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Dietary supplement

Liquid Evening Primrose Oil Ingredients & Drug Interactions

by Nature's Answer

Liquid Category: Fat/fatty Acid
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

Liquid Evening Primrose Oil is a dietary supplement by Nature's Answer with 2 active ingredients. Its ingredients are commonly taken for general antioxidant support, skin and hair care, heart health.Based on those ingredients, 902 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Vitamin E, Evening Primrose (Oenothera biennis) (seed) oil. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of Liquid Evening Primrose Oil by Nature's Answer

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

What’s inside

Partial disclosure
Ingredient Transparency · database check
Partial

Most active ingredients list an amount, but at least one is hidden in a blend or missing.

Why this rating?
  • The label discloses an exact amount for 5 of its 6 active ingredients.
  • “Evening Primrose (Oenothera biennis) (seed) oil” is listed as a grouped ingredient — the label gives one combined amount (2 Gram(s)) without saying how much of each component you get.

Nature's Answer Liquid Evening Primrose Oil contains 6 ingredients. The active ones are vitamin E (a fat-soluble antioxidant), gamma-linolenic acid and linoleic acid (omega fatty acids from the evening primrose seed oil), oleic acid (a monounsaturated fatty acid), and palmitic acid (a saturated fatty acid).

The product also contains Quik-Sorb as an inactive ingredient.

Does it work?

Moderate evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: natural source of essential fatty acids.
  • We looked for evidence on: Atopic dermatitis (eczema), Aging skin, Dry skin, Mastalgia, Dysmenorrhea, Fibrocystic breast disease — and 4 related terms.
  • The strongest evidence on file: Vitamin E is rated "Possibly Effective" for Dysmenorrhea (Natural Medicines).
  • Also on file: Vitamin E is rated "Possibly Ineffective" for Atopic dermatitis (eczema).
  • Also on file: Vitamin E is rated "Likely Ineffective" for Cardiovascular disease (CVD), Fibrocystic breast disease.

Vitamin E in this product is effective for preventing or treating vitamin E deficiency and for a condition called AVED (ataxia with vitamin E deficiency). It's possibly effective for Alzheimer disease, beta-thalassemia, G6PD deficiency, and intracranial hemorrhage, though the evidence isn't as strong.

Oleic acid is possibly effective for high cholesterol and coronary heart disease. We don't have effectiveness data on file for the other fatty acids in evening primrose oil.

The evidence, ingredient by ingredient Vitamin E Evening Primrose Oleic Acid

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 2 of 2.
  • General safety write-ups exist for 2 of 2.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Vitamin E from food and normal dietary amounts is generally well tolerated. However, high-dose long-term supplements may raise your risk of bleeding and other complications, including rare but serious events like hemorrhagic stroke and cardiovascular problems.

In pregnancy, food amounts and prenatal vitamins are appropriate, but avoid high-dose supplements unless your doctor directs it. While breastfeeding, normal dietary amounts are fine, but check with your doctor before taking high-dose supplements.

Oleic acid from foods is safe, but concentrated supplement doses haven't been well studied in pregnancy or while breastfeeding.

Side effects, ingredient by ingredient Vitamin E Evening Primrose Oleic Acid

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 2 of the 2 matched ingredients can interact with medications — Vitamin E, Oleic Acid.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; cancer treatments; diabetes medications.
  • For scale: 845 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking this product, check if you're on blood thinners or antiplatelet drugs (like warfarin, aspirin, or clopidogrel) — vitamin E increases bleeding risk. Also double-check if you take chemotherapy drugs, cyclosporine, or niacin.

If selumetinib is part of your regimen, let your pharmacist know, since it already contains vitamin E.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glancePartially disclosed formula with some supporting evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

This product might work for vitamin E deficiency or certain conditions like Alzheimer disease or high cholesterol, but it's not without risk — especially if you take blood thinners, chemotherapy drugs, cyclosporine, or niacin. If you're pregnant, breastfeeding, or taking any prescription medications, check with your pharmacist before starting.

High-dose vitamin E supplements carry real bleeding risks that need to be weighed against any benefit.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 2 of 6 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Feb 25, 2019.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Liquid Evening Primrose Oil, straight from the product label.

Brand Nature's Answer
Barcode (UPC) 083000261404
Net contents 4 fl. Oz.; 120 mL
Market status On market
Date entered into DSLD Feb 25, 2019
DSLD ID 184275
Product type Fat/fatty Acid
Supplement form Liquid
Dietary claims / uses Nutrient, All Other
Intended target group(s) Adult (18 - 50 Years), Gluten Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Liquid Evening Primrose Oil by Nature's Answer, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
0.5 tsp
Maximum serving Sizes:
0.5 tsp
Servings per container
48
UPC/BARCODE
083000261404
IngredientAmount% DV
Calories25 Calorie(s)--
Vitamin E1 mg7%
Total Fat2.5 Gram(s)4%
Gamma-Linolenic Acid195 mg--
Linoleic Acid1.4 Gram(s)--
Oleic Acid115 mg--
Palmitic Acid120 mg--
Typical Fatty Acid Profile0 NP--
Evening Primrose (Oenothera biennis) (seed) oil2 Gram(s)--

Other ingredients: Quik-Sorb

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Formula

Evening Primrose Oil is a natural source of some essential fatty acids such as Linoleic Acid and Gamma-Linolenic Acid (GLA).

Natural Source of GLA

With Quik-Sorb

Contains: Soy.

Brand IP Statement(s)

Nature's Answer. High-quality natural products for vital healthy lifestyles since 1972.

Quik-Sorb is a registered trademark of Bio-Botanica, Inc.

2017 Nature's Answer

General Statements

Unconditionally Guaranteed.

Since 1972

Precautions

Warning: Keep out of reach of children.

Do not use if safety seal is damaged or missing.

Do not use if you are pregnant or nursing. If you are taking any medications, planning any medical procedure or have a medical condition, consult with your healthcare practitioner before use.

Contains: Soy.

General

27140 Rev. 917

FDA Statement of Identity

Dietary Supplement

Seals/Symbols

Gluten Free

Formulation

Gluten Free

Suggested/Recommended/Usage/Directions

Suggested Use: As a dietary supplement, take 1/2 teaspoon (2.5 mL) daily with 6-8 oz. of water or food. Shake well before use.

Storage

Refrigerate after opening.

See for yourself

Liquid Evening Primrose Oil by Nature's Answer label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

What’s inside

The Ingredients in Liquid Evening Primrose Oil by Nature's Answer

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size0.5 tsp Dosage formLiquid Servings per container48 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Vitamin E

Interacts with
764 drugs
1 mg per serving Form: D-Alpha-Tocopheryl Acetate

Vitamin E is an essential fat-soluble vitamin and antioxidant that most people get in adequate amounts from a normal diet. Supplements can help correc...

Vitamin E monograph & interactions
2 Gram(s) per serving

Evening primrose oil is a seed oil rich in gamma-linolenic acid (GLA), an omega-6 fatty acid, that is popularly used for skin conditions, PMS, and bre...

Evening Primrose (Oenothera biennis) (seed) oil monograph & interactions
  • › Gamma-Linolenic Acid
  • › Linoleic Acid
  • Oleic Acid
  • › Palmitic Acid
  • › Typical Fatty Acid Profile

Other (inactive) ingredients: Quik-Sorb. These complete the product’s ingredient list but are not active constituents.

Interaction report

Liquid Evening Primrose Oil by Nature's Answer Drug Interactions

Want to check YOUR meds against Liquid Evening Primrose Oil?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

Go to the checker
902Drugs
861 Moderate 41 Minor

Ingredients driving the most interactions

Vitamin E 764

Each ingredient & the kinds of drugs it affects

For each ingredient in Liquid Evening Primrose Oil with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Vitamin E8 drug types · 764 drugs

Alkylating Agents

Theoretically, antioxidant effects of vitamin E might reduce the effectiveness of alkylating agents.
There's concern that antioxidants could reduce the activity of chemotherapy drugs which generate free radicals, such as cyclophosphamide, chlorambucil, carmustine, busulfan, and thiotepa. However, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that might interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effect, if any, antioxidants such as vitamin E have on chemotherapy. Advise patients to consult their oncologist before using vitamin E supplements, especially in high doses.

Likelihood Possible Evidence D
Anticoagulant/Antiplatelet Drugs

Concomitant use of vitamin E and anticoagulant or antiplatelet agents might increase the risk of bleeding.
Vitamin E seems to inhibit of platelet aggregation and antagonize the effects of vitamin K-dependent clotting factors. These effects appear to be dose-dependent, and are probably only likely to be clinically significant with doses of at least 800 units daily. Mixed tocopherols, such as those found in food, might have a greater antiplatelet effect than alpha-tocopherol. RRR alpha-tocopherol (natural vitamin E) 1000 IU daily antagonizes vitamin K-dependent clotting factors. Advise patients to avoid high doses of vitamin E, especially in people with low vitamin K intake or other risk factors for bleeding.

Likelihood Possible Evidence B
Antitumor Antibiotics

Theoretically, antioxidant effects of vitamin E might reduce the effectiveness of antitumor antibiotics.
There's concern that antioxidants could reduce the activity of antitumor antibiotic drugs such as doxorubicin, which generate free radicals. However, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that might interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effect, if any, antioxidants such as vitamin E have on chemotherapy involving antitumor antibiotics. Advise patients to consult their oncologist before using vitamin E supplements, especially in high doses.

Likelihood Possible Evidence D
Cyclosporine (Neoral, Sandimmune)

A specific form of vitamin E might increase absorption and levels of cyclosporine.
There is some evidence that one specific formulation of vitamin E (D-alpha-tocopheryl-polyethylene glycol-1000 succinate, TPGS, tocophersolan, Liqui-E) might increase absorption of cyclosporine. This vitamin E formulation forms micelles which seems to increase absorption of cyclosporine by 40% to 72% in some patients. However, this interaction is unlikely to occur with the usual forms of vitamin E.

Likelihood Unlikely Evidence B
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, vitamin E might induce metabolism of CYP3A4, possibly reducing the levels CYP3A4 substrates.
Vitamin E appears to bind with the nuclear receptor, pregnane X receptor (PXR), which results in increased expression of CYP3A4. Although the clinical significance of this is not known, use caution when considering concomitant use of vitamin E and other drugs affected by these enzymes.

Likelihood Possible Evidence D
Selumetinib (Koselugo)

Taking selumetinib with vitamin E can result in a total daily dose of vitamin E that exceeds safe limits and therefore might increase the risk of bleeding.
Selumetinib contains 48-54 IU vitamin E per capsule. The increased risk of bleeding with vitamin E appears to be dose-dependent. Be cautious when using selumetinib in combination with supplemental vitamin E, especially in patients at higher risk of bleed, such as those with chronic conditions and those taking antiplatelet drugs.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Using vitamin E with warfarin might increase the risk of bleeding.
Due to interference with production of vitamin K-dependent clotting factors, use of more than 400 IU of vitamin E daily with warfarin might increase prothrombin time (PT), INR, and the risk of bleeding,. At a dose of 1000 IU per day, vitamin E can antagonize vitamin K-dependent clotting factors even in people not taking warfarin. Limited clinical evidence suggests that doses up to 1200 IU daily may be used safely by patients taking warfarin, but this may not be applicable in all patient populations.

Likelihood Possible Evidence B
Niacin

Vitamin E might decrease the beneficial effects of niacin on high-density lipoprotein (HDL) cholesterol levels.
A combination of niacin and simvastatin (Zocor) effectively raises high-density lipoprotein (HDL) cholesterol levels in people with coronary disease and low HDL levels. Clinical research shows that taking a combination of antioxidants (vitamin C, vitamin E, beta-carotene, and selenium) along with niacin and simvastatin (Zocor) attenuates this rise in HDL, specifically the HDL-2 and apolipoprotein A1 fractions, by more than 50%. Vitamin E alone combined with a statin does not seem to decrease HDL levels. It is not known whether the adverse effect on HDL is due to one of the other antioxidants or to the combination. It also is not known whether it will occur in other patient populations.

Likelihood Possible Evidence A

Evening Primrose (Oenothera biennis) (seed) oil5 drug types · 233 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Evening primrose oil contains gamma linolenic acid (GLA). There is preliminary clinical evidence that GLA can reduce platelet aggregation and prolong bleeding time.

Likelihood Possible Evidence D
Lithium

Theoretically, concomitant use of lithium with evening primrose oil might decrease lithium levels and effects.
In a case report, a patient on a stable dose of lithium for 10 years experienced a reduction in lithium levels after taking evening primrose oil 500 mg daily. Baseline levels were 0.69 mmol/L, which decreased to 0.37 mmol/L after 2 months and 0.23 mmol/L after 3 months of use. Lithium levels increased within 6 weeks of discontinuing evening primrose oil, to 0.73 mmol/L; no clinical effects were noted.

Likelihood Possible Evidence D
Lopinavir/Ritonavir (Kaletra)

Theoretically, evening primrose oil might increase the levels and effects of lopinavir.
In a case report, an HIV patient who took evening primrose oil (Efamol) along with lopinavir/ritonavir experienced an increase in serum levels of lopinavir to 15.2 mg/L. Six weeks after discontinuing evening primrose oil, levels of lopinavir returned to the normal range of 5-10 mg/L. When re-challenged with evening primrose oil for a week, the patient's lopinavir levels increased from 6.69 to 8.11 mg/L. It is suspected that evening primrose oil increases levels of lopinavir by inhibiting cytochrome P450 3A4 (CYP3A4), which metabolizes lopinavir. However, this effect has not been reported in other research.

Likelihood Possible Evidence D
Phenothiazines

Theoretically, taking evening primrose oil with phenothiazines might increase the risk of convulsions.
Evening primrose oil contains gamma-linolenic acid (GLA). There is some concern that taking supplements containing GLA might cause seizures, or lower the seizure threshold, when taken with phenothiazines. In one report, three patients with schizophrenia who had received phenothiazines developed EEG changes suggestive of temporal lobe epilepsy after starting treatment with GLA, although none experienced an actual seizure. In another report, two patients with schizophrenia who were stabilized on phenothiazines developed seizures when evening primrose oil 4 grams daily was added. One of these patients had a prior history of seizures. It is unclear whether evening primrose oil had any additive epileptogenic effects with the phenothiazines; there is no evidence that taking evening primrose oil alone causes seizures.

Likelihood Possible Evidence D
Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
In vitro research shows that linoleic acid, a constituent of evening primrose oil, inhibits CYP2C9.

Likelihood Possible Evidence D
The maker

Brand information

Manufacturer and brand details for Liquid Evening Primrose Oil, from the product label.

Nature's Answer

See all Nature's Answer products
Name
Nature's Answer
Street Address
85 Commerce Drive
City
Hauppauge
State
NY
ZipCode
11788
Phone Number
(800) 439-2324
Web Address
www.naturesanswer.com
Pharmacist Counseling Corner

Liquid Evening Primrose Oil by Nature's Answer: Common Questions

Does Liquid Evening Primrose Oil by Nature's Answer interact with any medications?
Yes. Based on its ingredients, Liquid Evening Primrose Oil has a known interaction with 902 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Liquid Evening Primrose Oil contains 2 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Will this help my vitamin E deficiency?
Yes — vitamin E is effective for vitamin E deficiency and for AVED (a rare genetic condition). If your doctor has identified a deficiency, this product can help. For other uses like Alzheimer disease or cholesterol, the evidence is weaker but possibly helpful.
Is it safe to take while I'm pregnant?
Food amounts of vitamin E and doses in prenatal vitamins are appropriate during pregnancy. However, high-dose supplements aren't well studied and should only be taken if your doctor directs it. Talk to your OB/GYN before starting.
Can I take this while breastfeeding?
Normal dietary amounts of vitamin E are considered likely safe while breastfeeding. High-dose supplements lack good safety data — check with your doctor before taking them. For oleic acid, food amounts are safe, but supplement-level doses haven't been well studied.
What are the side effects?
Vitamin E is generally well tolerated at normal doses. High doses carry a real risk of increased bleeding. Rarely, very high-dose long-term use has been linked to hemorrhagic stroke and cardiovascular problems. If you notice unusual bruising, bleeding, or signs of stroke, stop and seek medical help.
Does evening primrose oil have other active ingredients besides vitamin E?
Yes — it also contains gamma-linolenic acid, linoleic acid, oleic acid, and palmitic acid, which are omega and other fatty acids. We don't have effectiveness data for those individual fatty acids on file.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Liquid Evening Primrose Oil label
Sources

Sources & How We Checked

Liquid Evening Primrose Oil's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 116 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Vitamin E 64 references
  1. Kim JM, White RH. Effect of vitamin E on the anticoagulant response to warfarin. Am J Cardiol 1996;77:545-6. PubMed
  2. Corrigan JJ Jr. The effect of vitamin E on warfarin-induced vitamin K deficiency. Ann N Y Acad Sci 1982;393:361-8. PubMed
  3. Corrigan JJ Jr. Coagulation problems relating to vitamin E. Am J Pediatr Hematol Oncol 1979;1:169-73.
  4. Corrigan JJ Jr, Marcus FI. Coagulopathy associated with vitamin E ingestion. JAMA 1974;230:1300-1. DOI
  5. Labriola D, Livingston R. Possible interactions between dietary antioxidants and chemotherapy. Oncology 1999;13:1003-8.
  6. Chang T, Benet LZ, Hebert MF. The effect of water-soluble vitamin E on cyclosporine pharmacokinetics in healthy volunteers. Clin Pharmacol Ther 1996;59:297-303. PubMed
  7. Pan SH, Lopez RR Jr, Sher LS, et al. Enhanced oral cyclosporine absorption with water-soluble vitamin E early after liver transplantation. Pharmacother 1996;16:59-65. DOI
  8. Anon. Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. Gruppo Italiano per lo Studio della Soprawivenza nell'Infarto miocardico. Lancet 1999;354:447-55. DOI
  9. Chappell LC, Seed PT, Briley AL, et al. Effect of antioxidants on the occurrence of pre-eclampsia in women at increased risk: a randomised trial. Lancet 1999;354:810-6. DOI
  10. Yusuf S, Dagenais G, Pogue J, et al. Vitamin E supplementation and cardiovascular events in high-risk patients. The heart outcomes prevention evaluation study investigators. N Engl J Med 2000;342:154-60. PubMed
  11. Stephens NG, Parsons A, Schofield PM, et al. Randomised controlled trial of vitamin E in patients with coronary disease: Cambridge Heart Antioxidant Study. Lancet 1996;347:781-6.
  12. The Alpha-Tocopherol, Beta Carotene Cancer Prevention Study Group. The effect of vitamin E and beta carotene on the incidence of lung cancer and other cancers in male smokers. N Engl J Med 1994;330:1029-35. PubMed
  13. Takahashi O. Haemorrhagic toxicity of a large dose of alpha-, beta-, gamma- and delta-tocopherols, ubiquinone, beta-carotene, retinol acetate and L-ascorbic acid in the rat. Food Chem Toxicol 1995;33:121-8.
  14. Briggs GB, Freeman RK, Yaffe SJ. Drugs in Pregnancy and Lactation. 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1998.
  15. Sano M, Ernesto C, Thomas RG, et al. A controlled trial of selegiline, alpha-tocopherol, or both as treatment for Alzheimer's disease. The Alzheimer's Disease Cooperative Study. N Engl J Med 1997;336:1216-22. PubMed
  16. Liede KE, Haukka JK, Saxen LM, Heinonen OP. Increased tendency towards gingival bleeding caused by joint effect of alpha-tocopherol supplementation and acetylsalicylic acid. Ann Med 1998;30:542-6.
  17. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press, 2000. Available at: http://www.nap.edu/books/0309069351/html/.
  18. Brown BG, Zhao XQ, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med 2001;345:1583-93. DOI
  19. Liu M, Wallmon A, Olsson-Mortlock C, et al. Mixed tocopherols inhibit platelet aggregation in humans: potential mechanisms. Am J Clin Nutr 2003;77:700-6. PubMed
  20. Sokol RJ, Johnson KE, Karrer FM, et al. Improvement of cyclosporin absorption in children after liver transplantation by means of water-soluble vitamin E. Lancet 1991;338:212-4.. PubMed
  21. Stein JH, Carlsson CM, Papcke-Benson K, et al. The effects of lipid-lowering and antioxidant vitamin therapies on flow-mediated vasodilation of the brachial artery in older adults with hypercholesterolemia. J Am Coll Cardiol 2001;38:1806-13.. PubMed
  22. Carlsson CM, Papcke-Benson K, Carnes M, et al. Health-related quality of life and long-term therapy with pravastatin and tocopherol (vitamin E) in older adults. Drugs Aging 2002;19:793-805. . PubMed
  23. Cheung MC, Zhao XQ, Chait A, et al. Antioxidant supplements block the response of HDL to simvastatin-niacin therapy in patients with coronary artery disease and low HDL. Arterioscler Thromb Vasc Biol 2001;21:1320-6. PubMed
  24. Schrogie JJ. Coagulopathy and fat-soluble vitamins (letter). JAMA 1975;232:19. DOI
  25. Celestini A, Pulcinelli FM, Pignatelli P, et al. Vitamin E potentiates the antiplatelet activity of aspirin in collagen-stimulated platelets. Haematologica 2002;87:420-6.
  26. Stampfer MJ, Jakubowski JA, Faigel D, et al. Vitamin E supplementation effect on human platelet function, arachidonic acid metabolism, and plasma prostacyclin levels. Am J Clin Nutr 1988;47:700-6. PubMed
  27. Jandak J, Steiner M, Richardson PD. Alpha-tocopherol, an effective inhibitor of platelet adhesion. Blood 1989;73:141-9. DOI
  28. Freedman JE, Farhat JH, Loscalzo J, Keaney JF. Alpha-tocopherol inhibits aggregation of human platelets by a protein kinase C-dependent mechanism. Circulation 1996;94:2434-40. PubMed
  29. Steiner M. Vitamin E, a modifier of platelet function: rationale and use in cardiovascular and cerebrovascular disease. Nutr Rev 1999;57:306-9. PubMed
  30. Brodkin RH, Bleiberg J. Sensitivity to topically applied vitamin E. Arch Dermatol 1965;92:76-7. DOI
  31. Booth SL, Golly I, Sacheck JM, et al. Effect of vitamin E supplementation on vitamin K status in adults with normal coagulation status. Am J Clin Nutr 2004;80:143-8. PubMed
  32. Miller ER 3rd, Pastor-Barriuso R, Dalal D, et al. Meta-analysis: High-dosage vitamin E supplementation may increase all-cause mortality. Ann Intern Med 2005;142:60520-53. PubMed
  33. Lonn E, Bosch J, Yusuf S, et al. HOPE and HOPE-TOO Trial Investigators. Effects of long-term vitamin E supplementation on cardiovascular events and cancer: a randomized controlled trial. JAMA 2005;293:1338-47. PubMed
  34. Landes N, Pfluger P, Kluth D, et al. Vitamin E activates gene expression via the pregnane X receptor. Biochem Pharmacol 2003;65:269-73. . PubMed
  35. Brigelius-Flohe R. Vitamin E and drug metabolism. Biochem Biophys Res Commun 2003;305:737-40. PubMed
  36. Prasad KN. Rationale for using high-dose multiple dietary antioxidants as an adjunct to radiation therapy and chemotherapy. J Nutr 2004;134:3182S-3S. PubMed
  37. Conklin KA. Cancer chemotherapy and antioxidants. J Nutr 2004;134:3201S-3204S. PubMed
  38. Schurks M, Glynn RJ, Rist PM, et al. Effects of vitamin E on stroke subtypes: meta-analysis of randomized controlled trials. BMJ 2010;341: c5702. doi: 10.1136/bmj.c5702.
  39. Lawson KA, Wright ME, Subar A, et al. Multivitamin use and risk of prostate cancer in the National Institutes of Health-AARP Diet and Health Study. J Natl Cancer Inst 2007;99:754-64. PubMed
  40. Gaziano JM, Glynn RJ, Christen WG, et al. Vitamins E and C in the prevention of prostate total cancer in men: the physicians' health study II randomised controlled trial. JAMA 2009;301:52-62.
  41. Hayden KM, Welsh-Bohmer KA, Wengreen HJ, et al; Cache County Investigators. Risk of mortality with vitamin E supplements: the Cache County study. Am L Med 2007;120:180-4. PubMed
  42. Smedts HP, de Vries JH, Rakhshandehroo M, et al. High maternal vitamin E intake by diet or supplements is associated with congenital heart defects in the offspring. BJOG 2009;116:416-23. PubMed
  43. Klein EA, Thompson IM Jr, Tangen CM, et al. Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA 2011;306:1549-56. PubMed
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