tailieunhanh - Chapter 071. Vitamin and Trace Mineral Deficiency and Excess (Part 11)

Vitamin E Deficiency: Treatment Symptomatic vitamin E deficiency should be treated with 800–1200 mg of αtocopherol per day. Patients with abetalipoproteinemia may need as much as 5000–7000 mg/d. Children with symptomatic vitamin E deficiency should be treated with 400 mg/d orally of water-miscible esters; alternatively, 2 mg/kg per d may be administered intramuscularly. Vitamin E in high doses may protect against oxygen-induced retrolental fibroplasia and bronchopulmonary dysplasia, as well as intraventricular hemorrhage of prematurity. Vitamin E has been suggested to increase sexual performance, to treat intermittent claudication, and to slow the aging process, but evidence for these properties is lacking | Chapter 071. Vitamin and Trace Mineral Deficiency and Excess Part 11 Vitamin E Deficiency Treatment Symptomatic vitamin E deficiency should be treated with 800-1200 mg of atocopherol per day. Patients with abetalipoproteinemia may need as much as 5000-7000 mg d. Children with symptomatic vitamin E deficiency should be treated with 400 mg d orally of water-miscible esters alternatively 2 mg kg per d may be administered intramuscularly. Vitamin E in high doses may protect against oxygen-induced retrolental fibroplasia and bronchopulmonary dysplasia as well as intraventricular hemorrhage of prematurity. Vitamin E has been suggested to increase sexual performance to treat intermittent claudication and to slow the aging process but evidence for these properties is lacking. When given in combination with other antioxidants vitamin E may help to prevent macular degeneration. High doses 60-800 mg d of vitamin E have been shown in controlled trials to improve parameters of immune function and to reduce colds in nursing home residents but intervention studies using vitamin E to prevent cardiovascular disease or cancer have not shown efficacy and at doses 400 mg d may even increase all-cause mortality. Toxicity All forms of vitamin E are absorbed and could contribute to toxicity. High doses of vitamin E 800 mg d may reduce platelet aggregation and interfere with vitamin K metabolism and are therefore contraindicated in patients taking warfarin. Nausea flatulence and diarrhea have been reported at doses 1 g d. Vitamin K There are two natural forms of vitamin K vitamin K1 also known as phylloquinone from vegetable and animal sources and vitamin K2 or menaquinone which is synthesized by bacterial flora and found in hepatic tissue. Phylloquinone can be converted to menaquinone in some organs. Vitamin K is required for the posttranslational carboxylation of glutamic acid which is necessary for calcium binding to y-carboxylated proteins such as prothrombin factor II factors VII IX