Beta-carotene: benefits, dosage, contraindications

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Beta-carotene belongs to a class of red, orange, and yellow pigments called carotenoids. There are hundreds of varieties of carotenoids that are precursors of vitamin A and are converted into vitamin A in the body. They are present in many fruits, grains, oils, and vegetables and in some animal-derived products, such as salmon, lobster, and egg yolk. In plants, carotenoids play an essential role in photosynthesis and protect plants from oxidative damage. The red, orange, and yellow colors of these compounds are due to their preferential absorption of blue light. Beta-carotene was the first carotenoid discovered. It was initially isolated from carrots. Carrots are the main contributors of beta-carotene in the diet, but it is also found in melon, broccoli, and spinach. The natural beta-carotene used in dietary supplements is generally obtained from palm oil or marine microalgae. In humans, beta-carotene is converted into retinal, essential for vision, and then into retinoic acid, which is used in processes involving growth and cell differentiation. In addition, carotenoids have antioxidant and immune-supporting properties.

Family or group: 

Phytochemicals


Indications

Scoring methodology

EFSA approval.

Several randomized, double-blind, controlled clinical trials (> 2), including a significant number of patients (>100), with consistently positive conclusions for the indication.
Several randomized, double-blind, controlled clinical trials (> 2), including a significant number of patients (>100), with positive conclusions for the indication.
One or more randomized studies, or several cohorts or epidemiological studies, with positive conclusions for the indication.
Clinical studies exist but are uncontrolled, with conclusions that may be positive or conflicting.
No clinical studies to date that can demonstrate the indication.


Erythropoietic protoporphyria
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Oral beta-carotene intake may help reduce sun sensitivity in people with erythropoietic protoporphyria (EPP), a genetic condition that disrupts porphyrin metabolism and manifests as photosensitivity due to the formation of free radicals after sun exposure.nnIn adults, 180 to 300 mg of beta-carotene per day are used. In children aged 1 to 4 years, the daily dose is 60 to 90 mg; 5 to 8 years, 90 to 120 mg; 9-12 years, 120-150 mg; 13-16 years, 150-180 mg; and 16 years and older, 180 mg. If an adequate response is not obtained, the beta-carotene dose can be increased by 30 to 60 mg per day for children under 16 years, and up to a maximum of 300 mg per day for those 16 years and older. nn

Posologie

posologieOral

posologie60 - 300 mg


Vitamin A deficiency
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In trials involving Nepalese women, beta-carotene supplementation reduced symptoms related to vitamin A deficiency, such as night blindness and high fever, thereby helping to decrease maternal mortality and the risk of infections. Vitamin A deficiency was likely the underlying cause of these symptoms and illnesses. Beta-carotene supplementation — as a precursor of vitamin A — provided benefits similar to those of vitamin A, with fewer health risks.

Posologie

posologieOral

posologie42 mg


UV exposure
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Beta-carotene supplementation, alone or in combination with other antioxidants, has shown a reduction in UV-induced erythema after 8-10 weeks of treatment, requiring doses of at least 24 mg/day. Controlled studies have observed protection against UV erythema with varied doses, highlighting a dose-dependent photoprotective effect. However, the effectiveness of beta-carotene as sun protection is modest and specific to people with certain photosensitivities, and does not extend to the prevention of non-melanoma skin cancer.

Posologie

posologieOral

posologie24 mg


Breast cancer
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More than 35 observational studies have found a positive association between dietary or serum beta-carotene levels and a reduced risk of cancer. However, this association does not necessarily imply a causal relationship and may reflect other dietary or lifestyle factors. nnObservational research indicates that a diet high in beta-carotene is associated with a reduced risk of breast cancer in premenopausal women, particularly those at higher risk because of family history or high alcohol consumption. An increase in beta-carotene intake is associated with up to an 18% decrease in breast cancer risk and up to a 30% improvement in overall survival among patients with this cancer.nn

Posologie

posologieOral

posologie6 - 8 mg


Age-related macular degeneration (AMD)
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Clinical research indicates that a combination of antioxidants including 15 mg of beta-carotene, 500 mg of vitamin C, 400 IU of vitamin E and 80 mg of zinc per day can reduce the risk of progression to advanced age-related macular degeneration (AMD) by up to 31%. This combination is particularly effective in patients with a severe form of the disease, reducing progression to advanced AMD by 34% and vision loss by 29%. The evidence regarding the use of beta-carotene in patients at low risk of AMD is conflicting, as is the role of dietary beta-carotene in reducing the risk of AMD.

Posologie

posologieOral

posologie15 mg


Synergies


Properties


Essential

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Beta-carotene is considered an essential nutrient when dietary intake of retinol (vitamin A) is insufficient. Indeed, beta-carotene is converted into retinoic acid by an enzyme present in the intestinal mucosa and the liver.

Usages associés

Vitamin A deficiency, AMD

Dermatological effect

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In humans, beta-carotene reduces the signs of skin aging. The mechanisms of action may involve increased collagen production and a reduction in harmful oxidative reactions induced by ultraviolet rays.

Usages associés

Erythropoietic protoporphyria, UV exposure

Antioxidant

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In the laboratory, beta-carotene is known for its antioxidant action, but the details of how it works are not completely understood. Although it effectively scavenges free radicals under normal conditions, its effectiveness decreases under high oxygen pressure, where it can even become pro-oxidant. The effectiveness of beta-carotene as an antioxidant in the human body is still a matter of debate, as it appears to vary depending on context for reasons that are still unclear.


Anticancer

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It appears there is an inverse relationship between dietary intake of carotenoids, or serum levels of beta-carotene, and the incidence of various cancers. In vitro studies show that beta-carotene and palm oil carotene inhibit tumor cell growth. Preliminary evidence indicates that carotenoids, including beta-carotene, may inhibit the growth of breast cancer cells. However, the anticancer effects of beta-carotene supplementation have not been demonstrated in humans. Despite these potentially documented beneficial effects, there is a risk of the opposite effect: pro-carcinogenicity due to accumulation of beta-carotene metabolites. It is important to note that the smoking, for example, could increase the production of carcinogenic metabolites of beta-carotene which, if not neutralized by other antioxidants, could lead to an increased risk of lung cancer.

Usages associés

Breast cancer

Anti-inflammatory

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Serum beta-carotene levels appear to be inversely associated with C-reactive protein levels and white blood cell count, which are markers of inflammation. nn


Immunomodulatory

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The mechanisms by which beta-carotene influences immune function are not yet very clear.nnBeta-carotene has direct and indirect effects on immune function through its pro-vitamin A activity:nn- By reducing oxidative damage to cell membranes and their receptors, nn- By influencing the activity of redox-sensitive transcription factors and the production of cytokines and prostaglandins,nn- By strengthening the ability of cells and receptors to adapt to redox changes.nn


Safe dosage

Adults 18 years and older: 3 mg - 30 mg

It is recommended to consume five or more servings of fruits and vegetables per day providing 3 to 6 mg of beta-carotene. Beta-carotene supplements range from 3 to 30 mg/day, but medicinal doses ranging from 30 to 300 mg/day are used to treat certain specific conditions such as erythropoietic protoporphyria. For effective sun protection, a dose greater than 24 mg/day for more than two months is recommended.

Pregnant women: 3 mg - 6 mg

There is no safety concern at dietary doses.

Breastfeeding women: 3 mg - 6 mg

There is no safety concern at dietary doses.

Children up to 18 years: 3 mg - 6 mg

There is no safety concern at dietary doses.


Interactions

Médicaments

Cholesterol-lowering agents: moderate interaction

Medications that reduce fat absorption, such as cholestyramine, colestipol, and orlistat, can also decrease the absorption of beta-carotene. To avoid this, it is recommended to space the administration of these medications and beta-carotene by at least 2 hours.


Precautions

Trisomy: avoid

In children with trisomy: cases of seizures during prolonged treatment with 5-HTP.