Chapter 12: Vitamins and Minerals Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
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Chapter 12:Chapter 12:
Vitamins and MineralsVitamins and Minerals
Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
22Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Chapter 12 OutlineChapter 12 Outline
Vitamins and MineralsVitamins and Minerals Measurements of vitamin needsMeasurements of vitamin needs Water-soluble vitaminsWater-soluble vitamins Fat-soluble vitaminsFat-soluble vitamins Selected mineralsSelected minerals Drug-induced vitamin deficienciesDrug-induced vitamin deficiencies
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Vitamins and MineralsVitamins and Minerals Haveles (p. 148)Haveles (p. 148)
Vitamins are essential in small quantities for Vitamins are essential in small quantities for maintenance of cell structure and metabolismmaintenance of cell structure and metabolism In normal quantities, a vitamin is used to replace In normal quantities, a vitamin is used to replace
the specific vitamin that is deficientthe specific vitamin that is deficient When vitamins are used to treat problems not When vitamins are used to treat problems not
associated with vitamin deficiency, they are associated with vitamin deficiency, they are regarded as drugsregarded as drugs
Few situations exist for which proof has been Few situations exist for which proof has been found that vitamins are useful for the treatment of found that vitamins are useful for the treatment of any condition except vitamin deficiencyany condition except vitamin deficiency
cont’d…cont’d…
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Vitamins and MineralsVitamins and Minerals
Haveles (pp. 148-149) (Table 12-1)Haveles (pp. 148-149) (Table 12-1) Vitamins are classified into two large groups: Vitamins are classified into two large groups:
water soluble and fat solublewater soluble and fat soluble Water-soluble vitamins include B vitamins and Water-soluble vitamins include B vitamins and
vitamin Cvitamin C Fat-soluble vitamins are vitamins A, D, E, and KFat-soluble vitamins are vitamins A, D, E, and K
Vitamins act in three different ways: Vitamins act in three different ways: coenzymes, antioxidants, or hormonescoenzymes, antioxidants, or hormones Water-soluble vitamins act as coenzymes, acting Water-soluble vitamins act as coenzymes, acting
with a specific enzyme that catalyzes a specific with a specific enzyme that catalyzes a specific reactionreaction
Vitamin C and E act as antioxidantsVitamin C and E act as antioxidants Vitamin A and D act as hormonesVitamin A and D act as hormones
55Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Measurements of Vitamin NeedsMeasurements of Vitamin Needs
Haveles (pp. 148-149)Haveles (pp. 148-149) The original recommended daily allowance (RDA) The original recommended daily allowance (RDA)
was designed with the goal of preventing the was designed with the goal of preventing the diseases produced by a deficiency of a certain diseases produced by a deficiency of a certain nutrientnutrient These values were meant to be used to make These values were meant to be used to make
recommendations for populations rather than specific recommendations for populations rather than specific peoplepeople
During subsequent years, the RDAs began to be used During subsequent years, the RDAs began to be used (inappropriately) to address specific patient needs(inappropriately) to address specific patient needs
cont’d…cont’d…
66Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Measurements of Vitamin NeedsMeasurements of Vitamin Needs
Haveles (pp. 148-149) (Box 12-1)Haveles (pp. 148-149) (Box 12-1) In 1993 the Food and Nutrition Board initiated In 1993 the Food and Nutrition Board initiated
a review process, beginning with a a review process, beginning with a symposiumsymposium The new RDAs are designed not only to prevent The new RDAs are designed not only to prevent
deficiency diseases, but also to minimize chronic deficiency diseases, but also to minimize chronic diseases such as heart diseasediseases such as heart disease
The original term The original term RDAsRDAs has been divided into has been divided into different, more specific recommendationsdifferent, more specific recommendations
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TerminologyTerminology
Haveles (p. 149)Haveles (p. 149) Dietary reference intakes (DRIs)Dietary reference intakes (DRIs) Estimated average requirement (EAR)Estimated average requirement (EAR) Recommended dietary allowance (RDA)Recommended dietary allowance (RDA) Adequate intake (AI)Adequate intake (AI) Tolerable upper intake level (UL)Tolerable upper intake level (UL)
88Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Water-Soluble VitaminsWater-Soluble Vitamins
Haveles (p. 149)Haveles (p. 149) Ascorbic acid (vitamin C)Ascorbic acid (vitamin C)
A sugar acid that readily undergoes oxidation to A sugar acid that readily undergoes oxidation to form dehydroascorbic acidform dehydroascorbic acid
Ascorbic acid is an effective reducing agentAscorbic acid is an effective reducing agent
cont’d…cont’d…
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Water-Soluble VitaminsWater-Soluble Vitamins
Haveles (p. 149) (Fig. 12-1)Haveles (p. 149) (Fig. 12-1) Ascorbic acid (vitamin C): sourcesAscorbic acid (vitamin C): sources
Good natural sources include citrus fruits, green Good natural sources include citrus fruits, green peppers, tomatoes, strawberries, broccoli, raw peppers, tomatoes, strawberries, broccoli, raw cabbage, baked potatoes, and papayacabbage, baked potatoes, and papaya
Ascorbic acid is readily destroyed through Ascorbic acid is readily destroyed through cooking, and as much as 50% of the ascorbic acid cooking, and as much as 50% of the ascorbic acid content of foods can be lost in this mannercontent of foods can be lost in this manner
cont’d…cont’d…
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Water-Soluble VitaminsWater-Soluble Vitamins
Haveles (p. 149)Haveles (p. 149) Ascorbic acid (vitamin C): RDAAscorbic acid (vitamin C): RDA
The RDA of ascorbic acid for a healthy female The RDA of ascorbic acid for a healthy female adult is 75 mg and 90 mg for a healthy male adultadult is 75 mg and 90 mg for a healthy male adult
During pregnancy and lactation, stress, or tobacco During pregnancy and lactation, stress, or tobacco smoking, the need for this vitamin increasessmoking, the need for this vitamin increases
cont’d…cont’d…
1111Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Water-Soluble VitaminsWater-Soluble Vitamins
Haveles (pp. 149-150)Haveles (pp. 149-150) Ascorbic acid (vitamin C): roleAscorbic acid (vitamin C): role
The metabolic role of ascorbic acid is probably related The metabolic role of ascorbic acid is probably related to the fact that ascorbic acid and dehydroascorbic acid to the fact that ascorbic acid and dehydroascorbic acid form a readily reversible oxidation-reduction systemform a readily reversible oxidation-reduction system
The belief is that this vitamin plays a role in biologic The belief is that this vitamin plays a role in biologic oxidations and reductions in cellular respirationsoxidations and reductions in cellular respirations
Ascorbic acid also plays a definite role in connective-Ascorbic acid also plays a definite role in connective-tissue metabolism because it is required for the tissue metabolism because it is required for the formation of collagenformation of collagen
cont’d…cont’d…
1212Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Water-Soluble VitaminsWater-Soluble Vitamins
Haveles (p. 150)Haveles (p. 150) Ascorbic acid (vitamin C): deficiencyAscorbic acid (vitamin C): deficiency
Deficiency of ascorbic acid produces scurvyDeficiency of ascorbic acid produces scurvy Manifestations occur because of the inability of the Manifestations occur because of the inability of the
connective tissue to produce and maintain connective tissue to produce and maintain intercellular substances such as collagen, bone intercellular substances such as collagen, bone matrix, dentin, cartilage, and vascular endotheliummatrix, dentin, cartilage, and vascular endothelium
Because humans and other primates cannot Because humans and other primates cannot synthesize vitamin C, they must obtain it daily from synthesize vitamin C, they must obtain it daily from their diettheir diet
cont’d…cont’d…
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Water-Soluble VitaminsWater-Soluble Vitamins
Haveles (p. 150)Haveles (p. 150) Ascorbic acid (vitamin C): adverse reactionsAscorbic acid (vitamin C): adverse reactions
Untoward effects have been reported with use of Untoward effects have been reported with use of megadoses of vitamin Cmegadoses of vitamin C
Daily intake of 1 gram of vitamin C may cause Daily intake of 1 gram of vitamin C may cause precipitation of oxalate stones in the urinary tractprecipitation of oxalate stones in the urinary tract
cont’d…cont’d…
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Water-Soluble VitaminsWater-Soluble Vitamins
Haveles (p. 150)Haveles (p. 150) Ascorbic acid (vitamin C): clinical considerationsAscorbic acid (vitamin C): clinical considerations
As long ago as 1942, the suggestion was made that As long ago as 1942, the suggestion was made that vitamin C could be therapeutically beneficial in vitamin C could be therapeutically beneficial in preventing the common coldpreventing the common cold• Based on current evidence, unrestricted use of ascorbic acid Based on current evidence, unrestricted use of ascorbic acid
for these purposes cannot be advancedfor these purposes cannot be advanced
Because vitamin C enhances the absorption of iron, Because vitamin C enhances the absorption of iron, iron is either combined with vitamin C or is taken with iron is either combined with vitamin C or is taken with orange juice to treat iron-deficiency anemiaorange juice to treat iron-deficiency anemia
cont’d…cont’d…
1515Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Water-Soluble VitaminsWater-Soluble Vitamins
Haveles (p. 151) (Fig. 12-2)Haveles (p. 151) (Fig. 12-2) B-complex vitaminsB-complex vitamins
Water-soluble vitamins, except for vitamin C, are known Water-soluble vitamins, except for vitamin C, are known as B-complex vitaminsas B-complex vitamins
These vitamins can be subdivided into the following These vitamins can be subdivided into the following three classesthree classes• Those that primarily release energy from carbohydrates and fatsThose that primarily release energy from carbohydrates and fats
• Those that, among other functions, catalyze the formation of red Those that, among other functions, catalyze the formation of red blood cellsblood cells
• Those that have not been shown to be required in human Those that have not been shown to be required in human nutritionnutrition
cont’d…cont’d…
1616Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Water-Soluble VitaminsWater-Soluble Vitamins Haveles (p. 151) (Fig. 12-2)Haveles (p. 151) (Fig. 12-2)
B-complex vitamins: thiamine (vitamin BB-complex vitamins: thiamine (vitamin B11)) Thiamine is an essential water-soluble vitamin in Thiamine is an essential water-soluble vitamin in
humanshumans Source: present in foods of both animal and vegetable originSource: present in foods of both animal and vegetable origin RDA: 1.2 mg for adult men and 1.1 mg for adult womenRDA: 1.2 mg for adult men and 1.1 mg for adult women Role: thiamine pyrophosphate (TPP) plays a principal role in Role: thiamine pyrophosphate (TPP) plays a principal role in
intermediary metabolismintermediary metabolism Deficiency: severe deficiency leads to Deficiency: severe deficiency leads to beriberiberiberi Adverse reactions: usually nontoxic; some patients are Adverse reactions: usually nontoxic; some patients are
hypersensitivehypersensitive Clinical considerations: used for treatment of a variety of Clinical considerations: used for treatment of a variety of
manifestations of deficienciesmanifestations of deficienciescont’d…cont’d…
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Water-Soluble VitaminsWater-Soluble Vitamins Haveles (pp. 152-153)Haveles (pp. 152-153)
B-complex vitamins: riboflavin (vitamin BB-complex vitamins: riboflavin (vitamin B22)) Riboflavin is a water-soluble vitamin composed Riboflavin is a water-soluble vitamin composed
of flavin and D-ribitolof flavin and D-ribitol Source: abundant in both plants and animalsSource: abundant in both plants and animals RDA ranges from 1.1 (adult women) to 1.2 mg (adult RDA ranges from 1.1 (adult women) to 1.2 mg (adult
men)men) Role: functions as two flavoprotein enzymesRole: functions as two flavoprotein enzymes Deficiency: symptoms usually involve the lips, tongue, Deficiency: symptoms usually involve the lips, tongue,
and skinand skin Adverse reactions: not associated with any toxicity Adverse reactions: not associated with any toxicity Clinical considerations: deficiency most likely seen in Clinical considerations: deficiency most likely seen in
alcoholics, economically deprived individuals, or alcoholics, economically deprived individuals, or patients with severe gastrointestinal (GI) diseasepatients with severe gastrointestinal (GI) disease
cont’d…cont’d…
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Water-Soluble VitaminsWater-Soluble Vitamins Haveles (p. 153)Haveles (p. 153)
B-complex vitamins: niacin or nicotinic acid (vitamin B-complex vitamins: niacin or nicotinic acid (vitamin BB33))
Alleviate a deficiency syndrome known as pellagraAlleviate a deficiency syndrome known as pellagra Source: lean meats, fish, liver, poultry, legumes, and Source: lean meats, fish, liver, poultry, legumes, and
whole grainswhole grains RDA: somewhat dependent on both caloric and protein RDA: somewhat dependent on both caloric and protein
intakeintake Role: plays a key role in metabolism by participating in a Role: plays a key role in metabolism by participating in a
variety of oxidation-reduction reactionsvariety of oxidation-reduction reactions Deficiency: clinical syndrome is pellagraDeficiency: clinical syndrome is pellagra Adverse reactions: side effects from large doses include Adverse reactions: side effects from large doses include
cutaneous flushing, pruritus, GI distresscutaneous flushing, pruritus, GI distress Clinical considerations: used as a vitamin in treatment of Clinical considerations: used as a vitamin in treatment of
pellagrapellagracont’d…cont’d…
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Water-Soluble VitaminsWater-Soluble Vitamins Haveles (p. 154) (Table 12-2)Haveles (p. 154) (Table 12-2)
B-complex vitamins: pyridoxine (vitamin BB-complex vitamins: pyridoxine (vitamin B66)) Pyridoxine is one of three different pyridoxine Pyridoxine is one of three different pyridoxine
derivativesderivatives Source: present in most foods of both plant and animal Source: present in most foods of both plant and animal
originorigin RDA: varies from 1.0 to 1.7 mg daily for men and women RDA: varies from 1.0 to 1.7 mg daily for men and women
ages 9 to older than 70 yearsages 9 to older than 70 years Deficiency: rare because of widespread distribution in Deficiency: rare because of widespread distribution in
foodfood Adverse reactions: usually nontoxicAdverse reactions: usually nontoxic Clinical considerations: can interact with isoniazid (INH); Clinical considerations: can interact with isoniazid (INH);
can cancel the therapeutic and side effects of levodopa; can cancel the therapeutic and side effects of levodopa; certain other drugs may produce a pyridoxine deficiencycertain other drugs may produce a pyridoxine deficiency
cont’d…cont’d…
2020Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Water-Soluble VitaminsWater-Soluble Vitamins Haveles (pp. 154-155) (Table 12-4)Haveles (pp. 154-155) (Table 12-4)
B-complex vitamins: folic acidB-complex vitamins: folic acid A form of water-soluble vitamin BA form of water-soluble vitamin B99
Sources: include glandular meats such as liver, some fruits and Sources: include glandular meats such as liver, some fruits and vegetables, wheat germ, and yeastsvegetables, wheat germ, and yeasts
RDA is 400 RDA is 400 µg daily for healthy, nonpregnant, or nonlactating µg daily for healthy, nonpregnant, or nonlactating adultsadults
Role: tetrahydrofolic acid functions primarily in the transfer and Role: tetrahydrofolic acid functions primarily in the transfer and utilization of one-carbon groupsutilization of one-carbon groups
Deficiency: produces megaloblastic anemia, the most common Deficiency: produces megaloblastic anemia, the most common deficiency in the United Statesdeficiency in the United States
Adverse reactions: relatively nontoxicAdverse reactions: relatively nontoxic Clinical considerations: will cause remission of hematologic Clinical considerations: will cause remission of hematologic
effects of pernicious anemia; will not prevent neurologic effects effects of pernicious anemia; will not prevent neurologic effects caused by deficiency of vitamin Bcaused by deficiency of vitamin B1212
cont’d…cont’d…
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Water-Soluble VitaminsWater-Soluble Vitamins Haveles (p. 155)Haveles (p. 155)
B-complex vitamins: cyanocobalamin (vitamin BB-complex vitamins: cyanocobalamin (vitamin B1212)) A chemically complex substance that contains four extensively A chemically complex substance that contains four extensively
substituted pyrrole rings surrounding an atom of cobaltsubstituted pyrrole rings surrounding an atom of cobalt Source: the only sources in nature are certain microorganisms that synthesize Source: the only sources in nature are certain microorganisms that synthesize
the vitaminthe vitamin RDA is 2.4 RDA is 2.4 µg, with an additional µg, with an additional 2.6 2.6 µg and µg and 2.8 2.8 µg during pregnancy and µg during pregnancy and
lactation respectively lactation respectively Role: a coenzyme required in conversion of methylmalonyl-CoA to succinyl-Role: a coenzyme required in conversion of methylmalonyl-CoA to succinyl-
CoACoA Deficiency: symptoms include inadequate hematopoiesis, GI disturbances, Deficiency: symptoms include inadequate hematopoiesis, GI disturbances,
inadequate myelin synthesis, and generalized debility, most common cause is inadequate myelin synthesis, and generalized debility, most common cause is pernicious anemiapernicious anemia
Adverse reactions: even large doses are usually nontoxicAdverse reactions: even large doses are usually nontoxic Clinical considerations: patients who are vegetarians or who have had a Clinical considerations: patients who are vegetarians or who have had a
gastrectomy can exhibit symptoms of deficiencygastrectomy can exhibit symptoms of deficiency
cont’d…cont’d…
2222Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Water-Soluble VitaminsWater-Soluble Vitamins
Haveles (p. 155)Haveles (p. 155) B-complex vitamins: pantothenic acidB-complex vitamins: pantothenic acid Pantothenic acid is another compound required to Pantothenic acid is another compound required to
form acetyl-CoAform acetyl-CoA Source: a part of all living materialSource: a part of all living material RDA: suggested daily dietary intake of 5 to 7 mg RDA: suggested daily dietary intake of 5 to 7 mg Role: incorporated into coenzyme-A, essential for Role: incorporated into coenzyme-A, essential for
normal epithelial functionnormal epithelial function Deficiency: clinical deficiencies are extremely rare in Deficiency: clinical deficiencies are extremely rare in
humanshumans Clinical considerations: apparently promotes GI motilityClinical considerations: apparently promotes GI motility
cont’d…cont’d…
2323Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Water-Soluble VitaminsWater-Soluble Vitamins Haveles (pp. 155-156)Haveles (pp. 155-156)
B-complex vitamins: biotinB-complex vitamins: biotin Initially demonstrated to be an essential Initially demonstrated to be an essential
growth factor for yeastgrowth factor for yeast Source: present in almost all foods, synthesized Source: present in almost all foods, synthesized
by microflora in the intestinal tractby microflora in the intestinal tract RDA: suggested daily dietary intake is 25 to 35 mgRDA: suggested daily dietary intake is 25 to 35 mg Role: a coenzyme required in metabolism in Role: a coenzyme required in metabolism in
carbon dioxide fixation reactionscarbon dioxide fixation reactions Deficiency: can occur with long-term parenteral Deficiency: can occur with long-term parenteral
nutritionnutrition Clinical considerations: antiinfective agents can Clinical considerations: antiinfective agents can
produce a biotin deficiencyproduce a biotin deficiencycont’d…cont’d…
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Water-Soluble VitaminsWater-Soluble Vitamins
Haveles (pp. 156-157)Haveles (pp. 156-157) B-complex vitamins: other B vitaminsB-complex vitamins: other B vitamins
Vitamin BVitamin B1515 and B and B1717, also known as pangamic acid , also known as pangamic acid
and amygdalin (Laetrile), have been shown to be and amygdalin (Laetrile), have been shown to be neither vitamins nor important in human nutritionneither vitamins nor important in human nutrition
Neither choline nor inositol has been Neither choline nor inositol has been demonstrated to be required in the human dietdemonstrated to be required in the human diet
2525Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Fat-Soluble VitaminsFat-Soluble Vitamins Haveles (p. 157)Haveles (p. 157)
Vitamin AVitamin A Necessary for normal growth and for maintaining Necessary for normal growth and for maintaining
health and integrity of certain epithelial tissueshealth and integrity of certain epithelial tissues The term The term vitamin Avitamin A represents a group of retinoids and represents a group of retinoids and
carotenoidscarotenoids Source: vitamin ASource: vitamin A11 occurs naturally in saltwater fish and occurs naturally in saltwater fish and
animal tissuesanimal tissues• Vitamin AVitamin A22 is found in freshwater fish is found in freshwater fish• Preformed vitamin A is found in milk, liver, and some cheesesPreformed vitamin A is found in milk, liver, and some cheeses
Carotenes provide the greatest source of vitamin A in most Carotenes provide the greatest source of vitamin A in most dietsdiets• Carotenes are found in pigmented fruit and in vegetablesCarotenes are found in pigmented fruit and in vegetables
cont’d…cont’d…
2626Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Fat-Soluble VitaminsFat-Soluble Vitamins Haveles (pp. 157-158)Haveles (pp. 157-158)
Vitamin A Vitamin A Adult RDA is 700 to 1300 retinol equivalents (REs)Adult RDA is 700 to 1300 retinol equivalents (REs) Role: essential for maintenance of photoreceptor mechanism Role: essential for maintenance of photoreceptor mechanism
of the retina; the integrity of the epithelia, and the mucosa of of the retina; the integrity of the epithelia, and the mucosa of the respiratory, GI, and genitourinary tracts; and lysosome the respiratory, GI, and genitourinary tracts; and lysosome stabilitystability
Deficiency: leads to impaired vision in dim light, nyctalopiaDeficiency: leads to impaired vision in dim light, nyctalopia Toxicity: characteristics include itching skin, desquamation, Toxicity: characteristics include itching skin, desquamation,
coarse or absent hair, painful subcutaneous swellings, coarse or absent hair, painful subcutaneous swellings, gingivitis, hyperirritability, and limitation of motiongingivitis, hyperirritability, and limitation of motion• When the Vikings landed in Iceland, they ingested polar bear liver and When the Vikings landed in Iceland, they ingested polar bear liver and
died from acute poisoningdied from acute poisoningcont’d…cont’d…
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Fat-Soluble VitaminsFat-Soluble Vitamins
Haveles (p. 158)Haveles (p. 158) Vitamin AVitamin A Vitamin A analogs Vitamin A analogs
Tretinoin is a topical product used to treat acneTretinoin is a topical product used to treat acne Isotretinoin is used orally for treatment of severe Isotretinoin is used orally for treatment of severe
cystic acnecystic acne
cont’d…cont’d…
2828Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Fat-Soluble VitaminsFat-Soluble Vitamins Haveles (pp. 158-159)Haveles (pp. 158-159)
Vitamin DVitamin D Source: vitamin DSource: vitamin D3 3 is produced in the skin of mammals by the is produced in the skin of mammals by the
action of sunlight on its precursoraction of sunlight on its precursor• Cholecalciferol (vitamin DCholecalciferol (vitamin D33) is also present in some foods and is added ) is also present in some foods and is added
to dairy productsto dairy products
• Ergocalciferol (vitamin DErgocalciferol (vitamin D22), is the vitamin D found in plants and is the ), is the vitamin D found in plants and is the
form of vitamin D used in vitamin supplementsform of vitamin D used in vitamin supplements
RDA: adequate daily dietary intake of vitamin D is 5 RDA: adequate daily dietary intake of vitamin D is 5 µg/day for µg/day for children and 5 to 15 µg/day for adultschildren and 5 to 15 µg/day for adults
Role: promotes normal mineralization of bone by stimulating Role: promotes normal mineralization of bone by stimulating intestinal absorption of calcium and decreasing excretion from intestinal absorption of calcium and decreasing excretion from the kidneythe kidney
cont’d… cont’d…
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Fat-Soluble VitaminsFat-Soluble Vitamins
Haveles (p. 158)Haveles (p. 158) Vitamin DVitamin D
Deficiency: produces inadequate absorption of Deficiency: produces inadequate absorption of calcium and phosphate with a decrease in plasma calcium and phosphate with a decrease in plasma calciumcalcium• Parathyroid hormone secretion is stimulated, which Parathyroid hormone secretion is stimulated, which
removes calcium from the bone to restore plasma levelsremoves calcium from the bone to restore plasma levels In children, this results in ricketsIn children, this results in rickets During pregnancy or in young children, deficiency may During pregnancy or in young children, deficiency may
result in enamel hypoplasiaresult in enamel hypoplasia In adults, it produces a disease state called osteomalaciaIn adults, it produces a disease state called osteomalacia
Toxicity: symptoms of hypervitaminosis D are Toxicity: symptoms of hypervitaminosis D are caused by abnormal calcium metabolismcaused by abnormal calcium metabolism
cont’d…cont’d…
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Fat-Soluble VitaminsFat-Soluble Vitamins
Haveles (p. 159)Haveles (p. 159) Vitamin DVitamin D
Clinical considerations: used to prevent and treat Clinical considerations: used to prevent and treat rickets, chronic hypocalcemia, hypophosphatemia, rickets, chronic hypocalcemia, hypophosphatemia, osteodystrophy, and osteomalaciaosteodystrophy, and osteomalacia
Osteoporosis: occurs when the equilibrium between Osteoporosis: occurs when the equilibrium between resorption and formation of bone becomes negativeresorption and formation of bone becomes negative• Most likely the thin, Caucasian, or Asian woman who Most likely the thin, Caucasian, or Asian woman who
smokessmokes
• Bisphosphonates are indicated for management of Bisphosphonates are indicated for management of osteoporosisosteoporosis
cont’d…cont’d…
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Fat-Soluble VitaminsFat-Soluble Vitamins Haveles (p. 159)Haveles (p. 159)
Vitamin EVitamin E There are eight naturally occurring tocopherols There are eight naturally occurring tocopherols
possessing vitamin E activitypossessing vitamin E activity Source: best sources are vegetable oils Source: best sources are vegetable oils RDA: estimated that a daily intake of 10 to 20 mg will keep RDA: estimated that a daily intake of 10 to 20 mg will keep
serum level within a normal range serum level within a normal range Role: action is probably exerted via its antioxidant effectRole: action is probably exerted via its antioxidant effect Deficiency: can occur in malabsorption syndromes and in Deficiency: can occur in malabsorption syndromes and in
premature infants with impaired absorption abilitypremature infants with impaired absorption ability Toxicity: thought to have low toxicityToxicity: thought to have low toxicity
cont’d…cont’d…
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Fat-Soluble VitaminsFat-Soluble Vitamins
Haveles (p. 160)Haveles (p. 160) Vitamin EVitamin E
Clinical considerations: recommended for Clinical considerations: recommended for treatment of a wide variety of human diseases treatment of a wide variety of human diseases similar to conditions of vitamin E deficiencysimilar to conditions of vitamin E deficiency• At present, no therapeutic use of vitamin E has been At present, no therapeutic use of vitamin E has been
proved by controlled scientific studies, with the exception proved by controlled scientific studies, with the exception of hemolytic anemia of the newbornof hemolytic anemia of the newborn
cont’d…cont’d…
3333Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Fat-Soluble VitaminsFat-Soluble Vitamins
Haveles (p. 160)Haveles (p. 160) Vitamin KVitamin K
Originally found to be a fat-soluble substance Originally found to be a fat-soluble substance present in hog liver fat and alfalfapresent in hog liver fat and alfalfa
Vitamin KVitamin K22 consists of several substances, with consists of several substances, with
menaquinone-4 being the most active formmenaquinone-4 being the most active form• It is synthesized by gram-positive bacteria present in the It is synthesized by gram-positive bacteria present in the
gastrointestinal tractgastrointestinal tract
Vitamin KVitamin K11 is found in plants is found in plants
cont’d…cont’d…
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Fat-Soluble VitaminsFat-Soluble Vitamins
Haveles (p. 160)Haveles (p. 160) Vitamin KVitamin K
Source: occurs in green vegetables, such as alfalfa, Source: occurs in green vegetables, such as alfalfa, cabbage, and spinach, and in egg yolk, soybean oil, and cabbage, and spinach, and in egg yolk, soybean oil, and liverliver• Synthesized by gram-positive bacteria and the microorganisms in Synthesized by gram-positive bacteria and the microorganisms in
intestinal flora intestinal flora RDA: adequate dietary intake is 60 to 120 RDA: adequate dietary intake is 60 to 120 µg for men and µg for men and
60 to 90 60 to 90 µg for womenµg for women
Role: essential for hepatic synthesis of four of the clotting Role: essential for hepatic synthesis of four of the clotting factorsfactors
Deficiency: can produce hypoprothrombinemiaDeficiency: can produce hypoprothrombinemiacont’d…cont’d…
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Fat-Soluble VitaminsFat-Soluble Vitamins
Haveles (p. 160)Haveles (p. 160) Vitamin KVitamin K
Toxicity: vitamins KToxicity: vitamins K11 and K and K22 are essentially nontoxic are essentially nontoxic
in massive doses; vitamin K must be administered in massive doses; vitamin K must be administered in large doses before toxicity can be demonstrated in large doses before toxicity can be demonstrated
Clinical considerations: anticoagulant drugs such as Clinical considerations: anticoagulant drugs such as warfarin competitively antagonize vitamin K and warfarin competitively antagonize vitamin K and interfere with the production of prothrombin (II) and interfere with the production of prothrombin (II) and factors VII, IX, and Xfactors VII, IX, and X• Vitamin K can be used to treat excessive Vitamin K can be used to treat excessive
hypoprothrombinemia caused by warfarin toxicityhypoprothrombinemia caused by warfarin toxicity
3636Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Selected MineralsSelected Minerals
Haveles (pp. 160-161 )Haveles (pp. 160-161 ) IronIron Widely distributed throughout the human body, Widely distributed throughout the human body,
principally found in hemoglobinprincipally found in hemoglobin Source: good sources include organ meats, wheat germ, Source: good sources include organ meats, wheat germ,
brewer’s yeast, egg yolks, oysters, red meats, and dried brewer’s yeast, egg yolks, oysters, red meats, and dried beansbeans
RDA: the body carefully conserves iron; no mechanism for RDA: the body carefully conserves iron; no mechanism for its excretion existsits excretion exists
Role: basic function is to allow for the movement of oxygen Role: basic function is to allow for the movement of oxygen and carbon dioxide from one tissue to anotherand carbon dioxide from one tissue to another
cont’d…cont’d…
3737Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Selected MineralsSelected Minerals
Haveles (pp. 161-162)Haveles (pp. 161-162) IronIron
Deficiency: can only occur with growth, blood loss, Deficiency: can only occur with growth, blood loss, or inadequate intake during pregnancy or lactationor inadequate intake during pregnancy or lactation• Produces microcytic and hypochromic anemiaProduces microcytic and hypochromic anemia
• Toxicity: bleeding into the intestine can occur with acute Toxicity: bleeding into the intestine can occur with acute overdose, resulting in shock or even deathoverdose, resulting in shock or even death
cont’d…cont’d…
3838Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Selected MineralsSelected Minerals Haveles (p. 162)Haveles (p. 162)
ZincZinc Only recently recognized as a mineral the body requiresOnly recently recognized as a mineral the body requires
Source: best sources are seafood and meatSource: best sources are seafood and meat RDA for adults is 11 mg for men and 8 mg for womenRDA for adults is 11 mg for men and 8 mg for women Role: required to transport carbon dioxide in the blood and Role: required to transport carbon dioxide in the blood and
eliminate it in the lungseliminate it in the lungs Deficiency: associated with delay in sexual maturity, slow Deficiency: associated with delay in sexual maturity, slow
healing of wounds, and slowed growthhealing of wounds, and slowed growth Toxicity: excessive intake has impaired lymphocyte and Toxicity: excessive intake has impaired lymphocyte and
polymorphonuclear leukocyte functions in healthy personspolymorphonuclear leukocyte functions in healthy persons Clinical considerations: long known to participate in wound Clinical considerations: long known to participate in wound
healing, no known advantage to administration of zinc in healing, no known advantage to administration of zinc in patients who have no zinc deficiencypatients who have no zinc deficiency
cont’d…cont’d…
3939Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Selected MineralsSelected Minerals Haveles (pp. 162-163 )Haveles (pp. 162-163 )
CalciumCalcium The level of calcium in the serum must be maintained The level of calcium in the serum must be maintained
within a narrow concentration to prevent serious within a narrow concentration to prevent serious problemsproblems Source: dairy products are the best source in the dietSource: dairy products are the best source in the diet RDA: adequate daily dietary intake is from 1000 to 1300 mg RDA: adequate daily dietary intake is from 1000 to 1300 mg
for the adultfor the adult Role: essential for function of nervous, muscular, and Role: essential for function of nervous, muscular, and
skeletal systems and for cell membrane and capillary skeletal systems and for cell membrane and capillary permeabilitypermeability
Deficiency: tetany, paresthesia, muscle cramps, and Deficiency: tetany, paresthesia, muscle cramps, and convulsions can result if blood levels fallconvulsions can result if blood levels fall
cont’d…cont’d…
4040Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Selected MineralsSelected Minerals
Haveles (pp. 162-163 )Haveles (pp. 162-163 ) CalciumCalcium
Adverse reactions: hypocalcemia can result if Adverse reactions: hypocalcemia can result if large doses are given to patients with chronic large doses are given to patients with chronic renal failurerenal failure
Clinical considerations calcium is used to treat a Clinical considerations calcium is used to treat a deficiency of calcium and secondary to low deficiency of calcium and secondary to low calcium levelscalcium levels
4141Copyright © 2011, 2007 Mosby, Inc., an affiliate of Elsevier. All rights reserved.
Drug-Induced Vitamin Drug-Induced Vitamin DeficienciesDeficiencies
Haveles (p. 163 ) (Table 12-4)Haveles (p. 163 ) (Table 12-4) Drugs from a large variety of drug groups Drugs from a large variety of drug groups
have the ability to produce vitamin deficiencyhave the ability to produce vitamin deficiency Some actually produce a deficiency, whereas Some actually produce a deficiency, whereas
others tend to lower the levels of some vitaminsothers tend to lower the levels of some vitamins• INH can produce a neuropathy resulting from vitamin BINH can produce a neuropathy resulting from vitamin B66
deficiencydeficiency
• Patients taking phenytoin may exhibit vitamin D Patients taking phenytoin may exhibit vitamin D deficiency because phenytoin stimulates the liver deficiency because phenytoin stimulates the liver microsomal enzymesmicrosomal enzymes
• Certain drugs, such as oral contraceptives tend to induce Certain drugs, such as oral contraceptives tend to induce a deficiency of vitamins Ba deficiency of vitamins B11, B, B22, and folic acid, and folic acid
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