Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042875 (vitamin E deficiency)
 916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Subjects with a variety of enteropathies, hemolytic anemias, acute respiratory distress syndrome, hepatitis, Gaucher's disease as well as those on TPN and hemodialysis, often have low ("deficient") blood levels of vitamin E. A deficiency of vitamin E can be manifested by accelerated red blood cell destruction and neuromuscular deficit. Supplementation of these patients may be advisable. Neurological dysfunction has been observed in adults with prolonged vitamin E deficiency resulting from lipid malabsorption. Long-term treatment with high doses of vitamin E results in improvement. Administration of 800 IU/day of vitamin E to subjects with G6PD deficiency, sickle-cell anemia and beta-thalassemia has resulted in improvement of hematological parameters. Supplementation with 300 IU/day for 3-6 months has resulted in improved walking distances and improved blood flow in patients with intermittent claudication. In a limited number of controlled studies, 300-600 IU/day resulted in improvement in premenstrual syndrome, tardive dyskinesia and also arthritis. Epidemiological studies suggest that high levels of serum vitamin E are associated with lower risk of certain cancers, cardiovascular disease and infections. In some cases the high levels are difficult to obtain by diet alone. High levels of vitamin E are contraindicated in subjects who are receiving vitamin K antagonists as anticoagulant therapy. Except for this interaction with vitamin K, there are no specific side effects associated with high doses of vitamin E. Thus, there are various reasons for supplementations with vitamin E and, with the exception noted, the risk of such supplementation is very low.
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PMID:Use and safety of elevated dosages of vitamin E in adults. 250 7

Fish oil supplements are currently being nationally advertised, and many physicians are being queried about their clinical utility. Epidemiologic studies reveal a low incidence of cardiovascular disease in people, such as the Eskimos, who eat large amounts of seafood. Cardiovascular health may be improved because fish and fish oil supplements lower plasma lipid levels (especially triglycerides), inhibit platelet aggregation, and may decrease blood pressure and viscosity and increase high-density lipoprotein (HDL) levels. Preliminary observations also suggest a potential future role for fish oils in the treatment of some autoimmune diseases, such as atopic dermatitis, psoriasis, and rheumatoid arthritis. Patients with serum triglyceride levels greater than 5.64 mmol/L and/or cholesterol levels greater than 7.75 mmol/L refractory to dietary management may benefit from a medically supervised trial of fish oil supplements. Data currently available are insufficient to recommend fish oil supplements for the general public, or for patients with other diseases, and side effects must also be considered. These include occasional adverse lipid changes, potential for bleeding and vitamin E deficiency, and, with some preparations, vitamin A and D toxicity.
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PMID:Clinical applications of fish oils. 291 Nov 58

There is a growing body of evidence implicating free radicals in a wide variety of medical diseases and conditions, especially the diseases of ageing, such as cancer and cardiovascular disease, which appear to be ultimate expressions of long-term, cumulative and sustained cellular damage. Vitamin E is an excellent lipid-soluble, chain-breaking antioxidant in the presence of other co-operative antioxidants such as vitamin C or ubiquinol, but it can act as a pro-oxidant in their absence. Epidemiological findings and animal studies support the belief that vitamin E is protective against cardiovascular disease and possibly cancer. The wide range of symptoms associated with vitamin E deficiency is consistent with a loss of antioxidant protection in those long-lived cells in which there is sufficient opportunity for accumulation of free radical damage. The cellular damage is proposed to arise from the generation of free radicals during normal aerobic metabolism. Some susceptible tissues may have enhanced levels of radicals that are produced, for example, by the action of cytochrome P-450 enzymes in steroidogenic tissues, or by the generation of NO in neural tissues.
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PMID:Vitamin E: molecular and biological function. 797 39

Atherosclerosis is characterised by a wide range of clinical manifestations. Hypercholesterolaemia is an independent risk factor for coronary heart disease, the correction of which with statins decreases the incidence of ischaemic events. Hypertension is a major risk for strokes. Prevention of coronary events by an action on the sole arterial blood pressure has been difficult to establish. Tobacco consumption is mainly involved in the risk of lower-limb arterial disease. Diabetes is a major and global enhancer of cardiovascular disease. Assessment of the other "emerging" risk factors (such as vitamin E deficiency, homocysteine, or the type of alcohol consumed) is still in progress. The level of classical risk factors only accounts for the variations between populations that are observed in the United States and in the Northern European countries.
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PMID:[Epidemiology of atherosclerosis: risks and paradoxes]. 1064 43

Vitamin E is indispensible for reproduction in female rats. In humans, vitamin E deficiency primarily causes neurologic dysfunctions, but the underlying molecular mechanisms are unclear. Because of its antioxidative properties, vitamin E is believed to help prevent diseases associated with oxidative stress, such as cardiovascular disease, cancer, chronic inflammation, and neurologic disorders. However, recent clinical trials undertaken to prove this hypothesis failed to verify a consistent benefit. Given these findings, a group of European scientists met to analyze the most recent knowledge of vitamin E function and metabolism. An overview of their discussions is presented in this article, which includes considerations of the mechanisms of absorption, distribution, and metabolism of different forms of vitamin E, including the alpha-tocopherol transfer protein and alpha-tocopherol-associated proteins; the mechanism of tocopherol side-chain degradation and its putative interaction with drug metabolism; the usefulness of tocopherol metabolites as biomarkers; and the novel mechanisms of the antiatherosclerotic and anticarcinogenic properties of vitamin E, which involve modulation of cellular signaling, transcriptional regulation, and induction of apoptosis. Clinical trials were analyzed on the basis of the selection of subjects, the stage of disease, and the mode of intake, dosage, and chemical form of vitamin E. In addition, the scarce knowledge on the role of vitamin E in reproduction was summarized. In conclusion, the scientists agreed that the functions of vitamin E were underestimated if one considered only its antioxidative properties. Future research on this essential vitamin should focus on what makes it essential for humans, why the body apparently utilizes alpha-tocopherol preferentially, and what functions other forms of vitamin E have.
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PMID:The European perspective on vitamin E: current knowledge and future research. 1232 81

Vitamin E has failed to protect humans from cardiovascular disease outcome, yet its role in experimental atherosclerosis remains less clear. A previous study (Proc. Natl. Acad. Sci. USA 97:13830-13834; 2000) showed that vitamin E deficiency caused by disruption of the alpha-tocopherol transfer protein gene (Ttpa) is associated with a modest increase in atherosclerosis in apolipoprotein E gene deficient (Apoe(-/-)) mice. Here we confirm this finding and report that in Apoe(-/-)Ttpa(-/-) mice dietary alpha-tocopherol (alphaT) supplements restored circulating and aortic levels of alphaT, and decreased atherosclerosis in the aortic root to a level comparable to that seen in Apoe(-/-) mice. However, such dietary supplements did not decrease disease in Apoe(-/-) mice, whereas dietary supplements with a synthetic vitamin E analog (BO-653), either alone or in combination with alphaT, decreased atherosclerosis in Apoe(-/-) and in Apoe(-/-)Ttpa(-/-) mice. Differences in atherosclerosis were not associated with changes in the arterial concentrations of F(2)-isoprostanes and cholesterylester hydro(pero)xides, nor were they reflected in the resistance of plasma lipids to ex vivo oxidation. These results show that vitamin E at best has a modest effect on experimental atherosclerosis in hyperlipidemic mice, and only in situations of severe vitamin E deficiency and independent of lipid oxidation in the vessel wall.
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PMID:Protective effect of vitamin E supplements on experimental atherosclerosis is modest and depends on preexisting vitamin E deficiency. 1689 92

This cross-sectional study assessed the prevalence of malnutrition and several metabolic risk factors for cardiovascular disease in 287 apparently healthy older adults from Northwest Mexico. Also, the impact of overweight and obesity on metabolic risk factors was assessed. Nutritional status was determined using serum albumin levels and anthropometry. Vitamin status was also assessed. Metabolic risk factors for cardiovascular disease were evaluated. The prevalence of undernutrition was 15.3%. Also, vitamin E deficiency was common (18%). On the contrary, 44.9% of men and women were in overweight and 24% were obese. A 50.9% of the older adults had hypertension, 52.6% hypercholesterolemia (HC), 38.3% hypertriglyceridemia (HTG), 26.1% impaired fasting glucose and 26.1% impaired glucose tolerance (IGT). HC and low-density-lipoprotein-cholesterol (LDL-C) were significantly more prevalent in women than in men. Mean adjusted values of fasting glucose, high-density-lipoprotein-cholesterol (HDL-C), total cholesterol (TC)/HDL-C ratio > or = 5, triglycerides (TG) and diastolic blood pressure (DBP) were significantly higher in subjects with body mass index (BMI) > or = 25.0 kg/m(2). Undernutrition, obesity and vitamin E deficiency, as well as several metabolic risk factors for cardiovascular disease coexisted in this studied group. Overweight and obesity were the most prevalent findings. BMI > or = 25 kg/m(2) was the common factor explaining most of the metabolic abnormalities. However, due to the sample size and the design of the study, the results must be seen with caution and cannot be generalized.
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PMID:Prevalence of malnutrition and associated metabolic risk factors for cardiovascular disease in older adults from Northwest Mexico. 1759 34

Vitamin E in nature is comprised of a family of tocopherols and tocotrienols. The most studied of these is alpha-tocopherol (alpha-TOH), because this form is retained within the body, and vitamin E deficiency is corrected with this supplement. alpha-TOH is a lipid-soluble antioxidant required for the preservation of cell membranes, and it potentially acts as a defense against oxidative stress. Many studies have investigated the metabolism, transport, and efficacy alpha-TOH in the prevention of sequelae associated with cardiovascular disease (CVD). Supplementation with vitamin E is considered to provide health benefits against CVD through its antioxidant activity, the prevention of lipoprotein oxidation, and the inhibition of platelet aggregation. However, the results from large prospective, randomized, placebo-controlled clinical trials with alpha-TOH have been largely negative. A recent meta-analysis suggests that alpha-TOH supplements may actually increase all-cause mortality; however, the mechanism for this increased risk is unknown. In vitro studies performed in human cell cultures and animal models suggest that vitamin E might increase the hepatic production of cytochrome P450s and MDR1. Induction of CYP3A4 or MDR1 by vitamin E could potentially lower the efficacy of any drug metabolized by CYP3A4 or MDR1. Other possibilities include an adverse effect of alpha-TOH on blood pressure in high-risk populations. Because of the wide popularity and use of vitamin E supplements, further research into potential adverse effects is clearly warranted.
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PMID:Vitamin E in human health and disease. 1871 29

During aging there is a tendency towards hyperlipidemia and changes in the distribution of lipoproteins. A decline in the functioning of the body's antioxidant defense system is also observed at this time. The objective of this study was to establish the relationship between serum concentrations of total cholesterol and fractions, triglycerides, and Vitamins C and E. 61 adults over 60 years of age were evaluated from January to March, 2006. Nutritional status was diagnosed by BMI (WHO); serum levels of triglycerides (TG), total cholesterol (TC) and fractions (HDL-c and LDL-c) were determined by enzyme method; Vitamin C (colorimetric method) and Vitamin E by HPLC. ATPIII values were used as a reference for risk of TG, TC, HDL, LDL-c, vitamin C: > 0.9 mg/dL (normal), < 0.9 mg/dL (deficit); vitamin E: = 1300 microg/dL (normal), 1300 = microg /dL (deficit). Consumption of vitamins C and E were estimated by the direct weighing method 3 days per week. According to BMI, 19.7% had nutritional deficit, 39.3% overweight, and 11.5% obesity. TG, TC, LDL-c levels were at risk in females, and HDL-c in both genders. Prevalence of risk for heart disease was: TG (45.2%), HDL-c (51.1%), and LDL-c (52.5%). Consumption and serum levels of vitamin E were low in both genders. There was no association between variables. A significant and positive correlation between TG, TC, LDL-C, serum vitamin E, and BMI was observed. The female group showed overweight, hypertriglyceridemia and hypercholesterolemia, HDL-c and LDL-c at risk, and vitamin E deficiency, all of which are important risk factors for cardiovascular disease in this age group.
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PMID:[Relationship between serum lipids and status of vitamin C and E as antioxidants in Venezuelan elderly people]. 1936 97

This review deals with the expectations of vitamin E ability of preventing or curing, as a potent antioxidant, alleged oxidative stress based ailments including cardiovascular disease, cancer, neurodegenerative diseases, cataracts, macular degeneration and more. The results obtained with clinical intervention studies have highly restricted the range of effectiveness of this vitamin. At the same time, new non-antioxidant mechanisms have been proposed. The new functions of vitamin E have been shown to affect cell signal transduction and gene expression, both in vitro and in vivo. Phosphorylation of vitamin E, which takes place in vivo, results in a molecule provided with functions that are in part stronger and in part different from those of the non-phosphorylate compound. The in vivo documented functions of vitamin E preventing the vitamin E deficiency ataxia (AVED), slowing down the progression of non-alcoholic steato-hepatitis (NASH), decreasing inflammation and potentiating the immune response are apparently based on these new molecular mechanisms. It should be stressed however that vitamin E, when present at higher concentrations in the body, should exert antioxidant properties to the extent that its chromanol ring is unprotected or un-esterified.
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PMID:The rise, the fall and the renaissance of vitamin E. 2709 24


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