Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Macronutrients Are Energy • Macronutrients: interchangeable as sources of energy – Fats yield 9 kilocalories of energy per 1 g consumed (9 kcal/g) – Proteins and carbohydrates yield 4 kcal/g • Water requirements: 1 mL/kcal of energy expended or about 2,500 mL/day Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Essential Amino Acids • Components of proteins that cannot be synthesized by the body and must be provided by diet • Nine of the 20 amino acids are essential Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Essential Fatty Acids • Required in amounts equaling 6% to 10% of fat intake (5–10 g/day) • Appear to play a role in decreasing triglyceride levels and the growth rate of atherosclerotic plaque • Required for the formation of prostaglandins and thromboxanes Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Types of Fatty Acids • Saturated – Dense, heavy, and solid at room temperature – Found in dairy products and meats • Unsaturated – Usually liquid at room temperature – From vegetables and legumes: corn, soy, peanuts, safflower Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Cholesterol • A natural lipid found in cell membranes • Found in highest concentrations in animal muscles and organs • Essential for certain cell structures • Excess cholesterol can form atherosclerotic plaque, leading to cardiovascular disease Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Carbohydrates • Provide about two thirds of daily energy needs • Aid in fat metabolism and help reserve protein for uses such as repairing and building tissues • Daily requirement 50% to 60% of total caloric intake Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Two Types of Carbohydrates • Simple sugars – Quickly absorbed – Found in fruits, some vegetables, milk, and table sugar • Complex carbohydrates – Must be processed by the body before absorption – Found in grain, fruits, and vegetables Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Storage of Carbohydrates • Glucose (a sugar) is stored in the liver and muscles as glycogen (starch). – Available to supplement dietary supplies of carbohydrates • Excess amounts of carbohydrates are stored in the body as adipose tissue (fat). Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Blood Glucose Levels The central nervous system (CNS) requires a constant supply of glucose to function properly. Sustained low blood glucose levels, which can be caused by an excessively low intake of carbohydrates, can result in brain damage and death. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Lactose Sensitivity • Lactose is a sugar in human and animal milk that must be broken down by the enzyme lactase to be digested. • Many infants and children have trouble digesting foods that contain lactose. • Lactose-free milk can be substituted. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Fiber: A Complex Carbohydrate • Soluble fiber: absorbs water and swells when eaten; found in oats, fruits, and vegetables • Insoluble fiber: not absorbed by body; found in bran of whole wheat and brown rice • Provides stool bulk, which stimulates peristalsis Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Micronutrients • Vitamins and essential trace nutrients needed in very small quantities • Insufficiencies cause biochemical alterations (such as changes in the structure and function of tissues and organs) and diseases Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Vitamins • Organic compounds needed for normal human growth, development, and maintenance of normal body function • Classified by solubility – Water soluble: B and C vitamins – Fat soluble: A, D, E, and K vitamins Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. B Vitamins: Thiamine (B1) • Sources: whole grains (especially wheat germ), lean meats, fish, soybeans, and other beans • Important in carbohydrate metabolic processes • Deficiency leads to beri-beri (edema, cardiovascular abnormalities, and neurologic symptoms) Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. B Vitamins: Riboflavin (B2) • Sources: dairy, yeast, and liver • Important in metabolism of fats, carbohydrates, and proteins • Deficiency causes cheilosis, stomatitis, glossitis, and seborrheic dermatitis • No danger of excessive consumption Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. B Vitamins: Nicotinamide (B3) • Also called niacin • Sources: liver, yeast products, peanuts, whole grain cereals, and fish • Large doses lower cholesterol, triglycerides, free fatty acids • Deficiency causes pellagra (dementia, dermatitis, diarrhea, and death) Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. B Vitamins: Nicotinamide (B3) (continued) • Toxicity includes hepatic impairment, severe hypotension, and various skin conditions Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Pharmacologic Doses of Niacin • At high doses, niacin decreases blood levels of low-density lipoprotein (LDL) cholesterol and triglyceride levels, which are linked to cardiovascular disease, and increases high-density lipoprotein levels (good cholesterol). • Niacin is used under physician’s supervision for this purpose. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. B Vitamins: Pantothenic Acid (B5) • Sources: whole grain cereals, legumes, meat, eggs • Needed for formation of coenzyme A • Deficiency is rare Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. B Vitamins: Pyridoxine (B6) • Sources: animal and plant products • Used to prevent neuritis in patients on isoniazid (INH) therapy and to treat hyperemesis gravidarum (nausea during pregnancy) • Deficiency is rare Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. B Vitamins: Biotin • Sources: widely available in foods and made by natural flora in intestines • Deficiency is almost unknown • No known toxicities Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. B Vitamins: Folate • Sources: dark green, leafy vegetables • Aids creation of DNA; essential to hemoglobin formation and amino acid synthesis • Deficiency causes anemia • Increased folic acid recommended in pregnancy to prevent spina bifida • No known toxicity Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. B Vitamins: Cobalamin (B12) • Sources: fish, dairy, organ meats, eggs • Promotes normal cell function, especially blood formation and nerve cell function • Lack of intrinsic factor in GI tract (caused by certain GI disorders) can block absorption of B12, leading to pernicious anemia – More common in elderly patients • No known toxicity Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Vitamin B Factors (Choline) • Sources: milk, eggs, liver, and peanuts • Needed to produce acetylcholine (neurotransmitter involved in memory and muscle control) • Deficiency linked to Huntington’s chorea, Parkinson’s disease, and Alzheimer’s disease Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Vitamin B Factors (Choline) (continued) • Excess doses may lower blood pressure; cause fishy body odor, sweating, and excessive salivation; and reduce growth rate Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Vitamin C: Ascorbic Acid • Sources: capsicums, guavas, kiwi, citrus • Aids wound healing, tissue repair, infection resistance, iron bioavailability, and calcium absorption • Antioxidant role: may reduce cancer risk and lower cholesterol levels • Deficiency causes scurvy • Excess may cause diarrhea and gastritis Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Vitamin C and Cataracts • Vitamin C may protect against cataracts because the body concentrates it in the lenses of the eye. • The use of vitamin C for 10 or more years is associated with 77 to 83% lower prevalence of early to moderate cataracts. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Fat-Soluble Vitamins • • • • • • Vitamin A (retinol) Vitamin D3 (cholecalciferol) Vitamin D2 (ergocalciferol) Vitamin E (alpha tocopherol) Vitamin K1 (phylloquinone) Vitamin K2 (menaquinone) Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Retinol (Vitamin A) • Sources: fish-liver oils, butter, egg yolk, liver – All milk is fortified with vitamin A – Carotene is converted to vitamin A in body • Aids tissue maintenance, skeletal and soft-tissue growth, protein synthesis, vision Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Retinol (Vitamin A) (continued) • Mild deficiency may cause night blindness • Toxicity (hypervitaminosis A) marked by hair loss, jaundice, joint pain, liver injury, ascites Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Vitamin A Deficiency Dietary vitamin A deficiency in the number one cause of blindness in children worldwide. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Overconsumption of Vitamins or Minerals • If overconsumption of vitamin or mineral occurs, patients should cut back, but not stop immediately, to allow the body to adjust. • Stopping immediately can trigger a deficiency. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Cholecalciferol (Vitamin D3) • Sources: yeast, fish-liver oils • Cholecalciferol (vitamin D3), made by the body in response to UV light; then activated by cholesterol to become calcitriol • Stimulates calcium and phosphorus absorption Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Cholecalciferol (Vitamin D3) (continued) • Deficiency causes rickets, osteomalacia, osteoporosis • Toxicity can occur, especially in children Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Tocopherol (Vitamin E) • Sources: vegetable oils, nuts, fortified cereals • Protects breakdown of red blood cells (RBCs) Deficiency can occur in premature infants who miss final 1-2 months of gestation Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Tocopherol (Vitamin E) (continued) • Deficiency in adults disrupts myelin production, affecting physical activity and vision • Excess intake may interfere with vitamin K and blood clotting Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Vitamin K • Phylloquinone (K1) is dietary form; menaquinone (K2) is synthesized by intestinal bacteria • Sources: green leafy vegetables • Aids blood clotting and bone development • Antidote for overdose of anticoagulants • Deficiency is rare • No known toxicity Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Vitamin K • Phylloquinone is routinely given to newborns to prevent hemorrhage when the umbilical cord is cut. • Trade names of this “vitamin K shot” are AquaMephyton, Mephyton, or Phytonadione. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Mineral and Vitamin Interactions • Insufficient vitamin D intake hinders the uptake of calcium. • High amounts of supplemental vitamin C reduce copper levels. • Vitamin C can increase iron absorption as much as 30%. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Mineral and Vitamin Interactions (continued) • Excessive amounts of vitamin E interfere with iron absorption. • Vitamin B6 is required to metabolize magnesium and zinc. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Proper Dosage of Vitamins • Advise patients about the proper dose of vitamins that are needed to maintain metabolic control and prevent disease. • Warn patients that certain health problems are related to inadequate or excessive intake. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Minerals • Major: daily requirements more than 100 mg/day – Calcium, phosphorus, sodium, potassium, magnesium, and chlorine • Minor (essential trade minerals): daily requirements less than 100 mg/day – Iron, iodine, fluoride, zinc, chromium, selenium, manganese, molybdenum, and copper Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Calcium • Sources: milk, cheese, salmon, green leafy vegetables, whole grains • Aids bone formation, nerve conduction, myocardial and skeletal muscle contractions • Absorption dependent on vitamin D • Deficiency causes rickets, osteomalacia, osteoporosis Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Calcium (continued) • Excess may cause constipation, nausea, hypotension, vomiting, kidney stones, cardiac arrhythmias Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Phosphorus • Sources: milk, cheese, legumes, beef, fish, pork • Needed for bone and tooth formation, energy, storage of fats, metabolism of other nutrients • Deficiency can cause anemia, bone brittleness, confusion, and weakness • Toxicity may cause hypocalcemia and kidney stones Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Sodium • Source: table salt • Needed for body fluid balance and acid– base balance; regulates nerve transmission and cell membrane irritability • Deficiency may cause headache, confusion, nausea, weakness, anxiety, muscle spasms, hypotension • Toxicity produces hypertension and edema Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Potassium • Sources: oranges, bananas, red meats, vegetables, yams, milk products, coffee • Helps maintain normal cardiac and muscle function • Deficiency can cause weakness, paralysis, cardiac arrhythmias, digitalis toxicity Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Potassium (continued) • Excessive intake may produce muscle weakness, diarrhea, severe dehydration, abdominal pain, hypotension, cardiac arrest Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Chlorine • Sources: table salt, meat, milk, processed foods • Major electrolyte that aids acid–base balance and fluid balance • Deficiency is rare • No known toxicity Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Iron • Sources: meat, eggs, vegetables, cereals • Aids in synthesis of hemoglobin and general metabolism • Deficiency causes anemia • Toxicity can be fatal Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Iron Toxicity • In the United States, iron overdose from supplements is leading cause of poisoning in young children. • Symptoms: nausea, vomiting, diarrhea • If not treated immediately, can result in brain, kidney, liver, and heart damage Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Iodine • Sources: iodized table salt, seafood • Helps synthesize thyroxine to control body’s basal metabolic rate • Deficiency can cause goiter, cretinism, and myxedema • Excess intake cause acne-like skin lesions or worsen acne Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Cretinism • Cretinism occurs in children born to mothers who had limited iodine intake during adolescence and pregnancy. • Children with cretinism have retarded physical and mental development. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Zinc • Source: meat • Important during growth periods • Deficiency may cause retarded physical growth (such as dwarfism) and retarded sexual maturation, poor wound healing, hair loss, diarrhea, skin irritation • Excess intake can inhibit copper absorption or cause nausea, vomiting, and decreased immune function Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Fluoride • Sources: fish, tea • Prevents dental caries by strengthening tooth’s ability to withstand bacterial erosion Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Copper • Sources: organ meats (liver), seafood, nuts, seeds, legumes, grains • Aid energy production and hemoglobin synthesis • Deficiency is rare; increased intake is recommended for pregnant or lactating women to meet increased needs Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Copper (continued) • Toxicity: Wilson’s disease is genetic disorder causing excess storage of copper in body that can result in liver and nerve damage Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Nutritional Requirements • Nutritional needs of infants in 1st year of life are increased. • Breast milk and commercially prepared formula contain the correct balance of nutrients. • Cow’s milk does not meet these standards. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Nutritional Requirements • Food and Nutrition Board issues recommended dietary allowances (RDAs) every 5 years • Body composition requires balancing energy intake with energy expenditure • Nutrition during pregnancy: 25–30 pound weight gain recommended Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Cachexia • A profound syndrome caused by malnutrition and a disturbance in glucose and fat metabolism. • Occurs in patients with terminal cancer or AIDS and in patients who are in generally poor health. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Nutritional Support • Enteral nutrition: used in patients with a functioning GI tract to supplement or completely replace oral feeding; administered through a tube • Parenteral nutrition: indicated for patients who require intensive protein and caloric support and who are unable or unwilling to take oral supplementation; administered IV Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Nutrient–Drug Interactions • Food affects drug absorption by slowing gastric emptying, by binding with a drug, decreasing the access of drugs to sites of absorption, altering the dissolution rate of drugs, or altering the pH of the GI contents. • Drugs can affect mineral and vitamin metabolism and absorption and suppress appetite. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved. Food Additives and Contaminants • Benefits of additives – Facilitate food processing and preservation – Enhance restorative or stimulating properties of foods – Control natural contaminants • Additives are strictly regulated. • Reported health problems related to additives have been trivial and largely anecdotal. Focus on Pharmacology, First Edition By Jahangir Moini Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.