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Focus on Pharmacology Essentials for Health Professionals. Jahangir Moini, MD, MPH. Chapter 8 Nutritional Aspects of Pharmacology. Nutrition. Nutrition: how the body takes in and uses food and other sources of nutrients for growth and repair of tissues
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Focus on PharmacologyEssentials for Health Professionals Jahangir Moini, MD, MPH Chapter 8Nutritional Aspects of Pharmacology
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
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
Seven Nutrients • Proteins • Fatty acids (also called lipids or fats) • Carbohydrates • Fiber • Vitamins • Minerals • Water
Macronutrients • Needed by body in large amounts for energy • Carbohydrates • Fats • Proteins • Macrominerals(dietary minerals needed in high quantities: grams) • Water
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
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
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
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
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
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
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
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).
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.
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.
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
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
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
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)
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
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)
B Vitamins: Nicotinamide (B3) (continued) • Toxicity includes hepatic impairment, severe hypotension, and various skin conditions
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.
B Vitamins: Pantothenic Acid (B5) • Sources: whole grain cereals, legumes, meat, eggs • Needed for formation of coenzyme A • Deficiency is rare
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
B Vitamins: Biotin • Sources: widely available in foods and made by natural flora in intestines • Deficiency is almost unknown • No known toxicities
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
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
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
Vitamin B Factors (Choline) (continued) • Excess doses may lower blood pressure; cause fishy body odor, sweating, and excessive salivation; and reduce growth rate
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
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.
Fat-Soluble Vitamins • Vitamin A (retinol) • Vitamin D3 (cholecalciferol) • Vitamin D2 (ergocalciferol) • Vitamin E (alpha tocopherol) • Vitamin K1 (phylloquinone) • Vitamin K2 (menaquinone)
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
Retinol (Vitamin A) (continued) • Mild deficiency may cause night blindness • Toxicity (hypervitaminosis A) marked by hair loss, jaundice, joint pain, liver injury, ascites
Vitamin A Deficiency Dietary vitamin A deficiency in the number one cause of blindness in children worldwide.
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.
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
Cholecalciferol (Vitamin D3) (continued) • Deficiency causes rickets, osteomalacia, osteoporosis • Toxicity can occur, especially in children
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
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
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
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.
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%.
Mineral and Vitamin Interactions (continued) • Excessive amounts of vitamin E interfere with iron absorption. • Vitamin B6 is required to metabolize magnesium and zinc.
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.
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
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