词条 | scurvy |
释义 | scurvy pathology 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 important in the formation of collagen (an element of normal tissues), and any deficiency of the vitamin 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. In 1753 Scottish naval surgeon James Lind (Lind, James) showed that scurvy could be cured and prevented by ingestion of the juice of oranges and lemons. Soon Citrus fruits became so common aboard ship that British sailors were referred to as “limeys.” In modern times, full-blown cases of vitamin C deficiency are relatively rare; they may still be seen in isolated elderly adults, in people following restrictive diets, and in infants fed reconstituted milk or milk substitutes without a vitamin C or orange juice supplement. Symptoms peculiar to infantile scurvy (Barlow disease) include swelling and pain of the lower extremities 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 mg (1 mg = 0.001 gram) for adults or 10 to 25 mg for infants and children, accompanied by a normal diet, commonly produces a cure within several days. |
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