1. A Survey of the Essential Biochemical Elements.- 1.1 Essentiality.- 1.1.1 Stimulatory Metals.- 1.1.2 Evolution of the Essential Trace Elements.- 1.2 A Survey of the Biochemistry of the Elements.- 1.2.1 The Nonmetals: Bromine.- 1.2.2 The Metals.- 1.2.3 Pretransition Metals.- 1.2.4 The Alkali Metals; Lithium, Rubidium.- 1.2.5 The Alkaline Earth Metals; Beryllium, Strontium, Barium.- 1.2.6 Remaining Pre-transition Metals.- 1.2.7 The Transition Metals.- 1.2.8 The Post-transition Metals.- 1.2.9 Lanthanides and Actinides.- 1.3 Mechanism of Action of the Essential Ultratrace Elements.- 1.4 Summary.- General References.- Specific References.- 2. The Discovery of the Essential Trace Elements: An Outline of the History of Biological Trace Element Research.- 2.1 Introduction.- 2.2 Classification of the Bioelements.- 2.3 The Concept of Essentiality.- 2.4 Trace Element Discoveries from 1925 to 1956.- 2.4.1 Copper.- 2.4.2 Manganese.- 2.4.3 Zinc.- 2.4.4 Cobalt.- 2.4.5 Molybdenum.- 2.5 Discoveries from 1956 to 1978: The Era of Klaus Schwarz.- 2.5.1 Selenium.- 2.5.2 Chromium.- 2.5.3 Tin.- 2.5.4 Vanadium.- 2.5.5 Fluoride.- 2.5.6 Silicon.- 2.5.7 Nickel.- 2.5.8 Lead, Cadmium, and Arsenic.- 2.6 Current Trends and Problems.- References.- 3. Iodine.- 3.1 Introduction.- 3.2 Chemistry of Iodine and Iodoamino Acids.- 3.2.1 Properties of Iodine.- 3.2.2 Iodine Isotopes.- 3.2.3 Important Chemical and Biochemical Reactions of Iodine.- 3.2.4 Iodotyrosines and Iodothyronines.- 3.3 Iodine Metabolism.- 3.3.1 Iodine Absorption, Evolution, and Thyroid Hormone Biosynthesis.- 3.3.2 Thyroid Hormones in Blood.- 3.3.3 Thyroid Hormones in Peripheral Tissues.- 3.3.4 Iodine Deficiency.- 3.3.5 Iodine Toxicity.- 3.4 Mechanism of Action of Thyroid Hormones.- 3.4.1 General and Cellular Effects.- 3.4.2 Structure-Activity Relationships.- 3.5 Summary.- References.- 4. Fluorine.- 4.1 Introduction.- 4.2 Fluoride in Cells and Tissues.- 4.2.1 Mineralized Tissues.- 4.2.2 Cells and Soft Tissues.- 4.2.3 Extracellular Fluid.- 4.3 Fluoride Deficiency and Function.- 4.3.1 Deficiency.- 4.3.2 Functions of Fluoride.- 4.4 Metabolism and Toxicity of Fluoride.- 4.4.1 Metabolism.- 4.4.2 Toxicity.- 4.5 Summary.- References.- 5. Manganese.- 5.1 Introduction.- 5.2 Manganese Concentration in Animal Tissues.- 5.3 Metabolism of Manganese.- 5.3.1 Absorption.- 5.3.2 Transport and Tissue Distribution.- 5.3.3 Excretion.- 5.4 Biochemistry of Manganese.- 5.4.1 Manganese Chemistry.- 5.4.2 Manganese as a Cofactor and in Metalloenzymes.- 5.4.3 Manganese and Carbohydrate Metabolism.- 5.4.4 Manganese and Lipid Metabolism.- 5.4.5 Manganese and Brain Function.- 5.5 Manganese Nutrition.- 5.5.1 Manganese Deficiency.- 5.5.2 Genetic Interactions and Manganese Metabolism.- 5.5.3 Human Requirements.- 5.5.4 Manganese Content of Foods.- 5.6 Manganese Toxicity.- 5.7 Manganese in Relation to Immunocompetence and Cancer.- 5.8 Summary.- References.- 6. Cobalt.- 6.1 Introduction and History.- 6.2 Cobalt and Its Compounds in Cells and Tissues.- 6.2.1 Cobalt in Soils.- 6.2.2 Cobalt in Plants.- 6.2.3 Cobalt in Animals.- 6.3 Cobalt Deficiency and Function.- 6.3.1 Cobalt in Animal Nutrition.- 6.3.2 Cobalt in Human Nutrition.- 6.4 Metabolism and Toxicity of Cobalt.- 6.4.1 Effect of Cobalt on Plants.- 6.4.2 Effect of Cobalt on Animals.- 6.4.3 Effect of Cobalt on Microorganisms.- 6.4.4 Toxicity of Cobalt.- 6.5 Conclusion.- References.- 7. Molybdenum.- 7.1 Introduction and History.- 7.2 Molybdenum and Its Compounds in Cells and Tissues.- 7.2.1 Molybdenum-Containing Enzymes.- 7.2.2 The Molybdenum Cofactor.- 7.2.3 General Aspects of Molybdenum Biochemistry.- 7.3 Nutritional Aspects of Molybdenum.- 7.3.1 Molybdenum in the Diet.- 7.3.2 Molybdenum Deficiency.- 7.3.3 Molybdenum Toxicity.- 7.4 Conclusion.- 7.5 Summary.- References.- 8. Chromium.- 8.1 Introduction.- 8.2 Chromium: Physical and Chemical Properties.- 8.3 Biologically Active Chromium.- 8.4 Absorption and Transport of Chromium.- 8.5 Chromium Occurrence in Blood, Tissues, and Hair.- 8.5.1 Blood.- 8.5.2 Tissues.- 8.5.3 Hair.- 8.6 Chromium Excretion.- 8.7 Functions of Chromium and Signs of Chromium Deficiency.- 8.8 Factors Affecting Chromium Metabolism.- 8.9 Chromium and Stress.- 8.10 Dietary Requirements of Chromium.- 8.11 Effects of Chromium Supplementation.- 8.12 Toxicity of Chromium.- 8.13 Summary.- References.- 9. Selenium.- 9.1 Introduction and History.- 9.2 Selenium and its Compounds in Cells and Tissues.- 9.2.1 Low Molecular Weight Compounds.- 9.2.2 Macromolecular Weight Compounds.- 9.3 Selenium Deficiency and Function.- 9.3.1 Dietary Liver Necrosis and Factor 3.- 9.3.2 Hepatosis Dietetica.- 9.3.3 Nutritional Muscular Dystrophy.- 9.3.4 Exudative Diathesis.- 9.3.5 Pancreatic Regeneration.- 9.3.6 Mulberry Heart Disease.- 9.3.7 Reproductive Problems.- 9.3.8 Myopathy of the Gizzard.- 9.3.9 Growth.- 9.3.10 Selenium-Responsive Unthriftiness of Sheep and Cattle.- 9.3.11 Periodontal Diseases of Ewes.- 9.3.12 Encephalomalacia.- 9.4 Metabolism and Toxicity of Selenium.- 9.4.1 Absorption.- 9.4.2 Excretion.- 9.4.3 Placental Transfer.- 9.4.4 Mechanism of the Antioxidant Action of Selenium.- 9.4.5 Interactions of Selenium with Other Substances.- 9.4.6 Toxicity of Selenium.- 9.5 Summary.- References.- 10. Vanadium.- 10.1 Introduction and History.- 10.1.1 Discovery and History.- 10.1.2 Occurrence and Distribution.- 10.1.3 Nuclear and Chemical Characteristics.- 10.1.4 Essentiality.- 10.2 Vanadium in Tissues.- 10.2.1 Vanadium in Plants and Plant Products.- 10.2.2 Vanadium in Tunicates, Crustaceans, Shellfish, and Fish.- 10.2.3 Human Intakes of Vanadium.- 10.2.4 Vanadium Levels in Human Beings.- 10.3 Vanadium Deficiency and Function.- 10.3.1 Growth.- 10.3.2 Reproduction.- 10.3.3 Nutritional Edema.- 10.3.4 Manic-Depressive Illness.- 10.3.5 Dental Caries.- 10.3.6 Inotropic Effects of Vanadium.- 10.3.7 Vanadium and Renal Function.- 10.3.8 Vanadium and Glucose Metabolism.- 10.3.9 Vanadium and Lipid Metabolism.- 10.3.10 Vanadium and ATPases.- 10.3.11 Additional Effects of Vanadium.- 10.4 Vanadium Metabolism.- 10.4.1 Absorption of Vanadium.- 10.4.2 Tissue Distribution of Vanadium.- 10.4.3 Effects of Hormones on Vanadium Metabolism.- 10.4.4 Excretion of Vanadium.- 10.5 Vanadium Toxicity.- 10.5.1 Factors Affecting Toxicity of Vanadium.- 10.5.2 Toxicity in Chicks, Rats, and Sheep.- 10.5.3 Toxicity in Human Beings.- 10.6 Summary.- References.- 11. Silicon.- 11.1 Introduction.- 11.1.1 Discovery and History.- 11.1.2 Occurrence and Distribution.- 11.1.3 Chemistry.- 11.1.4 Essentiality.- 11.2 Silicon in Tissues.- 11.2.1 Primitive Organisms.- 11.2.2 Higher Plants.- 11.2.3 Animals and Man.- 11.3 Silicon Deficiency and Functions.- 11.3.1 Growth and Development.- 11.3.2 Calcification.- 11.3.3 Bone Formation.- 11.3.4 Cartilage and Connective Tissue Formation.- 11.3.5 Connective Tissue Matrix.- 11.3.6 Enzyme Activity.- 11.3.7 Connective Tissue Cellular Component.- 11.3.8 Structural Component.- 11.3.9 Aging.- 11.4 Metabolism.- 11.4.1 Absorption.- 11.4.2 Transport.- 11.4.3 Excretion.- 11.4.4 Interaction with Molybdenum.- 11.4.5 Enzyme Interaction.- 11.5 Toxicity.- 11.5.1 Pneumoconioses in Man.- 11.5.2 Silicosis.- 11.5.3 Asbestosis.- 11.5.4 Renal Toxicity.- 11.6 Summary.- References.- 12. Nickel.- 12.1 Introduction and History.- 12.2 Nickel and Its Compounds in Cells and Tissues.- 12.3 Nickel Deficiency.- 12.4 Nickel Function.- 12.5 Biological Interactions between Nickel and Other Trace Elements.- 12.6 Nickel Metabolism and Toxicity.- 12.7 Summary.- References.- 13. Tin.- 13.1 Introduction.- 13.2 Tin in Cells and Tissues.- 13.2.1 Chemical Properties.- 13.2.2 Distribution in Mammalian Tissues.- 13.3 Deficiency and Function.- 13.4 Metabolism and Toxicity.- 13.4.1 Inorganic Tin.- 13.4.2 Organotin Compounds.- 13.5 Summary.- References.- 14. Arsenic.- 14.1 Introduction and History.- 14.2 Arsenic and Its Compounds in Cells and Tissues.- 14.3 Arsenic Deficiency and Interaction with Other Nutrients.- 14.4 Arsenic Function.- 14.5 Arsenic Metabolism.- 14.6 Arsenic Toxicity.- 14.7 Summary.- References.- 15. Cadmium.- 15.1 Introduction.- 15.1.1 Historical Perspectives and Properties of Cadmium.- 15.1.2 Metallothionein and Its Interactions with Cadmium.- 15.2 Chemistry of Cadmium: Biological Perspectives.- 15.2.1 General Chemical Properties of Cadmium.- 15.2.2 Biological Implications.- 15.3 Evidence for the Possible Essentiality of Cadmium.- 15.4 Metabolism of Cadmium.- 15.4.1 Absorption of Cadmium.- 15.4.2 Transport of Cadmium in Blood.- 15.4.3 Organ, Tissue, and Subcellular Distribution of Cadmium.- 15.4.4 Cadmium Excretion.- 15.5 Biochemical Effects of Cadmium.- 15.5.1 Nucleic Acid and Protein Synthesis.- 15.5.2 Induction of Thionein by Cadmium.- 15.5.3 Other Biochemical Effects of Cadmium.- 15.6 Summary.- References.- 16. Lead.- 16.1 Introduction and History.- 16.2 Metabolism of Lead.- 16.2.1 Occurrence and Intake.- 16.2.2 Absorption of Lead.- 16.2.3 Excretion of Lead.- 16.2.4 Transport and Distribution.- 16.2.5 Interactions.- 16.3 Lead Deficiency.- 16.4 Toxicity of Lead.- 16.4.1 Hematologic Effects of Toxic Lead Doses.- 16.4.2 Neurotoxic Effects of Lead.- 16.4.3 Renal Effects of Toxic Lead.- 16.4.4 Intranuclear Inclusion Body.- 16.4.5 Mutagenic, Mitogenic, and Teratogenic Effects of Lead.- 16.5 Conclusions.- References.- 17. Boron.- 17.1 Boron in Biology.- 17.1.1 Introduction.- 17.1.2 Criteria for Essentiality.- 17.1.3 Effect of Boron on the Growth of Organisms.- 17.1.4 Plant Evolution and an Essential Role for Boron.- 17.1.5 Boron Toxicity.- 17.1.6 Problems Associated with Studies of BoronMetabolism.- 17.1.7 10B (n, a) 7Li Nuclear Reaction.- 17.1.8 Therapeutic Uses for Boron and Organoborates in Medicine.- 17.2 Carbohydrate Metabolism.- 17.2.1 Boron Complexes.- 17.2.2 Sugar Translocation.- 17.2.3 Photosynthesis.- 17.2.4 Respiration.- 17.2.5 Starch.- 17.2.6 Cellulose and Cell Wall Glucans.- 17.2.7 Phenols.- 17.2.8 Lignin.- 17.2.9 Boron in Enzymic Reactions.- 17.2.10 Pollen Germination.- 17.2.11 Conclusions.- 17.3 Hormone Action.- 17.4 Membrane Structure and Function.- 17.5 Nucleic Acid Biosynthesis.- 17.6 Summary.- References.