Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Chapter 7 Vitamins.

Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

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– 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):– 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– 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– 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– 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


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– 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– 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– 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

• Vitamin K1

– Phylloquinone

• Vitamin K2

– Menaquinone

(continues)


Vitamin K

• Synthetic vitamin K– 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


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– Anemia

• 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)



• Measured in niacin equivalents (NE)

• Excessive amounts can cause flushing– Due to vascular dilation, gastrointestinal problems, itching,

and liver damage

(continues)



• May be used as cholesterol-lowering agent under close supervision of physician– Due to adverse side effects:

• Liver damage

• Peptic ulcers

(continues)



• 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)



• Sources:– Poultry, fish, liver, kidney, potatoes, bananas, spinach, and

unrefined whole grains (oats and wheat)

• Measured in mg

• Deficiency symptoms:– Irritability, depression, and dermatitis

(continues)



• Deficiency in infants can cause various neurological symptoms and abdominal problems

• Toxicity rare– May cause temporary neurological problems



• Cobalamin– Contains mineral cobalt

• Involved in the following:– Folate metabolism

– Maintenance of myelin sheath

– Preservation of healthy RBCs

(continues)



• 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)



• 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)



• 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)



• 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)



• Deficiency linked to neural tube defects in fetus:– Spina bifida

• Spinal cord or spinal fluid bulge through back

– Anencephaly• Absence of brain

(continues)



• 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)



• May be involved with formation or functioning of norepinephrine, some amino acids, folate, leukocytes, immune system, and allergic reactions

(continues)



• 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– 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:– Vitamin A, vitamin D, vitamin E, and vitamin K

• Water-soluble vitamins:– Vitamin B complex and vitamin C

Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Chapter 7 Vitamins.

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Transcript of Copyright © 2011 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Chapter 7 Vitamins.