It is “largely impossible” for provitamin carotenoids, such as beta-carotene, to cause toxicity, as their conversion to retinol is highly regulated.[19] No vitamin A toxicity has ever been reported from ingestion of excessive amounts.[22] Overconsumption of beta-carotene can only cause carotenosis, a harmless and reversible cosmetic condition in which the skin turns orange.
It is “largely impossible” for provitamin carotenoids, such as beta-carotene, to cause toxicity, as their conversion to retinol is highly regulated.
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Studies have shown there is a convincing association between β-carotene supplements and an increased risk of lung cancer in current smokers
https://wiki.cancer.org.au/policy/Position_statement_-_Beta-carotene_and_cancer_risk
Some studies have suggested that beta-carotene supplementation may increase the risk of lung cancer, particularly among smokers or former smokers.
https://acsjournals.onlinelibrary.wiley.com/doi/10.1002/cncr.23527