| vitamin d-resistant rickets | <radiology> X-linked recessive, defect in renal tubular resorption of phosphate, presents at 1 yr, progressive limb deformities X-ray: less severe changes than other rickets, presents later Differential diagnosis features: family hx, normal serum calcium, marked hypophosphataemia (decreased PO4), no secondary hyperparathyroidism (12 Dec 1998) |
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| vitamin D unit | The antirachitic activity contained in 0.025 ug of a preparation of crystalline vitamin D3 (activated 7-dehydrocholesterol). See: Steenbock unit. (05 Mar 2000) |
| vitamin E | <biochemistry> Functions as an antioxidant, binds oxygen free radicals that can cause tissue damage, may also play a protective role in the coronary arteries from the damaging effects of cholesterol. (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 E unit | Potency usually expressed in terms of weight of pure alpha-tocopherol. (05 Mar 2000) |
| vitamin F | Term sometimes applied to the essential unsaturated fatty acids, linoleic, linolenic, and arachidonic acids. (05 Mar 2000) |
| vitamin G | An obsolete term for riboflavin. (05 Mar 2000) |
| vitamin H | <biochemistry> A prosthetic group for carboxylase enzymes. Important in fatty acid biosynthesis and catabolism and has found widespread use as a covalent label for macromolecules which may then be detected by high affinity binding of labelled avidin or streptavidin. Essential growth factor for many cells. (18 Nov 1997) |
| vitamin K | <biochemistry> A fat soluble vitamin that plays an important role in blood clotting. (27 Sep 1997) |
| vitamin K1 | Vitamin K1 or K1(20); 2-methyl-3-phytyl-1,4-naphthoquinone; 3-phytylmenaquinone; isolated from alfalfa;also prepared synthetically; major form of vitamin K found in plants. Synonym: phytomenadione, phytonadione, vitamin K1, vitamin K1(20). (05 Mar 2000) |
| vitamin K2 | Hexaprenylmenaquinone; prenylmenaquinone-6; 2-methyl-3-hexaprenyl-1,4-naphthoquinone;isolated from putrified fish meal; potency is about 60% of that of phylloquinone (vitamin K1). Synonym: farnoquinone, vitamin K2, vitamin K2(30). (05 Mar 2000) |
| vitamin K2(35) | Menaquinone-6 with a 3-heptaprenyl side chain. Synonym: vitamin K2(35). (05 Mar 2000) |
| vitamin K3 | A fat soluble vitamin that plays an important role in blood clotting. (27 Sep 1997) |
| vitamin K4 | 2-Methyl-1,4-naphthohydroquinone diacetate;menadiol acetylated at both OH groups; a prothrombogenic vitamin. Synonym: acetomenaphthone, vitamin K4. (05 Mar 2000) |
| vitamin K5 | 4-amino-2-methyl-1-naphthol;an antihemorrhagic vitamin. (05 Mar 2000) |