178 ASCORBIC ACID 



B. Chemical Methods 244 



1. Preparation of Sample Extract 244 



2. Estimation of Ascorbic Acid in Sample Extract 247 



C. Physical Methods 257 



VI. Standardization of Activity 259 



VII. Occurrence in Food 261 



A. Untreated Foods 261 



1. Storage of Untreated Foods 264 



B. Processed Foods 265 



1. Boiling, Steaming, and Pressure Cooking 265 



2. Jam (Preserves) 267 



3. Freezing 267 



4. Dehydration 268 



5. Canning and Bottling 268 



6. Assessment of Ascorbic Acid Content of Diets 268 



VIII. Effects of Deficiency in Animals 269 



A. Outstanding Discoveries 269 



B. Gross Effects of Deficiency 270 



C. Pathology 272 



1. Mesenchymal Tissues 272 



2. Muscles 283 



3. Nervous System 285 



4. Circulatory System 286 



5. Other Organs 295 



6. Some General Cytological Aspects of Vitamin C Deficiency . . 301 



D. Functional Aspects 302 



1. Functions, Locus of Action, Mode of Action 302 



2. Relation to Growth 306 



3. Distribution in Organs and Tissues 310 



4. Relation to Metabolism 312 



5. Enzymes Affected by Ascorbic Acid Deficiency 331 



6. Respiration 333 



7. Excretion and Retention 334 



8. Chemotherapeutic, Immunologic, and Allergic Relations. . . . 339 



9. Reproduction 344 



10. Relation to Hormones and Stress 345 



IX. Effects of Deficiency in Human Beings 348 



A. Introduction 348 



B. Clinical Aspects 350 



1. Incidence 350 



2. Prodromata 351 



3. Clinical Deficiency State in the Adult 353 



4. Scurvy in Infancy and Childhood 358 



C. Laboratory Diagnostic Aids 360 



1. Roentgenological Study of the Bones 360 



2. Tests for Capillary Fragility 362 



3. Ascorbic Acid Levels in Blood and Urine 362 



4. Saturation and Tolerance Tests 363 



5. Intradermal Test with Dichlorophcnolindophenol 364 



