Caution: Synthetic beta-carotene has been linked to increased risk of lung cancer in smokers. Until more is known, smokers should avoid all beta-carotene supplements.

Beta-carotene is the most widely used supplement in the treatment of leukoplakia. In a clinical trial of betel nut chewers with leukoplakia, supplementation with 150,000 IU of beta-carotene twice per week for six months significantly increased the remission rate compared with placebo (14.8% vs. 3.0%).² The effectiveness of beta-carotene for treating leukoplakia was also confirmed in a double-blind trial that used 100,000 IU per day for six months.³ In one trial, supplementation with 33, 333 IU of beta-carotene per day, alone or combined with 50 IU of vitamin E, was reported not to reduce the incidence of leukoplakia.⁴ These results have also been observed in smaller trials.^5,6

Drug therapy with a synthetic, prescription form of vitamin A (known as Accutane, isotretinoin, and 13-cis retinoic acid) has been reported to be more effective than treatment with 50,000 IU per day of beta-carotene.⁷ However, because of the potential toxicity of the vitamin A-like drug, it may be preferable to treat leukoplakia with beta-carotene, which is much safer.

Before the research on beta-carotene was published, vitamin A was used to treat leukoplakia.⁸ One group of researchers reported that vitamin A (28,500 IU per day) was more effective than beta-carotene in treating people with leukoplakia.⁹ Another trial found that the combination of 150,000 IU per week of beta-carotene plus 100,000 IU per week of vitamin A led to a significant increase in remission time compared to beta carotene alone in betel nut chewers.² Women who are or who could become pregnant should not take 100,000 IU of vitamin A per week without medical supervision.

Beta-carotene is the most widely used supplement in the treatment of leukoplakia. In a clinical trial of betel nut chewers with leukoplakia, supplementation with 150,000 IU of beta-carotene twice per week for six months significantly increased the remission rate compared with placebo (14.8% vs. 3.0%).¹⁰ The effectiveness of beta-carotene for treating leukoplakia was also confirmed in a double-blind trial that used 100,000 IU per day for six months.¹¹ In one trial, supplementation with 33, 333 IU of beta-carotene per day, alone or combined with 50 IU of vitamin E, was reported not to reduce the incidence of leukoplakia.¹² These results have also been observed in smaller trials.^13,14

Drug therapy with a synthetic, prescription form of vitamin A (known as Accutane®, isotretinoin, and 13-cis retinoic acid) has been reported to be more effective than treatment with 50,000 IU per day of beta-carotene.¹⁵ However, because of the potential toxicity of the vitamin A-like drug, it may be preferable to treat leukoplakia with beta-carotene, which is much safer.

Before the research on beta-carotene was published, vitamin A was used to treat leukoplakia.¹⁶ One group of researchers reported that vitamin A (28,500 IU per day) was more effective than beta-carotene in treating people with leukoplakia.¹⁷ Another trial found that the combination of 150,000 IU per week of beta-carotene plus 100,000 IU per week of vitamin A led to a significant increase in remission time compared to beta carotene alone in betel nut chewers.¹⁰ Women who are or who could become pregnant should not take 100,000 IU of vitamin A per week without medical supervision.

In a double-blind trial, people with leukoplakia took 3 grams per day of a mixture of whole green tea, green tea polyphenols, and green tea pigments orally and also painted the mixture of the tea on their lesions three times per day for six months.¹⁸ Those in the green tea group had significant improvement in the healing of their lesions.

According to a review of clinical trials, the combination of beta-carotene and vitamin E has led to complete or partial remissions in six of eight trials studying people with leukoplakia.¹⁹ In one trial, administration of 50,000 IU of beta-carotene, 1 gram of vitamin C, and 800 IU of vitamin E per day for nine months led to improvement in 56% of people with leukoplakia, with stronger effects in those who also stopped using tobacco and alcohol.²⁰ In a double-blind trial, a group of men with leukoplakia was given a combination of vitamin A (100,000 IU per week), beta-carotene approximately 67,000 IU per day), and vitamin E (80 IU per week).²¹ A 38% decrease in the incidence of leukoplakia was observed after six months of treatment.

Although vitamin E has been used in successful trials in which patients are also given beta-carotene, few trials have investigated the effects of vitamin E when taken by itself. One trial used 400 IU of vitamin E two times per day.²² After 24 weeks, 46% showed some improvement in signs or symptoms of leukoplakia or related conditions and 21% showed microscopic evidence of improvement.