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    Ingredient guide · Ingredient reference

    Beta-carotene and vitamin A: CARET found harm despite an antioxidant rationale

    A large prevention trial in people at high lung-cancer risk found no benefit and a harmful signal from combined high-dose beta-carotene and retinyl palmitate. Nutrient biology did not predict the trial outcome.

    Read the evidence ↓

    Supplement Science Insights Editorial Team

    Published September 23, 2026

    What the source establishes

    CARET randomized 18,314 high-risk participants to the nutrient combination or placebo. The intervention stopped early after excess lung cancer and mortality emerged in the active group. [1]

    The report’s prespecified analysis confirmed increased lung-cancer incidence and lung-cancer mortality. Observational associations with fruit and vegetable intake had not predicted benefit from this concentrated supplement combination. [1]

    What it does not establish

    This was a high-dose combination in a high-risk population, not a trial of ordinary vegetable consumption. It cannot assign every effect to one ingredient alone. Funding and conflicts were not established from the abstract; antioxidant terminology does not establish prevention efficacy. [1]

    A hypothetical distinction

    Imagine a dietary pattern is associated with lower disease risk. Isolating selected compounds at much higher doses creates a new intervention whose outcomes must be tested directly.

    Evidence summary — Beta-carotene and vitamin A
    DetailInterpretation
    High-dose combinationDifferent from foods
    Randomized outcomesHarm signal
    Antioxidant labelNot efficacy proof
    Beta-carotene and vitamin A: CARET found harm despite an antioxidant rationale — original article outline diagram
    Original editorial diagram of this article’s sections; no product photograph or clinical finding is depicted.

    Sources for this article

    1. Risk factors for lung cancer and for intervention effects in CARET, the Beta-Carotene and Retinol Efficacy Trial - PubMed
      Source consulted: 2026-09-19. This is a reference resource, not a claim that we conducted the studies or tested a product.