Introduction to Nutrition and Metabolism

 

Description:

 

Introduction to Nutrition and Metabolism equips readers with an understanding of the scientific basis of what we call a healthy diet. Now in its sixth edition, this highly recognized textbook provides clear explanations of how nutrients are metabolized and gives the principles of biochemistry needed for comprehending the science of nutrition. This full-color textbook explores the need for food and the uses to which food is put in the body, as well as the interactions between health and diet. Outlining the scientific basis behind nutritional requirements and recommendations, this new edition has been extensively revised to reflect current knowledge. Features: Lists key objectives at the beginning, and summary points at the end of each chapter. Accompanying online resources include interactive tutorial exercises based on interpretation of clinical and research data. Covers topics including: Chemical reactions and catalysis by enzymes; the role of ATP; digestion and absorption of carbohydrates, fats and proteins; issues associated with being overweight; problems of malnutrition; diet and health; and vitamin and mineral requirements and functions. Updated sections focus on the interaction of the gut microbiome and epigenetics with our metabolic responses to diet. Provides a foundation of scientific knowledge for the interpretation and evaluation of future advances in nutrition and health sciences. Following its predecessors, this sixth edition is relevant to any student or practitioner interested in how diet influences our health, including in the fields of nutrition, dietetics, medicine and public health.

 

 

Table of Contents:

 

Preface

Authors

Additional Resources on the Website: Metabolism Online – The Virtual Tutorial

chapter one Why Eat?

Objectives

1.1 The Need for Water

1.2 The Need for Energy

1.2.1 Units of Energy

1.3 Metabolic Fuels

1.3.1 The Need for Carbohydrate and Fat

1.3.2 The Need for Protein

1.3.3 The Need for Micronutrients: Minerals and Vitamins

1.4 Hunger and Appetite

1.4.1 Hunger and Satiety: Short-Term Control of Feeding

1.4.1.1 Nutrient Sensing in the Hypothalamus

1.4.1.2 Ghrelin: The Appetite-Stimulating Hormone

1.4.2 Long-Term Control of Food Intake and Energy Expenditure: The Hormone Leptin

1.4.3 Appetite

1.4.3.1 Taste and Flavor

1.4.4 Why Do People Eat What They Do?

1.4.4.1 The Availability and Cost of Food

1.4.4.2 Religion, Habit and Tradition

1.4.4.3 Organic Foods

1.4.4.4 Luxury Status of Scarce and Expensive Foods

1.4.4.5 Social Functions of Food

1.4.4.6 Food Allergy and Intolerance

1.4.5 Eating Disorders

1.4.5.1 Anorexia Nervosa

1.4.5.2 Bulimia Nervosa

1.4.5.3 Binge Eating Disorder

1.4.5.4 Other Eating Disorders

Key Points

chapter two Enzymes and Metabolic Pathways

Objectives

2.1 Chemical Reactions: Breaking and Making Covalent Bonds

2.1.1 Equilibrium

2.1.2 Catalysis

2.2 Enzymes

2.2.1 Specificity of Enzymes

2.2.2 Stages in an Enzyme-Catalyzed Reaction

2.2.3 Units of Enzyme Activity

2.3 Factors Affecting Enzyme Activity

2.3.1 The Effect of pH

2.3.2 The Effect of Temperature

2.3.3 The Effect of Substrate Concentration

2.3.3.1 Experimental Determination of Km and Vmax

2.3.3.2 Enzymes with Two Substrates

2.3.3.3 Cooperative (Allosteric) Enzymes

2.3.4 Inhibition of Enzyme Activity

2.3.4.1 Irreversible Inhibitors

2.3.4.2 Competitive Reversible Inhibitors

2.3.4.3 Noncompetitive Reversible Inhibitors

2.3.4.4 Uncompetitive Reversible Inhibitors

2.4 Coenzymes and Prosthetic Groups

2.4.1 Coenzymes and Metal Ions in Oxidation and Reduction Reactions

2.4.1.1 Metal Ions

2.4.1.2 Riboflavin and Flavoproteins

2.4.1.3 The Nicotinamide Nucleotide Coenzymes: NAD and NADP

2.5 The Classification and Naming of Enzymes

2.6 Metabolic Pathways

2.6.1 Linear and Branched Pathways

2.6.2 Spiral or Looped Reaction Sequences

2.6.3 Cyclic Pathways

2.7 Enzymes in Clinical Chemistry and Medicine

2.7.1 Measurement of Metabolites in Blood, Urine and Tissue Samples

2.7.2 Measurement of Enzymes in Blood Samples

2.7.3 Assessment of Vitamin Nutritional Status

Key Points

chapter three The Role of ATP in Metabolism

Objectives

3.1 Adenine Nucleotides

3.2 Functions of ATP

3.2.1 The Role of ATP in Endothermic Reactions

3.2.2 Transport of Materials across Cell Membranes

3.2.2.1 Protein Binding for Concentrative Uptake

3.2.2.2 Metabolic Trapping

3.2.2.3 Active Transport

3.2.2.4 P-Type Transporters

3.2.2.5 ATP-Binding Cassette (ABC) Transporters

3.2.2.6 Sodium Pump

3.2.3 The Role of ATP in Muscle Contraction

3.2.3.1 Creatine Phosphate in Muscle

3.3 Phosphorylation of ADP to ATP

3.3.1 Oxidative Phosphorylation: ATP Synthesis Linked to the Oxidation of Metabolic Fuels

3.3.1.1 The Mitochondrion

3.3.1.2 The Mitochondrial Electron Transport Chain

3.3.1.3 Phosphorylation of ADP Linked to Electron Transport

3.3.1.4 Coupling of Electron Transport, Oxidative Phosphorylation and Fuel Oxidation

3.3.1.5 Uncouplers

3.3.1.6 Respiratory Poisons

Key Points

chapter four Digestion and Absorption

Objectives

4.1 The Gastrointestinal Tract

4.2 Digestion and Absorption of Carbohydrates

4.2.1 Classification of Carbohydrates

4.2.1.1 Glycemic Index

4.2.1.2 Monosaccharides

4.2.1.3 Sugar Alcohols

4.2.1.4 Disaccharides

4.2.1.5 Reducing and Nonreducing Sugars

4.2.1.6 Polysaccharides: Starches and Glycogen

4.2.1.7 Dietary Fiber

4.2.2 Carbohydrate Digestion and Absorption

4.2.2.1 Starch Digestion

4.2.2.2 Digestion of Disaccharides

4.2.2.3 Absorption of Monosaccharides

4.3 Digestion and Absorption of Fats

4.3.1 Classification of Dietary Lipids

4.3.1.1 Fatty Acids

4.3.1.2 Phospholipids

4.3.1.3 Cholesterol and the Steroids

4.3.2 Digestion and Absorption of Triacylglycerols

4.3.2.1 Bile Salts

4.3.2.2 Lipid Absorption and Chylomicron Formation

4.4 Digestion and Absorption of Proteins

4.4.1 Amino Acids

4.4.2 Protein Structure and Denaturation of Proteins

4.4.2.1 Secondary Structure of Proteins

4.4.2.2 Tertiary and Quaternary Structures of Proteins

4.4.2.3 Denaturation of Proteins

4.4.3 Protein Digestion

4.4.3.1 Activation of Zymogens of Proteolytic Enzymes

4.4.3.2 Absorption of the Products of Protein Digestion

4.5 Absorption of Vitamins and Minerals

4.5.1 Absorption of Lipid-Soluble Vitamins and Cholesterol

4.5.2 Absorption of Water-Soluble Vitamins

4.5.2.1 Absorption of Vitamin B12

4.5.3 Absorption of Minerals

4.5.3.1 Iron Absorption

Key Points

chapter five Energy Nutrition: The Metabolism of Carbohydrates and Fats

Objectives

5.1 Estimation of Energy Expenditure

5.1.1 Indirect Calorimetry and the Respiratory Quotient (RQ)

5.1.2 Long-Term Measurement of Energy Expenditure: The Dual Isotopically Labeled Water Method

5.1.3 Calculation of Energy Expenditure

5.1.3.1 Basal Metabolic Rate

5.1.3.2 Energy Costs of Physical Activity

5.1.3.3 Diet-Induced Thermogenesis

5.2 Energy Balance and Changes in Body Weight

5.3 Metabolic Fuels in the Fed and Fasting States

5.3.1 The Fed State

5.3.2 The Fasting State

5.4 Energy-Yielding Metabolism

5.4.1 Glycolysis: The (Anerobic) Metabolism of Glucose

5.4.1.1 Transfer of NADH Formed during Glycolysis into the Mitochondria

5.4.1.2 Reduction of Pyruvate to Lactate: Anaerobic Glycolysis

5.4.2 The Pentose Phosphate Pathway: An Alternative to Glycolysis

5.4.2.1 The Pentose Phosphate Pathway in Red Blood Cells: Favism

5.4.3 Metabolism of Pyruvate

5.4.3.1 Oxidation of Pyruvate to Acetyl CoA

5.4.4 Oxidation of Acetyl CoA: The Citric Acid Cycle

5.4.4.1 The Citric Acid Cycle as Pathway for Metabolic Interconversion

5.4.4.2 Complete Oxidation of Four- and Five-Carbon Compounds

5.5 Metabolism of Fats

5.5.1 Carnitine and the Transport of Fatty Acids into the Mitochondrion

5.5.2 ß-Oxidation of Fatty Acids

5.5.3 Ketone Bodies

5.6 Tissue Reserves of Metabolic Fuels

5.6.1 Synthesis of Fatty Acids and Triacylglycerols

5.6.1.1 Unsaturated Fatty Acids

5.6.1.2 Synthesis of Triacylglycerol

5.6.2 Plasma Lipoproteins

5.6.2.1 Chylomicrons

5.6.2.2 Very Low Density Lipoproteins, Intermediate-Density Lipoproteins and Low-Density Lipoproteins

5.6.2.3 High-Density Lipoproteins

5.6.3 Glycogen

5.6.3.1 Glycogen Utilization

5.7 Gluconeogenesis: The Synthesis of Glucose from Noncarbohydrate Precursors

Key Points

chapter six Diet and Health: Nutrition and Chronic Noncommunicable Diseases

Objectives

6.1 Chronic Noncommunicable Diseases (the “Diseases of Affluence”)

6.2 Types of Evidence Linking Diet and Chronic Diseases

6.2.1 Secular Changes in Diet and Disease Incidence

6.2.2 International Correlations between Diet and Disease Incidence

6.2.3 Studies of Migrants

6.2.4 Case-Control Studies

6.2.5 Prospective Studies

6.3 Guidelines for a Prudent Diet

6.3.1 Energy Intake

6.3.2 Fat Intake

6.3.2.1 The Type of Fat in the Diet

6.3.3 Carbohydrate Intake

6.3.3.1 Sugars in the Diet

6.3.3.2 Undigested Carbohydrates (Dietary Fiber and Non-starch Polysaccharides)

6.3.4 The Gut Microbiome, Diet and Disease

6.3.5 Salt

6.3.6 Alcohol

6.4 Nutritional Genomics: Interactions between Diet and Genes

6.4.1 Epigenetic Programming of the Genome

6.4.1.1 Epigenetic Mechanisms

6.4.1.2 Nutritional Epigenetics

6.4.1.3 In Utero and Transgenerational Epigenetic Inheritance

6.5 Free Radicals, Oxidative Damage and Antioxidant Nutrients

6.5.1 Tissue Damage by Oxygen Radicals

6.5.2 Sources of Oxygen Radicals

6.5.2.1 Reoxidation of Reduced Flavins

6.5.2.2 The Macrophage Respiratory Burst

6.5.2.3 Formation of Nitric Oxide

6.5.2.4 Nonenzymic Formation of Radicals

6.5.3 Antioxidant Nutrients and Non-Nutrients: Protection against Radical Damage

6.5.3.1 Superoxide Dismutase, Peroxidases and Catalase

6.5.3.2 Glutathione Peroxidase

6.5.3.3 ß-Carotene and Other Carotenes

6.5.3.4 Vitamin C: An Antioxidant and a Prooxidant

6.5.3.5 Intervention Trials with Vitamin E

6.5.3.6 The Antioxidant Paradox

6.6 Homocysteine in Cardiovascular Disease

6.6.1 Factors Affecting Plasma Homocysteine

6.6.1.1 Polymorphisms of Methylene Tetrahydrofolate Reductase

6.6.1.2 Intervention Trials with Folate and VitaminsB6 and B12

6.7 Other Potentially Protective Compounds in Foods

6.7.1 Inhibition of Cholesterol Absorption or Synthesis

6.7.2 Inhibition of Carcinogen Activation and Increased Conjugation of Activated Metabolites

6.7.2.1 Allyl Sulfur Compounds

6.7.2.2 Glucosinolates

6.7.2.3 Flavonoids

6.7.3 Phytoestrogens

6.7.4 Miscellaneous Actions of Phytochemicals

Key Points

chapter seven Overweight and Obesity

Objectives

7.1 Desirable Body Weight

7.1.1 Body Mass Index (BMI)

7.1.2 Estimation of Body Fat

7.1.2.1 Determination of Body Density

7.1.2.2 Determination of Total Body Water or Potassium

7.1.2.3 Imaging Techniques

7.1.2.4 Measurement of Whole Body Electrical Conductivity and Impedance

7.1.2.5 Measurement of Skinfold Thickness

7.2 Problems of Overweight and Obesity

7.2.1 Social Problems of Obesity

7.2.2 Health Risks of Obesity

7.2.2.1 The Distribution of Excess Adipose Tissue

7.2.3 Obesity and the Metabolic Syndrome

7.2.3.1 Insulin Resistance and Hyperinsulinism

7.2.3.2 Adiponectin

7.2.3.3 Resistin

7.2.3.4 Chemerin

7.2.3.5 Macrophage Infiltration of Adipose Tissue

7.2.3.6 Excessive Synthesis of Cortisol

7.3 Causes and Treatment of Obesity

7.3.1 Energy Expenditure

7.3.2 Availability of Food

7.3.3 Control of Appetite

7.3.4 How Obese People Can be Helped to Lose Weight

7.3.4.1 Starvation

7.3.4.2 Very Low Energy Diets

7.3.4.3 Conventional Diets

7.3.4.4 Very Low Carbohydrate (Ketogenic) Diets

7.3.4.5 Low Glycemic Index Diets

7.3.4.6 High-Fiber Diets

7.3.4.7 Alternating Food Restriction and Free Consumption

7.3.4.8 “Diets” That Probably Won’t Work

7.3.4.9 Slimming Patches

7.3.4.10 Sugar Substitutes

7.3.4.11 Fat Substitutes

7.3.4.12 Pharmacological Treatment of Obesity

7.3.4.13 Surgical Treatment of Obesity

7.3.4.14 Help and Support

Key Points

chapter eight Protein-Energy Malnutrition: Problems of Undernutrition

Objectives

8.1 Problems of Deficiency

8.2 Protein-Energy malnutrition

8.2.1 Detection of Malnutrition in Adults

8.3 Marasmus

8.3.1 Causes of Marasmus and Vulnerable Groups of the Population

8.3.1.1 Malabsorption

8.3.1.2 Food Intolerance and Allergy

8.4 Cachexia

8.4.1 Hypermetabolism in Cachexia

8.4.2 Increased Protein Catabolism in Cachexia

8.5 Kwashiorkor

8.5.1 Factors in the Etiology of Kwashiorkor

8.5.2 Rehabilitation of Malnourished Children

Key Points

chapter nine Protein Nutrition and Metabolism

Objectives

9.1 Nitrogen Balance and Protein Requirements

9.1.1 Dynamic Equilibrium

9.1.1.1 Mechanisms Involved in Tissue Protein Catabolism

9.1.2 Protein Requirements

9.1.2.1 Protein Requirements for Physical Activity and Body Building

9.1.2.2 Protein Requirements of Children

9.1.2.3 Protein Losses in Trauma and Infection: Requirements for Convalescence

9.1.3 Essential Amino Acids

9.1.3.1 Protein Quality and Complementation

9.1.3.2 Unavailable Amino Acids and Protein Digestibility

9.2 Protein Synthesis

9.2.1 The Structure and Information Content of DNA

9.2.1.1 DNA Replication

9.2.1.2 The Genetic Code

9.2.2 Ribonucleic Acid

9.2.2.1 Transcription to Form Messenger RNA

9.2.3 Translation of mRNA: The Process of Protein Synthesis

9.2.3.1 Transfer RNA

9.2.3.2 Protein Synthesis on the Ribosome

9.2.3.3 The Energy Cost of Protein Synthesis

9.2.3.4 Posttranslational Modification of Proteins

9.3 Metabolism of Amino Acids

9.3.1 Metabolism of the Amino Nitrogen

9.3.1.1 Deamination

9.3.1.2 Transamination

9.3.1.3 Metabolism of Ammonia

9.3.1.4 Synthesis of Urea

9.3.1.5 Incorporation of Nitrogen in Biosynthesis

9.3.2 Metabolism of Amino Acid Carbon Skeletons

Key Points

chapter ten The Integration and Control of Metabolism

Objectives

10.1 Patterns of Metabolic Regulation

10.2 Intracellular Regulation of Enzyme Activity

10.2.1 Allosteric Modification of the Activity of Regulatory Enzymes

10.2.2 Control of Glycolysis: The Allosteric Regulation of Phosphofructokinase

10.2.2.1 Feedback Control of Phosphofructokinase

10.2.2.2 Feed-Forward Control of Phosphofructokinase

10.2.2.3 Substrate Cycling

10.3 Responses to Fast-Acting Hormones by Covalent Modification of Enzyme Proteins

10.3.1 Membrane Receptors and G-Proteins

10.3.2 Cyclic AMP and Cyclic GMP as Second Messengers

10.3.2.1 Amplification of the Hormone Signal

10.3.2.2 Desensitization of the Adrenaline Receptor

10.3.3 Inositol Trisphosphate and Diacylglycerol as Second Messengers

10.3.3.1 Amplification of the Hormone Signal

10.3.4 The Insulin Receptor

10.4 Responses to Slow-Acting Signals by Changes in Enzyme Synthesis

10.4.1 Slow-Acting Hormones

10.4.1.1 Amplification of the Hormone Signal

10.4.2 Dietary Control of Enzyme Expression

10.5 Hormonal Control in the Fed and Fasting States

10.5.1 Hormonal Control of Adipose Tissue Metabolism

10.5.2 Control of Lipid Metabolism in the Liver

10.6 Selection of Fuels for Muscle Activity

10.6.1 The Effect of Work Intensity on Muscle Fuel Selection

10.6.2 Muscle Fuel Utilization in the Fed and Fasting States

10.6.2.1 Regulation of Fatty Acid Metabolism in Muscle

10.7 Diabetes Mellitus: A Failure of Regulation of Blood Glucose Concentration

10.7.1 Adverse Effects of Poor Glycemic Control

Key Points

chapter eleven Micronutrients: The Vitamins and Minerals

Objectives

11.1 Determination of Requirements and Reference Intakes

11.1.1 Dietary Reference Values

11.1.1.1 Supplements and Safe Levels of Intake

11.1.2 The Vitamins

11.2 Vitamin A

11.2.1 Vitamers and International Units

11.2.2 Metabolism and Storage of Vitamin A and Provitamin A Carotenoids

11.2.2.1 Carotene Dioxygenase

11.2.2.2 Plasma Retinol-Binding Protein

11.2.3 Metabolic Functions of Vitamin A and Carotenes

11.2.3.1 Vitamin A in Vision

11.2.3.2 Retinoic Acid and the Regulation of Gene Expression

11.2.3.3 The Antioxidant Function of Carotenes

11.2.4 Vitamin A Deficiency: Night Blindness and Xerophthalmia

11.2.5 Vitamin A Requirements and Reference Intakes

11.2.5.1 Assessment of Vitamin A Status

11.2.6 Toxicity of Vitamin A

11.2.6.1 Teratogenicity of Vitamin A

11.2.7 Interactions of Vitamin A with Drugs and Other Nutrients

11.3 Vitamin D

11.3.1 Vitamers and International Units

11.3.2 Absorption and Metabolism of Vitamin D

11.3.2.1 Synthesis of Vitamin D in the Skin

11.3.2.2 Metabolism of Cholecalciferol

11.3.2.3 Regulation of Vitamin D Metabolism

11.3.3 Metabolic Functions of Vitamin D

11.3.4 Vitamin D Deficiency: Rickets and Osteomalacia

11.3.5 Vitamin D Requirements and Reference Intakes

11.3.6 Vitamin D Toxicity

11.3.7 Interactions with Drugs and Other Nutrients

11.4 Vitamin E

11.4.1 Vitamers and Units of Activity

11.4.2 Absorption and Metabolism of Vitamin E

11.4.3 Metabolic Functions of Vitamin E

11.4.3.1 Non-antioxidant Actions of Vitamin E

11.4.4 Vitamin E Deficiency

11.4.5 Vitamin E Requirements

11.4.5.1 Indices of Vitamin E Status

11.4.5.2 Higher Levels of Intake

11.4.6 Interactions with Other Nutrients

11.5 Vitamin K

11.5.1 Vitamers

11.5.2 Dietary Sources, Bacterial Synthesis and Metabolism of Vitamin K

11.5.3 Metabolic Functions of Vitamin K

11.5.4 Vitamin K Deficiency and Requirements

11.5.5 Toxicity and Drug Interactions

11.6 Thiamin (Vitamin B1)

11.6.1 Absorption and Metabolism of Thiamin

11.6.2 Metabolic Functions of Thiamin

11.6.3 Thiamin Deficiency

11.6.3.1 Dry Beriberi

11.6.3.2 Wet Beriberi

11.6.3.3 Acute Pernicious (Fulminating) Beriberi: Shoshin Beriberi

11.6.3.4 Wernicke–Korsakoff Syndrome

11.6.4 Thiamin Requirements

11.6.5 Assessment of Thiamin Status

11.7 Riboflavin (Vitamin B2)

11.7.1 Absorption and Metabolism of Riboflavin

11.7.1.1 Riboflavin Balance

11.7.2 Metabolic Functions of the Flavin Coenzymes

11.7.2.1 Flavins and Oxidative Stress

11.7.3 Riboflavin Deficiency

11.7.3.1 Resistance to Malaria in Riboflavin Deficiency

11.7.4 Riboflavin Requirements

11.7.5 Assessment of Riboflavin Nutritional Status

11.7.6 Interactions with Drugs and Other Nutrients

11.8 Niacin

11.8.1 Vitamers and Niacin Equivalents

11.8.1.1 Unavailable Niacin in Cereals

11.8.2 Absorption and Metabolism of Niacin

11.8.2.1 Catabolism of NAD(P)

11.8.2.2 Urinary Excretion of Niacin and Metabolites

11.8.3 Metabolic Functions of Niacin

11.8.4 Pellagra: A Disease of Tryptophan and Niacin Deficiency

11.8.4.1 Additional Factors in the Etiology of Pellagra

11.8.5 Niacin Requirements

11.8.6 Assessment of Niacin Status

11.8.7 Niacin Toxicity

11.9 Vitamin B6

11.9.1 Vitamers

11.9.2 Absorption and Metabolism of Vitamin B6

11.9.3 Metabolic Functions of Vitamin B6

11.9.4 Vitamin B6 Deficiency

11.9.5 Vitamin B6 Requirements

11.9.5.1 Requirements of Infants

11.9.6 Assessment of Vitamin B6 Status

11.9.6.1 Coenzyme Saturation of Transaminases

11.9.6.2 The Tryptophan Load Test

11.9.6.3 The Methionine Load Test

11.9.7 Non-nutritional Uses of Vitamin B6

11.9.8 Vitamin B6 Toxicity

11.10 Vitamin B12

11.10.1 Structure and Vitamers

11.10.2 Absorption and Metabolism of Vitamin B12

11.10.2.1 Enterohepatic Circulation of Vitamin B12

11.10.3 Metabolic Functions of Vitamin B12

11.10.4 Vitamin B12 Deficiency: Pernicious Anemia

11.10.4.1 Drug-Induced Vitamin B12 Deficiency

11.10.5 Vitamin B12 Requirements

11.10.6 Assessment of Vitamin B12 Status

11.10.6.1 The Schilling Test for Vitamin B12 Absorption

11.10.6.2 Methylmalonic Aciduria

11.11 Folic Acid and the Folates

11.11.1 Vitamers and Dietary Equivalence

11.11.2 Absorption and Metabolism of Folate

11.11.2.1 Tissue Uptake of Folate

11.11.2.2 Folate Excretion

11.11.3 Metabolic Functions of Folate

11.11.3.1 Thymidylate Synthetase and Dihydrofolate Reductase

11.11.3.2 Methionine Synthetase and the Methyl-Folate Trap

11.11.3.3 Methylene-Tetrahydrofolate Reductase and Hyperhomocysteinemia

11.11.3.4 Folate in Pregnancy

11.11.3.5 Folate and Cancer

11.11.4 Folate Deficiency: Megaloblastic Anemia

11.11.5 Folate Requirements

11.11.6 Assessment of Folate Status

11.11.6.1 Histidine Metabolism: The Formiminoglutamate (FIGLU) Test

11.11.6.2 The dUMP Suppression Test

11.11.7 Drug–Nutrient Interactions of Folate

11.11.8 Folate Toxicity

11.12 Biotin

11.12.1 Absorption and Metabolism of Biotin

11.12.2 Metabolic Functions of Biotin

11.12.3 Biotin Deficiency and Requirements

11.12.3.1 Glucose Metabolism in Biotin Deficiency

11.12.3.2 Lipid Metabolism in Biotin Deficiency

11.12.4 Safe and Adequate Levels of Intake

11.13 Pantothenic Acid

11.13.1 Absorption, Metabolism and Metabolic Functions of Pantothenic Acid

11.13.1.1 Coenzyme A and Acyl Carrier Protein

11.13.2 Pantothenic Acid Deficiency and Safe and Adequate Levels of Intake

11.13.3 Nonnutritional Uses of Pantothenic Acid

11.14 Vitamin C (Ascorbic Acid)

11.14.1 Absorption and Metabolism of Vitamin C

11.14.2 Metabolic Functions of Vitamin C

11.14.2.1 Copper-Containing Hydroxylases

11.14.2.2 Oxoglutarate-Linked Iron-Containing Hydroxylases

11.14.2.3 Prooxidant and Antioxidant Roles of Ascorbate

11.14.3 Vitamin C Deficiency: Scurvy

11.14.3.1 Anemia in Scurvy

11.14.4 Vitamin C Requirements

11.14.5 Assessment of Vitamin C Status

11.14.6 Possible Benefits of High Intakes of Vitamin C

11.14.6.1 Iron Absorption

11.14.6.2 Inhibition of Nitrosamine Formation

11.14.6.3 Pharmacological Uses of Vitamin C

11.14.7 Toxicity of Vitamin C

11.15 Marginal Compounds

11.15.1 Carnitine

11.15.2 Choline

11.15.3 Inositol

11.15.4 Taurine

11.15.5 Ubiquinone (Coenzyme Q, “Vitamin Q”)

11.16 Minerals

11.16.1 Calcium

11.16.1.1 Calcium Homeostasis

11.16.1.2 Osteoporosis

11.16.2 Minerals That Function as Prosthetic Groups in Enzymes

11.16.2.1 Cobalt

11.16.2.2 Copper

11.16.2.3 Iron

11.16.2.4 Molybdenum

11.16.2.5 Selenium

11.16.2.6 Zinc

11.16.3 Minerals That Have a Regulatory Role (in Neurotransmission, as Enzyme Activators or in Hormones)

11.16.3.1 Calcium

11.16.3.2 Chromium

11.16.3.3 Iodine

11.16.3.4 Magnesium

11.16.3.5 Manganese

11.16.3.6 Sodium and Potassium

11.16.4 Minerals Known to Be Essential, but Whose Function Is not Known

11.16.4.1 Silicon

11.16.4.2 Vanadium

11.16.4.3 Nickel and Tin

11.16.5 Minerals That Have Effects in the Body, but Whose Essentiality Is Not Established

11.16.5.1 Fluoride

11.16.5.2 Lithium

11.16.5.3 Other Minerals

11.17 Nutritional Anemias

Key Points

Index

Read Less

 

An aparitie	5 Feb. 2021
Autor	David A Bender
Dimensiuni	17.27 x 3.3 x 24.38 cm
Editura	CRC Press
Format	Paperback
ISBN	9780367190811
Limba	Engleza
Nr pag	452