SCURVY

also called Vitamin C Deficiency, one of the oldest known nutritional disorders of humankind, caused by a dietary lack of vitamin C (ascorbic acid), a nutrient found in many fresh fruits and vegetables, particularly the citrus fruits. Vitamin C is required in the diet of humans, though most other vertebrates, lower animals, and plants can synthesize the vitamin from glucose. Ascorbic acid is important in the formation of collagen (an element of normal tissues), and any deficiency interferes with normal tissue synthesis, a problem that underlies the clinical manifestations of the disorder. Scurvy is characterized by swollen and bleeding gums with loosened teeth, soreness and stiffness of the joints and lower extremities, bleeding under the skin and in deep tissues, slow wound healing, and anemia. Although accounts of what was probably scurvy are found in ancient writings, the first clear-cut descriptions appear in the records of the medieval Crusades. Later, toward the end of the 15th century, scurvy became the major cause of disability and mortality among sailors on long sea voyages. Not until 1753 was scurvy recognized as related to diet and the concept of deficiency diseases established for the first time, when the Scottish naval surgeon James Lind showed that scurvy could be cured and prevented by ingestion of the juice of oranges, lemons, or limes. In modern times, full-blown cases of vitamin C deficiency have become relatively rare; in the United States, they may still be seen in isolated elderly adults, usually men whose diet is limited to foods lacking in vitamin C, and in infants fed reconstituted milk or milk substitutes without a vitamin C or orange juice supplement. Symptoms peculiar to infantile scurvy (Barlow's disease) include swelling of the lower extremities, pain upon flexing them, and lesions of the growing bones. Administration of vitamin C is the specific therapy for scurvy. Even in cases of severe deficiency, a daily dose of 100 milligrams for adults or 10 to 25 milligrams for infants and children, accompanied by a normal diet, commonly produces a cure within several days.