| vitamin a deficiency | A nutritional condition produced by a deficiency of vitamin a in the diet, characterised by night blindness and other ocular manifestations such as dryness of the conjunctiva and later of the cornea (xerophthalmia). Vitamin a deficiency is a very common problem worldwide, particularly in developing countries as a consequence of famine or shortages of vitamin a-rich foods. In the united states it is found among the urban poor, the elderly, alcoholics, and patients with malabsorption. (12 Dec 1998) |
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| vitamin B12 deficiency | A form of anaemia (low red blood cell counts) that results when the bone marrow fails to produce adequate numbers of red blood cells due to a deficiency in vitamin B12. Intrinsic factor, necessary for normal B12 absorption, may be the underlying cause for B12 deficiency if is not produced in the gastric glands (in the stomach). (27 Sep 1997) |
| vitamin b 12 deficiency | A nutritional condition produced by a deficiency of vitamin b 12 in the diet, characterised by megaloblastic anaemia. Since vitamin b 12 is not present in plants, humans have obtained their supply from animal products, from multivitamin supplements in the form of pills, and as additives to food preparations. A wide variety of neuropsychiatric abnormalities is also seen in vitamin b 12 deficiency and appears to be due to an undefined defect involving myelin synthesis. (12 Dec 1998) |
| vitamin B6 deficiency | Member of the water soluble B vitamin group. Vitamin B6 or pyridoxine, is active in the metabolism of proteins, carbohydrates and fats. It is also a necessary part of haemoglobin synthesis. B6 deficiency results in retarded growth and a peripheral neuropathy. (27 Sep 1997) |
| vitamin C deficiency | A disease due to the deficiency of vitamin C (ascorbic acid). Symptoms include weakness, anaemia, spongy gums and mucocutaneous bleeding (mouth ulcers). Synonym: scurvy. (27 Sep 1997) |
| vitamin D deficiency | A vitamin D deficiency disease of infancy or childhood with a disturbance of the normal process of ossification and bone growth. Often manifests with bone deformity. (27 Sep 1997) |
| vitamin e deficiency | A nutritional condition produced by a deficiency of vitamin e in the diet, characterised by posterior column and spinocerebellar tract abnormalities, areflexia, ophthalmoplegia, and disturbances of gait, proprioception, and vibration. In premature infants vitamin e deficiency is associated with haemolytic anaemia, thrombocytosis, oedema, intraventricular haemorrhage, and increasing risk of retrolental fibroplasia and bronchopulmonary dysplasia. An apparent inborn error of vitamin e metabolism, named familial isolated vitamin e deficiency, has recently been identified. (cecil textbook of medicine, 19th ed, p1181) (12 Dec 1998) |
| vitamin k deficiency | A nutritional condition produced by a deficiency of vitamin k in the diet, characterised by an increased tendency to haemorrhage (haemorrhagic diathesis). Such bleeding episodes may be particularly severe in newborn infants. (12 Dec 1998) |
| antibody deficiency disease | <syndrome> Any of a group of disorders associated with a defective antibody production due to defects in the B-type lymphocyte system or in T-type lymphocytes; chief manifestation is an increased susceptibility to infection by various microorganisms. See: agammaglobulinaemia, hypogammaglobulinaemia, immunodeficiency. Synonym: antibody deficiency disease. (05 Mar 2000) |
| deficiency disease | Any disease resulting from undernutrition or an inadequacy of calories, proteins, essential amino acids, fatty acids, vitamins, or trace minerals. (05 Mar 2000) |
| thrombotic disease due to protein c deficiency | Protein C is a protein in plasma that enters into the cascade of biochemical events leading to the formation of a clot. Deficiency of protein c results in thrombotic (clotting) disease and excess platelets with recurrent thrombophlebitis (inflammation of the vein that occurs when a clot forms). The clot can break loose and travel through the blood stream (thromboembolism) to the lungs causing a pulmonary embolism, brain causing a stroke (cerebrovascular accident), heart causing an early heart attack, skin causing what in the newborn is called neonatal purpura fulminans, the adrenal gland causing haemorrhage with abdominal pain, abnormally low blood pressure (hypotension), and salt loss. Protein c deficiency is due to possession of one gene (heterozygosity) in chromosome band 2q13-14. The possession of two such genes (homozygosity) is usually lethal. (12 Dec 1998) |
| antiberiberi vitamin | A member of the water-soluble B vitamin group, necessary for energy production and carbohydrate metabolism. Deficiency is known as beriberi. (27 Sep 1997) |
| antihemorrhagic vitamin | <biochemistry> A fat soluble vitamin that plays an important role in blood clotting. (27 Sep 1997) |
| antineuritic vitamin | A member of the water-soluble B vitamin group, necessary for energy production and carbohydrate metabolism. Deficiency is known as beriberi. (27 Sep 1997) |
| antiscorbutic vitamin | <biochemistry> A requisite in the diet of man and guinea pigs. May act as a reducing agent in enzymic reactions, particularly those catalysed by hydroxylases. Synonym: Vitamin C. (18 Nov 1997) |