7 Vitamins. Copyright © 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All...

7

Vitamins

Copyright © 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.7-2

Objectives

State one or more functions of each of the 13 vitamins discussed.

Identify at least two food sources of each of the vitamins discussed.

Identify some symptoms of, or diseases caused by, deficiencies of the vitamins discussed.


Facts

Organic (carbon-containing) compounds that are essential in small amounts for body processes

Do not provide energy Enable the body to use the energy

provided by fats, carbohydrates, and proteins

Megadoses can be toxic.


Vitamin Types (13)

Fat-soluble (4): A, D, E, K Water-soluble (9):

Vitamin C Vitamin B complex which includes: thiamin

(B1), riboflavin (B2), niacin, vitamin B6, folate, vitamin B12 (cobalamin), pantothenic acid, biotin


Requirements

Vitamin allowances given by weight in milligrams (mg) or micrograms (mcg or g).

Dietary reference intakes (DRIs) have replaced the recommended dietary allowances (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


• Match the following terms with the correct definition.

Copyright © 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

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1. Avitaminosis a. Concentrated form of vitamins

2. Hypervitaminosis b. Without vitamins

3. Vitamin supplement c. Condition caused by ingestion of excess vitamins


• Answers 1. b 2. c 3. a


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Avoiding Vitamin Loss

Buy fresh, unbruised vegetables and fruits and use them raw when possible.

Prepare fresh vegetables and fruits just before serving.

Heat canned vegetables quickly and in their own liquid.

Follow package directions when cooking frozen vegetables or fruit.

(continues)


Avoiding Vitamin Loss

Steam, or use as little water as possible. Cover pan and cook for a short period of

time. Save cooking liquid for soups, stews, and

gravy. Store fruits and vegetables in a cool, dark

place.

(continued)


Fat-Soluble Vitamins

Vitamins A, D, E, K Not lost easily in cooking Lost when mineral oil is ingested Excess amounts are stored in the liver. Deficiencies are slow to appear.


Vitamin A

Preformed Retinol: the 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 Normal bone growth and reproduction Healthy immune system 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, egg yolk Beta carotene

Carrots, sweet potatoes, spinach, broccoli, pumpkin, squash, mango, and cantaloupe


Vitamin A Requirements

Commonly listed as retinol equivalents (RE)

A retinol equivalent is 1 g retinol or 6 g beta carotene


• What are the signs and symptoms you would expect to see with too much vitamin A?

• What are the signs and symptoms you would expect to see with too little vitamin A?


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• Excess Birth defects, hair

loss, dry skin, headaches, nausea, dry mucous mem-branes, liver damage, and bone and joint pain


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• Deficit Night blindness, dry,

rough skin, increased susceptibility to infections, and blindness or xerophthalmia


Vitamin D

Prohormone: it is converted to a hormone in the body

D2 (ergocalciferol) is formed in plants. D3 (cholecalciferol) is formed in humans

from cholesterol in the skin.


Functions of Vitamin D

Promotes calcium and phosphorus absorption in the body

Values are given in micrograms or in international units.


Sources of Vitamin D

Sunlight: changes provitamin to vitamin D3

Food sources: milk, fish liver oils, egg yolk, butter, and fortified margarine

Most milk in the U.S. has 10 g of vitamin D concentrate added per quart.


• What are the signs and symptoms you would expect to see with too much vitamin D?

• What are the signs and symptoms you would expect to see with too little vitamin D?


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• Excess Deposits of calcium

and phosphorus in soft tissues, kidney, and heart damage, and bone fragility


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• Deficit Poor bone and tooth

formation, rickets which causes malformed bones and pain in infants

Osteomalacia (softening of 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

Antioxidant Prevention of hemolytic anemia among

premature infants Enhances immune system Retards spoilage of commercial foods


Sources of Vitamin E

Vegetable oils: corn, soybean, safflower, and cottonseed, and products made from them, such as margarine

Wheat germ, nuts, and green leafy vegetables

The U.S. diet is thought to contain sufficient vitamin E.


• 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?


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• Excess Relatively nontoxic,

fat-soluble vitamin Excess stored in

adipose tissue Avoid long-term

megadoses.


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• 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) Synthetic vitamin K (menadione) Vitamin K is destroyed by light and alkalis.


Functions of Vitamin K

Formation of prothrombin for clotting of blood

Candidates likely to receive vitamin K Newborns immediately after birth Clients who suffer from faulty fat absorption After extensive antibiotic therapy Antidote for an overdose of anticoagulant or

treatment of hemorrhage


Sources of Vitamin K

Green leafy vegetables such as broccoli, cabbage, spinach, and kale

Dairy products, cow’s milk, eggs, meats, fruits, and cereals

Bacteria in small intestine synthesizes some vitamin K, but must be supplemented by dietary sources.

Measured in micrograms


• What signs and/or symptoms can result from too much vitamin K?

• What signs and/or symptoms can result from too little vitamin K?


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• Excess Anemia can result

from excessive amounts of synthetic vitamin K.


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• Deficit Defective blood

coagulation, which increases clotting time and makes client prone to hemorrhage.


Water-Soluble Vitamins

Vitamin B complex and C Dissolve in water Easily destroyed by air, light, and cooking


Vitamin B Complex: Thiamin/B1

Essential for nerve and muscle action, and metabolism of carbohydrates and some amino acids

Sources include unrefined and enriched cereals, yeast, wheat germ, lean pork, organ meats, and legumes

(continues)


Vitamin B Complex: Thiamin/B1

Deficiency symptoms include loss of appetite, fatigue, nervous irritability, and constipation

Beriberi is a disease caused by extreme deficiency of vitamin B1

(continued)


Vitamin B Complex: Riboflavin/B2

Necessary for the metabolism of carbohydrates, protein, and fats; tissue maintenance (especially the skin around the mouth); and healthy eyes

Sources: milk, meats, poultry, fish, enriched breads, cereals, broccoli, spinach, and asparagus

(continues)


Vitamin B Complex: Riboflavin/B2

Deficiency can cause cheilosis (sores on the lips and cracks at the corners of the mouth); glossitis (inflammation of the tongue); dermatitis; and eye strain in the form of itching, burning, and eye fatigue

(continued)


Vitamin B Complex: Niacin

Generic name for nicotinic acid and nicotinamide

A coenzyme in energy metabolism Sources include meats, poultry, fish,

peanuts, and legumes Milk and eggs are sources of tryptophan

(precursor of niacin) Measured in niacin equivalents (NE)

(continues)



Excessive amounts of niacin can cause flushing due to vascular dilation, gastrointestinal problems, itching, and liver damage.

May be used as a cholesterol-lowering agent under close supervision of a physician because of adverse side effects, which include liver damage and peptic ulcers

(continues)

(continued)



Deficiency symptoms include weakness, anorexia, indigestion, anxiety, and irritability.

Pellagra is an extreme deficiency causing sores on the skin, diarrhea, anxiety, confusion, irritability, poor memory, dizziness, and untimely death.

(continued)


Pyridoxine, pyridoxal, and pyridoxamine Essential for protein metabolism and

absorption, and aids in the release of glucose from glycogen

Serves as a catalyst in conversion of tryptophan to niacin; helps synthesize neurotransmitters such as serotonin and dopamine

Vitamin B Complex: B6

(continues)



Measured in milligrams Sources include poultry, fish, liver, kidney,

potatoes, bananas, spinach, and unrefined whole grains (oats and wheat)

Deficiency symptoms include irritability, depression, and dermatitis

(continues)

(continued)



Deficiency in infants can cause various neurological symptoms and abdominal problems

Toxicity is rare; may cause temporary neurological problems

(continued)


Vitamin B Complex: Folate

Folate, folacin, and folic acid are chemically similar compounds, and names are used interchangeably.

Needed for DNA synthesis, protein metabolism, and formation of hemoglobin

Sources include cereals fortified with folate, green leafy vegetables, legumes, sunflower seeds, fruits such as oranges and strawberries

(continues)



Measured in micrograms Average adult requires 400 g/day 600 g/day required 1 month before

conception through first 6 weeks of pregnancy

Excess can mask vitamin B12 deficiency and inactivates phenytoin, an anticonvulsant drug used by epileptics

(continues)

(continued)



Deficiency linked to neural tube defects in fetus, such as spina bifida (spinal cord or spinal fluid bulge through the back) and anencephaly (absence of the brain).

Other signs include inflammation of mouth and tongue, poor growth, depression and mental confusion, problems with nerve functions, and megaloblastic anemia.

(continued)


Cobalamin: contains mineral cobalt Involved in folate metabolism,

maintenance of the myelin sheath, and healthy red blood cells

To be absorbed, must bind with intrinsic factor in stomach.

Sources include animal foods, especially organ meats, lean meat, seafood, eggs, and dairy products


(continues)



Increased need during pregnancy and lactation

Deficiency is rare and may be due to congenital problems of absorption or years of a vegetarian diet with no animal foods.

Symptoms include megaloblastic anemia, pernicious anemia (if intrinsic factor absent), anorexia, glossitis, sore mouth, tongue, pallor, depression, dizziness, weight loss, neurological system damage

(continued)


Vitamin B Complex: Pantothenic Acid

Involved in metabolism of carbohydrates, fats, and proteins

Essential for synthesis of neurotransmitter acetylcholine, and steroid hormones

Sources include meats, poultry, fish, eggs, whole-grain cereals, and legumes

Thought to be synthesized by the body

(continues)


Vitamin B Complex: Pantothenic Acid

Toxicity from excess not confirmed Natural deficiencies unknown Signs include weakness, fatigue, burning

sensation in feet (deficiencies produced experimentally)

(continued)


Vitamin B Complex: Biotin

Coenzyme in synthesis of fatty acids and amino acids

Sources include liver, egg yolk, soy flour, cereals, and yeast

Synthesized in intestine by micro-organisms

(continues)


Vitamin B Complex: Biotin

Toxicity from excess unknown Deficiency symptoms include nausea,

anorexia, depression, pallor, dermatitis, and increase in serum cholesterol

(continued)


Vitamin C: Ascorbic Acid

Has antioxidant properties and protects food from oxidation

Role in formation of collagen and absorption of nonheme iron

Prevents scurvy May be involved with formation or

functioning of norepinephrine, some amino acids, folate, leukocytes, the immune system, and allergic reactions

(continues)


Vitamin C: Ascorbic Acid

Sources include citrus fruits, melon, strawberries, tomatoes, potatoes, red and green peppers, cabbage, and broccoli

Stress and cigarette smoking increase need

(continued)


• 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?


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• Scurvy: disease characterized by gingivitis, easy bruising, pinpoint hemorrhages of the skin, poor wound healing, sore joints and muscles, and weight loss. Extreme cases result in death.

• Found in sailors who lived without fresh fruits and vegetables


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• Deficiency of vitamin C: bleeding gums, loose teeth, tendency to bruise easily, poor wound healing, scurvy

• Excess: diarrhea, nausea, cramps, excessive absorption of food iron, rebound scurvy (when megadoses are stopped abruptly) and possibly oxalate kidney stones; generally considered nontoxic


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Vitamin Supplementation

Balanced diet provides nutritional needs of healthy people.

No amount of vitamins will build muscles. Vitamins do not provide energy; they help

to release the energy provided by nutrients.

Heart disease, cancer, and the common cold cannot be cured by vitamin supplements


Conclusion

Organic compounds that regulate body functions and promote growth

Each vitamin has a specific function. Well-balanced diet provides sufficient

vitamins to fulfill body requirements. Fat-soluble vitamins: A, D, E, K Water-soluble vitamins: B complex, C

7 Vitamins. Copyright © 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All...

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