Manifestations of vitamin E deficiency includes all except:
Ref: Harrison's Principles of Internal Medicine, 18edExplanation:Vitamin Eit includes ail stereoisomers of tocopherols and tocotrienols.Vitamin E acts as a chain-breaking antioxidant and is an efficient pyroxyl radical scavenger that protects low-density lipoproteins (LDLs) and polyunsaturated fats in membranes from oxidation.A network of other antioxidants (e.g.. vitamin C. glutathione) and enzymes maintains vitamin E in a reduced state.Vitamin E also inhibits prostaglandin synthesis and the activities of protein kinase C and phospholipase .42.Absorption and MetabolismAfter absorption, vitamin E is taken up from chylomicrons by the liver, and a hepatic - tocopherol transport protein mediates intracellular vitamin E transport and incorporation into very low density lipoprotein (VLDL).The transport protein has particular affinity for the RRR isomeric form of -tocopherol; thus, this natural isomer has the most biologic activity.RequirementThe RDA for vitamin E is 15 mg/d (34.9 mol or 22.5 IU) for all adults.Dietary deficiency of vitamin E does not exist.Vitamin E deficiency is seen along with certain diseases.Prolonged malabsorptive diseasesCeliac diseaseSmall-intestinal resection Cystic fibrosisProlonged cholestasisAbetalipoproteinemiaFamilial isolated vitamin E deficiency (Detect in the -tocopherol transport protein)Clinical FeaturesAreflexiaHemolytic anemiaAxonal degeneration of the large myelinated axonsPosterior column and spinocerebellar symptomsPeripheral neuropathyAtaxic gaitDecreased vibration and position sensations.OphthalmoplegiaSkeletal myopathyPigmented retinopathyThe laboratory diagnosis of vitamin E deficiency is made on the basis of low blood levels of - Tocopherol (<5 g/mL, or <0.8 mg of - tocopherol per gram of total lipids).Treatment: Vitamin E DeficiencySymptomatic vitamin E deficiency - 800-1200 mg of -tocopherol per day.Patients with abetalipoproteinemia need high doses- 5000-7000 mg/d.Children - 400 mg/d orallyToxicityHigh doses of vitamin E (>800 mg/d)Nausea, flatulence, and diarrheaReduced platelet aggregationInterfere w ith vitamin K metabolismContraindicated in patients taking warfarin and antiplatelet agents (such as aspirin or clopidogrel).
Hemolysis
Testicular atrophy
Neurological involvement
Thrombocytopenia
Immunology and Rheumatology