Beta-Carotene : Interactions

by MedlinePlus

(Page 5 of 5)

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs

Alcohol (ethanol):High consumption of alcohol can decrease serum concentrations of beta-carotene and other carotenoids such as alpha-carotene and beta-cryptoxanthin, and increase serum concentrations of retinol. Researchers have raised concerns that increased retinol concentrations might promote cancer. Further study is needed to determine whether this effect actually occurs. Preliminary studies in animals indicate that beta-carotene supplementation, when combined with heavy alcohol consumption, may increase liver toxicity. Alcohol intake and cigarette smoking appear to modify the effect of beta-carotene supplementation on the risk of colorectal adenoma recurrence.

Cigarettes: Cigarette smoking decreases serum concentrations of beta-carotene and other carotenoids, and depletes body stores of beta-carotene. However, oral beta-carotene supplementation should not be recommended in smokers because supplemental beta-carotene in doses greater than 20mg per day is associated with a significantly higher risk of lung and prostate cancer in smokers. Smokers and people with a history of asbestos exposure should avoid taking beta-carotene supplements.

Bile acid sequestrants: Cholestyramine (Questran) and colestipol (Colestid) can reduce absorption of fat-soluble vitamins, including beta-carotene. Serum levels of beta-carotene can be reduced, but this is probably only in proportion to the lowering of cholesterol (on which beta-carotene is transported). Supplements are not usually necessary.

Colchicine: Colchicine can cause disruption of intestinal mucosal function, resulting in malabsorption. Limited evidence suggests that short-term treatment with colchicine 1.9 to 3.9mg/day can reduce absorption and serum levels of beta-carotene. Long-term use of 1 to 2mg daily does not seem to affect beta-carotene levels. Clinical significance is unlikely.

HMG-CoA reductase inhibitors ("Statins"): Concomitant use of beta-carotene in combination with selenium, vitamin C, and vitamin E appears to decrease the effectiveness of the combination of simvastatin (Zocor) and niacin. Simvastatin (20mg daily) has been shown to decrease the level of beta-carotene by 20%. Theoretically, beta-carotene could reduce the effectiveness of other HMG-CoA reductase inhibitors such as atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Mevacor), and pravastatin (Pravachol).

Mineral oil: Mineral oil reduces absorption of fat-soluble vitamins, including beta-carotene. Clinical significance in unlikely when mineral oil is used for four months or less.

Neomycin: Oral neomycin sulfate in doses of 4 to 12 grams per day can reduce beta-carotene absorption, but short-term use is unlikely to have a significant effect.

Niacin: Use of beta-carotene in combination with selenium, vitamin C, and vitamin E appears to decrease the effectiveness of the combination of niacin and simvastatin (Zocor).

Orlistat (Xenical): Orlistat can decrease absorption of beta-carotene and other fat-soluble vitamins. It is recommended that patients take a multivitamin supplement, and separate the dosing time by at least two hours from orlistat.

Proton pump inhibitors (PPIs):Loss of stomach acid can reduce absorption of a single dose of beta-carotene. Clinical significance is unknown, and it is unknown if this occurs with dietary beta-carotene intake. Example PPIs include esomeprazole (Nexium), lansoprazole (Prevacid), omeprazole (Prilosec, Losec), rabeprazole (Aciphex), and pantoprazole (Protonix, Pantoloc).

Interactions with Herbs and Dietary Supplements

Fish oil: Consumption of a natural carotenoid mixture has been shown to lower the increase in oxidative stress induced by the fish oil. This carotenoid mixture may also enhance the plasma triglyceride-lowering effect of the fish oil.

Iron: Iron supplementation in infants with marginal vitamin A status has led to lower plasma vitamin A concentrations and greater vitamin A liver stores. Some researchers recommend that iron supplementation in infants should be accompanied by measures to improve vitamin A status.

Lutein: Beta-carotene supplementation has been shown to lower serum lutein concentrations. Lutein from food sources does not seem to result in the decrease in beta-carotene concentrations that accompanies administration of lutein supplements.

Plant sterols: Plant sterols have been shown to reduce beta-carotene bioavailability in some studies and not to have a significant effect in others. The effects on cholesterol levels are also unproven.

Vitamin E: Supplementation of beta-carotene in doses of 25000 IU/day may decrease the vitamin E concentration in tissues.

Interactions with Foods

Fat: Beta-carotene requires some dietary fat for absorption, although supplemental beta-carotene seems to be similarly absorbed when taken with high-fat (36 grams fat) or low-fat (3 grams fat) meals.

Dark green leafy vegetables:A substantial increase in serum beta-carotene has been seen in children after feeding with a moderately high cumulative dose of dark green leafy vegetables for 6 weeks.

Olestra (fat substitute)/sucrose polyesters (SPE): Olestra may interfere with supplemental beta-carotene activity. Olestra has been shown to lower serum beta-carotene concentrations in healthy people by 27%. Sucrose polyesters are dietary fat replacers that have been shown to lower concentrations of serum carotenoids in short-term studies.

Red palm oil/sunflower oils: Consumption of red palm oil has been shown to increase concentrations of alpha- and beta-carotene in breast milk and serum and to maintain breast milk retinol concentrations. Sunflower oil consumption seems to conserve breast-milk retinol similarly to consumption of red palm oil.

Salad dressing: Essentially no absorption of carotenoids was observed when salads with fat-free salad dressing were consumed in one study. A substantially greater absorption of carotenoids was observed when salads were consumed with full-fat than with reduced-fat salad dressing.

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