The Healthspan Map · Nutrient

Carotenoids (provitamin A)

Linked to getting too little

Where a shortfall of Carotenoids (provitamin A) is linked — 5 sources.In the order the Map holds them: strongest evidence first. That is a statement about the evidence, not about what matters most.
Nutrient or lever	Direction	Strength	Evidence type	What was found	Source
Carotenoids (provitamin A)	Eat enough of	Emerging	Review / narrative	Dietary beta-carotene has been associated with lower sperm chromosomal aneuploidy and provides antioxidant/provitamin-A support.	Diet & men’s fertility (Fertil Steril 2018) (opens in a new tab)
Carotenoids (provitamin A)	Eat enough of	Emerging	Review / narrative	Dietary provitamin-A carotenoids support epithelial/mucosal integrity and antioxidant defence in the airway.	Multivitamin-mineral & respiratory infection (PMC12310427) (opens in a new tab)
Carotenoids (provitamin A)	Eat enough of	Emerging	Review / narrative	Dietary carotenoids act as antioxidants that help protect skin against UV-induced oxidative damage.	Carotenoids & photoprotection (opens in a new tab)
Carotenoids (provitamin A)	Eat enough of	Strong	RCT / meta-analysis	The macular xanthophylls lutein and zeaxanthin (dietary carotenoids) form macular pigment and protect against late AMD in AREDS2 — note these are non-provitamin-A carotenoids.	AREDS2 macular xanthophyll review (PMC7015456) (opens in a new tab)
Carotenoids (provitamin A)	Eat enough of	Emerging	Established clinical	As a provitamin A source, adequate carotenoid intake supports vitamin A status and immune function.	NIH ODS – Vitamin A & Carotenoids (opens in a new tab)

Linked to getting too much

Where an excess of Carotenoids (provitamin A) is linked — 5 sources.In the order the Map holds them: strongest evidence first. That is a statement about the evidence, not about what matters most.
Nutrient or lever	Direction	Strength	Evidence type	What was found	Source
Carotenoids (provitamin A)	Don't overdo	Moderate	Systematic review	High-dose beta-carotene supplements increased lung cancer and mortality in smokers/asbestos-exposed adults (CARET) — an excess harm concentrated in smokers.	Vitamin A / beta-carotene for respiratory infection (Cochrane, incl. CARET) (opens in a new tab)
Carotenoids (provitamin A)	Don't overdo	Strong	RCT / meta-analysis	High-dose beta-carotene supplements increased lung cancer incidence and mortality in smokers (ATBC +18%, CARET +28%); FNB advises against beta-carotene supplements for the general population. (Cancer folded into system.)	ATBC / CARET trials (NEJM); NIH ODS (opens in a new tab)
Carotenoids (provitamin A)	Don't overdo	Strong	RCT / trial	High-dose beta-carotene supplements increased lung cancer incidence and mortality in smokers (ATBC +18%, CARET +28%); FNB advises against beta-carotene supplements for the general population. (Cancer folded into system.)	The Beta-Carotene and Retinol Efficacy Trial (CARET): incidence of lung cancer and cardiovascular disease mortality during 6-year follow-up after stopping beta-carotene and retinol supplements, J Natl Cancer Inst 2004 (opens in a new tab)
Carotenoids (provitamin A)	Don't overdo	Strong	Established clinical	High-dose beta-carotene supplements increased lung cancer incidence and mortality in smokers (ATBC +18%, CARET +28%); FNB advises against beta-carotene supplements for the general population. (Cancer folded into system.)	NIH Office of Dietary Supplements — Vitamin A and Carotenoids (opens in a new tab)
Carotenoids (provitamin A)	Don't overdo	Emerging	Established clinical	Very high carotenoid intake causes carotenodermia, a harmless yellow-orange skin discoloration; no Upper Limit is set for carotenoids.	NIH ODS – Vitamin A & Carotenoids (opens in a new tab)