Supplement
Beta-carotene
SaveA provitamin A carotenoid that the body converts to retinol as needed. Supplementation has a troubled history due to increased lung cancer risk in smokers.
Quick verdict
Best obtained from food (carrots, sweet potatoes). Supplemental beta-carotene is not recommended for smokers and offers little benefit over a varied diet.
Evidence score
A rough internal score reflecting quantity, quality, and consistency of human evidence. Not a clinical recommendation.
What the research shows
The ATBC and CARET trials showed increased lung cancer incidence in smokers taking 20–30 mg/day. Dietary beta-carotene from food is consistently associated with positive outcomes. Conversion to retinol is tightly regulated.
Benefits
- Provitamin A conversion meets retinol needs
- Dietary sources associated with reduced cancer risk
- Acts as an antioxidant in tissues
Dosage notes
No supplemental dose is broadly recommended. Dietary intake of 3–6 mg/day from food is considered adequate.
Side effects
- Carotenodermia at high doses
- Increased lung cancer risk in smokers (supplemental)
Who should be cautious
Do NOT supplement if you smoke or have a history of asbestos exposure. Excess intake causes harmless orange skin discolouration (carotenodermia).
What this page cannot tell you
Food-based intake and supplemental intake have divergent risk profiles. The body self-regulates conversion from food but not from supplements.
Leaderboard scores
- Immunity35
- Longevity25
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