Two studies showed that individuals taking phenytoin and phenobarbital had lower blood vitamin E levels than those who received no treatment for seizures.^{27 , 28} Though the consequences of lower blood levels of vitamin E are unknown, people taking multiple anticonvulsant drugs might supplement with 100 to 200 IU of vitamin E daily to help prevent a deficiency.

Bile acid sequestrants may prevent absorption of folic acid and the fat-soluble vitamins A, D, E, and K.^{36 , 37} Other medications and vitamin supplements should be taken one hour before or four to six hours after bile acid sequestrants for optimal absorption.³⁸ Animal studies suggest calcium and zinc may also be depleted by taking cholestyramine.³⁹

Bile acid sequestrants may prevent absorption of folic acid and the fat-soluble vitamins A, D, E, and K.^{54 , 55} Other medications and vitamin supplements should be taken one hour before or four to six hours after bile acid sequestrants for optimal absorption.⁵⁶ Animal studies suggest calcium and zinc may also be depleted by taking cholestyramine.⁵⁷

Bile acid sequestrants, including colestipol, may prevent absorption of folic acid and the fat-soluble vitamins A, D, E, K.^{58 , 59} People taking colestipol should consult with their doctor about vitamin malabsorption and supplementation. People should take other drugs and vitamin supplements one hour before or four to six hours after colestipol to improve absorption.⁶⁰

Animal studies suggest calcium and zinc may be depleted by taking cholestyramine, another bile acid sequestrant. ⁶¹ Whether these same interactions would occur with colestipol is not known.

Two studies showed that individuals taking phenytoin and phenobarbital had lower blood vitamin E levels than those who received no treatment for seizures.^{89 , 90} Though the consequences of lower blood levels of vitamin E are unknown, people taking multiple anticonvulsant drugs might supplement with 100 to 200 IU of vitamin E daily to help prevent a deficiency.

In a randomized study of 21 men with combined hyperlipidemia, ten to twelve weeks of gemfibrozil therapy reduced alpha- and gamma-tocopherol blood levels to the levels seen in healthy men.¹⁰⁷ The clinical significance of this finding is unknown and may reflect a normal physiological response to a reduction in serum cholesterol levels.

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Isoniazid may interfere with the activity of other nutrients, including vitamin B3 (niacin), vitamin B12, vitamin D, and vitamin E, folic acid, calcium, and magnesium.^{126 , 127} Supplementation with vitamin B6 is thought to help prevent isoniazid-induced niacin deficiency; however, small amounts of vitamin B6 (e.g. 10 mg per day) appear to be inadequate in some cases.¹²⁸ People should consider using a daily multivitamin-mineral supplement during isoniazid therapy.

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Two studies showed that individuals taking phenytoin and phenobarbital had lower blood vitamin E levels than those who received no treatment for seizures.^{130 , 131} Though the consequences of lower blood levels of vitamin E are unknown, people taking multiple anticonvulsant drugs might supplement with 100 to 200 IU of vitamin E daily to help prevent a deficiency.

Mineral oil has interfered with the absorption of many nutrients, including beta-carotene, calcium, phosphorus, potassium, and vitamins A, D, K, and E in some,¹⁴⁶ but not all,¹⁴⁷ research. Taking mineral oil on an empty stomach may reduce this interference. It makes sense to take a daily multivitamin-mineral supplement two hours before or after mineral oil. It is important to read labels, because many multivitamins do not contain vitamin K or contain inadequate (less than 100 mcg per day) amounts.

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Taking orlistat dramatically reduces the absorption of vitamin E,¹⁴⁸ which might result in deficiency symptoms. Therefore, people taking orlistat for long periods of time should supplement with vitamin E.

Two studies showed that individuals taking phenytoin and phenobarbital had lower blood vitamin E levels than those who received no treatment for seizures.^{149 , 150} Though the consequences of lower blood levels of vitamin E are unknown, people taking multiple anticonvulsant drugs might supplement with 100 to 200 IU of vitamin E daily to help prevent a deficiency.

Two studies showed that individuals taking phenytoin and phenobarbital had lower blood vitamin E levels than those who received no treatment for seizures.^{158 , 159} Though the consequences of lower blood levels of vitamin E are unknown, people taking multiple anticonvulsant drugs should probably supplement with 100 to 200 IU of vitamin E daily to prevent a deficiency.

Two studies showed that individuals taking phenytoin and phenobarbital had lower blood vitamin E levels than those who received no treatment for seizures.^{167 , 168} Though the consequences of lower blood levels of vitamin E are unknown, people taking multiple anticonvulsant drugs might supplement with 100 to 200 IU of vitamin E daily to help prevent a deficiency.

Two studies showed that individuals taking phenytoin and phenobarbital had lower blood vitamin E levels than those who received no treatment for seizures.^{179 , 180} Though the consequences of lower blood levels of vitamin E are unknown, people taking multiple anticonvulsant drugs might supplement with 100 to 200 IU of vitamin E daily to help prevent a deficiency.

Two studies showed that individuals taking phenytoin and phenobarbital had lower blood vitamin E levels than those who received no treatment for seizures.^{181 , 182} Though the consequences of lower blood levels of vitamin E are unknown, people taking multiple anticonvulsant drugs might supplement with 100 to 200 IU of vitamin E daily to help prevent a deficiency.

Test tube research on human lung tissue suggests that vitamin E might reduce lung toxicity caused by amiodarone.¹⁸ More research is needed to further investigate this possibility.

Anthralin can cause inflammation of the skin. A preliminary study found that topical use of vitamin E was able to protect against this side effect.¹⁹ This report used a tocopherol form of the vitamin rather than tocopheryl. This makes sense, as there is no conclusive proof that the tocopheryl forms (which require an enzyme to split vitamin E from the fatty acid to which it is attached) have any activity on the skin.

Chemotherapy frequently causes mouth sores. In one trial, people were given approximately 400,000 IU of beta-carotene per day for three weeks and then 125,000 IU per day for an additional four weeks.²⁰ Those taking beta-carotene still suffered mouth sores, but the mouth sores developed later and tended to be less severe than mouth sores that formed in people receiving the same chemotherapy without beta-carotene.

In a study of chemotherapy-induced mouth sores, six of nine patients who applied vitamin E directly to their mouth sores had complete resolution of the sores compared with one of nine patients who applied placebo.²¹ Others have confirmed the potential for vitamin E to help people with chemotherapy-induced mouth sores.²² Applying vitamin E only once per day was helpful to only some groups of patients in another trial,²³ and not all studies have found vitamin E to be effective.²⁴ Until more is known, if vitamin E is used in an attempt to reduce chemotherapy-induced mouth sores, it should be applied topically twice per day and should probably be in the tocopherol (versus tocopheryl) form.

In a preliminary study, the addition of oral vitamin E (300 IU per day) to cisplatin chemotherapy significantly reduced the incidence of drug-induced damage to the nervous system (neurotoxicity).²⁵ A similar protective effect was seen in another trial in which 600 IU of vitamin E per day was used.²⁶

Chemotherapy frequently causes mouth sores. In one trial, people were given approximately 400,000 IU of beta-carotene per day for three weeks and then 125,000 IU per day for an additional four weeks.²⁹ Those taking beta-carotene still suffered mouth sores, but the mouth sores developed later and tended to be less severe than mouth sores that formed in people receiving the same chemotherapy without beta-carotene.

In a study of chemotherapy-induced mouth sores, six of nine patients who applied vitamin E directly to their mouth sores had complete resolution of the sores compared with one of nine patients who applied placebo.³⁰ Others have confirmed the potential for vitamin E to help people with chemotherapy-induced mouth sores.³¹ Applying vitamin E only once per day was helpful to only some groups of patients in another trial,³² and not all studies have found vitamin E to be effective.³³ Until more is known, if vitamin E is used in an attempt to reduce chemotherapy-induced mouth sores, it should be applied topically twice per day and should probably be in the tocopherol (versus tocopheryl) form.

In a preliminary study, the addition of oral vitamin E (300 IU per day) to cisplatin chemotherapy significantly reduced the incidence of drug-induced damage to the nervous system (neurotoxicity).³⁴ A similar protective effect was seen in another trial in which 600 IU of vitamin E per day was used.³⁵

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Chemotherapy frequently causes mouth sores. In one trial, people were given approximately 400,000 IU of beta-carotene per day for three weeks and then 125,000 IU per day for an additional four weeks.⁴⁰ Those taking beta-carotene still suffered mouth sores, but the mouth sores developed later and tended to be less severe than mouth sores that formed in people receiving the same chemotherapy without beta-carotene.

In a study of chemotherapy-induced mouth sores, six of nine patients who applied vitamin E directly to their mouth sores had complete resolution of the sores compared with one of nine patients who applied placebo.⁴¹ Others have confirmed the potential for vitamin E to help people with chemotherapy-induced mouth sores.⁴² Applying vitamin E only once per day was helpful to only some groups of patients in another trial,⁴³ and not all studies have found vitamin E to be effective.⁴⁴ Until more is known, if vitamin E is used in an attempt to reduce chemotherapy-induced mouth sores, it should be applied topically twice per day and should probably be in the tocopherol (versus tocopheryl) form.

In a preliminary study, the addition of oral vitamin E (300 IU per day) to cisplatin chemotherapy significantly reduced the incidence of drug-induced damage to the nervous system (neurotoxicity).⁴⁵ A similar protective effect was seen in another trial in which 600 IU of vitamin E per day was used.⁴⁶

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Chemotherapy frequently causes mouth sores. In one trial, people were given approximately 400,000 IU of beta-carotene per day for three weeks and then 125,000 IU per day for an additional four weeks.⁴⁷ Those taking beta-carotene still suffered mouth sores, but the mouth sores developed later and tended to be less severe than mouth sores that formed in people receiving the same chemotherapy without beta-carotene.

In a study of chemotherapy-induced mouth sores, six of nine patients who applied vitamin E directly to their mouth sores had complete resolution of the sores compared with one of nine patients who applied placebo.⁴⁸ Others have confirmed the potential for vitamin E to help people with chemotherapy-induced mouth sores.⁴⁹ Applying vitamin E only once per day was helpful to only some groups of patients in another trial,⁵⁰ and not all studies have found vitamin E to be effective.⁵¹ Until more is known, if vitamin E is used in an attempt to reduce chemotherapy-induced mouth sores, it should be applied topically twice per day and should probably be in the tocopherol (versus tocopheryl) form.

In a preliminary study, the addition of oral vitamin E (300 IU per day) to cisplatin chemotherapy significantly reduced the incidence of drug-induced damage to the nervous system (neurotoxicity).⁵² A similar protective effect was seen in another trial in which 600 IU of vitamin E per day was used.⁵³

Chemotherapy can injure cancer cells by creating oxidative damage. As a result, some oncologists recommend that patients avoid supplementing antioxidants if they are undergoing chemotherapy. Limited test tube research occasionally does support the idea that an antioxidant can interfere with oxidative damage to cancer cells.⁶² However, most scientific research does not support this supposition.

Cyclophosphamide requires activation by the liver through a process called oxidation. In theory, antioxidant nutrients (vitamin A, vitamin E, beta-carotene and others) might interfere with the activation of cyclophosphamide. There is no published research linking antioxidant vitamins to reduced cyclophosphamide effectiveness in cancer treatment. In a study of mice with vitamin A deficiency, vitamin A supplementation enhanced the anticancer action of cyclophosphamide.⁶³ Another animal research report indicated that vitamin C may increase the effectiveness of cyclophosphamide without producing new side effects.⁶⁴ Preliminary human research found that adding antioxidants (beta-carotene, vitamin A, and vitamin E) to cyclophosphamide therapy increased the survival of people with small-cell lung cancer treated with cyclophosphamide.⁶⁵ It is too early to know if adding antioxidants to cyclophosphamide for cancer treatment is better than cyclophosphamide alone. Vitamin A can be toxic in high amounts.

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Chemotherapy frequently causes mouth sores. In one trial, people were given approximately 400,000 IU of beta-carotene per day for three weeks and then 125,000 IU per day for an additional four weeks.⁶⁷ Those taking beta-carotene still suffered mouth sores, but the mouth sores developed later and tended to be less severe than mouth sores that formed in people receiving the same chemotherapy without beta-carotene.

In a study of chemotherapy-induced mouth sores, six of nine patients who applied vitamin E directly to their mouth sores had complete resolution of the sores compared with one of nine patients who applied placebo.⁶⁸ Others have confirmed the potential for vitamin E to help people with chemotherapy-induced mouth sores.⁶⁹ Applying vitamin E only once per day was helpful to only some groups of patients in another trial,⁷⁰ and not all studies have found vitamin E to be effective.⁷¹ Until more is known, if vitamin E is used in an attempt to reduce chemotherapy-induced mouth sores, it should be applied topically twice per day and should probably be in the tocopherol (versus tocopheryl) form.

In a preliminary study, the addition of oral vitamin E (300 IU per day) to cisplatin chemotherapy significantly reduced the incidence of drug-induced damage to the nervous system (neurotoxicity).⁷² A similar protective effect was seen in another trial in which 600 IU of vitamin E per day was used.⁷³

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

In large amounts, dapsone causes oxidative damage to red blood cells. This damage may be reduced by using lower amounts of dapsone. Fifteen people who took dapsone for dermatitis herpetiformis were given 800 IU of vitamin E per day for four weeks, followed by four weeks with 1,000 mg of vitamin C per day, followed by four weeks of vitamin E and vitamin C together.⁷⁴ The authors reported only vitamin E therapy offered some protection against dapsone-induced hemolysis.

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Animal studies show that the antioxidant activity of vitamin E protects against doxorubicin-induced cardiotoxicity.^{75 , 76} Test tube evidence suggests that vitamin E might also enhance the anticancer action of the drug.⁷⁷ Human trials exploring the cardioprotective action of vitamin E in people taking doxorubicin remain inconclusive; however, some evidence suggests that vitamin E may allow for higher drug doses without increasing toxicity.⁷⁸

Anecdotal reports indicate that very high (1,600 IU) amounts of vitamin E may reduce the amount of hair loss accompanying use of doxorubicin.⁷⁹ However, while protection against hair loss was confirmed in a rabbit study, human research has not found this to be true.⁸⁰

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Chemotherapy frequently causes mouth sores. In one trial, people were given approximately 400,000 IU of beta-carotene per day for three weeks and then 125,000 IU per day for an additional four weeks.⁸¹ Those taking beta-carotene still suffered mouth sores, but the mouth sores developed later and tended to be less severe than mouth sores that formed in people receiving the same chemotherapy without beta-carotene.

In a study of chemotherapy-induced mouth sores, six of nine patients who applied vitamin E directly to their mouth sores had complete resolution of the sores compared with one of nine patients who applied placebo.⁸² Others have confirmed the potential for vitamin E to help people with chemotherapy-induced mouth sores.⁸³ Applying vitamin E only once per day was helpful to only some groups of patients in another trial,⁸⁴ and not all studies have found vitamin E to be effective.⁸⁵ Until more is known, if vitamin E is used in an attempt to reduce chemotherapy-induced mouth sores, it should be applied topically twice per day and should probably be in the tocopherol (versus tocopheryl) form.

In a preliminary study, the addition of oral vitamin E (300 IU per day) to cisplatin chemotherapy significantly reduced the incidence of drug-induced damage to the nervous system (neurotoxicity).⁸⁶ A similar protective effect was seen in another trial in which 600 IU of vitamin E per day was used.⁸⁷

Animal studies show that benzoyl peroxide promotes tumor growth, yet the significance of this finding in humans is unknown. A test tube study showed that when exposed to vitamin E, human skin cells were more resistant to damage caused by benzoyl peroxide.⁸⁸ Controlled research is needed to determine whether use of benzoyl peroxide products by humans promotes tumor growth and whether vitamin E might prevent this damage.

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Several studies have shown that fenofibrate enhances the toxic effect of ultraviolet (UV) radiation from the sun, which might result in side effects such as skin rashes. One controlled study showed that taking 2 grams of vitamin C and 1,000 IU of vitamin E prior to ultraviolet exposure dramatically blocked UV-fenofibrate damage to red blood cells.⁹¹ though further controlled studies are needed, people taking fenofibrate should probably supplement with vitamins C and E until more information is available.

Chemotherapy frequently causes mouth sores. In one trial, people were given approximately 400,000 IU of beta-carotene per day for three weeks and then 125,000 IU per day for an additional four weeks.⁹² Those taking beta-carotene still suffered mouth sores, but the mouth sores developed later and tended to be less severe than mouth sores that formed in people receiving the same chemotherapy without beta-carotene.

In a study of chemotherapy-induced mouth sores, six of nine patients who applied vitamin E directly to their mouth sores had complete resolution of the sores compared with one of nine patients who applied placebo.⁹³ Others have confirmed the potential for vitamin E to help people with chemotherapy-induced mouth sores.⁹⁴ Applying vitamin E only once per day was helpful to only some groups of patients in another trial,⁹⁵ and not all studies have found vitamin E to be effective.⁹⁶ Until more is known, if vitamin E is used in an attempt to reduce chemotherapy-induced mouth sores, it should be applied topically twice per day and should probably be in the tocopherol (versus tocopheryl) form.

In a preliminary study, the addition of oral vitamin E (300 IU per day) to cisplatin chemotherapy significantly reduced the incidence of drug-induced damage to the nervous system (neurotoxicity).⁹⁷ A similar protective effect was seen in another trial in which 600 IU of vitamin E per day was used.⁹⁸

The chemotherapy drug cisplatin may cause kidney damage, resulting in depletion of calcium and phosphate.⁹⁹

Chemotherapy frequently causes mouth sores. In one trial, people were given approximately 400,000 IU of beta-carotene per day for three weeks and then 125,000 IU per day for an additional four weeks.¹⁰⁰ Those taking beta-carotene still suffered mouth sores, but the mouth sores developed later and tended to be less severe than mouth sores that formed in people receiving the same chemotherapy without beta-carotene.

In a study of chemotherapy-induced mouth sores, six of nine patients who applied vitamin E directly to their mouth sores had complete resolution of the sores compared with one of nine patients who applied placebo.¹⁰¹ Others have confirmed the potential for vitamin E to help people with chemotherapy-induced mouth sores.¹⁰² Applying vitamin E only once per day was helpful to only some groups of patients in another trial,¹⁰³ and not all studies have found vitamin E to be effective.¹⁰⁴ Until more is known, if vitamin E is used in an attempt to reduce chemotherapy-induced mouth sores, it should be applied topically twice per day and should probably be in the tocopherol (versus tocopheryl) form.

In a preliminary study, the addition of oral vitamin E (300 IU per day) to cisplatin chemotherapy significantly reduced the incidence of drug-induced damage to the nervous system (neurotoxicity).¹⁰⁵ A similar protective effect was seen in another trial in which 600 IU of vitamin E per day was used.¹⁰⁶

Haloperidol and related antipsychotic drugs can cause a movement disorder called tardive dyskinesia. Several double-blind studies suggest that vitamin E may be beneficial for treatment of tardive dyskinesia.¹¹⁰ Taking the large amount of 1,600 IU per day of vitamin E simultaneously with antipsychotic drugs has also been shown to lessen symptoms of tardive dyskinesia.¹¹¹ It is unknown if combining vitamin E with haloperidol could prevent tardive dyskinesia.

Chemotherapy frequently causes mouth sores. In one trial, people were given approximately 400,000 IU of beta-carotene per day for three weeks and then 125,000 IU per day for an additional four weeks.¹¹² Those taking beta-carotene still suffered mouth sores, but the mouth sores developed later and tended to be less severe than mouth sores that formed in people receiving the same chemotherapy without beta-carotene.

In a study of chemotherapy-induced mouth sores, six of nine patients who applied vitamin E directly to their mouth sores had complete resolution of the sores compared with one of nine patients who applied placebo.¹¹³ Others have confirmed the potential for vitamin E to help people with chemotherapy-induced mouth sores.¹¹⁴ Applying vitamin E only once per day was helpful to only some groups of patients in another trial,¹¹⁵ and not all studies have found vitamin E to be effective.¹¹⁶ Until more is known, if vitamin E is used in an attempt to reduce chemotherapy-induced mouth sores, it should be applied topically twice per day and should probably be in the tocopherol (versus tocopheryl) form.

In a preliminary study, the addition of oral vitamin E (300 IU per day) to cisplatin chemotherapy significantly reduced the incidence of drug-induced damage to the nervous system (neurotoxicity).¹¹⁷ A similar protective effect was seen in another trial in which 600 IU of vitamin E per day was used.¹¹⁸

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Chemotherapy frequently causes mouth sores. In one trial, people were given approximately 400,000 IU of beta-carotene per day for three weeks and then 125,000 IU per day for an additional four weeks.¹¹⁹ Those taking beta-carotene still suffered mouth sores, but the mouth sores developed later and tended to be less severe than mouth sores that formed in people receiving the same chemotherapy without beta-carotene.

In a study of chemotherapy-induced mouth sores, six of nine patients who applied vitamin E directly to their mouth sores had complete resolution of the sores compared with one of nine patients who applied placebo.¹²⁰ Others have confirmed the potential for vitamin E to help people with chemotherapy-induced mouth sores.¹²¹ Applying vitamin E only once per day was helpful to only some groups of patients in another trial,¹²² and not all studies have found vitamin E to be effective.¹²³ Until more is known, if vitamin E is used in an attempt to reduce chemotherapy-induced mouth sores, it should be applied topically twice per day and should probably be in the tocopherol (versus tocopheryl) form.

In a preliminary study, the addition of oral vitamin E (300 IU per day) to cisplatin chemotherapy significantly reduced the incidence of drug-induced damage to the nervous system (neurotoxicity).¹²⁴ A similar protective effect was seen in another trial in which 600 IU of vitamin E per day was used.¹²⁵

Preliminary research has found that combined administration of isotretinoin and vitamin E (alpha-tocopherol) substantially reduces the initial toxicity of high-dose isotretinoin without reducing drug efficacy.¹²⁹ Additional research is needed to further clarify this potentially beneficial interaction.

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Test tube studies reveal that vitamin E protects white blood cells from damage caused by lindane.¹³² Lindane is known to promote the formation of tumors,¹³³ and more research is needed to determine whether vitamin E, when applied at the same time as lindane, can prevent this adverse effect.

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Chemotherapy frequently causes mouth sores. In one trial, people were given approximately 400,000 IU of beta-carotene per day for three weeks and then 125,000 IU per day for an additional four weeks.¹³⁴ Those taking beta-carotene still suffered mouth sores, but the mouth sores developed later and tended to be less severe than mouth sores that formed in people receiving the same chemotherapy without beta-carotene.

In a study of chemotherapy-induced mouth sores, six of nine patients who applied vitamin E directly to their mouth sores had complete resolution of the sores compared with one of nine patients who applied placebo.¹³⁵ Others have confirmed the potential for vitamin E to help people with chemotherapy-induced mouth sores.¹³⁶ Applying vitamin E only once per day was helpful to only some groups of patients in another trial,¹³⁷ and not all studies have found vitamin E to be effective.¹³⁸ Until more is known, if vitamin E is used in an attempt to reduce chemotherapy-induced mouth sores, it should be applied topically twice per day and should probably be in the tocopherol (versus tocopheryl) form.

In a preliminary study, the addition of oral vitamin E (300 IU per day) to cisplatin chemotherapy significantly reduced the incidence of drug-induced damage to the nervous system (neurotoxicity).¹³⁹ A similar protective effect was seen in another trial in which 600 IU of vitamin E per day was used.¹⁴⁰

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Chemotherapy frequently causes mouth sores. In one trial, people were given approximately 400,000 IU of beta-carotene per day for three weeks and then 125,000 IU per day for an additional four weeks.¹⁴¹ Those taking beta-carotene still suffered mouth sores, but the mouth sores developed later and tended to be less severe than mouth sores that formed in people receiving the same chemotherapy without beta-carotene.

In a study of chemotherapy-induced mouth sores, six of nine patients who applied vitamin E directly to their mouth sores had complete resolution of the sores compared with one of nine patients who applied placebo.¹⁴² Others have confirmed the potential for vitamin E to help people with chemotherapy-induced mouth sores.¹⁴³ Applying vitamin E only once per day was helpful to only some groups of patients in another trial,¹⁴⁴ and not all studies have found vitamin E to be effective.¹⁴⁵ Until more is known, if vitamin E is used in an attempt to reduce chemotherapy-induced mouth sores, it should be applied topically twice per day and should probably be in the tocopherol (versus tocopheryl) form.

Chemotherapy frequently causes mouth sores. In one trial, people were given approximately 400,000 IU of beta-carotene per day for three weeks and then 125,000 IU per day for an additional four weeks.¹⁵¹ Those taking beta-carotene still suffered mouth sores, but the mouth sores developed later and tended to be less severe than mouth sores that formed in people receiving the same chemotherapy without beta-carotene.

In a study of chemotherapy-induced mouth sores, six of nine patients who applied vitamin E directly to their mouth sores had complete resolution of the sores compared with one of nine patients who applied placebo.¹⁵² Others have confirmed the potential for vitamin E to help people with chemotherapy-induced mouth sores.¹⁵³ Applying vitamin E only once per day was helpful to only some groups of patients in another trial,¹⁵⁴ and not all studies have found vitamin E to be effective.¹⁵⁵ Until more is known, if vitamin E is used in an attempt to reduce chemotherapy-induced mouth sores, it should be applied topically twice per day and should probably be in the tocopherol (versus tocopheryl) form. In another study, supplementation with vitamin E orally (600 IU per day) reduced the incidence of paclitaxel-induced nerve damage.¹⁵⁶

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Chemotherapy frequently causes mouth sores. In one trial, people were given approximately 400,000 IU of beta-carotene per day for three weeks and then 125,000 IU per day for an additional four weeks.¹⁶⁰ Those taking beta-carotene still suffered mouth sores, but the mouth sores developed later and tended to be less severe than mouth sores that formed in people receiving the same chemotherapy without beta-carotene.

In a study of chemotherapy-induced mouth sores, six of nine patients who applied vitamin E directly to their mouth sores had complete resolution of the sores compared with one of nine patients who applied placebo.¹⁶¹ Others have confirmed the potential for vitamin E to help people with chemotherapy-induced mouth sores.¹⁶² Applying vitamin E only once per day was helpful to only some groups of patients in another trial,¹⁶³ and not all studies have found vitamin E to be effective.¹⁶⁴ Until more is known, if vitamin E is used in an attempt to reduce chemotherapy-induced mouth sores, it should be applied topically twice per day and should probably be in the tocopherol (versus tocopheryl) form.

In a preliminary study, the addition of oral vitamin E (300 IU per day) to cisplatin chemotherapy significantly reduced the incidence of drug-induced damage to the nervous system (neurotoxicity).¹⁶⁵ A similar protective effect was seen in another trial in which 600 IU of vitamin E per day was used.¹⁶⁶

Vitamin E along with vitamin B6 was used to treat a side effect of risperidone called neuroleptic malignant syndrome in a 74-year-old woman, and results were encouraging.¹⁶⁹ However, whether vitamin E and vitamin B6 supplementation might help prevent this condition in people taking risperidone is unknown.

One of the side effects of sorafenib is a severe skin reaction (hand-foot skin syndrome) that often ends treatment. In a preliminary study, supplementing with 300 IU per day of vitamin E produced marked improvement in sorafenib-induced hand-foot skin syndrome within 10 to 12 days, even though the patients continued to take the sorafenib.¹⁷¹

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Chemotherapy frequently causes mouth sores. In one trial, people were given approximately 400,000 IU of beta-carotene per day for three weeks and then 125,000 IU per day for an additional four weeks.¹⁷² Those taking beta-carotene still suffered mouth sores, but the mouth sores developed later and tended to be less severe than mouth sores that formed in people receiving the same chemotherapy without beta-carotene.

In a study of chemotherapy-induced mouth sores, six of nine patients who applied vitamin E directly to their mouth sores had complete resolution of the sores compared with one of nine patients who applied placebo.¹⁷³ Others have confirmed the potential for vitamin E to help people with chemotherapy-induced mouth sores.¹⁷⁴ Applying vitamin E only once per day was helpful to only some groups of patients in another trial,¹⁷⁵ and not all studies have found vitamin E to be effective.¹⁷⁶ Until more is known, if vitamin E is used in an attempt to reduce chemotherapy-induced mouth sores, it should be applied topically twice per day and should probably be in the tocopherol (versus tocopheryl) form.

In a preliminary study, the addition of oral vitamin E (300 IU per day) to cisplatin chemotherapy significantly reduced the incidence of drug-induced damage to the nervous system (neurotoxicity).¹⁷⁷ A similar protective effect was seen in another trial in which 600 IU of vitamin E per day was used.¹⁷⁸

Twenty-six liver transplant patients (both adults and children) unable to achieve or maintain therapeutic cyclosporine blood levels during the early post-transplant period were given water-soluble vitamin E in the amount of 6.25 IU/2.2 pounds of body weight two times per day.⁶⁶ Addition of vitamin E in the early post-transplant period reduced the required amount of cyclosporine and the cost of cyclosporine therapy by 26%. These results imply that the addition of vitamin E to established cyclosporine therapy allows for a decrease in the amount of cyclosporine. Combining vitamin E and cyclosporine requires medical supervision to avoid cyclosporine toxicity.

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Adding 50 IU of vitamin E per day was reported to increase blood levels of this drug within four weeks in children, allowing the drug dose to be cut in half. Reducing the amount of griseofulvin should decrease the likelihood of side effects. This evidence is preliminary, so people taking griseofulvin should not supplement vitamin E on their own but may wish to discuss this matter with their doctor.¹⁰⁸

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

The combination of vitamin E and pentoxifylline has been used successfully to reduce damage to normal tissues caused by radiation therapy.¹⁵⁷

Vitamin E increases the resistance of tooth enamel to acids that cause cavities, and test tube studies show that fluoride, when added to vitamin E, enhances this effect.¹⁷⁰ Controlled research is needed to determine whether people might develop fewer cavities when taking vitamin E and fluoride together.

Although vitamin E is thought to act like a blood thinner, very little research has supported this idea. In fact, a double-blind trial found that very high amounts of vitamin E do not increase the effects of the powerful blood-thinning drug warfarin.¹⁸³ Nonetheless, a double-blind study of smokers found the combination of aspirin plus 50 IU per day of vitamin E led to a statistically significant increase in bleeding gums compared with taking aspirin alone (affecting one person in three versus one in four with just aspirin).¹⁸⁴ The authors concluded that vitamin E might, especially if combined with aspirin, increase the risk of bleedings.

Animal studies suggest that vitamin E may improve the efficacy of AZT.¹⁸⁵ The practical importance of this finding remains unclear.

Oxidative damage to LDL (“bad”) cholesterol is widely believed to contribute to heart disease. In a double-blind trial, lovastatin was found to increase oxidative damage to LDL cholesterol and vitamin E was reported to protect against such damage, though not to completely overcome the negative effect of lovastatin.¹⁸⁶ This study suggests that people taking lovastatin might benefit from supplemental vitamin E.

In a study of seven patients with hypercholesterolemia, eight weeks of simvastatin plus vitamin E 300 IU improved markers of blood vessel elasticity more than simvastatin alone.¹⁸⁷

The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Two studies showed that individuals taking phenytoin and phenobarbital had lower blood vitamin E levels than those who received no treatment for seizures.^{188 , 189} It is not known whether this same interaction occurs with valproic acid. Though the consequences of lower blood levels of vitamin E are unknown, people taking multiple anticonvulsant drugs should probably supplement with 100 to 200 IU of vitamin E daily to prevent a deficiency.

On the basis of the biochemical actions of valproic acid, it has been suggested that people taking valproic acid should make sure they have adequate intakes of vitamin E and selenium.¹⁹⁰ The importance of supplementation with either nutrient has not yet been tested, however.