Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.1 Chapter 7 Vitamins “In the middle of difficulty lies opportunity.” Albert Einstein

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.2 Key Concept Vitamins are noncaloric essential nutrients necessary for many vital metabolic functions and the prevention of associated deficiency diseases. Recommendations for nutrient intake by healthy population groups are based on gender and age

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.3 Discovery: Early Observations Vitamins were discovered while searching for cures for classic diseases –Dr. James Lind and scurvy Sailors dying on long voyages without fresh food Lemons and limes provided, no one became ill British soldiers got the nickname “limeys”

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.4 Definition of Vitamin It must be a vital, organic substance that is only necessary in extremely small amounts – mg or mcg. It cannot be manufactured by the body in sufficient quantities to sustain life, so it must be supplied by diet. The body uses vitamins to make coenzymes required for some enzymatic function.

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.5 Function of Vitamins Metabolism: Enzymes and coenzymes B vitamins are part of coenzymes –Coenzymes needed to perform certain functions, such as: Glucose metabolism Protein metabolism Fatty acid metabolism

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.6 Functions of Vitamins, cont’d Tissue structure and protection –Vitamin C Prevention of deficiency diseases –Scurvy (lack of vitamin C) –Beriberi (lack of thiamine [B]) –Pellagra (corn and rice are low in niacin, a B vitamin)

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.7 Periodontal Disease in Scurvy EAT YOUR VITAMIN C EVERY DAY!!

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.8 Vitamin Metabolism Fat soluble vitamins –Vitamins incorporated with absorbed fat and transported by chylomicrons in the lymph –Best absorbed when eaten with fat –May be stored for long periods in fat tissues Water soluble vitamins –Easily absorbed and transported by the portal circulation to the liver –Not stored, so must be eaten on regular basis (exceptions: B12 and B6)

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.9 Fat-Soluble Vitamins: Vitamin A (Retinol) Functions –Vision- adjusts to light levels –Tissue strength and immunity – prevents macular degeneration –Growth – skeletal and soft tissue Toxicity symptoms – liver damage Food sources – orange foods, broccoli, tomato juice, and beef liver

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.10 Vitamin D (Cholecalciferol) Functions –Absorption of calcium and phosphorus –Bone mineralization Deficiency disease: Rickets and osteoporosis Food sources – egg yolk, liver, fatty fish Ultraviolet light makes the precursor to Vitamin D in our skin, so get 15 minutes of sunshine a day!

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.11 Child with Rickets Low Vitamin D prevents Calcium absorption; leads to weak bones

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.12 Vitamin E (Tocopherol) Functions –Antioxidant function –Relation to selenium metabolism Deficiency disease: Hemolytic anemia Food sources – plant oils, soy, shrimp, cod, wheat germ, sunflower seeds

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.13 Vitamin K Functions –Blood clotting –Bone development Food sources – Brussel sprouts, leafy green vegetables, liver Produced in our colon by bacteria

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.14 Water-Soluble Vitamins: Vitamin C (Ascorbic Acid) Functions –Connective tissue building –General body metabolism –Antioxidant function Deficiency disease: Scurvy Toxicity symptoms – GI “distress” Food sources – fruits

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.15 Thiamin (Vitamin B1) Functions –Gastrointestinal system –Nervous system –Cardiovascular system –Helps store fat as energy Deficiency disease: Beriberi Levels are low in alcoholics Food sources – spinach, green peas, tomato juice, watermelon, lean ham & pork chops, soy milk

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.16 BERIBERI UNABLE TO STORE FAT, NO DEMENTIA

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.17 Riboflavin (Vitamin B2) Functions –Energy production –Normal vision, & skin health –Tissue protein building Deficiency disease – tissue inflammation, poor wound healing Food sources – spinach, broccoli, mushrooms, eggs, milk, liver, oyster, clams

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.18 Niacin (Vitamin B3) Functions –Energy metabolism –DNA repair Deficiency disease: Pellagra Toxicity symptoms – flushing skin Food sources – spinach, tomato juice, lean ground beef, chicken breast, canned tuna, liver, shrimp

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.19 Niacin Deficiency: Pellagra DERMATITIS, DIARRHEA, DEMENTIA AND DEATH

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.20 Vitamin B6 (Pyridoxine) Functions –Protein metabolism –Neurotransmitter Deficiency disease – microcytic, hypochromic anemia & abnormal CNS function Food sources – bananas, watermelon, tomato juice, spinach, acorn squash, potato, white rice, chicken breast

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.21 Folate Functions –Aids in: DNA synthesis; Regulation of blood homocysteine levels Deficiency diseases: Megaloblastic anemia, Neural tube defects Food sources – tomato juice, green beans, broccoli, spinach, asparagus, okra, black eyed peas, beans (navy, lentil, pinto, & garbanzo)

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.22 Cobalamin (Vitamin B12) Functions –Regulation of blood homocysteine levels –Heme synthesis –Nervous system functioning Deficiency disease: Pernicious anemia Food sources – meats, poultry, fish, shellfish, milk, eggs

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.23 Choline Associated with the B-complex vitamins –Functions Structural integrity of cell membranes Neurotransmission (ACH) –Deficiency disease: Liver damage –Food sources- milk, eggs, liver, peanuts

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.24 Phytochemicals Bioactive molecules with health benefits -those plant compounds that act as antioxidants or hormones Need to have seven colors on your plate for benefits! Seven colors with corresponding phytochemical Lycopene, zeaxanthin, anthocyanin, beta- carotene, flavonoids, glucosinolate, allyl sulfides Only found in whole foods –(grains, fruit and vegetables)

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.25 BENEFITS What are some of the beneficial effects of phytochemicals that have been documented? –Reduced risk of chronic disease, –Protection against coronary heart disease –Improved overall colon function –Prevention of age-related macular degeneration and cancer –Increased antioxidant status

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.26 Vitamin Supplementation Ongoing debate Biochemical individuality –Life cycle needs Pregnancy & lactation – folic acid & vitamins Infancy – Vitamins K & D Children and adolescents – need all during growth spurts Aging – need more vitamins b/c eat less food and absorb less nutrients

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.27 Vitamin Supplementation, cont’d Megadoses –Toxic effects Fat soluble are stored Vit B6 – ataxia and nerve damage Vit C leads to GI issues, kidney stones and decreased immune function –“Artificially induced” deficiencies Supplementation principles

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.28 Summary Vitamins are food substances required in very small amounts. Body cannot make vitamins, but a well-balanced and varied diet usually supplies sufficient intake. Fat-soluble vitamins are A, D, E, K. Water-soluble vitamins are C and B-complex.

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.29 Summary, cont’d Possibility of toxicity is increased for fat-soluble vitamins compared with water-soluble vitamins. Water-soluble vitamins C and pyridoxine (B6) in megadoses can be harmful. Phytochemicals are found in whole and unrefined plant foods.

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.30 Basic Energy Needs The body uses most of the daily energy supply for constant use in voluntary and involuntary activity Voluntary work and exercise –Includes all physical actions related to usual activities and additional physical exercise –Seems to require most of the energy output, but is usually not the case

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.31 Basic Energy Needs, cont’d Involuntary work: includes all activities of the body that are not consciously performed –Circulation, respiration, digestion, absorption –Requirements include: Chemical energy: in many metabolic products Electrical energy: in brain and nerve activities Mechanical energy: in muscle contraction Thermal energy: to keep the body warm

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.32 Basic Energy Needs, cont’d Fuel is provided in the form of nutrients Only three energy-containing nutrients: –Carbohydrate is primary fuel –Fat assists as storage fuel –Protein is a back-up fuel source Alcohol also provides energy but is not a nutrient

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.33 Measurement of Energy Calorie: Amount of energy in food or expended in physical actions Kilocalorie (1000 calories or 1 Calorie): Amount of heat necessary to raise 1 kg of water 1° C –Large Calorie unit used in nutrition science to avoid dealing with large numbers –Abbreviation: kcalorie or kcal or Cal

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.34 Fuel Factors Carbohydrate: 4 kcal/g Fat: 9 kcal/g Protein: 4 kcal/g Alcohol: 7 kcal/g

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.35 Caloric and Nutrient Density Density: The degree of concentration of material in a given substance Caloric density: Concentration of energy in a given amount of food (think of the bakery!) –Foods high in fat have the highest caloric density Nutrient density: Concentration of all nutrients in a given amount of food (Think of an apple)

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.36 Energy Intake The body’s energy balance depends on energy intake in relation to energy output Energy intake –Three macronutrients are stored as: Glycogen Adipose tissue Muscle mass –Energy intake is the calculated energy value of actual food consumption

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.37 Energy Output Activities to sustain life require energy from food and body reserves Three demands for energy determine the body’s total energy requirements –Resting energy expenditure (REE) –Physical activity –Thermic effect of food (TEF)

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.38 Resting Energy Expenditure Sum of all internal working activities of the body at rest Expressed as kcal/day

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.39 Measurement of Resting Metabolic Rate How are resting metabolic rate (RMR) or basal metabolic rate (BMR) measured? –Indirect calorimetry Metabolic rate calculated on the basis of the rate of oxygen utilization –Thyroid function test – responsible for body metabolism Measures the activity of the thyroid gland and the blood levels of the hormone thyroxine

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.40 Measurement of Resting Metabolic Rate, cont’d General formula –Men 1 kcal x kg body weight x 24 hours –Women 0.9 kcal x kg body weight x 24 hours Calculate your Basal Metabolic Rate 1 kg = 2.2 pounds

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.41 Factors Influencing Basal Metabolic Rate Lean body mass (muscles and organs) –Greater metabolic activity in lean tissues Growth periods –Growth hormone stimulates cell metabolism and raises BMR Body temperature –Fever increases BMR Hormonal status –Example: Hypothyroidism = Decreased BMR

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.42 BODY MASS INDEX Body mass index (BMI) is measure of body fat based on height and weight that applies to both adult men and women. BMI Categories: Normal weight = Overweight = Obesity = BMI of 30 or greater Calculate your BMI BMI = weight in pounds x 703 / inches squared Ex: 150 pounds x 703 = ’ 8” = 68 inches x 68 inches = / 4624 = 22.8 BMI

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.43 Physical Activity Energy expenditure for physical activity goes above and beyond energy used for resting energy needs. Energy output during physical activity varies widely across individuals extra calories = 1 pound; –That is 500 extra calories per day to gain 1 pound in a week or exercise 500 calories off per day to lose 1 pound in a week

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.44 Physical Activity Level Factors Categorize physical activity level (PAL) according to standard values –1.2: Chair or bed bound – : Sedentary – : Very light – : Moderate – : Heavy

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.45 Thermic Effect of Food Extra energy for digestion, absorption, and transport is required after eating. 5% to 10% of the body’s total energy needs for metabolism relate to the processing of food.

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.46 Total Energy Requirement Total energy requirement: Resting energy expenditure + Physical activity + Thermic Effect of Food To maintain daily energy balance: –Food energy intake = Body energy output –Intake > output = Weight gain (extreme: obesity) –Intake < output = Weight loss (extreme: anorexia)

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.47 Life Cycle Growth periods –Extra energy per unit of body weight is necessary to build new tissue –Infancy, adolescence, pregnancy Adulthood –Energy needs level off –With aging, energy needs decline

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.48 Gradual Reduction of Kilocalorie Needs During Adulthood

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.49 Dietary Reference Intakes Dietary guidelines for healthy Americans indicate energy needs based on three recommendations: –Maintain body weight in a healthy range –To prevent gradual weight gain over time, make small decreases in food and beverage calories and increase physical activity –Make recommended intakes within energy needs USDA Food Guide DASH eating plan

Copyright © 2009, by Mosby, Inc. an affiliate of Elsevier, Inc. All rights reserved.50 Summary Energy is the force or power to do work. Energy is measured in “large” calories, or kilocalories. Metabolism is the sum of the body processes involved in converting food into various forms of energy. When food is not available for energy, stored energy is used in the form of glycogen, fat, and tissue protein.