Chapter 7 Vitamins

Objectives Of the 13 vitamins discussed: State one or more functions of each vitamin Identify at least two food sources of each vitamin Identify some symptoms of or diseases caused by vitamin deficiencies

Facts Organic (carbon-containing) compounds Essential in small amounts for body processes Do not provide energy Enable body to use energy provided by fats, CHO, and proteins Megadoses can be toxic

Thirteen Vitamin Types Four fat-soluble: Vitamin A Vitamin D Vitamin E Vitamin K (continues)

Thirteen Vitamin Types Nine water-soluble: Vitamin B complex, including the following: Thiamine (B1), riboflavin (B2), niacin, vitamin B6, folate, vitamin B12 (cobalamin), pantothenic acid, and biotin Vitamin C

Requirements Vitamin allowances given by weight in mg or micrograms (mcg or g) DRIs have replaced RDAs Tolerable upper limits (UL) Maximum level of daily intake unlikely to cause adverse effects

Vitamin Deficiency People prone to vitamin deficiency: Alcoholics Poor and incapacitated elderly Clients with serious diseases that affect appetite Mentally retarded Children receiving inadequate care

Deficiency of Fat-Soluble Vitamins Chronic malabsorption diseases: Cystic fibrosis Celiac disease Crohn’s disease

Stop and Share Match the following terms with their correct definition: 1. Avitaminosis A. Concentrated form of vitamins 2. Hypervitaminosis B. Without vitamins 3. Vitamin supplement C. Condition caused by ingestion of excess vitamins (continues)

Stop and Share Answers: 1  B 2  C 3  A

Preserving Vitamin Content in Food Buy fresh, unbruised vegetables and fruits Use them raw when possible Prepare fresh vegetables and fruits just before serving (continues)

Preserving Vitamin Content in Food Heat canned vegetables quickly and in their own liquid Follow package directions when cooking frozen vegetables or fruit

Avoiding Vitamin Loss Steam or use as little water as possible Cover pan and cook vegetables until bright in color and crisp-tender Save any cooking liquid for soups, stews, and gravy (continues)

Avoiding Vitamin Loss Store fruits and vegetables in cool, dark place Microwave produce in 1 to 2 tablespoons (tbsp) of water

Fat-Soluble Vitamins Vitamin A, vitamin D, vitamin E, and vitamin K Not lost easily in cooking Lost when mineral oil ingested Excess amounts stored in liver Deficiencies slow to appear

Vitamin A Preformed Provitamin A carotenoids Retinol Active form of vitamin A Provitamin A carotenoids Beta carotene, lutein, lycopene, and zeaxanthin Inactive form of vitamin A found in plants Converted to retinol

Functions of Vitamin A Maintains healthy eyes and skin Maintains normal bone growth and reproduction Sustains healthy immune system Has antioxidants that protect cells from free radicals

Sources of Vitamin A Preformed vitamin A (retinol): Beta carotene: Fat-containing animal foods Liver, butter, cream, whole milk, cheese, and egg yolk Beta carotene: Carrots, sweet potatoes, spinach, broccoli, pumpkin, squash, mango, and cantaloupe

Vitamin A Requirements Commonly listed as retinol equivalents (RE) 1 g retinol or 6 g beta carotene

Stop and Share Consider the following questions: What are the signs and symptoms you would expect to observe with too much vitamin A? What are the signs and symptoms you would expect to observe with too little vitamin A? (continues)

Stop and Share Excess Deficit Birth defects Hair loss Dry skin Headaches Nausea Dry mucous membranes Liver damage Bone and joint pain Deficit Night blindness Dry, rough skin Increased susceptibility to infections Blindness or xerophthalmia

Vitamin D Prohormone D2 D3 Values given in mcg or International Units Converted to hormone in body D2 Ergocalciferol Formed in plants D3 Cholecalciferol Formed in humans from cholesterol in skin Values given in mcg or International Units

Functions of Vitamin D Promotes calcium and phosphorus absorption Building and maintenance of normal bones and teeth Prevention of tetany

Sources of Vitamin D Sunlight Food sources: Changes provitamin to vitamin D3 People with little sun exposure must get sufficient intake from diet Food sources: Milk, fish liver oils, egg yolk, butter, and fortified margarine Most milk in U.S. has 10 g vitamin D concentrate added per quart

Stop and Share Consider the following questions: What are the signs and symptoms you would expect to observe with too much vitamin D? What are the signs and symptoms you would expect to observe with too little vitamin D? (continues)

Stop and Share Excess Deficit Deposits of calcium and phosphorus in soft tissues Kidney and heart damage Bone fragility Deficit Poor bone and tooth formation Rickets Causes malformed bones and pain in infants Osteomalacia Soft bones Osteoporosis Brittle, porous bones

Vitamin E Tocopherols Tocotrienols Alpha Most biologically active Beta, delta, and gamma Tocotrienols Given as -TE (alpha-tocopherol equivalents) 1 mg of -TE = 1 International Unit

Functions of Vitamin E Serves as antioxidant Prevents hemolytic anemia among premature infants Enhances immune system Retards spoilage of commercial foods

Sources of Vitamin E Vegetable oils: Corn, soybean, safflower, cottonseed, and products made from them E.g., margarine Wheat germ, nuts, and green leafy vegetables U.S. diet typically contains sufficient amount

Stop and Share Consider the following questions: Your client asks you if it is possible to take too much vitamin E. How would you advise the client? What signs and/or symptoms can result from too little vitamin E? (continues)

Stop and Share Excess Deficit Relatively nontoxic, fat-soluble vitamin Stored in adipose tissue Avoid long-term megadoses Deficit Serious neurological defects can occur from malabsorption

Vitamin K Made up of several compounds essential to blood clotting Phylloquinone Vitamin K2 Menaquinone (continues)

Vitamin K Synthetic vitamin K Destroyed by light and alkalies Menadione Destroyed by light and alkalies Must be ingested daily Measured in mcg

Functions of Vitamin K Forms prothrombin for blood clotting Candidates likely to receive vitamin K: Newborns immediately after birth Clients with faulty fat absorption People who have had extensive antibiotic therapy People who need antidote for overdose of anticoagulant or treatment of hemorrhage

Sources of Vitamin K Green leafy vegetables E.g., broccoli, cabbage, spinach, kale Dairy products, cow’s milk, eggs, meats, fruits, and cereals Bacteria in small intestine synthesizes some, but must be supplemented by dietary sources

Stop and Share Consider the following questions: What are the signs and symptoms you would expect to observe with too much vitamin K? What are the signs and symptoms you would expect to observe with too little vitamin K? (continues)

Stop and Share Excess Deficit Anemia Defective blood coagulation From synthetic form Deficit Defective blood coagulation Increases clotting time Makes client prone to hemorrhage

Water-Soluble Vitamins Vitamin B complex and vitamin C Dissolve in water Easily destroyed by air, light, and cooking

Vitamin B Complex: Thiamine (B1) Essential for the following: Nerve and muscle action Metabolism of carbohydrates and some amino acids Sources: Unrefined and enriched cereals, whole grains, lean pork, liver, seeds, nuts, and legumes (continues)

Vitamin B Complex: Thiamine (B1) Deficiency rare Symptoms: Loss of appetite, fatigue, nervous irritability, and constipation Beriberi Disease caused by extreme deficiency

Vitamin B Complex: Riboflavin (B2) Necessary for the following: Metabolism of carbohydrates, protein, and fats Tissue maintenance Especially skin around mouth Healthy eyes Sources: Milk, meats, poultry, fish, enriched breads, cereals, broccoli, spinach, and asparagus (continues)

Vitamin B Complex: Riboflavin (B2) Deficiency symptoms: Cheilosis Sores on lips and cracks at corners of mouth Glossitis Inflammation of tongue Dermatitis Eye strain Itching, burning, and eye fatigue

Vitamin B Complex: Niacin Generic name for nicotinic acid and nicotinamide Coenzyme in energy metabolism Sources: Meats, poultry, fish, peanuts, and legumes Sources of tryptophan, precursor of niacin: Milk and eggs (continues)

Vitamin B Complex: Niacin Measured in niacin equivalents (NE) Excessive amounts can cause flushing Due to vascular dilation, gastrointestinal problems, itching, and liver damage (continues)

Vitamin B Complex: Niacin May be used as cholesterol-lowering agent under close supervision of physician Due to adverse side effects: Liver damage Peptic ulcers (continues)

Vitamin B Complex: Niacin Deficiency symptoms: Weakness, anorexia, indigestion, anxiety, and irritability Pellagra Disease caused by extreme deficiency Symptoms: Sores on skin, diarrhea, anxiety, confusion, irritability, poor memory, dizziness, and untimely death

Vitamin B Complex: B6 Pyridoxine, pyridoxal, and pyridoxamine Essential for the following: Protein metabolism and absorption Aiding release of glucose from glycogen Catalyst in conversion of tryptophan to niacin Helps synthesize neurotransmitters E.g., serotonin, dopamine (continues)

Vitamin B Complex: B6 Sources: Measured in mg Deficiency symptoms: Poultry, fish, liver, kidney, potatoes, bananas, spinach, and unrefined whole grains (oats and wheat) Measured in mg Deficiency symptoms: Irritability, depression, and dermatitis (continues)

Vitamin B Complex: B6 Deficiency in infants can cause various neurological symptoms and abdominal problems Toxicity rare May cause temporary neurological problems

Vitamin B Complex: B12 Cobalamin Involved in the following: Contains mineral cobalt Involved in the following: Folate metabolism Maintenance of myelin sheath Preservation of healthy RBCs (continues)

Vitamin B Complex: B12 To be absorbed, must bind with intrinsic factor in stomach Sources: Animal foods Especially organ meats, lean meats, seafood, eggs, and dairy products Increased need during pregnancy and lactation (continues)

Vitamin B Complex: B12 Deficiency rare May be due to congenital problems of absorption or years of vegetarian diet with no animal foods Symptoms: Megaloblastic anemia, pernicious anemia (if intrinsic factor absent), anorexia, glossitis, sore mouth, tongue, pallor, depression, dizziness, and weight loss

Vitamin B Complex: Folate Folate, folacin, and folic acid Chemically similar compounds Names used interchangeably Necessary for the following: Deoxyribonucleic acid (DNA) synthesis Protein metabolism Formation of hemoglobin (continues)

Vitamin B Complex: Folate Sources: Cereals fortified with folate, green leafy vegetables, legumes, sunflower seeds, and fruits (e.g., oranges, strawberries) Measured in mcg Average adult requires 400 g per day (continues)

Vitamin B Complex: Folate One month before conception through first six weeks of pregnancy requires 600 g per day Excess can mask vitamin B12 deficiency and inactivate phenytoin Anticonvulsant drug used by epileptics Important role in some cancer prevention (continues)

Vitamin B Complex: Folate Deficiency linked to neural tube defects in fetus: Spina bifida Spinal cord or spinal fluid bulge through back Anencephaly Absence of brain (continues)

Vitamin B Complex: Folate Other deficiency symptoms: Inflammation of mouth and tongue, poor growth, depression and mental confusion, problems with nerve functions, and megaloblastic anemia

Vitamin B Complex: Biotin Coenzyme in synthesis of fatty acids and amino acids Sources: Egg yolks, milk, poultry, fish, broccoli, spinach, and cauliflower Also synthesized in intestine by micro-organisms (continues)

Vitamin B Complex: Biotin Toxicity from excess unknown Deficiency symptoms: Nausea, anorexia, depression, pallor, dermatitis, and increase in serum cholesterol

Vitamin B Complex: Pantothenic Acid Involved in metabolism of carbohydrates, fats, and proteins Essential for the following: Synthesis of neurotransmitter acetylcholine Synthesis of steroid hormones Sources: Meats, poultry, fish, eggs, whole-grain cereals, and legumes (continues)

Vitamin B Complex: Pantothenic Acid Considered synthesized by body Toxicity from excess unknown Natural deficiencies unknown Deficiencies produced experimentally Symptoms include weakness, fatigue, burning sensation in feet

Vitamin C: Ascorbic Acid Antioxidant properties Protects food from oxidation Role in formation of collagen and absorption of nonheme iron Prevents scurvy (continues)

Vitamin C: Ascorbic Acid May be involved with formation or functioning of norepinephrine, some amino acids, folate, leukocytes, immune system, and allergic reactions (continues)

Vitamin C: Ascorbic Acid Sources: Citrus fruits, melons, strawberries, tomatoes, potatoes, red and green peppers, cabbage, and broccoli Stress and cigarette smoking increase need

Stop and Share Consider the following questions: What disease results from a deficiency in vitamin C? What are the associated signs and/or symptoms? What results from an excess of vitamin C? (continues)

Stop and Share Scurvy Disease characterized by gingivitis, easy bruising, pinpoint hemorrhages of skin, poor wound healing, sore joints and muscles, and weight loss Extreme cases result in death Found in sailors who have lived without fresh fruits and vegetables (continues)

Stop and Share Excess Deficit Diarrhea Nausea Cramps Excessive absorption of food iron Deficit Bleeding gums Loose teeth Tendency to bruise easily Poor wound healing Scurvy (continues)

Stop and Share Excess Rebound scurvy (when megadoses abruptly stopped) Possibly oxalate kidney stones Generally considered nontoxic

Vitamin Supplementation Balanced diet provides nutritional needs of healthy people No amount of vitamins will build muscles Vitamins do not provide energy Help release energy provided by nutrients Supplements should not exceed 100 percent of DRI for each vitamin

Conclusion Vitamins: Organic compounds that regulate body functions and promote growth Each has specific function Well-balanced diet provides sufficient vitamins to fulfill body requirements (continues)

Conclusion Fat-soluble vitamins: Water-soluble vitamins: Vitamin A, vitamin D, vitamin E, and vitamin K Water-soluble vitamins: Vitamin B complex and vitamin C