Taking excessive dietary supplements that contain vitamin e may lead to uncontrolled bleeding.
UsesVitamin E is an antioxidant that protects cell membranes and other fat-soluble parts of the body, such as low-density lipoprotein (LDL; “bad” cholesterol) cholesterol, from damage. Show
What Are Star Ratings? Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people. For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being. 3 Stars Reliable and relatively consistent scientific data showing a substantial health benefit. 2 Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit. 1 Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support. This supplement has been used in connection with the following health conditions:
How It WorksHow to Use ItThe recommended dietary allowance for vitamin E is low, just 15 mg or approximately 22 International Units (IU) per day. The most commonly recommended amount of supplemental vitamin E for adults is 400 to 800 IU per day. However, some leading researchers suggest taking only 100 to 200 IU per day, since trials that have explored the long-term effects of different supplemental levels suggest no further benefit beyond that amount. In addition, research reporting positive effects with 400 to 800 IU per day has not investigated the effects of lower intakes.1 For tardive dyskinesia, the best results have been achieved from 1,600 IU per day,2 a large amount that should be supervised by a healthcare practitioner. Where to Find ItWheat germ oil, nuts and seeds, whole grains, egg yolks, and leafy green vegetables all contain vitamin E. Certain vegetable oils should contain significant amounts of vitamin E. However, many of the vegetable oils sold in supermarkets have had the vitamin E removed in processing. The high amounts found in supplements, often 100 to 800 IU per day, are not obtainable from eating food. Possible DeficienciesSevere vitamin E deficiencies are rare. People with a genetic defect in a vitamin E transfer protein have severe vitamin E deficiency, characterized by low blood and tissue levels of vitamin E and progressive nerve abnormalities.3, 4 Low vitamin E status has been associated with an increased risk of rheumatoid arthritis5 and major depression.6 Women with preeclampsia have been found to have lower blood levels of vitamin E than women without the condition.7 Very old people with type 2 diabetes have shown a significant age-related decline in blood levels of vitamin E, irrespective of their dietary intake.8 Best Form to TakeVitamin E occurs naturally as eight separate compounds (four tocopherols and four tocotrienols) with antioxidant activity. Most clinical research has focused on one of these compounds—alpha-tocopherol. The naturally occurring form of alpha-tocopherol is called D-alpha-tocopherol (or RRR-alpha tocopherol), and the synthetic form is called DL-alpha-tocopherol (or all-rac-alpha tocopherol). Although many studies have shown benefits from the synthetic form, the synthetic form contains isomers not normally found in the human body. Therefore, the naturally-occurring form—D-alpha-tocopherol—might be the preferred form.9 In addition, there is some evidence that supplements containing a mixture of all four vitamin E tocopherols (alpha, beta, gamma, and delta) may be safer and more effective than D-alpha-tocopherol by itself. One researcher has recommended that these mixed tocopherol supplements contain 50 to 100 mg of gamma-tocopherol per 400 IU of D-alpha-tocopherol. Also, water-miscible preparations of vitamin E may be better absorbed than fat-soluble preparations.10 InteractionsInteractions with Supplements, Foods, & Other CompoundsPatients on kidney dialysis who are given injections of iron frequently experience “oxidative stress.” This is because iron is a pro-oxidant, meaning that it interacts with oxygen molecules in ways that may damage tissues. These adverse effects of iron therapy may be counteracted by supplementation with vitamin E.11 A diet high in unsaturated fat increases vitamin E requirements. Interactions with MedicinesCertain medicines interact with this supplement. Types of interactions: Beneficial Adverse Check Replenish Depleted Nutrients
Reduce Side Effects
Support Medicine
Reduces Effectiveness
Potential Negative Interaction
Explanation Required
The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers’ package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a supplement with your doctor or pharmacist. Side EffectsSide EffectsVitamin E toxicity is very rare and supplements are widely considered to be safe. The National Academy of Sciences has established the daily tolerable upper intake level for adults to be 1,000 mg of vitamin E, which is equivalent to 1,500 IU of natural vitamin E or 1,100 IU of synthetic vitamin E.12 In a double-blind study of healthy elderly people, supplementation with 200 IU of vitamin E per day for 15 months had no effect in the incidence of respiratory infections, but increased the severity of those infections that did occur.13 For elderly individuals, the risks and benefits of taking this vitamin should be assessed with the help of a doctor or nutritionist. In contrast to trials suggesting vitamin E improves glucose tolerance in people with diabetes, one trial reported that 600 IU per day of vitamin E led to impairment in glucose tolerance in obese people with diabetes.14 The reason for the discrepancy between reports is not known. In a double-blind study of people with established heart disease or diabetes, participants who took 400 IU of vitamin E per day for an average of 4.5 years developed heart failure significantly more often than did those taking a placebo.15 Hospitalizations for heart failure occurred in 5.8% of those in the vitamin E group, compared with 4.2% of those in the placebo group, a 38.1% increase. Considering that some other studies have shown a beneficial effect of vitamin E against heart disease, the results of this study are difficult to interpret. Nevertheless, individuals with heart disease or diabetes should consult their doctor before taking vitamin E. A review of 19 clinical trials of vitamin E supplementation concluded that long-term use of large amounts of vitamin E (400 IU per day or more) was associated with a small (4%) but statistically significant increase in risk of death.16 Long-term use of less than 400 IU per day was associated with a small and statistically nonsignificant reduction in death rates. This research has been criticized because many of the studies on which it was based used a combination of nutritional supplements, not just vitamin E. For example, the adverse effects reported in some of the studies may have been due to the use of large amounts of zinc or synthetic beta-carotene, and may have had nothing to do with vitamin E. It is also possible that long-term use of large amounts of pure alpha-tocopherol may lead to a deficiency of gamma-tocopherol, with potential negative consequences. For that reason, some doctors recommend that people who need to take large amounts of vitamin E take at least part of it in the form of mixed tocopherols. References1. Rimm E. Micronutrients, Coronary Heart disease and cancer: Should we all be on supplements? Presented at the 60th Annual Biology Colloquium, Oregon State University, February 25, 1999. 2. Hashim S, Sajjad A. Vitamin E in the treatment of tardive dyskinesia: a preliminary study over 7 months at different doses. Int Clin Psychopharmacol 1988;13:147-55. 3. Traber MG. Vitamin E. In: Shils ME, Olsen JA, Shike M, Ross AC (eds). Modern Nutrition in Health and Disease. Baltimore: Williams & Wilkins, 1999, 347-62. 4. Cavalier L, Ouahchi K, Kayden HJ, et al. Ataxia with isolated vitamin E deficiency: heterogeneity of mutations and phenotypic variability in a large number of families. Am J Hum Genet 1998;62:301-10. 5. Knekt P, Heliovaara M, Aho K, et al. Serum selenium, serum alpha-tocopherol, and the risk of rheumatoid arthritis. Epidemiology 2000;11:402-5. 6. Maes M, De Vos N, Pioli R, et al. Lower serum vitamin E concentrations in major depression. Another marker of lowered antioxidant defenses in that illness. J Affect Disord 2000;58:241-6. 7. Kharb S. Total free radical trapping antioxidant potential in pre-eclampsia. Int J Gynaecol Obstet 2000;69:23-6. 8. Polidori MC, Mecocci P, Stahl W, et al. Plasma levels of lipophilic antioxidants in very old patients with type 2 diabetes. Diabetes Metab Res Rev 2000;16:15-9. 9. Gaby, AR. Nutritional Medicine. Concord, NH: Fritz Perlberg Publishing, 2011. 10. Gaby, AR. Nutritional Medicine. Concord, NH: Fritz Perlberg Publishing, 2011. 11. Roob JM, Khoschsorur G, Tiran A, et al. Vitamin E attenuates oxidative stress induced by intravenous iron in patients on hemodialysis. J Am Soc Nephrol 2000;11:539-49. 12. Panel on Dietary Antioxidants and Related Compounds, Food and Nutrition Board, Institute of Medicine, National Academy of Sciences. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. National Academy Press, Washington, D.C., 2000. 13. Graat JM, Schouten EG, Kok FJ. Effect of daily vitamin E and multivitamin-mineral supplementation on acute respiratory tract infections in elderly persons: a randomized controlled trial. JAMA 2002;288:715-21. 14. Skrha J, Sindelka G, Kvasnicka J, Hilgertova J. Insulin action and fibrinolysis influenced by vitamin E in obese type 2 diabetes mellitus. Diabetes Res Clin Pract 1999;44:27-33. 15. Zoler ML. Supplemental vitamin E linked to heart failure. Fam Pract News 2003 (October 1):28 [News report]. 16. Miller ER III, Pastor-Barriuso R, Dalal D, et al. Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality. Ann Intern Med 2005;142:37-46. Can vitamin E cause bleeding?Vitamin E toxicity is rare, but occasionally high doses cause a risk of bleeding, as well as muscle weakness, fatigue, nausea, and diarrhea. The greatest risk from vitamin E toxicity is bleeding. Diagnosis is based on a person's symptoms.
What happens if we take excess of vitamin E?Vitamin E toxicity can cause major bleeding events. These can be serious, including the potential for intracranial hemorrhage. To avoid the morbidity and mortality that can be associated with vitamin E toxicity, it is important to identify the cause and know how to treat it.
How does vitamin E affect bleeding?Vitamin E has been heralded for its ability to reduce the risk of blood clots, heart attack, and sudden death. Yet in some people, vitamin E causes bleeding. Scientists have known for more than 50 years that excess vitamin E promotes bleeding by interfering with vitamin K, which is essential in blood clotting.
Does vitamin E inhibit blood clotting?Although vitamin E intake does not alter coagulation times in humans, experimental evidence indicates that vitamin E supplementation may inhibit vitamin K and hence vitamin K–dependent clotting factors. Vitamin E has also been shown to inhibit platelet adherence.
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